Secure key replacement system, secure key replacement device, and secure key replacement method

Abstract

To provide a secure key replacement system, device, and method for making backup copies of a private key and storing the private key in one or more secure locations if needed.SOLUTION: An active signing server 14 includes a secure storage and processing unit 16 that stores a first private key, generates signatures using the first private key, performs authentication by devices storing a first public key forming a key pair with the first private key, and signs a replacement command using the first private key. The replacement command is to be used to instruct the devices to replace the first public key with a second public key forming a key pair with a second private key. The active signing server includes an interface that provides the signatures to the devices and provides the replacement command for an entity. The entity performs storage remotely to the active signing server and the devices and includes an orchestration server or at least one other signing server.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a computer system, and more particularly, to but not limited to secure key replacement.

Background Art

[0002] A signature server or other centrally managed entity can provide data to a device (such as a secure flash device) signed with the private key of the signature server and generate a signature. Since each device holds a corresponding public key, the public key can be used to authenticate the data against the signature. It is important to prevent the public key from being overwritten by an attacker attempting to spoof the signature server.

[0003] On the signature server side, since the private key may be lost, damaged, or become unavailable, it becomes impossible to generate a signature using the private key and perform authentication by the device using the corresponding public key.

Summary of the Invention

Problems to be Solved by the Invention

[0004] One solution is to create a backup copy of the private key and store the private key in one or more secure locations as needed.

Means for Solving the Problems

[0005] According to one embodiment of the present invention, a secure key replacement system is provided. The secure key replacement system is configured to save a first secret key, perform authentication by a device that generates a signature using the first secret key and saves a first public key that forms a key pair with the first secret key, and sign a replacement command using the first secret key. The replacement command is configured to be used to instruct a device to replace the first public key with a second public key that forms a key pair with a second secret key. The secure key replacement system includes a secure storage and processing unit, and an active signature server. The secure storage and processing unit is configured to provide the signature to the device and provide the replacement command to at least one entity. The at least one entity includes an interface that stores the active signature server and the device separately and includes an active signature server that includes an orchestration server and / or at least one other signature server.

[0006] Also, according to another embodiment of the present invention, a secure key replacement device is provided. The secure key replacement device includes a secure storage configured to securely store a first public key that forms a key pair with a first secret key stored by an active signature server, and a secure processor. The secure processor is configured to reject an instruction to replace the first public key if the instruction is not authorized by a signature formed by the active signature server using the first secret key, receive a replacement command signed by the first secret key, where the replacement command is configured to be used to instruct the device to replace the first public key with a second public key that forms a key pair with a second secret key stored by a new active signature server, authenticate the replacement command using the first public key, and replace the first public key with the second public key in response to authenticating the replacement command using the first public key.

[0007] Further, according to yet another embodiment of the present invention, a secure key replacement method is provided. The secure key replacement method includes storing a first secret key, generating a signature by an active signature server using the first secret key, performing authentication by a device that stores the first secret key and a first public key that forms a key pair with the first secret key, signing a replacement command by the active signature server using the first secret key, where the replacement command is configured to be used to instruct the device to replace the first public key with a second public key that forms a key pair with a second secret key, providing the signature to the device and providing the replacement command to at least one entity, where the at least one entity stores the signature and the replacement command away from the active signature server and the device, and the at least one entity includes an orchestration server and / or at least one other signature server.

[0008] Further, according to yet another embodiment of the present invention, a secure key replacement method is provided. The secure key replacement method includes securely storing a first public key that forms a key pair with a first secret key stored by an active signature server, receiving a replacement command signed by the first secret key, where the replacement command is configured to be used to instruct the device to replace the first public key with a second public key that forms a key pair with a second secret key stored by a new active signature server, authenticating the replacement command using the first public key, and in response to authenticating the replacement command using the first public key, replacing the first public key with the second public key.

Advantages of the Invention

[0009] As described above, each device can protect the currently stored public key by approving the replacement commands signed by the live signature server and rejecting the replacement commands not signed by the signature server. And since the signature server corresponding to the replacement command becomes the new active signature server and can generate signatures using its private key, each device can authenticate data using the new public key.

Brief Description of the Drawings

[0010] The present invention will be understood from the following detailed description when read in conjunction with the drawings.

