Authentication management of offline devices in a wireless power system

Abstract

This disclosure provides systems, methods and apparatuses for updating authentication information or other configuration information in an offline device of a wireless power system. The examples of this detailed description are related to updating authentication information (such as one or more public keys, a private key, a block list, an allowed list, or an authentication message schema, among other examples). A first wireless power apparatus can obtain a newer version of authentication information from a second wireless power apparatus after a successful authentication of the second wireless power apparatus. The first wireless power apparatus can update its local storage to store the newer version of the authentication information. The techniques of this disclosure enable authentication information updates to propagate in a wireless power system that includes one or more offline devices.

Description

AUTHENTICATION MANAGEMENT OF OFFLINE DEVICES IN A WIRELESSPOWER SYSTEMRELATED APPLICATIONS

[0001] This application claims priority benefit of U.S. Provisional Patent Application No. 63 / 503,475, filed May 20, 2023.TECHNICAL FIELD

[0002] This disclosure relates generally to wireless power and some aspects relate to authentication and configuration of offline devices in a wireless power system.DESCRIPTION OF RELATED TECHNOLOGY

[0003] A wireless power system includes a Power Transmitter (PTx, sometimes also referred to as a wireless power transmission apparatus) and a Power Receiver (PRx, sometimes also referred to as a wireless power reception apparatus). The Power Transmitter includes a primary’ coil that produces an electromagnetic field during a power state to induce a voltage in a secondary coil of the Power Receiver when the secondary coil is placed in an electromagnetic field of the primary coil. The induced voltage can generate power for a load or for use by a rectifier that powers the load. Thus, the Power Transmitter can wirelessly transfer power to the Power Receiver using inductive coupling between the primary coil and the secondary coil. The Power Receiver can receive the wireless power and provide it to a load (such as a motor, a heating element, electronics, or a power storage device, among other examples) of an appliance. An appliance (sometimes also referred to as a device) might include a Power Transmitter, a Power Receiver, or both. For example, a first appliance (such as a kitchen hob) might include one or more Power Transmitters. A second appliance (such as a kitchen device) might include a Power Receiver as well as the load.

[0004] A wireless power system can include appliances from different manufacturers. For example, a first appliance that includes the Power Receiver might be manufactured by a first manufacturer, while a second appliance that includes the Power Transmitter might be manufactured by a second manufacturer. The manufacturers might implement a common specification so that their respective Power Transmitter or Power Receiver are compatible with one another. The common specification might specify communication protocols, circuit designs, and wireless power features. Failure of a wireless power apparatus (such as the Power Transmitter or the Power Receiver in a first appliance) to comply with the common specification can potentially cause damage to the wireless power apparatus in anotherappliance. Furthermore, incompatible wireless power apparatuses can potentially cause damage to other components of their respective appliance or to the environment in which the appliances are operated.

[0005] To mitigate the risk of incompatible wireless power apparatuses, manufacturers might undertake product testing to ensure proper implementation of the specification. Manufacturers might participate in a manufacturer registration to indicate they have successfully tested and comply with the specification. The specification may define an authentication in which one appliance can verify that another appliance is from a manufacturer that has registered and that a Power Transmitter or Power Receiver in the other appliance is compatible with the specification. Authentication can also be referred to as an authentication mechanism, authentication procedure, authentication protocol, or other similar terms. An appliance that cannot be authenticated might be produced by a manufacturer that does not fully support the features of the specification. To enable successful authentication, an appliance from a registered manufacture might store authentication information (such as a private key, registration information, configuration settings, or authentication software, among other examples).BRIEF SUMMARY

[0006] The systems, methods, and apparatuses of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0007] In one aspect, a method performed by a first wireless power apparatus includes storing a first version of authentication information in a local storage of the first wireless power apparatus. The method also includes detecting a second wireless power apparatus and authenticating the second wireless power apparatus using a first authentication message exchange that is based, at least in part, on the first version of the authentication information. The method also includes, after a successful authentication of the second wireless power apparatus, obtaining a second version of the authentication information from the second wireless power apparatus and storing the second version of the authentication information in the local storage of the first wireless power apparatus for use with a subsequent authentication message exchange.

[0008] In one aspect, a method performed by a second wireless power apparatus includes storing authentication information in a local storage of the second wireless power apparatus. The method also includes authenticating the first wireless power apparatus based, at least in part, on the authentication information. The method also includes, after a successfulauthentication of the first wireless power apparatus, providing a currently -stored version of the authentication information to the first wireless power apparatus based on a determination that the currently -stored version of the authentication information is a more recent than an earlier version of the authentication information stored at the first wireless power apparatus.

[0009] In one aspect, a first wireless power apparatus includes a power transfer coil configured to transmit or receive wireless power from a second wireless power apparatus. The first wireless power apparatus also includes a local storage configured to initially store a first version of authentication information. The first wireless power apparatus also includes a controller configured to detect a second wireless power apparatus and authenticate the second wireless power apparatus using a first authentication message exchange that is based, at least in part, on the first version of the authentication information. The controller is also configured to, after a successful authentication of the second wireless power apparatus, obtain a second version of the authentication information from the second wireless power apparatus. The controller is also configured to store the second version of the authentication information in the local storage of the first wireless power apparatus for use with a subsequent authentication message exchange.

[0010] In one aspect, a second wireless power apparatus includes a power transfer coil configured to transmit or receive wireless power from a second wireless power apparatus. The second wireless power apparatus also includes a local storage configured to store authentication information. The second wireless power apparatus also includes a controller configured to authenticate the first wireless power apparatus based, at least in part, on the authentication information. The controller is also configured to, after a successful authentication of the first wireless pow er apparatus, provide a currently-stored version of the authentication information to the first wireless power apparatus based on a determination that the currently-stored version of the authentication information is a more recent than an earlier version of the authentication information stored at the first wireless power apparatus.

[0011] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0012] Like reference numbers and designations in the various drawings indicate like elements. Note that the relative dimensions of the figures may not be drawn to scale.

[0013] FIG. 1 illustrates an example wireless power system that includes a Power Transmitter and a Power Receiver.

[0014] FIG. 2 illustrates a state diagram of a wireless power system.

[0015] FIG. 3 illustrates a message diagram illustrating public key infrastructure (PKI)- based authentication.

[0016] FIG. 4 illustrates an example authentication between the Power Transmitter and the Power Receiver.

[0017] FIG. 5A illustrates a scenario in which an authentication between two wireless power apparatuses is based on a first version of authentication information.

[0018] FIG. 5B illustrates a scenario in which a first wireless power apparatus can receive an updated version of authentication information from a second wireless power apparatus.

[0019] FIG. 5C illustrates a scenario in which the first wireless power apparatus can provide an updated version of authentication information to a third wireless power apparatus.

[0020] FIG. 6 illustrates example authentication information.

[0021] FIG. 7 illustrates examples of updating authentication information.

[0022] FIG. 8 illustrates a scenario in which an updated version of authentication management can propagate among multiple wireless power apparatuses in operation within a common location.

[0023] FIG. 9 illustrates a flow chart with example operations of a first wireless power apparatus in accordance with some aspects of this disclosure.

[0024] FIG. 10 illustrates a flow chart with example operations of a second wireless power apparatus in accordance with some aspects of this disclosure.

[0025] FIG. 11 illustrates another flow chart with example operations of a wireless power apparatus in accordance with some aspects of this disclosure.

[0026] FIG. 12 illustrates a block diagram of an example apparatus for use in a wireless power system.DETAILED DESCRIPTION

[0027] The following description is directed to certain implementations for the purpose of describing innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The described implementations can be implemented in any means, apparatus, system, or method for transmitting or receiving wireless power.

[0028] A wireless power system includes wireless power apparatuses, such as a Power Transmitter (PTx, sometimes also referred to as a wireless power transmission apparatus) and a Power Receiver (PRx, sometimes also referred to as a wireless power reception apparatus). In some implementations, the Power Transmitter may include a countertopmounted primary coil or a primary coil that is embedded or manufactured in a surface on which a Power Receiver can be placed. A Power Receiver can be configured to wirelessly receive power from the Power Transmitter. Some examples of this disclosure are based on a kitchen environment. For example, the Power Transmitter might be part of a kitchen equipment such as a hob, a countertop, or range, while the Power Receiver might be part of a cordless appliance such as a cordless blender, kettle, toaster, or cooking vessel, among other examples.

[0029] Each wireless power apparatus (such as the Power Transmitter or the Power Receiver) might have a capability to authenticate the other wireless power apparatus (the other of the Power Transmitter or the Power Receiver), and vice versa. An authentication typically involves messaging, which can be referred to as an authentication message exchange. For example, the authentication message exchange can include the communication of a key, a certificate digest, a challenge, a response, or any combination thereof. Furthermore, in some implementations, each authentication might be a bi-directional authentication such that each wireless power apparatus can authenticate the other wireless power apparatus.

[0030] Some wireless power apparatuses are manufactured as offline devices. An offline device is an appliance that does not have a network interface for accessing a wide area network, such as an Internet-connected network. By eliminating the network interface, the cost of such appliances can be reduced. Typically, an offline device is manufactured with initial configuration information, which may include authentication information used for authenticating other wireless power apparatuses. There may be advantages to updating the configuration information occasionally. For example, authentication information may be updated to include newly registered manufacturers. In another example, authentication information may be updated to revise or include a blocklist of untrusted appliances or manufacturers to prevent damage from a wireless power apparatus that does not comply with a specification. If a private key becomes hacked or otherwise published, there is a potential for physical harm if an appliance does not comply with the standard. In such situations, it is desirable to update authentication information to include a revocation list or some indication of appliances that should not be authenticated. Updating an offline device can be cumbersome for an end user. For example, field servicing might make use of a local cable, a memory card, a part replacement, or other user interaction. Some appliances do not have these capabilities.Adding a manual update mechanisms might require additional design considerations or technical expertise, potentially increasing the cost and manufacturing process for an appliance.

