Method and apparatus for secure and efficient sharing of sensitive data via device credential provisioning

Abstract

A method and apparatus for securely providing data D1 to an Internet of Things (IoT) device is disclosed. In one embodiment, this is evidenced by a method comprising receiving a certificate signing request (CSR) including a device public key of a device key pair of the device, wherein the device public key and an associated device private key of the device key pair are stored by the IoT device; generating an ephemeral key pair having an ephemeral public key and an ephemeral private key; generating a secret key K from the ephemeral private key and the public key; and transmitting a CSR response message to the IoT device, the message comprising the signed certificate and the ephemeral public key.

Description

Atorney Docket No. 7651-PCT METHOD AND APPARATUS FOR SECURE AND EFFICIENT SHARING OF SENSITIVE DATA VIA DEVICE CREDENTIAL PROVISIONINGInventors: Oscar Jiang, Jason Pasion, and Lisa YinCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is an international patent application which claims priority to U.S. Provisional Application No. 63 / 755,090 filed February 6, 2025, the contents of which are each incorporated herein by reference in their entirety.BACKGROUND1. Field

[0002] The present disclosure relates to systems and methods for securely transmitting data among devices.2. Description of the Related Art

[0003] With the proliferation of Internet of Things (loT) devices, there has been a growing demand in the industry for provisioning unique device credentials. The typical provisioning process involves executing certain cryptographic protocols and exchanging cryptographic data, such as keys and certificates, between a device and a provisioning server. Besides certificate signing requests (CSR) from the device to the server and certificates from the server to the device, additional sensitive data may need to be transmitted for future applications beyond credential provisioning.SUMMARY

[0004] To address the needs described above, the following presents a new cryptographic mechanism designed to securely and efficiently share sensitive data during the credential provisioning process. By leveraging existing cryptographic protocols, this mechanism ensures data confidentiality and significantly enhances the efficiency of data transmission.

[0005] In one embodiment, this is evidenced by a method of securely providing data Di to an Internet of Things (loT) device comprising receiving a certificate signing request (CSR) including a public key of a key pair of the device, wherein the public key and an associated private key of theAttorney Docket No. 7651-PCTkey pair are stored by the loT device; generating an ephemeral key pair having an ephemeral public key and an ephemeral private key; generating a secret key K from the ephemeral private key and the public key; and transmitting a message to the loT device, the message comprising the signed certificate and the ephemeral public key.

[0006] Another embodiment is evidenced by an apparatus having a processor and a communicatively coupled memory storing processor instructions for performing the foregoing operations.

[0007] The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present invention or may be combined in yet other embodiments, further details of which can be seen with reference to the following description and drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Referring now to the drawings in which like reference numbers represent corresponding parts throughout:

[0009] FIG. 1 is a diagram illustrating a diagram of a communication system having a device, a secondary device, a provisioning server, and a device monitoring utility;

[0010] FIGs. 2A-2C are diagrams depicting an exemplary technique for securely providing data DI to a device;

[0011] FIGs. 3A-3C are diagrams depicting a technique that can be used to securely provide data from a device to an external device such as a monitoring device or utility; and

[0012] FIG. 4 is a diagram illustrating an exemplary computer system that could be used to implement processing elements of the geolocation system.DESCRIPTION

[0013] In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown, by way of illustration, several embodiments. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present disclosure.Attorney Docket No. 7651-PCTOverview

[0014] FIG. 1 is a diagram illustrating a diagram of a communication system 100 having a device 102, a secondary device 104, a provisioning server 106 and a device monitoring utility 108. The device 102 can comprise any processing device, but the systems and methods described herein are particularly useful for devices such as Internet of Things (loT) devices. loT devices are individually addressable devices have processing ability that are connected to a network to exchange data with other devices. Typically, loT devices have limited capability in terms of processing, memory, and communication. For example, many loT devices have the ability to communicate with other devices via Bluetooth, but not by Wi-Fi.