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0012] As described above, the signing server can back up the private key to one or more secure locations in the event that the private key in use is lost, damaged, or becomes unavailable. However, backing up the private key may not, in some cases, be a solution to the problem, and an example is given below.

[0013] The National Institute of Standards and Technology (NIST) recommends the use of hashed-based signatures (i.e., stateful signatures). These are one-time signatures that use an index that is advanced each time a signature is generated and have the advantage of not being decodable by a quantum computer. However, it is extremely important that the same index is not used twice, or else the signature will be broken. Therefore, simply backing up the private key is insufficient, and the index also needs to be backed up, but there is no practical solution for this. For this reason, NIST recommends always storing the index and the key together inside a hardware module (e.g., a hardware security module (HSM)). However, since the index is incremented each time the key is used, it becomes impossible to back up the key as if one had deleted it oneself, the connection to the index is lost, and the security of the signature scheme cannot be ensured. The signing server is an entity that securely stores the private key and includes an HSM for performing an encryption process (e.g., signature generation) with the private key.

[0014] If the private key cannot be backed up and the private key is lost, damaged, or becomes unavailable, it has been proposed to generate a new key pair by a signature server or another signature server to sign data and perform authentication by the device. However, since each device has the public key corresponding to the "lost" private key installed in a protected manner and the public key cannot be replaced, simply generating a new key pair by oneself does not solve the problem. Therefore, since the device cannot overwrite the old public key with the new public key, it becomes unusable in this regard, and the ability of the signature server to provide signatures to all devices is permanently lost.

[0015] Embodiments of the present invention solve the above drawbacks by providing a system that can use a replacement command generated from the original private key when the original private key becomes unavailable (e.g., lost, damaged, or for other reasons). Next, it is sent to the device to replace the original public key with the new public key to recover from the situation where the private key is unavailable.

[0016] Description of the System

[0017] Referring now to FIG. 1, FIG. 1 is a block diagram of a secure key replacement system (referred to as the system) 10 constructed and operating in accordance with one embodiment of the present invention. The system 10 includes N signature servers SS including an active signature server SS and N - 1 non - active signature servers SS. N may be any suitable number greater than or equal to 2. As shown in FIG. 1, at this time, signature server 0 functions as the active signature server 14, and signature servers 1 to N - 1 function as backup signature servers. The system 10 also includes an orchestration server 18 and a device 20, and the device 20 is, for example, a secure flash storage device.

[0018] Each signature server SS includes a secure storage and processing unit 16 (e.g., a hardware security module (HSM)), and an interface 26 for sharing data with another one of the signature server SS, the orchestration server 18, and the device 20 (e.g., via the orchestration server 18). In the example of FIG. 1, signature server 0 includes a secure storage and processing unit 16 (HSM 0), signature server 1 includes a secure storage and processing unit 16 (HSM 1), and signature server N-1 includes HSM N-1. The secure storage and processing unit 16 (HSM) is a physical computing device that protects and manages secrets and performs encryption and decryption functions used for digital signatures, strong authentication, and other cryptographic functions. Each secure storage and processing unit 16 is configured to store one or more private keys 30 (private key, PRVK) and selectively store an index associated with the private key 30. In the example of FIG. 1, the secure storage and processing unit 16 (HSM 0) stores a private key 30 (PRVK_0), the secure storage and processing unit 16 (HSM 1) stores a private key 30 (PRVK_1), and the secure storage and processing unit 16 (HSM N-1) stores a private key 30 (PRVK_N-1), the details of which will be described with reference to FIG. 2.

[0019] Each device 20 includes an interface 28 for sharing data with the orchestration server 18 and each signature server SS. Each device 20 also includes a secure processor 22 and a secure storage 24. The secure storage 24 of each device 20 is configured to store a public key (public key, PUBK) 32 (e.g., a public key 32 (PUBK_0) that forms a key pair with the private key 30 (PRVK_0) of the active signature server 14 (signature server 0)).

[0020] FIG. 2 is a flowchart 200 including steps in the method of operating the system 10 of FIG. 1. Refer to FIGS. 1 and 2.