[0031] This disclosure provides systems, methods and apparatuses for updating authentication information or other configuration information in an offline device of a wireless power system. While the examples of this detailed description are related to updating authentication information, the same techniques can be used to update other types of information (such as configuration settings, firmware, or protocols, among other examples) in an offline device. In some implementations, authentication information might include a root public key, a private key associated with a manufacturer or appliance, a block list, an allowed list, or an authentication message schema, among other examples. A first wireless power apparatus might have an earlier version of authentication information. For example, the earlier version may have been current at the original manufacture date of the first wireless power apparatus but which has been replaced by a newer version developed since the original manufacture date. Meanwhile, a second wireless power apparatus might have been manufactured at a later date and might include the newer version of the authentication information. In accordance with aspects of this disclosure, the first wireless power apparatus can obtain the newer version of authentication information from the second wireless power apparatus after a successful authentication of the second wireless power apparatus. The first wireless power apparatus can update its local storage to store the second version of the authentication information. Thus, the first wireless power apparatus can benefit from the updated authentication information even if the first wireless power apparatus is an offline device without a network interface.

[0032] In some aspects of this disclosure, authentication information can be updated among several wireless power apparatuses within a location (such as different kitchen appliances used with wireless power systems of a kitchen environment). As one or more wireless power apparatuses interact with other wireless power apparatuses, the authentication information can propagate to the other wireless power apparatuses, and so on. When a newer wireless power apparatus is introduced to the location and as various wireless power apparatuses are used with each other, the various wireless power apparatuses can be updated with the most recent authentication information, such as the authentication information of the newer wireless power apparatus.

[0033] Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. Authentication (potentially including a bi-directional authentication) can ensure that a detected wirelesspower apparatus is certified by a trusted authority and confirmed to implement a wireless power specification. Use of certified wireless power apparatuses can reduce the occurrence of damage that otherwise might result from a wireless power apparatus that has not been certified to comply with the wireless power specification. The techniques of this disclosure enable offline devices to benefit from updated authentication information. Authentication information might be updated as a result of changes to authentication procedures, changes to manufacturer registrations, or discovery of untrusted appliances, among other examples. Furthermore, the ability to update authentication information can be added to an offline device without incurring additional cost associated with a network interface or complex network communication configurations or protocols. Ultimately, the disclosed techniques can improve user experience and confidence when using the wireless power apparatuses.

[0034] FIG. 1 illustrates an example wireless power system 100 that includes a Power Transmitter 102 and a Power Receiver 118. In FIG. 1, dashed lines represent communications to distinguish from solid lines that represent electrical circuit lines.

[0035] the Power Transmitter 102 and the Power Receiver 118 are two types of wireless power apparatuses that are used together. The Power Transmitter 102 includes a primary coil 104 and a Power Transmitter (PTx) controller 108. The primary coil 104 may be associated with a power transmitter circuit 106 (sometimes also referred to as a power signal generator or a driver circuit). The primary coil 104 may be a wire coil which transmits wireless power (which also may be referred to as wireless energy). The primary coil 104 may transmit wireless energy using an inductive or a resonant magnetic field. The power transmitter circuit 106 may include components (not shown) to prepare the wireless power. For example, the power transmitter circuit 106 may include one or more switches, drivers, series capacitors, rectifiers, inverters, or other components. In some implementations, the power transmitter circuit 106, PTx controller 108 and other components (not shown) may be collectively referred to as a Power Transmitter unit 110. Some or all of the Power Transmitter unit 110 may be embodied as an integrated circuit (IC) that implements features of this disclosure for controlling and transmitting wireless power to one or more wireless power reception apparatuses. The PTx controller 108 may be implemented as a microcontroller, dedicated processor, integrated circuit, application specific integrated circuit (ASIC) or any other suitable electronic device.

[0036] A power source 112 provides power to the Power Transmitter unit 110. In some implementations, the power source 112 may convert alternating current (AC) power to direct current (DC) power. For example, the power source 112 may include a converter that receives an AC power from an external power supply and converts the AC power to a DC power usedby the power transmitter circuit 106. Alternatively, or additionally, a component (such as an inverter) of the power transmitter circuit 106 may convert the DC power to the AC power. The power source 112 may be integrated as part of the Power Transmitter 102 or may be external to the Power Transmitter 102.

[0037] In some implementations, the Power Transmitter 102 causes the power source 112 to regulate the DC output voltage of the power source 112. For example, the PTx controller 108 can set DC voltage of the power source 112 based on information (such as a value indicating a requested power) received from the Power Receiver 118. The Power Transmitter 102 can receive power configuration information from the Power Receiver 118 and use the information to set a parameter (such as the DC output voltage of the power source 112). The Power Transmitter 102 can receive the power configuration information during various operating states, such as the discovery state or power state. In some implementations, the Power Transmitter 102 includes a DC-DC converter (not shown) between the power source 112 and the Power Transmitter circuit 106 to control the variable DC output voltage.

[0038] The PTx controller 108 is connected to a first communication interface 114. The first communication interface 114 is connected to a first communication coil 116. In some implementations, the first communication interface 114 and the first communication coil 116 may be collectively referred to as the first communication unit 122. In some implementations, the first communication unit 122 may support short-range radio frequency communication, such as Near-Field Communication (NFC) or Bluetooth (BT). NFC is a technology by which data transfer occurs on a carrier frequency of 13.56 Megahertz (MHz). The first communication unit 122 also may support any suitable communication protocol. The first communication unit 122 may contain modulation and demodulation circuits to wirelessly communicate via the first communication coil 116. Alternatively, or additionally, the PTx controller 108 may use frequency, amplitude, current, or voltage modulation of a wireless power signal to communicate via an in-band communication link (not shown) that includes the primary coil 104. The first communication interface 114 is different from a network interface in that it is not configured to access a network of devices. Rather, the first communication interface 114 is configured for local communication from the Power Transmitter 102 to a Power Receiver, such as Power Receiver 118. Some wireless power appliances might include both a communication unit (such as first communication interface 114) as well as a network interface (not shown). For example, a “smart appliance” might have a wireless local area network (WLAN) interface for communicating with a Wi-Fi™ network or a cellular network interface for communicating with a wireless wide area network (WWAN). As described herein, an offline device might include a communication unit (suchas first communication interface 114) for peer communication with another wireless power apparatus, but does not include a network interface for communication with a network.

[0039] The Power Receiver 118 may include a secondary coil 120, a rectifier 124, a Power Receiver (PRx) controller 126. a second communication interface 130, a load controller 134, a load 128, and a memory (not shown). In some implementations, the load 128 can include a drive (not shown) for controlling at least one parameter such as charging current, speed, or torque of the load. In some implementations, the rectifier 124 may be omitted such as when the voltage induced in the secondary coil 120 can directly power the load 128. In some implementations, a series switch (not shown) may be included in series with the secondary coil 120 or in series between the rectifier 124 and the load 128. Although not shown, a load capacitance can be used after the rectifier 124 to reduce the rate of rise of load voltage that would otherwise occur when the load 128 suddenly reduces power consumption. Although shown as different components, some components may be packaged or implemented in the same hardware. For example, in some implementations, the PRx controller 126 and the load controller 134 may be implemented as a single controller. The PRx controller 126, the load controller 134, or any combination thereof, may be implemented as a microcontroller, dedicated processor, integrated circuit, application specific integrated circuit (ASIC) or any other suitable electronic device.

[0040] The PTx controller 108 may detect the presence or proximity of a Power Receiver 118. This detection may happen during a periodic pinging process of the first communication interface 114. During the pinging process, the first communication interface 114 also may supply power to the second communication interface 130 when the Power Receiver 118 is in proximity' to the Power Transmitter 102. The second communication interface 130 may “wake up” and power-up the PRx controller 126 and may send a reply signal back to the first communication interface 114. Prior to power transfer, a handshaking process may take place during which the PTx controller 108 may receive identification and configuration data, among other information, from the Power Receiver 118. The PTx controller 108 may control characteristics of wireless power it provides to the Power Receiver 118 based on the configuration data.

[0041] A PRx controller 126 may be operationally coupled to the rectifier 124 and the second communication interface 130. The second communication interface 130 may contain modulation and demodulation circuits to wirelessly communicate via the second communication coil 132. Thus, the PRx controller 126 may wirelessly communicate feedback information to the PTx controller 108 via the second communication interface 130 to the first communication interface 114 using short-range radio frequency communication, such asNFC. Alternatively, or additionally, the PRx controller 126 may use load modulation to communicate via an in-band communication link (not shown) that includes the secondary coil 120.

[0042] A load controller 134 may be operationally coupled to the load 128 and the second communication interface 130. The load controller 134 may detect changes to load states such as change in charging currents in a battery charging application. The load controller 134 also may determine a load voltage reference. The load controller 134 also may send load voltage references, load current, and any other suitable information to the PRx controller 126 or the second communication interface 130 for communication to the Power Transmitter 102. The PRx controller 126 may additionally determine and provide feedback information indicating a measured load voltage available to the load 128. In some feedback messages, the feedback information may include a reference voltage indicating a required voltage for the load 128. In some feedback messages, the feedback information may indicate an error in the output voltage of the load 128. In some feedback messages, the feedback information may include the required power for the load. Although the PRx controller 126 and load controller 134 are shown separately, they may be included in the same component of the Power Receiver 118.