[0015] loT devices can collect and exchange data, and analyze and respond to data. With respect to the collection and exchange of data, loT devices use sensors to gather data about themselves or their environment and to send the data they collect to an loT platform or other device. The loT platform can analyze or otherwise use the data to generate insights, enable remote control, or trigger an automated response in the loT device. The loT platform analyzes the data from many devices. Importantly, the processing of the data itself is typically performed by the loT platform, not the loT device, as loT devices typically have limited processing power and memory. Examples of loT devices include smart televisions, smart appliances, smart lights, pet finders, and wearable devices.

[0016] In order to communicate with external entities securely, the device 102 may include credentials such as digital certificates, in order to allow entities that it communicates with to authenticate that the device 102 is the device it claims to be. Such credentials may be provided to the device 102 after the device 102 is deployed to the consumer, or may be preloaded in the device 102 However, even when the credentials are preloaded, they may need to be updated over time, or as circumstances change. For example, a security vulnerability may have been identified which requires updated credentials. Further, the device 102 may require updated software or data, such as new secrets.

[0017] The device 102 typically receives this credentials or data from a provisioning server 106. However, many devices 102 have limited communication capabilities. For example, many loT devices can communicate via Bluetooth, but not by other means such as Wi-Fi. Although someAttorney Docket No. 7651-PCTdevices 102 may communicate directly with the provisioning server 106, devices that cannot perform such communication directly with the provisioning server 106 may do so via a secondary device 104 such as a tablet, laptop, or similar, communicatively coupled to both the device 12 (e.g., via Bluetooth) and the provisioning server (e.g. via Wi-Fi).

[0018] The device 102 may also communicate with the device monitoring utility 108, either directly, or via the secondary device 104. The secondary device may comprise, for example, a programming station, which can be a personal computer, tablet, or similar computing device. The device monitoring utility accepts data from the device 102. Such data may be pushed from the device 102 to the device monitoring utility 108 or pulled from the device 102.

[0019] In the following examples, additional steps essentially provide a Diffie-Hellman (DH) key exchange that is “piggy bagged” on top of the provisioning protocol. The result of the DH key exchange is a shared secret key K between the device and the server. That shared key K can be computed from either the private key of the device 102 and the public key of the provisioning server 106 or with the private key of the provisioning server 106 and the public key of the device. This K can be used to encrypt and protect sensitive data D to be transmitted between the device and the server.

[0020] In one embodiment, the secret data D that is communicated includes, post quantum cryptography (PQC) based keys that can be shared with the device for future use. In other embodiments, the secret shared key K is used to create a secure communications channel that allows additional information to be transmitted from the device 102 to a monitoring device 108, potentially via the secondary device 104. For example, telemetry data may be sent from the device 102 to an AMAZON web server (AWS) or similar via a tablet. Finally, some devices 102 may only be capable of generating ECDSA (Elliptic Curve Digital Signature Algorithm) key pairs and not other kinds of key pairs such as EdDSA (Edwards Curve Digital Signature Algorithm) key pairs. The techniques described below can be used to transmit such key pairs to the device 102.

[0021] In the protocol described below, the device 102 uses the device credential (it’s public and private keys) as its keys in the DH key exchange. So, the device doesn’t need to generate an additional key pair, thus increasing efficiency.Attorney Docket No. 7651-PCT

[0022] In the discussion that follows, elliptic curve public key cryptography (ECC) techniques are employed. ECC uses pairs of public and private keys to encrypt and decrypt data. When compared to Rivest-Shamir-Adleman (RSA) and other techniques, ECC can use smaller keys and can operate on devices with low CPU and memory resources. ECC can also encrypt and decrypt data faster than RSA. RSA techniques could be employed, but straightforward use of RSA would essentially involve using the same device key pair for both signing and encryption, which is not typical for best security practices. However, RSA techniques may be used in some applications and embodiments.