[0021] The orchestration server 18 is configured to assign the signature server 0 as the active signature server 14 (step 202). The secure storage and processing unit 16 of the signature server 14 (signature server 0) is configured to generate a key pair, store the generated private key 30 (PRVK_0), and selectively store an index related to the private key 30 (not shown). The secure storage and processing unit 16 of the active signature server 14 (signature server 0) is configured to distribute the generated public key 32 (PUBK_0) to each device 20. The public key 32 (PUBK_0) of the active signature server 14 (signature server 0) is then stored in the secure storage 24 of each device 20 (step 204). In one embodiment, the secure storage and processing unit 16 of the active signature server 14 (signature server 0) is also configured to distribute the generated public key 32 (PUBK_0) to all signature servers SS and / or the orchestration server 18 (not shown).

[0022] Each secure storage and processing unit 16 (HSM 1 to HSM N-1) of the backup signature servers (signature server 1 to signature server N-1) is configured to generate a key pair (public key 32 (PUBK_1 to PUBK_N-1) and private key 30 (PRVK_1 to PRVK_N-1)), store the generated private key 30, and selectively store an index related to the private key 30 (not shown) (step 206). That is, the secure storage and processing unit 16 of the N-1 signature servers is configured to generate N-1 corresponding key pairs, and each key pair includes its respective public key and its respective private key. As shown in the example of FIG. 1, HSM 1 generates a key pair including public key PUBK_1 and private key PRVK_1, and stores the generated private key PRVK_1. HSM N-1 generates a key pair including public key PUBK_N-1 and private key PRVK_N-1, and stores the generated private key PRVK_N-1. The same applies hereinafter. In one embodiment, optionally, the secure storage and processing unit 16 of the backup signature server SS is configured to distribute the public key 32 generated thereby to all signature servers SS and / or the orchestration server 18 (step 210).

[0023] The secure storage and processing unit 16 of the active signature server 14 (signature server 0) is configured to sign the replacement command corresponding to each backup signature server SS using its private key 30 (PRVK_0) (step 212). When N is equal to 2, there will be one replacement command. Here, each replacement command can include the public key of each backup signature server and a signature signed on the data including the public key using the private key 30 of the active signature server 14. For example, "replacement command 0>1" can include the public key 32 (PUBK_1) of backup signature server 1 and the signature signed by the active signature server 14 (signature server 0) using the private key 30 (PRVK_0) of the active signature server 14 (signature server 0).

[0024] The replacement command is configured to be used to instruct the device 20 to replace the public key 32 (PUBK_0) of the active signature server 14 (signature server 0) with the public key 32 corresponding to the replacement command. For example, the secure storage and processing unit 16 of the active signature server 14 (signature server 0) can use its private key 30 (PRVK_0) to sign the "replacement command 0>1" corresponding to the backup signature server 1 (block 34 in FIG. 1), and the "replacement command 0>1" is configured to instruct the device 20 to replace the stored public key PUBK_0 with the public key PUBK_1. The secure storage and processing unit 16 of the active signature server 14 (signature server 0) can use its private key PRVK_0 to sign the "replacement command 0>N-1" corresponding to the signature server N-1 (block 36 in FIG. 1), and the "replacement command 0>N-1" is configured to instruct the device 20 to replace the stored public key PUBK_0 with the public key PUBK_N-1.

[0025] The interface 26 of the active signature server 14 (signature server 0) is configured to provide (e.g., transmit) the replacement command to one or more entities (e.g., the orchestration server 18 and / or the backup signature server (e.g., signature servers 1 to N-1)), and the one or more entities store the replacement command away from the active signature server 14 and the device 20 (step 214). In one embodiment of the present invention, the orchestration server 18 may store all the replacement commands, and / or each replacement command may be stored by the associated signature server 12. For example, the "command 0>1" (block 34) can be stored by the signature server 1, and the "command 0>N-1" (block 36) can be stored by the signature server N-1.

[0026] The secure storage and processing unit 16 of the active signature server 12 is configured to generate a signature 38 using its private key 30 (PRVK_0) and perform authentication by the device 20 (step 216). In one embodiment, the secure storage and processing unit 16 of the active signature server 14 (signature server 0) is configured to generate a hash-based signature using the private key PRVK_0 and the stored index (stored in the secure storage and processing unit 16 of the active signature server 14) and perform authentication by the device 20. In an embodiment in which a hash-based signature is generated, the secure storage and processing unit 16 of the active signature server 14 is configured to update (e.g., increment) the index in response to generating each hash-based signature (optionally, step 218). The interface 26 of the active signature server 14 is configured to provide the signature 38 to the device 20 (e.g., via the orchestration server 18), whereby the device 20 can perform authentication using the stored public key 32 (PUBK_0) corresponding to the active signature server 14 (signature server 0) (step 220). Steps 216-220 may be repeated (arrow 222).