[0043] In some implementations, the Power Transmitter 102, the Power Receiver 118, or both, may be configured to authenticate the other of the Power Transmitter 102 or the Power Receiver 118. One type of authentication is referred to as a bi-directional authentication. In bi-directional authentication, the Power Transmitter 102 authenticates the Power Receiver 118 and the Power Receiver 118 authenticates the Power Transmitter 102. In some implementations, each authentication can include an authentication message exchange to verify that the second wireless power apparatus is in possession of a private key issued by a trusted authority. The trusted authority might issue private keys to manufacturers that are certified to comply with a wireless power specification. In some implementations, the trusted authority might include a central node or machine that distributes public and private keys as part of a public key infrastructure (PKI). For example, a trusted authority can issue authentication information (such as a private key) to a certified wireless power apparatus. The private key has a corresponding public key. The public key or a root public key can be provided to any wireless power apparatuses configured to authenticate another wireless power apparatus. Using the authentication message exchange, a wireless power apparatus (such as the Power Transmitter 102 or the Power Receiver 118) can verify that the other wireless power apparatus is in possession of a private key issued by the trusted authority. Although this disclosure describes PKI-based authentication as one type of authentication, other types ofauthentications (and their respective protocol for authentication message exchange) can be used for authentication of a wireless power apparatus.

[0044] In some implementations, the private key and one or more root public keys might be stored in a secure memory that is attached, affixed, or integrated, or otherwise non-removable within a wireless power apparatus. For example, the Power Transmitter 102 might include PTx authentication information 136 stored in a secured manner such that the PTx authentication information 136 cannot be removed or becomes unusable if not used with the PTx controller 108 or other components of the Power Transmitter 102. Similarly, the Power Receiver 118 can include PRx authentication information 138 that is securely stored, affixed, attached, integrated, or otherwise non-removable within the Power Receiver 118.

[0045] In this disclosure, authentication information might include one or more parameters of the PTx authentication information 136 or the PRx authentication information 138. For example, authentication information might include one or more public keys provided by a trusted authority. Alternatively, or additionally, the authentication information (such as the PTx authentication information 136 or the PRx authentication information 138) might include a block list to cause authentication to fail for a particular wireless power apparatus or a plurality of untrusted wireless power apparatuses. Alternatively, or additionally, the authentication information might include an allowed list. In some implementations, the allowed list can reduce the time or messaging overhead to successfully authenticate a trusted wireless power apparatus or a plurality of trusted wireless power apparatuses.

[0046] FIG. 2 illustrates a state diagram 200 of a wireless power system. The state diagram 200 illustrates the operating states in which the wireless power system may operate. When a Power Receiver is placed within an operating volume on the interface surface of a Power Transmitter, the two start to communicate with the aim to configure and control the power transfer. There can be four operating states associated with the wireless power system: a standby state 202 (sometimes also referred to as a ping state), a discoven' state 204 (sometimes referred to as a configuration state), a connected state 206, and a power state 208 (sometimes referred to as a power transfer state). A technical specification may define how the Power Transmitter and Power Receiver can transition between the operating states. For example, the wireless power system ty pically begins in the standby state 202 until the Power Transmitter detects a Power Receiver, moving it to the discovery state 204. In the discovery’ state 204 the Power Transmitter establishes communication and receives the first identification information of the Power Receiver and its static configuration data. In the connected state 206 and the power state 208, the Power Transmitter and Power Receiver exchange information to agree and adjust parameters related to wireless power transfer. Thesystem can move to a reinitialization state (not shown) as needed to reinitialize or return to the standby state when communication, powering, or other activities are no longer taking place. Each of the operating states are briefly described herein for reference.

[0047] In the standby state 202, the Power Transmitter tries to establish communications with a Power Receiver. The Power Receiver may be just placed on the interface surface or may not be present during this operating state. The Power Transmitter may attempt to communicate or detect the presence of the Power Receiver. For example, the Power Transmitter may use an analog ping, out-of-band communication (such as NFC), a digital ping, or any combination thereof, to determine that a compatible Power Receiver is present. Once the wireless power system determines that a Power Receiver is present (such as by confirming NFC communication), the wireless power system may transition to the discover)’ state 204.

[0048] In the discovery state 204, the Power Receiver may establish communication 210 with the Power Transmitter and send static configuration information (such as identification and configuration information 212) to the Power Transmitter. For example, the Power Transmitter may retrieve static configuration information from the Power Receiver via the NFC communication. The Power Transmitter and the Power Receiver may use this information to verify that they both use compatible versions of a technical specification or protocol for wireless power transfer. The Power Transmitter and Power Receiver may communicate basic settings or communicate regarding their respective capabilities. From the discovery state 204, the wireless power system may transition to the connected state 206.

[0049] In the connected state 206, the Power Transmitter and the Power Receiver may exchange further communications to negotiate the parameters that govern the power state. For example, a power negotiation can occur during the connected state 206. After negotiating the parameters, the Power Transmitter may be prepared to transfer wireless power and the Power Receiver may be prepared to receive the wireless power. However, the Power Transmitter may wait for a request or command from the Power Receiver before transitioning to the power state 208. This may be useful, for example, when a cordless appliance (such as a blender, toaster, mixer, or microwave, among other examples) is configured for use pending a user interaction. The user may initiate the power state 208 by a user interface (such as an activation switch) of the Power Receiver, which in turn communicates to the Power Transmitter to transition to the power state 208.

[0050] This disclosure describes an authentication procedure that might occur during the discover)’ state 204 or the connected state 206. For brevity, FIG. 2 shows the authentication214 occurring as part of the discovery state 204. A potential advantage of performing the authentication 214 in the discovery state 204 or early in the connected state 206 is so that a failure to authenticate can limit or eliminate some functionality for a power negotiation in the 206 or the power state 208. In some implementations, when an authentication fails, the Power Transmitter can implement a limitation on the wireless power transfer between the Power Transmitter and the Power Receiver. For example, the limitation can include no power or limited power (limited to a maximum power rating).

[0051] FIG. 3 illustrates a message diagram 300 illustrating PKI-based authentication. The example Power Receiver 118 is certified by a trusted authority 302. The trusted authority 302 might create a public key and a private key associated with the manufacturer or product model of the Power Receiver 118. The public key and the private key might be based on a root public key of the trusted authority 302 such that the public key of the manufacturer or product model can be verified by the root public key 304. The trusted authority' 302 can provide the root public key 304 (or the public key associated with the Power Receiver 118) to a manufacturer of the Power Transmitter 102. The manufacturer of the Power Transmitter 102 might store the root public key 304 (or the public keys of one or more Power Receivers) as authentication information 308 in a local storage of the Power Transmitter 102. The trusted authority 302 also provides the private key 306 to the manufacturer of the Power Receiver 118 and the manufacturer can securely store the private key in the Power Receiver 118. Although FIG. 3 illustrates the private key 306 for the Power Receiver 118, in some implementations, the trusted authority 302 also can generate and provide a different public / private key pair associated with the Power Transmitter 102. In some implementations, authentication information 308 might include a private key (not shown) of the Power Transmitter 102 or other information used for the authentication 312. In some implementations, the authentication information 308 can also include or refer to algorithms for verifying a public / private key pair. In some implementations, the authentication information 308 can include revocation data (such as a block list of revoked public / private keys) or explicit permission (such as an allowed list or indentation information for trusted wireless power apparatuses that do not require authentication).

[0052] In some implementations, the Power Transmitter 102, the Power Receiver 118, or both are offline devices. An offline device does not have the capability' of communicating via a network 318. In contrast, a network-connected device (also sometimes referred to as a smart appliance) might have a capability to communicate with the trusted authority 302 via the network 318. In FIG. 3, the Power Transmitter 102 and the 118 are offline devices such they do not have the capability' to obtain an authentication information update 310 (for thePower Transmitter 102) or authentication information update 314 (for the Power Receiver 118) via the network 318.

[0053] In some implementations, authentication information might refer to a public or global set of public keys, block list, allowed list, among other examples. The authentication information might change over time as the trusted authority 302 or one or more manufacturers make updates to the authentication information. For pedagogical purposes, authentication information might be referred to as having a version. A version might be based on a version number or date when the authentication information was generated or updated, such as when the trusted authority 302 makes a change to one or more public keys, a private key, revocation data, or permission data.

[0054] In the example of FIG. 3, the Power Transmitter 102 might have a previous version of the authentication information stored as authentication information 308. The Power Receiver 118 might have a newer version of the authentication information stored as the authentication information 320. In accordance with aspects of this disclosure, following a successful authentication 312. the Power Transmitter 102 can obtain an authentication information update 322 from the Power Receiver 118. For example, the authentication information update 322 might include updates to the root public key 304, one or more public keys, revocation data, permission data, authentication message schema, authentication algorithms, among other examples. The authentication information update 322 is based on the authentication information 320 stored at the Power Receiver 118.

