A revocable pairing-free certificateless proxy signature method, storage medium and device

Abstract

The application discloses a revocable non-pairing non-certificate proxy signature method, a storage medium and equipment, and comprises six stages of system initialization, user registration, proxy key generation, proxy signature, proxy signature verification and proxy right revocation. The application adopts a non-certificate public key cryptography system to avoid key escrow and certificate management, does not depend on a bilinear pairing operation to reduce the calculation cost, and introduces an RSA accumulator-based proxy right revocation mechanism to realize efficient update and verification of the proxy authorization state.

Description

Technical Field

[0001] This invention belongs to the technical field of information security, and mainly relates to a revocable unpaired, certificate-free proxy signature method, storage medium, and device. Background Technology

[0002] Proxy signature mechanisms allow the original signer to delegate their signing authority to a proxy signer, who then generates a valid signature on behalf of the original signer. This mechanism has broad application prospects in scenarios such as mobile edge computing, the Internet of Things (IoT), and distributed systems. However, existing proxy signature schemes generally suffer from the following problems:

[0003] (1) High computational overhead: Most existing solutions are based on bilinear pairing construction, which has high computational complexity and is difficult to deploy on resource-constrained devices such as sensors and mobile terminals.

[0004] (2) Key management is complex or key escrow exists: Schemes based on public key infrastructure require the maintenance and management of a large number of digital certificates, which is costly; schemes based on identity cryptography have key escrow issues, where the key generation center can forge any user's signature, and security depends on absolute trust in third parties.

[0005] (3) Low efficiency of agency revocation: Existing agency revocation strategies are mainly divided into three categories: relying on online trusted third-party collaboration, which limits the real-time performance of the system; adopting a time period mechanism, which results in a time window for authorization expiration; and maintaining a global revocation list, where the verification complexity increases linearly with the scale of revocation. None of the above solutions can achieve efficient agency revocation without introducing additional online interaction or excessively increasing the verification burden.

[0006] Therefore, how to design a proxy signature method that is free from bilinear pairing, key escrow, and supports efficient revocation is a technical problem that urgently needs to be solved in the field of cryptography. Summary of the Invention

[0007] This invention addresses the problems of high computational overhead, key escrow issues, and insufficient efficiency in revoking proxy rights caused by existing proxy signature schemes that rely on bilinear pairing. It provides a revocable, unpaired, certificate-free proxy signature method, storage medium, and device. This invention adopts a certificate-free public-key cryptography system to avoid key escrow and certificate management, does not rely on bilinear pairing operations to reduce computational overhead, and introduces a proxy rights revocation mechanism based on RSA accumulators to achieve efficient updating and verification of proxy authorization status.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a revocable unpaired, certificate-free proxy signature method, comprising at least the following steps:

[0009] S1, System Initialization Phase: The Key Generation Center (KGC) generates system common parameters and master key pairs, and initializes the RSA accumulator;

[0010] S2, User Registration Phase: The original signer and the proxy signer register their identity identifiers with KGC, and KGC generates communication identity identifiers for them; KGC generates partial private keys for the original signer and the proxy signer; the original signer or the proxy signer combines their own secret value with the partial private key to generate a complete public-private key pair;

[0011] S3, Proxy Key Generation Stage: The original signer generates a delegation credential and, based on its complete private key and the delegation credential, generates a partial proxy key, which is then sent to the proxy signer and KGC; the proxy signer and KGC verify the partial proxy key. Upon successful verification, KGC adds the delegation credential to the RSA accumulator and generates a corresponding witness value; the proxy signer generates a complete proxy key based on the partial proxy key, the witness value, and its own complete private key.

[0012] S4, Proxy Signature Stage: The proxy signer uses the complete proxy key to generate a proxy signature for the message to be sent;

[0013] S5, Proxy Signature Verification Phase: The verifier verifies the legality of the proxy signature and uses an RSA accumulator to verify the validity of the authorization certificate;

[0014] S6, Delegation Revocation Phase: When it is detected that the proxy signer has abused his / her authority or the original signer requests revocation, KGC will delete the corresponding delegation credential from the RSA accumulator and update the accumulated value and the witness value of the relevant entity in the system.