[0027] Figure 3 is a flowchart 300 including steps in one method of device 20 in system 10 of FIG. 1. Referring to FIGS. 1 and 3, secure storage 24 is configured to securely store public key 32 (PUBK_0) corresponding to private key 30 (PRVK_0) stored by active signature server 14 (signature server 0) (step 302). Secure processor 22 authenticates the received replacement command using the stored public key 32 (PUBK_0), and upon successful authentication, approves the replacement command with a signature signed by active signature server 14 (signature server 0) in response thereto, but upon failed authentication, rejects the replacement command without a signature signed by active signature server 14 (signature server 0) in response thereto (step 304). Secure processor 22 is configured to receive one or more signatures 38 (step 306). Secure processor 22 is configured to authenticate whether the received signature 38 is a signature signed by active signature server 14 (signature server 0) using the stored public key 32 (PUBK_0) (step 308). Steps 306 - 308 may be repeated (arrow 310).

[0028] Figure 4 is a block diagram of system 10 of FIG. 1 when the original active signature server (signature server 0) and / or its active private key 30 (PRVK_0) becomes unavailable (block 40). Figure 5 is a flowchart 500 showing steps in the method of operation of system 10 of FIG. 1 that are executed in response thereto when the original active signature server (signature server 0) and / or the original active private key 30 (PRVK_0) becomes unavailable. Figure 6 is a block diagram of system 10 showing the situation when system 10 assigns a new active signature server 14' (block 42).

[0029] Referring to FIGS. 4 to 6, the orchestration server 18 can be configured to detect that the active signature server 14 (signature server 0) and / or its private key 30 (PRVK_0) has become unavailable (e.g., destroyed) (step 502).

[0030] The orchestration server 18 is configured to assign a backup signature server (e.g., signature server 1) as the new active signature server 14' (step 504). The orchestration server 18 is configured to provide the device 20 with a replacement command (e.g., "replacement command 0>1" (block 34 in FIG. 6)) corresponding to the new active signature server 14' (e.g., signature server 1). In response to the original active signature server 14 (signature server 0) stopping and / or its private key 30 (PRVK_0) becoming unavailable, the device 20 replaces the originally stored public key 32 (PUBK_0) with the public key 32 (PUBK_1) corresponding to the replacement command (step 506). The step of the device 20 replacing PUBK_0 with PUBK_1 will be described in detail with reference to FIG. 7.

[0031] The orchestration server 18 can be configured to add a new signature server SS (block 48 in FIG. 6) having a secure storage and processing unit 16 as a backup signature server to the system (step 508). The secure storage and processing unit 16 of the added signature server SS (signature server N) (e.g., HSM N) is configured to generate a key pair including a public key 32 (PUBK_N) and a private key 30 (PRVK_N), store the generated private key 30 (PRVK_N), and selectively store an index (not shown) associated with the private key 30 (step 510). In one embodiment, optionally, the secure storage and processing unit 16 of the added signature server SS is configured to distribute the generated public key 32 (PUBK_N) to all signature servers SS and / or the orchestration server 18 (step 514).

[0032] The secure storage and processing unit 16 of the new active signature server 14' (signature server 1) is configured to sign the replacement command corresponding to each backup signature server SS using its private key 30 (PRVK_1) (block 516). Here, each replacement command can include a signature of data including a public key using the public key of each backup signature server and the private key 30 of the active signature server 14'. For example, "replacement command 1>N" can include a signature signed by the active signature server 14 (signature server 1) using the public key 32 (PUBK_N) of the backup signature server N and the private key 30 (PRVK_1) of the active signature server 14' (signature server 1).