[0055] Although the scenario of FIG. 3 is based on the Power Receiver 118 having a newer version of the authentication information compared to the Power Transmitter 102, it might also be possible that the Power Transmitter 102 has a newer version of the authentication information compared to the Power Receiver 118. In some implementations, whichever wireless power apparatus has the newest version of the authentication information can provide the newest version to the other wireless power apparatus. For example, the Power Transmitter 102 can provide an authentication information update to the Power Receiver 118 if the Power Transmitter 102 has the newer version of the authentication information.

[0056] FIG. 4 illustrates an example authentication 312 between the Power Transmitter 102 and the Power Receiver 118. The authentication 312 might be a bi-directional authentication in which a first part 402 enables the Power Transmitter 102 to authenticate the Power Receiver 118 and a second part 404 enables the Power Receiver 118 to authenticate the Power Transmitter 102. The order of the first part 402 and the second part 404 can be reversed insome implementations. Furthermore, some example authentications 312 might include only one of the first part 402 or the second part 404.

[0057] The first part 402 describes messaging in which the Power Transmitter 102 authenticates the Power Receiver 118 using a PKl-based authentication after the Power Receiver 118 provides first identification information (of the PRx) 406 to the Power Transmitter 102. The Power Transmitter 102 transmits a first message 408 to request a certificate chain digest from the Power Receiver 118. In a second message 410, the Power Receiver 118 communicates the certificate chain digest to the Power Transmitter 102. The Power Transmitter 102 can verify 412 the certificate chain digest using the root public key 304 (such as from its locally stored authentication information). The Power Transmitter 102 transmits a third message 414 to the Power Receiver 118. The third message 414 can be referred to as a challenge. For example, the challenge can include a nonce (such as a random string). The nonce might be encrypted using the public key of the Power Receiver 118. The Power Receiver 118 can decrypt 416 the challenge and sign a response based on the decry pted nonce its private key 306. A fourth message 418 can be referred to as a challenge response. The Power Transmitter 102 can decrypt and verify the challenge response based on a comparison to the originally transmitted challenge.

[0058] The second part 404 might use the same authentication messaging as the first part 402 except in reverse. For example, messages and procedures 422, 424, 428, 430, 434. and 436 are similar to their counterparts described in messages and procedures 408, 410. 412, 414, 416, and 418 except in the reverse direction and using the private key 432 of the Power Transmitter 102 and the public key 426 of the Power Receiver 118. Furthermore, the Power Transmitter 102 might provide second identification information (of the PTx) 420 to the Power Receiver 118.

[0059] In the example shown in FIG. 4, both the Power Transmitter 102 and the Power Receiver 118 successfully authenticate the other wireless power apparatus in the bidirectional authentication 312. At block 440, the Power Transmitter 102, the Power Receiver 118, or both, might provide or obtain authentication information from the other so that both the Power Transmitter 102 and the Power Receiver 118 can store the most recent version of authentication information from among the authentication data stored in the Power Transmitter 102 or the Power Receiver 118.

[0060] In some example implementations of block 440, a first wireless power apparatus (such as the Power Transmitter 102 or the Power Receiver 118) communicates a request message to the second wireless power apparatus (the other one of the Power Transmitter 102or the Power Receiver 118) to request an authentication information update. The second wireless power apparatus responds to the request message by communicating the requested authentication information update.

[0061] In some example implementations of block 440. a first wireless power apparatus (such as the Power Transmitter 102 or the Power Receiver 118) communicates a status message to indicate the version information or date information of a currently-stored version of the authentication information at the first wireless power apparatus. If the second wireless power apparatus determines that it has a newer version of the authentication information, the second wireless power apparatus may communicate an authentication information update to the first wireless power apparatus as a response to the status message. Alternatively, or additionally, if the second wireless power apparatus determines that it has an older version of the authentication information, the second wireless power apparatus might communicate a request message to the first wireless power apparatus to request the newer version of the authentication information from the first wireless power apparatus.

[0062] In some other example implementations of block 440. the first wireless power apparatus might communicate status message to indicate version information or date information indicative of a first version of the authentication information stored at the first wireless power apparatus. The second wireless power apparatus might communicate an acknowledgement if the first version matches the currently-stored version in the second wireless power apparatus. In some implementations, the acknowledgement might be implicitly indicated if the second wdreless power apparatus does not respond to the status message or communicates a request to move to the next operating state. Alternatively, the second wireless power apparatus might communicate an authentication information update if the first version is older than the currently -stored version in the second wireless power apparatus.

[0063] The example implementations of block 440 are only examples, and other protocols and messages can easily be conceived by a person of skill in the art to request, provide, obtain or exchange authentication information between the Power Transmitter 102 and the Power Receiver 118.

[0064] In some implementations, the operations of block 440 can be integrated with the authentication message exchange for authentication 312. For example, a message that includes the first identification information (of the PRx) 406 might also include a version number or other indicia of the authentication information stored at the Pow er Receiver 118. Similarly, a message that includes the second identification information (of the PTx) 420might include a version number or other indicia of the authentication information stored at the Power Transmitter 102. Alternatively, or additionally, version information might be included in, with or immediately following, a challenge response (such as challenge response 418 or challenge response 436). In some implementations, an authentication information update or a request for an authentication information update might be communicated following either or both of the challenge responses.

[0065] FIGs. 5A, 5B, and 5C illustrated various scenarios in which authentication information is updated as a result of interactions between a Power Transmitter 502 and one or more Power Receivers 518a, 518b, and 518c. The Power Transmitter 502 can be any Power Transmitter, such as Power Transmitter 102 described with reference to FIG. 1 or other FIGs. of this disclosure. The Power Receiver 518a, 518b, and 518c can be any Power Receiver, such as Power Receiver 118 described with reference to FIG. 1 or other FIGs. of this disclosure. In FIG. 5 A, both the Power Transmitter 502 and the first Power Receiver 518a have the same first version of the authentication information. In FIG. 5B, the Power Transmitter 502 receives an update of the authentication information from second Power Receiver 518b. In FIG. 5C, the Power Transmitter 502 provides an update of the authentication information to a third Power Receiver 518c.

[0066] FIG. 5A illustrates a scenario in which an authentication between two wireless power apparatuses is based on a first version of authentication information. The Power Transmitter 502 stores first version of authentication information (at PTx) 536 and the first Power Receiver 518a stores first version of authentication information (at PRx) 538. The first version of authentication information (at PTx) 536 and the first version of authentication information (at PRx) 538 might include some common elements, such as a root public key, one or more public keys of other wireless power apparatus, a block list, an allowed list, or other configuration settings related to authentication. The first version of authentication information (at PTx) 536 and the first version of authentication information (at PRx) 538 also might include some different elements, such as a private key or other non-shared private authentication information. For example, the first version of authentication information (at PTx) 536 also might include a private key of the Power Transmitter 502, and the first version of authentication information (at PRx) 538 might include a private key of the first Power Receiver 518a. Despite having some different private elements, the first version of authentication information (at PTx) 536 and the first version of authentication information (at PRx) 538 might both be referred to as the same first version based on the public or shared elements of being the same in both the first version of authentication information (at PTx) 536 and the first version of authentication information (at PRx) 538. Alternatively, oradditionally, the authentication information 536 and 538 might be associated with the same version number or date information. The first version of authentication information (at PTx) 536 and the first version of authentication information (at PRx) 538 can be used for the authentication 540 between the Power Transmitter 502 and the first Power Receiver 518a.

[0067] FIG. 5B illustrates a scenario in which a first wireless power apparatus can receive an updated version of authentication information from a second wireless power apparatus. The Power Transmitter 502 stores the first version of authentication information (at PTx) 536. However, different from the scenario of FIG. 5A, in FIG. 5B, the second Power Receiver 518b might have a second version of authentication information 544. The second version of authentication information 544 might be in addition to the first version of authentication information (at PRx) 538 (as shown in FIG. 5B) or might be in lieu of the first version of authentication information (at PRx) 538. After a successful authentication 542. the second Power Receiver 518b provides the second version of authentication information 544 (shown as an authentication information update message 546) to the Power Transmitter 502. The Power Transmitter 502 can store the second version of authentication information (shown as second version of authentication information 548). In the example of FIG. 5B, the Power Transmitter 502 might maintain the first version of authentication information (at PTx) 536 in local storage while also storing the second version of authentication information 548.

[0068] In some implementations, the Power Transmitter 502 may discard or replace the first version and store the second version. In some implementations, the Power Transmitter 502 might save the changes (delta update) from the first version to update the first version to the second version.

[0069] FIG. 5C illustrates a scenario in which the first wireless power apparatus can provide an updated version of authentication information to a third wireless power apparatus. Continuing with the example from FIG. 5B, the Power Transmitter 502 might later interact with a different Power Receiver (such as a third Power Receiver 518c). Following an authentication 550. the Power Transmitter 502 can provide the second version of authentication information 548 (shown as an authentication information update message 552) to the third Power Receiver 518c. The third Power Receiver 518c can store the second version of authentication information (shown as second version of authentication information 544).

[0070] FIG. 6 illustrates example authentication information 604 that might be stored in a local storage 602. The example authentication information 604 might include one or more of the example elements illustrated in FIG. 6. In some implementations, authentication information might include or be associated with version information 622, date information624, or both. In some implementations, the version information 622 or the date information 624 is meta data 626 related to the example authentication information 604. For each of the example elements of the example authentication information 604, a brief description follows.

[0071] The example authentication information 604 might include a root public key 606, such as when a root public key of a trusted authority changes following a key revocation, expiration, or security threat associated with a compromised root private key.