[0015] As an improvement of the present invention, the system initialization stage of step S1 specifically includes the following steps:

[0016] S11, KGC input security parameters Then choose one Elliptic curve group of order and generator ;

[0017] S12, KGC randomly selects and sets the master private key. The master public key of the computing system ;

[0018] S13, KGC chooses the following six different hash functions. ,in express The set of prime numbers for bits The length of the kana;

[0019]

[0020] S14, KGC maintains the RSA accumulator and initializes its parameters. Two safe large prime numbers are randomly selected. ,calculate And Keep it secret, Modulus The quadratic residue subgroup, i.e. KGC randomly selected As the base of the accumulator; let the set of valid entrustment vouchers in the system be... KGC then sets the initial accumulated value of the accumulator. ;

[0021] S15, KGC Public Parameters .

[0022] As an improvement of the present invention, step S2, the user registration stage, specifically includes the following steps:

[0023] S21, User Submit your real identity to KGC via secure channel KGC calculation kana ,in The validity period of the pseudonym; KGC randomly selects. ,calculate Obtain a portion of the private key ,in KGC will use a secure channel to... For users ;

[0024] S22, User receive Then, calculate Randomly select secret value ,calculate ,set up Set up the complete private key. Generate the complete public key and make it public.

[0025] As an improvement of the present invention, the proxy key generation stage in step S3 specifically includes the following steps:

[0026] S31, the original signer For proxy signer Generate authorized delegation credentials ,in and These are the scope of authorization and the validity period, respectively; randomly selected. ,calculate , , , ,in A timestamp generated for the current parameter; Then set up part of the proxy key. Transmitted via public channel Give and KGC;

[0027] S32, Upon receiving Next, check the freshness of the message, the pseudonym, and the validity period of the authorization certificate; according to , ,examine Whether it is valid or not, if approved, the power of attorney will be issued. Add to the RSA accumulator to calculate the new accumulated value. and as a warrant Generate witness value and broadcast in the system ;

[0028] S33, Upon receiving Next, check the freshness of the message, the pseudonym, and the validity period of the authorization certificate; according to , ,examine If the condition is met, receive the broadcast message from KGC. Then you can set the full proxy key. .

[0029] As an improvement of the present invention, the proxy signature stage in step S4 specifically includes the following steps:

[0030] S41, for messages to be sent , Random selection ,calculate , , , ,in, Set the current timestamp; set the proxy signature. ;

[0031] S42, Will Send message The recipient is the verifier of the proxy signature.

[0032] As an improvement of the present invention, step S5, the proxy signature verification stage, specifically includes the following steps:

[0033] S51, the verifier determines the pseudonym based on the timestamp. and warrant If the message has expired, discard it and verification fails; otherwise, check the latest accumulated RSA value stored locally. Power of Attorney and its witness value Verify the delegation certificate using the membership proof function of the RSA accumulator. If the message is valid, proceed with step S52; otherwise, discard the message and the verification fails.

[0034] S52, the verifier performs the calculation: , , , , , and judge If the statement is valid, the proxy signature verification is successful; otherwise, the proxy signature verification fails.

[0035] As an improvement of the present invention, in step S6, the proxy revocation stage, KGC uses the batch deletion function of the RSA accumulator to delete the proxy certificate to be revoked from the RSA accumulator, updates the accumulated value, and broadcasts the update information to the system. Other proxy signers update their own witness values ​​according to the update information.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) No certificate and no bilinear pairing: The method of this invention combines certificateless public key cryptography with elliptic curve cryptography, avoiding the certificate management overhead of PKI and the key escrow problem of IBC. At the same time, it does not use expensive bilinear pairing operations, which significantly reduces the computational overhead and is suitable for resource-constrained environments.

[0038] (2) Efficient proxy revocation mechanism: The method of this invention introduces an RSA accumulator, which manages the proxy certificate as a member of the accumulator. When revoking, only the accumulated value needs to be updated and broadcast. The verifier can quickly verify the validity of the certificate through the accumulator member proof. The revocation status verification is decoupled from the number of revocations, supports batch revocation, and has good scalability.