[0023] FIGs. 2A-2C are diagrams depicting an exemplary technique for securely providing data DI to a device 102 such as an loT device. In this embodiment, the device 102 communicates directly with the provisioning server 106. In block 202, the device 102 generates a key pair having a private key and a public key. In one embodiment, the key pair comprises an elliptic curve key pair having an elliptic curve private key da and an elliptic curve public key Qa. The device 102 may also not need to be generated by the device 102, but rather stored by the device 102 in a secure memory. For example, the key pair may be pre-loaded by the manufacturer of the device 102 and simply recalled from secure memory for use.

[0024] In block 204, the device 102 generates a certificate signing request (CSR). The CSR includes the name of the requestor, the public key of the requestor, and may also include other information. The CSR is transmitted to the provisioning server 106, as shown in block 206. Such transmission may occur via the secondary device 104, in particular, in cases where the device 102 does not have the capability to transmit data directly to the provisioning server 106, for example, in cases where the device 102 has Bluetooth capability, but not Wi-Fi or other communication capability.

[0025] In block 208, the provisioning server 106 receives the CSR. The provisioning server then authenticates the CSR (for example, using out of band data), as shown in block 210. The provisioning server 106 generates a key pair having a private key and a public key. In an elliptic curve embodiment, the key pair comprises an elliptic curve private key db and an elliptic curve public key Qb.

[0026] In one embodiment, this key pair is ephemeral. That is, the key pair exist only for time approximating the time period that it takes to securely provide the data DI to the device 102, afterAttorney Docket No. 7651-PCTwhich, the key pair is deleted, written over, rendered inaccessible, or inactive. In other embodiments, the key pair is persistent, for example, by storing the key pair in memory for later access.

[0027] The key pair may be generated in response to receipt of the CSR from the device 102, or generated in advance, and stored for later use.

[0028] The provisioning server 106 then generates a secret key K from the private key and the public key, as shown in block 214. In embodiments wherein the key pair comprises elliptical curve keys, the secret key K computed by computing the point (xk, yk) = (db • Qz ), wherein xk is the xk coordinate of the point,refers to Elliptic Curve Scalar Multiplication and yk is the y coordinate of the point, then computing the secret key K from xk.

[0029] A CSR response message is then generated, as shown in block 216. The CSR response message includes the requested signed digital certificate, the public key generated by the provisioning server (e.g. Qb), and optionally encrypted data. In one embodiment, the provisioning server 106 encrypts data Di according to the secret key K to produce EK[DI], and sends the encrypted data to the device 102 in the CSR response message. In other embodiments, the provisioning server 106 encrypts data Di according to the secret key K to produce EK[DI], and sends the encrypted data to the device 102 in another message.

[0030] In block 218, the generated message is transmitted to the device 102, and in block 220, the device 102 receives the message.

[0031] Turing to FIG. 2B, the device 102 authenticates the message received from the provisioning server 106 (again, using out of band data as necessary), and validates and stored the received signed digital certificate, as shown in blocks 224 and 226. The device 102 then computes the secret key K from the device’s private key and the provisioning server’s public key as shown in block 228 and decrypts the encrypted data EK[DI] using the secret key K to produce the data Di. Decrypted data Di may be stored in a secure memory as shown in block 232.

[0032] In embodiments wherein the key pair comprises elliptical curve keys, the secret key K computed by computing the point (xk, yk) = (da • Qb ), wherein xk is the xk coordinate of the point, and yk is the y coordinate of the point, then computing the secret key K from xk.Attorney Docket No. 7651-PCT

[0033] The computed secret key K may be stored in secure storage for future use or may be deleted or written over.

[0034] FIGs. 3A-3C are diagrams depicting a technique that can be used to securely provide data from a device to an external device such as a monitoring device or utility 108. In this embodiment, a secondary device 104 such as a tablet is interposed between the device 102, and the provisioning server 106, and the device 102 and the monitoring device 108.

[0035] Turning first to FIG. 3A, in block 302, the device 102 generates a key pair. Alternatively, the device 102 may be pre-provided with a key pair rather than generating it with the device 102. In one embodiment, the key pair is an elliptic curve (EC) key pair including private key da, and public key Qa. Using the key pair, the device 102 generates and transmits a CSR, as shown in block 304, using techniques similar to those depicted in blocks 204 and 206.