[0072] The example authentication information 604 might include one or more public keys 608. For example, the one or more public keys 608 might be public keys of trusted or affiliated manufacturers.

[0073] The example authentication information 604 might include a private key 610. For example, the private key 610 of a manufacturer might be updated by the trusted authority as a result of compromise or expiration. In some implementations, the private key 610 can be encrypted by a secret key (or proprietary' mechanism) so that it can be shared in an authentication information update between appliances from the same manufacturer. A potential technical advantage of updating the private key is so that a manufacturer can mitigate the risks or actual instances of counterfeiting or hacking. Another potential technical advantage is that updating a private key can enable a manufacturer to sunset or disable authentication for one or more appliances later discovered to pose a potential hazard.

[0074] The example authentication information 604 might include a block list 612. The block list 612 might include a list of blocked public keys, manufacturer identifications, device identifications, certificates, or other indicia that can be used to block authentication for one or more wireless power apparatuses. A potential technical advantage of a block list is to prevent unauthorized manufacturers or appliances from improperly authenticating, thereby mitigating potential risks from a manufacturer or appliance that might not comply with the specification or cause harm to the wireless power system.

[0075] The example authentication information 604 might include revocation data 614. The revocation data 614 might include indicia of public keys, manufacturer identifications, device identifications, certificates, or other information about manufacturers or appliances that should not be permitted to authentication. A potential technical advantage of revocation data 614 is to prevent authentication by unauthorized manufacturers or appliances that no longer comply with the specification or which have had new public / private keys issued by the trusted authority.

[0076] The example authentication information 604 might include an allowed list 61 . The allowed list 616 might include a list of trusted public keys, manufacturer identifications,device identifications, certificates, or other indicia that can be used to expressly permit authentication or trust (possibly without authentication) one or more wireless power apparatuses. A potential technical advantage of an allowed list 616 is that a manufacturer can explicitly indicate one or more manufacturers or appliances as being trusted. A potential technical advantage is that authentication of allowed manufacturers or appliances can be streamlined or eliminated, thereby reducing time and communication overhead.

[0077] The example authentication information 604 might include an authentication configuration setting 618. For example, authentication configuration setting 618 might be a timeout value, handshake procedure, or other parameter that modifies an authentication procedure. A potential technical advantage of updating an authentication configuration setting 618 is that an authentication procedure can be modified based on new developments in the specification, proprietary authentication procedures, or empirical results to optimize authentication procedures.

[0078] The example authentication information 604 might include an authentication message schema 620. For example, the authentication message schema 620 might indicate a message format, permitted field values, or structure of one or more messages for an authentication message exchange. A potential technical advantage of updating the authentication message schema 620 is the capability7to implement a protocol change or software update based on a change to the authentication protocol in a wireless power specification.

[0079] Other example authentication information is possible, and the elements illustrated in FIG. 6 are provided as a non-limiting list of example elements that might be included as part of authentication information update.

[0080] FIG. 7 illustrates examples of updating authentication information. The examples of FIG. 7 might be implemented by any wireless power apparatus (such as a Power Transmitter or a Power Receiver) that receives an authentication information update from another wireless power apparatus.

[0081] In the first example 708, a wireless power apparatus might replace (shown as arrow 706) a first version of authentication information 702 with a second version of authentication information 704. For example, the wireless power apparatus might erase the first version of authentication information 702 from the local storage and cause the second version of authentication information 704 to be stored in the local storage.

[0082] In the second example 712, a wireless power apparatus might process an authentication information update 710 as an update to the first version of authenticationinformation 702. For example, the authentication information update 710 might include a subset of the elements stored in the first version of authentication information 702. An advantage of this technique is that communication overhead and time can be reduced because the authentication information update 710 might include only those elements that have changed from the first version of authentication information 702 to the second version of authentication information 704. The second version of authentication information 704 can be derived as a combination of the first version of authentication information 702 with additions or modifications from the authentication information update 710.

[0083] In the third example 718, a wireless power apparatus might receive authentication information updates 716a, 716b, and 716c from different other wireless power apparatuses (following various instances when the other wireless power apparatuses are used with the wireless power apparatus). The wireless power apparatus might maintain the most recent version of authentication information 714 in a local memory of the wireless power apparatus. For example, the most recent version of authentication information 714 might be the authentication information that has the highest version number or latest date information from among the first version of authentication information 702 and the authentication information updates 716a, 716b. and 716c.

[0084] FIG. 8 illustrates a scenario in which an updated version of authentication management can propagate among multiple wireless power apparatuses in operation within a common location. FIG. 8 includes a combination of several updates such as those described with reference to FIG. 5 A, FIG. 5B, and FIG. 5C. Consider an example scenario in which a home or business includes a plurality of appliances including a first Power Transmitter 802a, a second Power Transmitter 802b, and several Power Receivers. A new appliance is purchased for use in the home or business. In the example of FIG. 8 the newest appliance (meaning the most recently manufactured) is the second Power Receiver 518b. The second Power Receiver 518b might include a most recent version of authentication information 822, while the other Power Receivers and Power Transmitters have an earlier version of the authentication information.

[0085] Using the techniques of this disclosure, when the second Power Receiver 518b interacts with the first Power Transmitter 802a, the first Power Transmitter 802a can be updated to store the most recent version of authentication information 824. For example, the second Power Receiver 518b might be included in a kettle appliance and the first Power Transmitter 802a might be included in a kitchen hob or countertop. As a result of using the kettle appliance with the kitchen hob or countertop, the most recent version of authentication information 824 can be communicated to the kitchen hob or countertop. The kitchen hob orcountertop might be an offline device. But using the techniques of this disclosure, the kitchen hob or countertop can be updated and maintained with minimal manual interaction by a user of the wireless power system.

[0086] Later, a different appliance might be used with the kitchen hob or countertop. For example, the first Power Receiver 518a might be included in a blender. The first Power Receiver 518a might have a version of the authentication information that is not as recent as the most recent version of the authentication information stored at the first Power Transmitter 802a. When the blender is placed on the kitchen hob or countertop, the first Power Receiver 518a can obtain an authentication information update 808 from the first Power Transmitter 802a. Similarly, when an appliance (such as a toaster) having the third Power Receiver 518c is used with the kitchen hob or countertop, the third Power Receiver 518c can receive an authentication information update 810 from the first Power Transmitter 802a.

[0087] The authentication information can continue to propagate as wireless power apparatuses are used with each other. Continuing with the foregoing example, when the toaster (containing the third Power Receiver 518c) is placed on a different wireless Power Transmitter (such as the second Power Transmitter 802b), the third Power Receiver 518c can provide an authentication information update 812 to the second Power Transmitter 802b. The second Power Transmitter 802b can provide an authentication information update 814 to a fourth Power Receiver 822a when an appliance containing the fourth Power Receiver 822a (such as a food processor) is used with the second Power Transmitter 802b.

[0088] Thus, each time a new appliance is introduced to the location, it can serve as the source of an authentication information update that propagates to other wireless power apparatuses as they are used. Therefore, in some implementations, updates can be accomplished by introducing a new appliance to the location. In some implementations, an inexpensive wireless power apparatus (such as an NFC tag or other device designed for the purpose of transmitting an update) can be used to source an authentication information update. An advantage of this technique is that registered users or subscribers can receive updates using material purchased at a store or by mail.

[0089] In some implementations, one of the wireless power apparatuses might be a smart appliance with a network connection. For example, referring to FIG. 8, the second Power Receiver 518b might include a network interface 818 for accessing a network 804. The network interface 818 might be a wireless local area network (WLAN, such as WiFi), a cellular interface for a wide area network, a satellite interface, or other suitable network interface for accessing a server 820 via the network 804. The second Power Receiver 518bcan obtain an authentication information update 816 from the server 820 via a periodic query, or on-demand request, or a push update. The second Power Receiver 518b can update its most recent version of authentication information 824 based on the authentication information update 816. Then, as described earlier, the authentication information can propagate to the other wireless power apparatuses (such as the first Power Transmitter 802a, the first Power Receiver 518a, the third Power Receiver 518c, the second Power Transmitter 802b, and the fourth Power Receiver 822a).

[0090] FIG. 9 illustrates a flow chart with example operations 900 of a first wireless power apparatus in accordance with some aspects of this disclosure. For example, the flow chart 900 might be performed by the Power Transmitter 102 or the Power Receiver 118 described with reference to other Figures of this disclosure.

[0091] In block 902, the first wireless power apparatus stores a first version of authentication information in a local storage of the first wireless power apparatus. In block 904, the first wireless power apparatus detects a second wireless power apparatus. In block 906, the first wireless power apparatus authenticates the second wireless power apparatus using a first authentication message exchange that is based, at least in part, on the first version of the authentication information. In block 908, after a successful authentication of the second wireless power apparatus, the first wireless power apparatus obtains a second version of the authentication information from the second wireless power apparatus. In block 910, the first wireless power apparatus stores the second version of the authentication information in the local storage of the first wireless power apparatus for use with a subsequent authentication message exchange.

[0092] FIG. 10 illustrates a flow chart with example operations 1000 of a second wireless power apparatus in accordance with some aspects of this disclosure. For example, the flow chart 1000 might be performed by the Power Transmitter 102 or the Power Receiver 118 described with reference to other Figures of this disclosure.