[0033] The replacement command is configured to be used to instruct the device 20 to replace the public key 32 (PUBK_1) of the active signature server with the public key 32 corresponding to the replacement command. For example, the secure storage and processing unit 16 of the active signature server 14' (signature server 1) can use its private key 30 (PRVK_1) to sign the "replacement command 1>N-1" (block 46 in FIG. 6) corresponding to the backup signature server N-1. The "replacement command 1>N-1" is configured to instruct the device 20 to replace the stored public key PUBK_1 with the public key PUBK_N-1. The secure storage and processing unit 16 of the active signature server 14' (signature server 1) can use its private key PRVK_1 to sign the "replacement command 1>N" (block 44 in FIG. 6) corresponding to the signature server N. The "replacement command 1>N" is configured to instruct the device 20 to replace the stored public key PUBK_1 with the public key PUBK_N.

[0034] The interface 26 of the active signature server 14' (signature server 1) is configured to provide (e.g., transmit) the replacement command to one or more entities (e.g., the orchestration server 18 and / or the backup signature servers (e.g., signature servers 2 to signature servers N)), and the one or more entities save the replacement command away from the active signature server 14' and the device 20 (step 518). In one embodiment, the orchestration server 18 may save all the replacement commands, and / or each replacement command may be saved by the associated signature server SS. For example, the "replacement command 1>N-1" (block 46 in FIG. 6) can be saved by the signature server N-1, and the "replacement command 1>N" (block 44 in FIG. 6) can be saved by the signature server N.

[0035] The secure storage and processing unit 16 of the active signature server 14' (signature server 1) is configured to generate a signature 38 using the private key 30 (PRVK_1) and perform authentication by the device 20 (step 520). In one embodiment of the present invention, the secure storage and processing unit 16 of the active signature server 14' (signature server 1) uses its private key PRVK_1 and the stored index (stored in the secure storage and processing unit 16 of the active signature server 14') to generate a hash-based signature 38 and is configured to perform authentication by the device 20. In an embodiment in which a hash-based signature is generated, the secure storage and processing unit 16 of the active signature server 14' is configured to update (e.g., increment) the index in response to generating each hash-based signature (optionally, step 522). The interface 26 of the active signature server 14' is configured to provide the signature 38 to the device 20 (e.g., via the orchestration server 18), whereby the device 20 can authenticate using the stored public key 32 (PUBK_1) corresponding to the active signature server 14' (signature server 1) (step 524). Steps 520 to 524 may be repeated (arrow 526).

[0036] FIG. 7 is a flowchart 700 including steps in one method of device 20 in system 10 of FIG. 1 after a new active signature server 14’ (signature server 1) has been assigned (block 42 in FIG. 6). Referring to FIGS. 6 and 7, secure processor 22 is configured to receive a replacement command (e.g., “replacement command 0>1” (block 34 in FIG. 6)) from a remote entity (step 702). Secure processor 22 is configured to authenticate the received replacement command using the originally stored public key 32 (PUBK_0) (private key 30 (PRVK_0) corresponding to the original active signature server 14 (signature server 0)) (block 704). When the authentication of the received replacement command (replacement command 0>1) succeeds, secure processor 22 is configured to respond by replacing the originally stored public key 32 (PRVK_0) with the public key 32 (PUBK_1) corresponding to the private key 30 (PRVK_1) of the new active signature server 14’ (signature server 1) (step 706). Secure processor 22 is configured to receive one or more signatures 38 (step 708). Secure processor 22 is configured to authenticate whether the received signature 38 is a signature signed by the active signature server 14’ (signature server 1) by using the new public key 32 (PUBK_1) (step 710). Steps 708-710 may be repeated (arrow 712).

[0037] As described above, based on some embodiments of the present invention, an active signature server includes a secure storage and a processing unit that generates a key pair including a public key and a private key and stores the generated private key. The public key generated by the active signature server is sent to the device (e.g., via an orchestration server), stored in the device's secure storage, and used for authentication. Each backup signature server includes a secure storage and a processing unit that generates a key pair including a public key and a private key and stores the generated private key. The secure storage and processing unit of the active signature server pre-signs the replacement commands corresponding to each backup signature server using its private key. Each replacement command can include the public key generated by the corresponding backup signature server and the signature signed by the active signature server. Each replacement command is used to instruct the device to replace the public key originally stored in the device with the public key corresponding to the replacement command, if necessary. Each replacement command is sent to and stored by a remote entity (e.g., an orchestration server or the signature server corresponding to the replacement command). If the active signature server or its private key becomes unavailable, the remote entity can provide this replacement command to the device. Each device authenticates the authenticity of the replacement command using the original public key and, upon successful authentication, responds by replacing the original public key with the public key corresponding to the replacement command. In this way, each device can protect the currently stored public key by approving the replacement command signed by the live signature server and rejecting the replacement command not signed by the signature server. Thereafter, the signature server corresponding to the replacement command becomes the new active signature server and can generate signatures using its private key, so that each device can authenticate data using the new public key.