[0036] In block 306, the secondary device 104 receives the CSR and transmits the SCR to the provisioning server 106. The provisioning server 106 receives the CSR, generates a signed device certificate, and transmits that signed device certificate to the secondary device, as shown in blocks 308 and 310. In block 312, the secondary device 104 generates and transmits a secondary device CSR (e.g., a request for the provisioning server to sign the certificate of the secondary device 104. The CSR includes a public key of a key pair that can be generated by the secondary device 104, prestored or otherwise provided to the secondary device 104.

[0037] In block 316, the provisioning server 106 receives the secondary device CSR and in block 318, generates and transmits a signed secondary device certificate. In block 420, the secondary device receives and stores the signed secondary device certificate. In block 322, the secondary device computes Diffe-Hellman a secret shared key K from the public key of the device 102 and the private key of the secondary device. In embodiments where the device key pair each include an elliptic curve key pair, the ECDH secret key K is computed from the secondary device’s elliptic curve private key db and the device’s elliptic curve public key Qa, for example, by computing the point (xk, yk) = db*Qa and computing K from xk. The secondary device 104 then transmits a message having the signed device certificate received from the provisioning server 106 to the device 102. The message includes the public key of the secondary device 104, as shown in block 324, and may optionally include secret data.Attorney Docket No. 7651-PCT

[0038] In block 328, the device 102 receives the message having the signed device certificate and public key of the secondary device public key. The device 102 then computes the shared key K from the private key of the device and the public key of the secondary device 104, as shown in block 330. In embodiments where the device key pair each include an elliptic curve key pair, the ECDH secret key K is computed from the device’s elliptic curve private key da and the secondary elliptic curve public key Qb, for example, by computing the point (xk, yk) = da*Qb and computing K from xk.

[0039] That computed shared key can be stored in secure storage within the device 102 for later use. Alternatively, the shared key K can be computed only in response to data requests such as those further described below.

[0040] In blocks 331 and 332, the device 102 receives a data request from the secondary device 104. The device 102 obtains the requested data and encrypts the data with the shared key computed in block 330. The device 102 then generates a message having the encrypted data, and signs that data with the device’s private key, and transmits that message to the secondary device 104, as shown in block 338. The secondary device 104 receives the message, and using the public key of the device, verifies the message, as shown in block 340.

[0041] Now referring to FIG. 3C, the secondary device 104 decrypts the data received in the message using the shared key K, and transmits that data to the monitoring device, for example using message queueing telemetry transport (MQTT), as shown in blocks 342. and 344. The monitoring device 108 then receives the data as shown in block 346.Hardware Environment

[0042] FIG. 4 illustrates an exemplary computer system 400 that could be used to implement processing elements of the above disclosure, including the any of the processors computing the processing threads. The computer 402 comprises a processor 404 and a memory, such as random access memory (RAM) 406. The computer 402 is operatively coupled to a display 422, which presents images such as windows to the user on a graphical user interface 418B. The computer 402 may be coupled to other devices, such as a keyboard 414, a mouse device 416, a printer 428, etc. Of course, those skilled in the art will recognize that any combination of the above components, or any number of different components, peripherals, and other devices, may be used with the computer 402.Attorney Docket No. 7651-PCT

[0043] Generally, the computer 402 operates under control of an operating system 408 stored in the memory 406, and interfaces with the user to accept inputs and commands and to present results through a graphical user interface (GUI) module 418A. Although the GUI module 418B is depicted as a separate module, the instructions performing the GUI functions can be resident or distributed in the operating system 408, the computer program 410, or implemented with special purpose memory and processors. The computer 402 also implements a compiler 412 which allows an application program 410 written in a programming language such as COBOL, C++, FORTRAN, or other language to be translated into processor 404 readable code. After completion, the application 410 accesses and manipulates data stored in the memory 406 of the computer 402 using the relationships and logic that was generated using the compiler 412. The computer 402 also optionally comprises an external communication device such as a modem, satellite link, Ethernet card, or other device for communicating with other computers.