[0093] In block 1002, the second wireless power apparatus stores authentication information in a local storage of the second wireless power apparatus. In block 1004, the second wireless power apparatus authenticates the first wireless power apparatus based, at least in part, on the authentication information. In block 1006, after a successful authentication of the first wireless power apparatus, the second wireless power apparatus provides a currently-stored version of the authentication information to the first wireless power apparatus based on a determination that the currently-stored version of the authentication information is a morerecent than an earlier version of the authentication information stored at the first wireless power apparatus.

[0094] FIG. 11 illustrates another flow chart with example operations 1100 of a wireless power apparatus in accordance with some aspects of this disclosure. For example, the flow chart 1000 might be performed by the Power Transmitter 102 or the Power Receiver 118 described with reference to other Figures of this disclosure.

[0095] At block 1102, the first wireless power apparatus authenticates a peer wireless power apparatus. At decision block 1104, the first wireless power apparatus determines whether the peer wireless power apparatus has an authentication information update for the first wireless power apparatus. For example, the first wireless power apparatus might provide version information or date information to the peer wireless power apparatus and request an authentication information update if the peer wireless power apparatus has a more recent version of the authentication information. Alternatively, or additionally, the first wireless power apparatus might receive version information or date information from the peer wireless power apparatus and determine whether to request an update from the peer wireless power apparatus. If the peer wireless power apparatus has an authentication information update available for the first wireless power apparatus, the flow chart continues to block 1106. Otherwise, the flow chart proceeds to decision block 1110.

[0096] At block 1106, the first wireless power apparatus obtains the authentication information update from the peer wireless power apparatus. At block 1108, the first wireless power apparatus updates a local storage based on the authentication information update. At block 1114, the first wireless power apparatus proceeds with a wireless charging protocol, the procedures of which are outside the scope of the authentication update scenario described with reference to FIG. 11.

[0097] Returning to decision block 1110, if the peer wireless power apparatus does not have an authentication information update for the first wireless power apparatus, then another inquiry is whether the first wireless power apparatus has an update for the peer wireless power apparatus. At decision block 1110, if the first wireless power apparatus does not have an update for the peer wireless power apparatus, the flow chart continues to block 1114 to proceed with the wireless charging protocol. Otherwise, if the first wireless power apparatus does have an update for the peer wireless power apparatus, the flow chart continues to block 1112. At block 1112, the first wireless power apparatus provides the authentication information update to the peer wireless apparatus. Thereafter, the flow chart continues to block 1114.

[0098] FIG. 12 illustrates a block diagram of an example apparatus for use in a wireless power system. In some implementations, the apparatus 1200 may be a wireless power apparatus (such as the Power Transmitter 102 or the Power Receiver 118) described herein. The apparatus 1200 can include a processor 902 (possibly including multiple processors, multiple cores, multiple nodes, or implementing multi -threading, etc.). The apparatus 900 also can include a memory 1204. The memory 1204 may be system memory or any one or more of the possible realizations of computer-readable media described herein. The apparatus 1200 also can include a bus 1208 (such as PCI, ISA, PCI-Express, HyperTransport®. InfiniBand®, NuBus.® AHB, AXI, etc.).

[0099] The apparatus 1200 may include one or more controllers 1210. In some implementations, the controller 1210 can be distributed within the processor 1202, the memory 1204, and the bus 1208. The controller 1210 may perform some or all of the operations described herein. For example, the controller 1210 may implement the processes described with reference to any one of FIG. 2 through FIG. 11, or any combination thereof.

[0100] The memory 1204 can include computer instructions executable by the processor 1202 to implement the functionality of the implementations described herein. Any one of these functionalities may be partially (or entirely) implemented in hardware or on the processor 1202. For example, the functionality may be implemented with an application specific integrated circuit, in logic implemented in the processor 1202, in a co-processor on a peripheral device or card, etc. Further, realizations may include fewer or additional components not illustrated in FIG. 12. The processor 1202, the memory 1204, and the controller 1210 may be coupled to the bus 1208. Although illustrated as being coupled to the controller 1210, the memory' 1204 may be coupled to the processor 1202.

[0101] The apparatus 1200 also includes an authentication module 1206. The authentication module 1206 might store authentication information (such as public keys, root public key, or a private key of the apparatus 1200). The authentication module 1206 may implement the processes described with reference to any one of FIG. 2 through FIG. 11, or any combination thereof.

[0102] FIG. 1 through FIG. 12 and the operations described herein are examples meant to aid in understanding example implementations and should not be used to limit the potential implementations or limit the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in a different order, and some operations differently.

[0103] The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects. While the aspects of the disclosure have been described in terms of various examples, any combination of aspects from any of the examples is also within the scope of the disclosure. The examples in this disclosure are provided for pedagogical purposes. Alternatively, or in addition to the other examples described herein, examples include any combination of the following implementation options (identified as clauses for reference).

[0104] Clauses

[0105] Clause 1. A method performed by a first wireless power apparatus, including: storing a first version of authentication information in a local storage of the first wireless power apparatus; detecting a second wireless power apparatus; authenticating the second wireless power apparatus using a first authentication message exchange that is based, at least in part, on first version of the authentication information; after a successful authentication of the second wireless power apparatus, obtaining a second version of the authentication information from the second wireless power apparatus; and storing the second version of the authentication information in the local storage of the first wireless power apparatus for use with a subsequent authentication message exchange.

[0106] Clause 2. The method of clause 1, further including: obtaining first identification information associated with the second wireless power apparatus as part of the first authentication message exchange; storing the first identification information in association with the second version of the authentication information; and when the first identification information is received during the subsequent authentication message exchange, authenticating the second wireless power apparatus using a second authentication message exchange that is based, at least in part, on the second version of the authentication information.

[0107] Clause 3. The method of clause 1 or 2, further including: where the first version of the authentication information includes at least one of a root public key, a private key, a block list of untrusted certificates, an allowed list of trusted certificates, an authentication message schema, an authentication configuration setting, or any combination thereof, and where the second version of the authentication information includes an update to the root public key, the private key, the block list of untrusted certificates, the allowed list of trusted certificates,the authentication message schema, the authentication configuration setting, or any combination thereof.

[0108] Clause 4. The method of clause 3, further including: obtaining, from the second wireless power apparatus, date information or version information associated with the second version of the authentication information; and determining that the second version of the authentication information is a more recent version of the authentication information compared to the first version based, at least in part, on the date information or the version information of the second version compared to that of the first version.

[0109] Clause 5. The method of any one of clauses 1 to 4, where storing the second version of the authentication information includes updating or replacing the first version of the authentication information with the second version of the authentication information.

[0110] Clause 6. The method of any one of clauses 1 to 4, where storing the second version of the authentication information includes: maintaining the first version of the authentication information in the local storage; and storing the second version of the authentication information in addition to the first version of the authentication information.

[0111] Clause 7. The method of any one of clauses 1 to 6, where authenticating the second wireless power apparatus includes communicating one or more messages of the first authentication message exchange via a wireless power signal or a short-range radio frequency communication interface, and where obtaining the second version of the authentication information includes receiving the second version in one or more other messages from the second wireless power apparatus via the wireless power signal or the short-range radio frequency communication interface.

[0112] Clause 8. The method of any one of clauses 1 to 7, further including: detecting a third wireless power apparatus; authenticating the third wireless power apparatus; and after a successful authentication of the third wireless power apparatus: providing the second version of the authentication information to the third wireless power apparatus when the second version is more recent than a third version of the authentication information currently stored at the third wireless power apparatus, or obtaining and storing the third version of the authentication information from the third wireless power apparatus when the third version is more recent than the second version.

[0113] Clause 9. The method of any one of clauses 1 to 8, where the first wireless power apparatus is an offline device such that the first wireless power apparatus does not have access to a wide area network, the method further including: obtaining one or more authentication information updates from one or more other wireless power apparatuses after one or moresuccessful authentications of the one or more other wireless power apparatuses; maintaining a currently -stored version of the authentication information when the currently-stored version is more recent than versions of the one or more one or more authentication information updates; and updating the currently -stored version of the authentication information when the currently-stored version is less recent than at least one version of the one or more one or more authentication information updates.

[0114] Clause 10. The method of clause 9, where updating the currently -stored version of the authentication information includes: storing a most recent version of the authentication information from among the one or more authentication information updates as the currently- stored version; or storing a compilation of the currently-stored version of the authentication information and at least the most recent version of the authentication information from among the one or more authentication information updates.

[0115] Clause 11. The method of any one of clauses 1 to 10, where the first wireless power apparatus is one of a Power Transmitter or a Power Receiver, and where the second wireless power apparatus is the other one of the Power Transmitter or the Power Receiver.

[0116] Clause 12. A method performed by a second wireless power apparatus, including: storing authentication information in a local storage of the second wireless power apparatus; authenticating the first wireless power apparatus based, at least in part, on the authentication information; and after a successful authentication of the first wireless power apparatus: providing a currently -stored version of the authentication information to the first wireless power apparatus based on a determination that the currently -stored version of the authentication information is a more recent than an earlier version of the authentication information stored at the first wireless power apparatus.

[0117] Clause 13. The method of clause 12, further including: obtaining one or more authentication information updates from one or more other wireless power apparatuses after one or more successful authentications of the one or more other wireless power apparatuses; maintaining the currently -stored version of the authentication information when the currently- stored version is more recent than versions of the one or more one or more authentication information updates; and updating the currently-stored version of the authentication information when the currently-stored version is less recent than at least one version of the one or more one or more authentication information updates.

[0118] Clause 14. The method of clause 13, where updating the currently-stored version of the authentication information includes: storing a most recent version of the authentication information from among the one or more authentication information updates as the currently-stored version; or storing a compilation of the currently-stored version of the authentication information and at least the most recent version of the authentication information from among the one or more authentication information updates.