[0039] (3) Improved security and privacy protection: The method of this invention meets the security requirements of identity authentication, message integrity, non-repudiation, distinguishability, and resistance to proxy abuse. It adopts a pseudonym mechanism to achieve conditional privacy protection, and only trusted institutions can trace the true identity of nodes. Attached Figure Description

[0040] Figure 1This is a timing diagram of the steps of a revocable, unpaired, certificateless proxy signature method according to the present invention. Detailed Implementation

[0041] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0042] Example 1

[0043] A revocable, unpaired, certificate-free proxy signing method involves the joint work of a key generation center (KGC), the original signer, the proxy signer, and the verifier.

[0044] Key Generation Center (KGC): Responsible for generating and publishing system public parameters; registering nodes, generating communication identity identifiers and partial private keys for nodes. Maintaining an RSA accumulator, managing delegation credentials as accumulator members. When authorization relationships change, the KGC updates the accumulator state and broadcasts the changes.

[0045] Original signer: Initiates proxy authorization, generates delegation credentials and part of the proxy key.

[0046] Proxy signer: Receives authorization from the original signer, generates a complete proxy key, and generates a proxy signature on behalf of the original signer.

[0047] Verifier: Verifies the legality of the proxy signature and the validity of the authorization certificate.

[0048] A revocable, unpaired, certificateless proxy signing method, such as Figure 1 As shown, the specific steps include the following:

[0049] Step S1: System initialization: The key generation center (KGC) generates system common parameters and master key pairs, and initializes the RSA accumulator.

[0050] KGC input security parameters Select elliptic curve Define the addition cyclic group Generator Randomly select and set the master private key. The master public key of the computing system Define a secure hash function Randomly select RSA module , Given two large prime numbers, randomly select... The base of the accumulator, the initial accumulated value. Public parameters .

[0051] Step S2, User Registration: The original signer and the proxy signer register their identity identifiers with KGC, and KGC generates communication identity identifiers for them; KGC generates partial private keys for the original signer and the proxy signer; the original signer or the proxy signer combines their own secret value with the partial private key to generate a complete public-private key pair.

[0052] This step simultaneously completes user registration, partial private key distribution, and the generation of a complete public-private key pair. The specific process is as follows:

[0053] S21: User Submit your real identity to KGC via secure channel KGC calculation kana KGC randomly selected ,calculate Obtain a portion of the private key KGC will use a secure channel to... For users ;

[0054] S22: User receive Then, calculate , Randomly select secret value ,calculate ,set up Set up the complete private key. To obtain the complete public key, save the complete public-private key pair and make the public key public.

[0055] Step 3, Proxy Key Generation: The original signer generates a delegation credential and, based on its full private key and the delegation credential, generates a partial proxy key, which is then sent to the proxy signer and KGC. The proxy signer and KGC verify the partial proxy key. Upon successful verification, KGC adds the delegation credential to the RSA accumulator and generates a corresponding witness value. The proxy signer generates a full proxy key based on the partial proxy key, the witness value, and its own full private key.

[0056] This step integrates partial proxy key generation, partial proxy key verification, and full proxy key setup functions. The specific process is as follows:

[0057] S31: Original Signer For proxy signer Generate authorized delegation credentials Random selection ,calculate , , , ; Set partial proxy key Transmitted via public channel Give and KGC;

[0058] S32: Upon receiving Next, check the freshness of the message, the pseudonym, and the validity period of the authorization certificate; according to , ,examine Whether it is valid or not, if approved, the power of attorney will be issued. Add to the RSA accumulator to calculate the new accumulated value. and as a warrant Generate witness value and broadcast in the system ;

[0059] S33: Upon receiving Then, perform the same check as KGC in S32 above. If it passes, receive the broadcast message from KGC. Then you can set the full proxy key. .

[0060] Step S4, Proxy Signature: The proxy signer uses the complete proxy key to generate a proxy signature for the message to be sent. The specific process is as follows:

[0061] S41: For messages to be sent , Random selection ,calculate , , Then calculate Then the message The proxy signature is: ;

[0062] S42: Will Send message The recipient is the verifier of the proxy signature.