[0038] Also, since the new signature server can then use its private key to sign new replacement commands for each backup signature server, it can be used, if necessary, to instruct the device to replace the stored public key with the public key generated by another backup signature server again. Each new replacement command is sent to a remote entity (e.g., an orchestration server or the signature server corresponding to the replacement command) and stored.

[0039] In practice, some or all of these functions may be combined into a single physical component, or may be implemented using multiple physical components. These physical components can include hard-wired devices or programmable devices, or combinations thereof. In some embodiments, at least some of the functions of the processing circuit can be performed by a programmable processor under the control of appropriate software. This software can be downloaded to the device in electronic form, for example, over a network. Alternatively, or additionally, the software may be stored on a tangible non-transitory computer-readable storage medium such as optical, magnetic, or electronic memory.

[0040] The above-described embodiments are cited for purposes of illustration, and the present invention is not limited to those specifically shown and described above. Rather, the scope of the present invention includes both the various combinations and sub-combinations of the features described above, as well as changes and modifications not disclosed in the prior art that would occur to those skilled in the art upon reading the above description.

Industrial Applicability

[0041] The secure key replacement system, secure key replacement device, and secure key replacement method of the present invention can be used to protect the currently stored public key by approving a replacement command signed by a live signature server and rejecting a replacement command not signed by the signature server.

Explanation of Signs

[0042] 10 System SS Signature server 14, 14’ Active signature server 16 Secure storage and processing unit 18 Orchestration server 20 Device 202~220, 302~308, 502~524, 702~710 Steps 22 Secure processor 24 Secure storage 26, 28 Interface 30 Secret key 32 Public key 34, 36, 40, 42, 44, 46, 48 Block 38 Signature 200, 300, 500, 700 Flowchart 222, 310, 526, 712 Arrow

Claims

1. A secure storage and processing unit including an active signature server, the active signature server being configured to store a first private key; generate a signature using the first private key and perform authentication by a device that stores a first public key that forms a key pair with the first private key; sign a replacement command using the first private key and be configured to be used to instruct the device to replace the first public key with a second public key that forms a key pair with a second private key; and an interface configured to provide the signature to the device and provide the replacement command to at least one entity, the at least one entity storing the replacement command away from the active signature server and the device, the at least one entity including an orchestration server and / or an interface including at least one other signature server. A secure key replacement system comprising:

2. The secure key replacement system of claim 1, further comprising N signature servers including the active signature server and N-1 signature servers, the N-1 signature servers being configured to generate N-1 corresponding key pairs, each key pair including a respective new public key and a respective new private key, the secure storage and processing unit of the active signature server being configured to sign N-1 replacement commands using the first private key, the N-1 replacement commands being configured to instruct the device to replace the first public key with the respective new public keys, and the interface being configured to provide the N-1 replacement commands to the orchestration server and / or the N-1 signature servers.

3. The secure storage and processing unit is configured to store an index; generate a hash-based signature using the first private key and the stored index and perform authentication by the device; and update the index in response to each generation of the hash-based signature. The secure key replacement system of claim 1, configured to perform the above steps.

4. ​ The secure key replacement system according to claim 1, wherein the orchestration server is configured to provide the replacement command to the device, and the device replaces the first public key with the second public key.

5. The secure key replacement system according to claim 4, wherein the orchestration server is configured to provide the replacement command to the device in response to the active signature server stopping, or the first private key being destroyed, or the use by the active signature server becoming unavailable.

6. Further comprising a new active signature server, the new active signature server being configured to store a second private key; generate a signature using the second private key and perform authentication by a device that stores the second public key; sign a new replacement command using the second private key and be configured to be used to instruct the device to replace the second public key with a third public key that forms a key pair with a third private key; a new secure storage and processing unit configured to perform the above; a new interface configured to provide the new replacement command to the at least one entity; The secure key replacement system according to claim 4, comprising the above.