[0119] Clause 15. The method of any one of clauses 12 to 14. further including: accessing a wide area network using a network interface of the second wireless power apparatus; obtaining an authentication information update from a server via the wide area network; updating the currently-stored version of the authentication information based the authentication information update; and providing the currently-stored authentication information update to the first wireless power apparatus or one or more other wireless power apparatus after a successful authentication with the first wireless power apparatus or the one or more other wireless power apparatus.

[0120] Clause 16. The method of any one of clauses 12 to 15, where providing the currently- stored version of the authentication information to the first wireless power apparatus includes: communicating one or more messages to the first wireless power apparatus via a wireless power signal or a short-range radio frequency communication interface.

[0121] Clause 17. A first wireless power apparatus, including: a power transfer coil configured to transmit or receive wireless power from a second wireless power apparatus; a local storage configured to initially store a first version of authentication information; a controller configured to: detect a second wireless power apparatus; authenticate the second wireless power apparatus using a first authentication message exchange that is based, at least in part, on the first version of the authentication information; after a successful authentication of the second wireless power apparatus, obtain a second version of the authentication information from the second wireless power apparatus; and store the second version of the authentication information in the local storage of the first wireless power apparatus for use with a subsequent authentication message exchange.

[0122] Clause 18. The first wireless power apparatus of clause 17, where the controller is further configured to: obtain first identification information associated with the second wireless power apparatus as part of the first authentication message exchange; store the first identification information in association with the second version of the authentication information; and when the first identification information is received during the subsequent authentication message exchange, authenticate the second wireless power apparatus using a second authentication message exchange that is based, at least in part, on the second version of the authentication information.

[0123] Clause 19. The first wireless power apparatus of clause 18, where the first version of the authentication information includes at least one of a root public key, a private key, a block list of untrusted certificates, an allowed list of trusted certificates, an authentication message schema, an authentication configuration set, or any combination thereof, and where the second version of the authentication information includes an update to the root public key, the private key, the block list of untrusted certificates, the allowed list of trusted certificates, the authentication message schema, the authentication configuration set, or any combination thereof.

[0124] Clause 20. The first wireless power apparatus of any one of clauses 17 to 19, where the controller is further configured to: obtain, from the second wireless power apparatus, date information or version information associated with the second version of the authentication information; and determine that the second version of the authentication information is a more recent version of the authentication information compared to the first version based, at least in part, on the date information or the version information of the second version compared to that of the first version.

[0125] Clause 21. The first wireless power apparatus of any one of clauses 17 to 20, where the controller is configured to: update or replacing the first version of the authentication information with the second version of the authentication information.

[0126] Clause 22. The first wireless power apparatus of any one of clauses 17 to 20, where the controller is configured to: maintain the first version of the authentication information in the local storage; and store the second version of the authentication information in addition to the first version of the authentication information.

[0127] Clause 23. The first wireless power apparatus of any one of clauses 17 to 22, where authenticating the second wireless power apparatus includes communicate one or more messages of the first authentication message exchange via a wireless power signal or a short- range radio frequency communication interface, and where obtaining the second version of the authentication information includes receive the second version in one or more other messages from the second wireless power apparatus via the wireless power signal or the short- range radio frequency communication interface.

[0128] Clause 24. The first wireless power apparatus of any one of clauses 17 to 23, where the controller is further configured to: detect a third wireless power apparatus; authenticate the third wireless power apparatus: and after a successful authentication of the third wireless power apparatus: provide the second version of the authentication information to the third wireless pow er apparatus when the second version is more recent than a third version of theauthentication information currently stored at the third wireless power apparatus, or obtain and store the third version of the authentication information from the third wireless power apparatus when the third version is more recent than the second version.

[0129] Clause 25. The first wireless power apparatus of any one of clauses 17 to 24, where the first wireless power apparatus is an offline device such that the first wireless power apparatus does not have access to a wide area network, and where the controller is further configured to: obtain one or more authentication information updates from one or more other wireless power apparatuses after one or more successful authentications of the one or more other wireless power apparatuses; maintain a currently-stored version of the authentication information when the currently-stored version is more recent than versions of the one or more one or more authentication information updates; and update the currently-stored version of the authentication information when the currently-stored version is less recent than at least one version of the one or more one or more authentication information updates.

[0130] Clause 26. The first wireless power apparatus of clause 25, where updating the currently-stored version of the authentication information includes: store a most recent version of the authentication information from among the one or more authentication information updates as the currently-stored version; or store a compilation of the currently- stored version of the authentication information and at least the most recent version of the authentication information from among the one or more authentication information updates.

[0131] Clause 27. A second wireless power apparatus including: a power transfer coil configured to transmit or receive wireless power from a second wireless power apparatus; a local storage configured to store authentication information; a controller configured to: authenticate the first wireless power apparatus based, at least in part, on the authentication information; and after a successful authentication of the first wireless power apparatus: provide a currently -stored version of the authentication information to the first wireless power apparatus based on a determination that the currently -stored version of the authentication information is a more recent than an earlier version of the authentication information stored at the first wireless power apparatus.

[0132] Clause 28. The second wireless power apparatus of clause 27, where the controller is further configured to: obtain one or more authentication information updates from one or more other wireless power apparatuses after one or more successful authentications of the one or more other wireless power apparatuses; maintain the currently-stored version of the authentication information when the currently-stored version is more recent than versions of the one or more one or more authentication information updates; and update the currently-stored version of the authentication information when the currently-stored version is less recent than at least one version of the one or more one or more authentication information updates.

[0133] Clause 29. The second wireless power apparatus of clause 28. where the controller is configured to: store a most recent version of the authentication information from among the one or more authentication information updates as the currently -stored version; or store a compilation of the currently-stored version of the authentication information and at least the most recent version of the authentication information from among the one or more authentication information updates.

[0134] Clause 30. The second wireless power apparatus of any one of clauses 27 to 29, further including: a network interface configured to access a wide area network, where the controller is further configured to: obtain an authentication information update from a server via the wide area network; update the currently -stored version of the authentication information based the authentication information update; and provide the currently -stored authentication information update to the first wireless power apparatus or one or more other wireless power apparatus after a successful authentication with the first wireless power apparatus or the one or more other wireless power apparatus.

[0135] Clause 31. The second wireless power apparatus of any one of clauses 27 to 30, further including: a communication unit configured to communicate the currently-stored version of the authentication information via one or more messages to the first wireless power apparatus using a wireless power signal or a short-range radio frequency communication interface.

[0136] Another innovative aspect of the subject matter described in this disclosure can be implemented as a computer-readable medium having stored therein instructions which, when executed by a processor, causes the processor to perform any one of the above-mentioned functionalities.

[0137] Another innovative aspect of the subject matter described in this disclosure can be implemented as a system having means for implementing any one of the above-mentioned functionalities.

[0138] Another innovative aspect of the subject matter described in this disclosure can be implemented as an apparatus having one or more processors configured to perform one or more operations from any one of the above-mentioned methods.

[0139] As used herein, a phrase referring to “at least one of’ or “one or more of’ a list of items refers to any combination of those items, including single members. For example, “atleast one of: a, b. or c’?is intended to cover the possibilities of: a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c.

[0140] The various illustrative components, logic, logical blocks, modules, circuits, operations and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.

[0141] The hardware and data processing apparatus used to implement the various illustrative components, logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes, operations and methods may be performed by circuitry that is specific to a given function.

[0142] As described above, some aspects of the subject matter described in this specification can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor-executable or computer-executable instructions encoded on one or more tangible processor-readable or computer-readable storage media for execution by, or to control the operation of, a data processing apparatus including the components of the devices described herein. By way of example, and not limitation, such storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other mediumthat may be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

[0143] Various modifications to the implementations described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

[0144] Additionally, various features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. As such, although features may be described above as acting in particular combinations, and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0145] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Claims

CLAIMSWhat is claimed is:

1. A method performed by a first wireless power apparatus, comprising: storing a first version of authentication information in a local storage of the first wireless power apparatus; detecting a second wireless power apparatus; authenticating the second wireless power apparatus using a first authentication message exchange that is based, at least in part, on first version of the authentication information; after a successful authentication of the second wireless power apparatus, obtaining a second version of the authentication information from the second wireless power apparatus; and storing the second version of the authentication information in the local storage of the first wireless power apparatus for use with a subsequent authentication message exchange.

2. The method of claim 1, further comprising: obtaining first identification information associated with the second wireless power apparatus as part of the first authentication message exchange; storing the first identification information in association w ith the second version of the authentication information; and when the first identification information is received during the subsequent authentication message exchange, authenticating the second wireless powder apparatus using a second authentication message exchange that is based, at least in part, on the second version of the authentication information.

3. The method of claim 1 or 2, further comprising: wherein the first version of the authentication information includes at least one of a root public key, a private key, a block list of untrusted certificates, an allowed list of trusted certificates, an authentication message schema, an authentication configuration setting, or any combination thereof, and wherein the second version of the authentication information includes an update to the root public key, the private key, the block list of untrusted certificates, the allowed list of trusted certificates, the authentication message schema, the authentication configuration setting, or any combination thereof.

4. The method of claim 3, further comprising: obtaining, from the second wireless power apparatus, date information or version information associated with the second version of the authentication information; and determining that the second version of the authentication information is a more recent version of the authentication information compared to the first version based, at least in part, on the date information or the version information of the second version compared to that of the first version.