[0063] Step 5, Proxy Signature Verification: The verifier verifies the legitimacy of the proxy signature and uses an RSA accumulator to verify the validity of the authorization document; this specifically includes the following steps:

[0064] S51: After receiving the message, the verifier determines the pseudonym based on the timestamp. and warrant If the message has expired, discard it and verification fails; otherwise, check the latest accumulated RSA value stored locally. Power of Attorney and its witness value ,calculate Is the authorization valid? If so, please explain the authorization document. If valid, continue to step S52; otherwise, discard the message and verification fails.

[0065] S52: The verifier performs the calculation: , , , , , and judge If the statement is valid, the proxy signature verification is successful; otherwise, the proxy signature verification fails.

[0066] Step S6, Revocation of Proxy Authority: When it is detected that a proxy signer has abused their proxy authority or the original signer requests revocation, KGC uses the batch deletion function of the RSA accumulator to delete the corresponding proxy certificate from the RSA accumulator, updates the accumulated value, and broadcasts the update information to the system. Other proxy signers update their own witness values ​​according to the update information.

[0067] When it is detected that a proxy signer has abused their power or the original signer requests revocation, the power of attorney to be revoked shall be used as the basis for the revocation. KGC calculates the new accumulated value. The new accumulated value is then broadcast. Other legitimate proxy signers, upon receiving this, update their own witness values ​​using the Extended Euclidean Algorithm. where α and β satisfy , A power of attorney held by a legitimate agent who signs on behalf of another.

[0068] Through the above steps, this embodiment realizes a proxy signature method that supports efficient revocation, no bilinear pairing, and no key escrow, which can effectively resist various known attacks and meet the requirements of secure delegated signature in a distributed environment.

[0069] In summary, this invention utilizes a proxy signature mechanism to achieve secure delegation of signature permissions; it employs a certificateless public-key cryptography system to avoid key escrow issues and certificate management overhead; the scheme does not rely on expensive bilinear pairing operations, reducing computational overhead; and it introduces a proxy revocation mechanism based on an RSA accumulator to support efficient updates and verification of proxy authorization status. While solving key escrow, avoiding bilinear pairing, and supporting proxy revocation, this invention achieves message authentication, non-repudiation, and verifiability of authorization relationships, demonstrating significant efficiency advantages over existing schemes in terms of computational overhead, communication overhead, and revocation mechanism.

[0070] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A revocable, unpaired, certificateless proxy signature method, characterized in that, Includes the following steps: S1, System Initialization Phase: The Key Generation Center (KGC) generates system common parameters and master key pairs, and initializes the RSA accumulator; S2, User Registration Phase: The original signer and the proxy signer register their identity identifiers with the Key Generation Center (KGC), and the Key Generation Center (KGC) generates communication identity identifiers for them. The Key Generation Center (KGC) generates partial private keys for the original signer and the proxy signer; the original signer or the proxy signer then generates a complete public-private key pair based on their own secret value and the partial private key. S3, Proxy Key Generation Stage: The original signer generates a delegation credential and, based on its complete private key and the delegation credential, generates a partial proxy key, which is then sent to the proxy signer and the key generation center KGC; the proxy signer and the key generation center KGC verify the partial proxy key. After successful verification, the key generation center KGC adds the delegation credential to the RSA accumulator and generates a corresponding witness value; the proxy signer generates the complete proxy key based on the partial proxy key, the witness value, and its own complete private key. S4, Proxy Signature Stage: The proxy signer uses the complete proxy key obtained in step S3 to generate a proxy signature for the message to be sent; S5, Proxy Signature Verification Phase: The verifier verifies the legality of the proxy signature generated in step S4 and uses the RSA accumulator to verify the validity of the delegation certificate. S6, Delegation Revocation Phase: When it is detected that the proxy signer has abused the proxy authority or the original signer requests revocation, the Key Generation Center (KGC) will delete the corresponding delegation certificate from the RSA accumulator and update the accumulated value and the witness value of the relevant entity in the system.