[0044] In one embodiment, instructions implementing the operating system 408, the computer program 410, and the compiler 412 are tangibly embodied in a computer-readable medium, e.g., data storage device 420, which could include one or more fixed or removable data storage devices, such as a zip drive, floppy disc drive 424, hard drive, CD-ROM drive, tape drive, etc. Further, the operating system 408 and the computer program 410 are comprised of instructions which, when read and executed by the computer 402, causes the computer 402 to perform the operations herein described. Computer program 410 and / or operating instructions may also be tangibly embodied in memory 406 and / or data communications devices 430, thereby making a computer program product or article of manufacture. As such, the terms “article of manufacture,” “program storage device” and “computer program product” as used herein are intended to encompass a computer program accessible from any computer readable device or media.

[0045] Those skilled in the art will recognize many modifications may be made to this configuration without departing from the scope of the present disclosure. For example, those skilled in the art will recognize that any combination of the above components, or any number of different components, peripherals, and other devices, may be used.Attorney Docket No. 7651-PCTConclusion

[0046] This concludes the description of the preferred embodiments of the present disclosure.

[0047] The foregoing description of the preferred embodiment has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of rights be limited not by this detailed description, but rather by the claims appended hereto.

Claims

Attorney Docket No. 7651-PCTCLAIMSWhat is Claimed is:

1. A method of securely providing data Di to an Internet of Things (loT) device, comprising:receiving a certificate signing request (CSR) including a device public key of a device key pair of the device, wherein the device public key and an associated device private key of the device key pair are stored by the loT device;generating an ephemeral key pair having an ephemeral public key and an ephemeral private key;generating a secret key K from the ephemeral private key and the device public key; and transmitting a CSR response message to the loT device, the CSR response message comprising the signed certificate and the ephemeral public key.

2. The method of claim 1, further comprising:encrypting the data Di according to the secret key K to generate encrypted data EK[DI]; and transmitting encrypted data EK[DI] to the loT device.

3. The method of claim 2, wherein the encrypted data EK[DI] is transmitted to the loT device in the CSR response message.

4. The method of claim 2, wherein:the loT device computes the secret key K from the device private key and the ephemeral public key; andthe loT device decrypts the encrypted data EK[DI] according to the computed secret key K to produce the data Di.

5. The method of claim 1, wherein:the device generates the device public key and the device private key.Attorney Docket No. 7651-PCT6. The method of claim 1, wherein:the CSR is received from the loT device in a provisioning server;the ephemeral key pair is generated by the provisioning server;the secret key K is generated by the provisioning server; andthe CSR response message is transmitted from the provisioning server to the loT device.

7. The method of claim 4, wherein:the device key pair is an elliptic curve device key pair (da, Qa) having an elliptic curve device private key da and an elliptic curve device public key Qa;the ephemeral key pair is an ephemeral elliptic curve key pair (db, Qb) having ephemeral elliptic curve private key db and an ephemeral elliptic curve public key Qb; andgenerating the secret key K from the ephemeral private key and the device public key comprises:computing a secret key K from the ephemeral elliptic curve private key db and the elliptic curve device public key Qa, comprising:computing (xkyk) ,= db*Qa; andcomputing K from xk.

8. The method of claim 7, wherein:the loT device computes the secret key K from the elliptic curve device private key da and the ephemeral elliptic curve public key Qb by:computing (xk,yk) = da *Qb; andcomputing K from xk; andthe loT device decrypts the encrypted data Exk[Di] to produce data Di.

9. The method of claim 1, wherein:the provisioning server is communicatively decoupled from direct communication with the loT device;Attorney Docket No. 7651-PCTthe CSR is received from the loT device via a secondary device communicatively coupled to the loT device and the provisioning server; andthe ephemeral key pair and the secret key are generated by the secondary device;the CSR response message is transmitted to the loT device by the secondary device;the CSR is transmitted from the secondary device to the provisioning server; andthe method further comprises:receiving the signed certificate from the provisioning server; andgenerating the CSR response message in the secondary device.