5. The method of any one of claims 1 to 4, wherein storing the second version of the authentication information includes updating or replacing the first version of the authentication information with the second version of the authentication information.

6. The method of any one of claims 1 to 4, wherein storing the second version of the authentication information includes: maintaining the first version of the authentication information in the local storage; and storing the second version of the authentication information in addition to the first version of the authentication information.

7. The method of any one of claims 1 to 6, wherein authenticating the second wireless power apparatus includes communicating one or more messages of the first authentication message exchange via a wireless power signal or a short-range radio frequency communication interface, and wherein obtaining the second version of the authentication information includes receiving the second version in one or more other messages from the second wireless power apparatus via the wireless power signal or the short-range radio frequency communication interface.

8. The method of any one of claims 1 to 7, further comprising: detecting a third wireless power apparatus; authenticating the third wireless power apparatus; and after a successful authentication of the third wireless power apparatus: providing the second version of the authentication information to the third wireless power apparatus when the second version is more recent than a third version of the authentication information currently stored at the third wireless power apparatus, orobtaining and storing the third version of the authentication information from the third wireless power apparatus when the third version is more recent than the second version.

9. The method of any one of claims 1 to 8, wherein the first wireless power apparatus is an offline device such that the first wireless power apparatus does not have access to a wide area network, the method further comprising: obtaining one or more authentication information updates from one or more other wireless power apparatuses after one or more successful authentications of the one or more other wireless power apparatuses; maintaining a currently-stored version of the authentication information when the currently-stored version is more recent than versions of the one or more one or more authentication information updates; and updating the currently-stored version of the authentication information when the currently-stored version is less recent than at least one version of the one or more one or more authentication information updates.

10. The method of claim 9, wherein updating the currently -stored version of the authentication information includes: storing a most recent version of the authentication information from among the one or more authentication information updates as the currently -stored version; or storing a compilation of the currently-stored version of the authentication information and at least the most recent version of the authentication information from among the one or more authentication information updates.

11. The method of any one of claims 1 to 10, wherein the first wireless power apparatus is one of a Power Transmitter or a Power Receiver, and wherein the second wireless power apparatus is the other one of the Power Transmitter or the Power Receiver.

12. A method performed by a second wireless power apparatus, comprising: storing authentication information in a local storage of the second wireless power apparatus; authenticating the first wireless power apparatus based, at least in part, on the authentication information; and after a successful authentication of the first wireless power apparatus:providing a currently-stored version of the authentication information to the first wireless power apparatus based on a determination that the currently-stored version of the authentication information is a more recent than an earlier version of the authentication information stored at the first wireless power apparatus.

13. The method of claim 12, further comprising: obtaining one or more authentication information updates from one or more other wireless power apparatuses after one or more successful authentications of the one or more other wireless power apparatuses; maintaining the currently -stored version of the authentication information when the currently-stored version is more recent than versions of the one or more one or more authentication information updates; and updating the currently-stored version of the authentication information when the currently-stored version is less recent than at least one version of the one or more one or more authentication information updates.

14. The method of claim 13. wherein updating the currently-stored version of the authentication information includes: storing a most recent version of the authentication information from among the one or more authentication information updates as the currently-stored version; or storing a compilation of the currently-stored version of the authentication information and at least the most recent version of the authentication information from among the one or more authentication information updates.

15. The method of any one of claims 12 to 14, further comprising: accessing a network using a network interface of the second wireless power apparatus; obtaining an authentication information update from an external device via the network; updating the currently -stored version of the authentication information based the authentication information update; and providing the currently-stored authentication information update to the first wireless power apparatus or one or more other wireless power apparatus after a successful authentication with the first wireless power apparatus or the one or more other wireless power apparatus.

16. The method of any one of claims 12 to 15, wherein providing the currently-stored version of the authentication information to the first wireless power apparatus includes:communicating one or more messages to the first wireless power apparatus via a wireless power signal or a short-range radio frequency communication interface.

17. A first wireless power apparatus, comprising: a power transfer coil configured to transmit or receive wireless power from a second wireless power apparatus; a local storage configured to initially store a first version of authentication information; a controller configured to: detect a second wireless power apparatus; authenticate the second wireless power apparatus using a first authentication message exchange that is based, at least in part, on the first version of the authentication information; after a successful authentication of the second wireless power apparatus, obtain a second version of the authentication information from the second wireless power apparatus; and store the second version of the authentication information in the local storage of the first wireless power apparatus for use with a subsequent authentication message exchange.

18. The first wireless power apparatus of claim 17, wherein the controller is further configured to: obtain first identification information associated with the second wireless power apparatus as part of the first authentication message exchange; store the first identification information in association with the second version of the authentication information; and when the first identification information is received during the subsequent authentication message exchange, authenticate the second wireless power apparatus using a second authentication message exchange that is based, at least in part, on the second version of the authentication information.

19. The first wireless power apparatus of claim 18, wherein the first version of the authentication information includes at least one of a root public key, a private key, a block list of untrusted certificates, an allowed list of trusted certificates, an authentication message schema, an authentication configuration set, or any combination thereof, andwherein the second version of the authentication information includes an update to the root public key, the private key, the block list of untrusted certificates, the allowed list of trusted certificates, the authentication message schema, the authentication configuration set, or any combination thereof.

20. The first wireless power apparatus of any one of claims 17 to 19, wherein the controller is further configured to: obtain, from the second wireless power apparatus, date information or version information associated with the second version of the authentication information; and determine that the second version of the authentication information is a more recent version of the authentication information compared to the first version based, at least in part, on the date information or the version information of the second version compared to that of the first version.

21. The first wireless power apparatus of any one of claims 17 to 20, wherein the controller is configured to: update or replacing the first version of the authentication information with the second version of the authentication information.

22. The first wireless power apparatus of any one of claims 17 to 20, wherein the controller is configured to: maintain the first version of the authentication information in the local storage; and store the second version of the authentication information in addition to the first version of the authentication information.

23. The first wireless power apparatus of any one of claims 17 to 22, wherein authenticating the second wireless power apparatus includes communicate one or more messages of the first authentication message exchange via a wireless power signal or a short-range radio frequency communication interface, and wherein obtaining the second version of the authentication information includes receive the second version in one or more other messages from the second wireless power apparatus via the wireless power signal or the short-range radio frequency communication interface.

24. The first wireless power apparatus of any one of claims 17 to 23. wherein the controller is further configured to: detect a third wireless power apparatus;authenticate the third wireless power apparatus; and after a successful authentication of the third wireless power apparatus: provide the second version of the authentication information to the third wireless power apparatus when the second version is more recent than a third version of the authentication information currently stored at the third wireless power apparatus, or obtain and store the third version of the authentication information from the third wireless power apparatus when the third version is more recent than the second version.

25. The first wireless power apparatus of any one of claims 17 to 24, wherein the first wireless power apparatus is an offline device such that the first wireless power apparatus does not have access to a network, and wherein the controller is further configured to: obtain one or more authentication information updates from one or more other wireless power apparatuses after one or more successful authentications of the one or more other wireless power apparatuses; maintain a currently-stored version of the authentication information when the currently-stored version is more recent than versions of the one or more one or more authentication information updates; and update the currently-stored version of the authentication information when the currently-stored version is less recent than at least one version of the one or more one or more authentication information updates.

26. The first wireless power apparatus of claim 25, wherein updating the currently-stored version of the authentication information includes: store a most recent version of the authentication information from among the one or more authentication information updates as the currently-stored version; or store a compilation of the currently-stored version of the authentication information and at least the most recent version of the authentication information from among the one or more authentication information updates.

27. A second wireless power apparatus comprising: a power transfer coil configured to transmit or receive wireless power from a second wireless power apparatus; a local storage configured to store authentication information; a controller configured to:authenticate the first wireless power apparatus based, at least in part, on the authentication information; and after a successful authentication of the first wireless power apparatus: provide a currently-stored version of the authentication information to the first wireless power apparatus based on a determination that the currently -stored version of the authentication information is a more recent than an earlier version of the authentication information stored at the first wireless power apparatus.

28. The second wireless power apparatus of claim 27, wherein the controller is further configured to: obtain one or more authentication information updates from one or more other wireless power apparatuses after one or more successful authentications of the one or more other wireless power apparatuses; maintain the currently-stored version of the authentication information when the currently-stored version is more recent than versions of the one or more one or more authentication information updates; and update the currently-stored version of the authentication information when the currently-stored version is less recent than at least one version of the one or more one or more authentication information updates.

29. The second wireless power apparatus of claim 28, wherein the controller is configured to: store a most recent version of the authentication information from among the one or more authentication information updates as the currently-stored version; or store a compilation of the currently-stored version of the authentication information and at least the most recent version of the authentication information from among the one or more authentication information updates.

30. The second wireless power apparatus of any one of claims 27 to 29, further comprising: a network interface configured to access a network, wherein the controller is further configured to: obtain an authentication information update from an external device via the network; update the currently -stored version of the authentication information based the authentication information update; and provide the currently -stored authentication information update to the first wireless power apparatus or one or more other wireless power apparatus after asuccessful authentication with the first wireless power apparatus or the one or more other wireless power apparatus.

31. The second wireless power apparatus of any one of claims 27 to 30, further comprising: a communication unit configured to communicate the currently -stored version of the authentication information via one or more messages to the first wireless power apparatus using a wireless power signal or a short-range radio frequency communication interface.

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