7. Further comprising a predetermined device among the devices, the predetermined device being configured to a secure storage configured to securely store the first public key; reject an instruction to replace the first public key if the instruction is not authorized by a signature formed using the first private key; receive the replacement command signed by the first private key; authenticate the replacement command using the first public key; upon authenticating the replacement command using the first public key, respond by replacing the first public key with the second public key; a secure processor configured to perform the above; The secure key replacement system according to claim 1, comprising the above.

8. The secure processor of the predetermined device is configured to authenticate a signature signed by the active signature server using the first public key; After the first public key is replaced with the second public key, authenticating a signature signed by a new active signature server using the second public key; The secure key replacement system according to claim 7, configured to perform the above.

9. A secure storage configured to securely store a first private key stored by an active signature server and a first public key forming a key pair; Rejecting an instruction to replace the first public key, where the instruction is not authorized by a signature formed by the active signature server using the first private key; Receiving a replacement command signed by the first private key, where the replacement command is configured to be used to instruct the device to replace the first public key with a second public key forming a key pair with a second private key stored by a new active signature server; Authenticating the replacement command using the first public key; When the replacement command is authenticated using the first public key, in response, replacing the first public key with the second public key; A secure processor configured to perform the above; A secure key replacement device including the above.

10. The secure processor is Authenticating a signature signed by the active signature server using the first public key; After the first public key is replaced with the second public key, authenticating a signature signed by the new active signature server using the second public key; The secure key replacement device according to claim 9, configured to perform the above.

11. Storing a first private key; Generating a signature by an active signature server using the first private key and performing authentication by a device that stores a first public key forming a key pair with the first private key; Signing a replacement command by the active signature server using the first private key, where the replacement command is configured to be used to instruct the device to replace the first public key with a second public key forming a key pair with a second private key; Provide the signature to the device, provide the replacement command to at least one entity, where the at least one entity stores the replacement command away from an active signature server and the device, and the at least one entity includes an orchestration server and / or at least one other signature server, A secure key replacement method including the above.

12. N - 1 signature servers generate N - 1 corresponding key pairs, each key pair including a respective new public key and a respective new private key, The secure storage and processing unit of the active signature server signs N - 1 replacement commands using the first private key, and the N - 1 replacement commands are configured to instruct the device to replace the first public key with the respective new public key, Provide the N - 1 replacement commands to the orchestration server and / or the N - 1 signature servers, The secure key replacement method according to claim 11, further including the above.

13. Save an index, Generate a hash - based signature using the first private key and the saved index, and perform authentication by the device, When each hash - based signature is generated, update the index in response, The secure key replacement method according to claim 11, further including the above.

14. The secure key replacement method according to claim 11, further including providing the replacement command to the device and the device replacing the first public key with the second public key.

15. The act of providing the replacement command to the device is executed in response to the active signature server stopping, or the first private key being destroyed, or the use by the active signature server becoming unavailable. The secure key replacement method according to claim 14.

16. Save the second private key by a new active signature server, Generate a signature using the second private key and perform authentication by the device storing the second public key. Sign the new replacement command using the second private key, and configure the new replacement command to be used to instruct the device to replace the second public key with a third public key that forms a key pair with a third private key. Provide the new replacement command to the at least one entity. The secure key replacement method according to claim 14, further comprising.

17. Receive the replacement command signed by the first private key. Authenticate the replacement command using the first public key. Upon authenticating the replacement command using the first public key, in response, replace the first public key with the second public key. The secure key replacement method according to claim 11, further comprising.

18. Authenticate the signature signed by the active signature server using the first public key. After the first public key is replaced with the second public key, authenticate the signature signed by the new active signature server using the second public key. The secure key replacement method according to claim 17, further comprising.

19. Securely store the first public key that forms a key pair with the first private key stored by the active signature server. Receive the replacement command signed by the first private key, and configure the replacement command to be used to instruct the device to replace the first public key with a second public key that forms a key pair with a second private key stored by the new active signature server. Authenticate the replacement command using the first public key. Upon authenticating the replacement command using the first public key, in response, replace the first public key with the second public key. A secure key replacement method, comprising.

20. Authenticate the signature signed by the active signature server using the first public key. After the first public key is replaced with the second public key, authenticate the signature signed by the new active signature server using the second public key. The secure key replacement method according to claim 19, further comprising.

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