2. The revocable, unpaired, certificateless proxy signature method as described in claim 1, characterized in that: In step S1, the system initialization phase, the key generation center (KGC) generates system common parameters. ,in, For the group generator, Indicates the modulus of the RSA accumulator. For the system master public key, They are different hash functions; The master key pair includes the master private key. and the master key ;in, Represents the multiplication group modulo q; The accumulated value in the initial state of the accumulator ,in, , Modulus The quadratic residue subgroup.

3. The revocable unpaired, certificateless proxy signature method as described in claim 2, characterized in that: The six different hash functions in step S1 Specifically: ； in express The set of prime numbers for bits The length of the kana.

4. The revocable unpaired, certificateless proxy signature method as described in claim 1, characterized in that: The user registration stage in step S2 specifically includes the following stages: S21, User Submit your real identity to the Key Generation Center (KGC) via a secure channel. Key Generation Center (KGC) computation kana ,in The validity period of the pseudonym; KGC randomly selects. ,calculate Obtain a portion of the private key ,in The Key Generation Center (KGC) transmits the key through a secure channel. For users ; S22, User receive Then, calculate , Randomly select secret value ,calculate ,set up Set up the complete private key. Generate the complete public key and make it public.

5. The revocable unpaired, certificateless proxy signature method as described in claim 4, characterized in that: The S3 proxy key generation stage specifically includes the following steps: S31, the original signer For proxy signer Generate authorized delegation credentials ,in and These are the scope of authorization and the validity period, respectively; randomly selected. ,calculate , , , ,in The timestamp generated for the current parameter; the original signer Then set up part of the proxy key. Transmitted via public channel For proxy signer and Key Generation Center (KGC); S32, Key Generation Center Upon receiving Next, check the freshness of the message, the pseudonym, and the validity period of the authorization certificate; according to , ,examine Is it valid? If valid, submit the power of attorney. Add to the RSA accumulator to calculate the new accumulated value. and as a warrant Generate witness value and broadcast in the system ; S33, Proxy Signer Upon receiving Next, check the freshness of the message, the pseudonym, and the validity period of the authorization certificate; according to , ,examine Is it valid? If valid, receive the broadcast message from the Key Generation Center (KGC). Then, set the complete proxy key. .

6. The revocable unpaired, certificateless proxy signature method as described in claim 5, characterized in that: The proxy signature generated by the proxy signer in step S4 is specifically... ;in, Random selection , Random selection , , , , This is the current timestamp.

7. The revocable unpaired, certificateless proxy signature method as described in claim 6, characterized in that: The S5 proxy signature verification stage specifically includes the following steps: S51, the verifier determines the pseudonym based on the timestamp. and warrant If the message has expired, discard it and verification fails; otherwise, check the latest accumulated RSA value stored locally. Power of Attorney and its witness value Verify the delegation certificate using the membership proof function of the RSA accumulator. If the message is valid, proceed with step S52; otherwise, discard the message and the verification fails. S52, the verifier performs the calculation: , , , , , and judge If the statement is valid, the proxy signature verification is successful; otherwise, the proxy signature verification fails.

8. A revocable, unpaired, certificateless proxy signature method as described in claim 6, characterized in that: In step S6, the proxy revocation phase, when it is detected that the proxy signer has abused their proxy authority or the original signer requests revocation, the Key Generation Center (KGC) determines the revocation based on the proxy certificate to be revoked. Calculate and broadcast the new accumulated value. ,in, express The inverse; after other legitimate proxy signers receive the new accumulated value, they update their own witness value using the extended Euclidean algorithm. where α and β satisfy , A power of attorney held by a legitimate agent who signs on behalf of another.

9. A non-transitory machine-readable storage medium, characterized in that: It stores executable code that, when executed by the processor of an electronic device, causes the processor to perform a revocable unpaired, certificateless proxy signature method as described in any one of claims 1-8.

10. A computer device, characterized in that: include: Memory, on which executable code is stored; A processor for executing the executable code, causing the computer device to perform operations of a revocable unpaired, certificateless proxy signing method as described in any one of claims 1-8.

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