10. The method of claim 9, wherein:a request for second data D2 is transmitted from the secondary device to the loT device; a data response message is received from the loT device, the response message comprising encrypted the second data EK[D2], wherein the second data is encrypted according to the secret key K;the secondary device decrypts the encrypted second data EK[D2] to produce the second data D2; andthe second data is transmitted from the secondary device.

11. An apparatus for securely providing data DI to an Internet of Things (loT) device, comprising:a processor;a memory, communicatively coupled to the processor, the memory storing processor instructions comprising processor instructions for:receiving a certificate signing request (CSR) including a device public key of a device key pair of the device, wherein the device public key and an associated device private key of the device key pair are stored by the loT device;generating an ephemeral key pair having an ephemeral public key and an ephemeral private key;Attorney Docket No. 7651-PCTgenerating a secret key K from the ephemeral private key and the device public key; andtransmitting a CSR response message to the loT device, the CSR response message comprising the signed certificate and the ephemeral public key.

12. The apparatus of claim 11, wherein the processor instructions further comprise processor instructions for:encrypting the data Di according to the secret key K to generate encrypted data EK[DI]; and transmitting encrypted data EK[DI] to the loT device.

13. The apparatus of claim 12, wherein the encrypted data EK[DI] is transmitted to the loT device in the CSR response message.

14. The apparatus of claim 12, wherein:the loT device computes the secret key K from the device private key and the ephemeral public key; andthe loT device decrypts the encrypted data EK[DI] according to the computed secret key K to produce the data Di.

15. The apparatus of claim 11, wherein:the device generates the device public key and the device private key.

16. The apparatus of claim 11, wherein:the CSR is received from the loT device in a provisioning server;the ephemeral key pair is generated by the provisioning server;the secret key K is generated by the provisioning server; andthe CSR response message is transmitted from the provisioning server to the loT device.

17. The apparatus of claim 14, wherein:Attorney Docket No. 7651-PCTthe device key pair is an elliptic curve device key pair (da, Qa) having an device elliptic curve device private key da and an elliptic curve device public key Qa;the ephemeral key pair is an ephemeral elliptic curve key pair (db, Qb) having ephemeral elliptic curve private key db and an ephemeral elliptic curve public key Qb; andthe processor instructions for generating the secret key K from the ephemeral private key and the device public key comprise processor instructions for:computing a secret key K from the ephemeral elliptic curve private key db and the elliptic curve device public key Qa, comprising:computing (xkyk) ,= db*Qa; andcomputing K from xk.

18. The apparatus of claim 17, wherein:the loT device computes the secret key K from the elliptic curve device private key da and the ephemeral elliptic curve public key Qb by:computing (xk,yk) = da *Qb; andcomputing K from xk; andthe loT device decrypts the encrypted data Exk[Di] to produce data Di.

19. The apparatus of claim 11, wherein:the provisioning server is communicatively decoupled from direct communication with the loT device;the CSR is received from the loT device via a secondary device communicatively coupled to the loT device and the provisioning server; andthe ephemeral key pair and the secret key are generated by the secondary device;the CSR response message is transmitted to the loT device by the secondary device; the CSR is transmitted from the secondary device to the provisioning server; andthe method further comprises:receiving the signed certificate from the provisioning server; andgenerating the CSR response message in the secondary device.Attorney Docket No. 7651-PCT20. An apparatus for securely providing data Di to an Internet of Things (loT) device, comprising:means for receiving a certificate signing request (CSR) including a device public key of a device key pair of the device, wherein the device public key and an associated device private key of the device key pair are stored by the loT device;means for generating an ephemeral key pair having an ephemeral public key and an ephemeral private key;means for generating a secret key K from the ephemeral private key and the device public key; andmeans for transmitting a CSR response message to the loT device, the CSR response message comprising the signed certificate and the ephemeral public key.

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