A cryptosystem and digital signature method

Abstract

The invention relates to a cryptographic system and a digital signature method. The cryptographic system comprises a key service system and a cryptographic component. The key service system has a master key sm adopting bilinear mapping cryptography. The cryptographic component has the master keys sU, PU1, PU2 and PUpub= [sU] PU2 adopting bilinear mapping cryptographic operation, where PU1 and PU2are the generators of bilinear mapping groups GU1 and GU2 of the cryptographic component, respectively. The key service system digitally signs the data including the user's identity information U, PUpub and key restriction information of the cryptographic component by using the master key sm to generate the authentication data CU of the PUpub. The cryptographic component uses the key sU to digitally sign the data by using the identification cryptographic algorithm or the elliptic curve cryptographic algorithm, and the signed data contains the CU. After verifying the validity of the CU, the signature verifier verifies the digital signature of the data by using PU1, PU2 and PUpub.

Description

technical field [0001] The invention belongs to the technical field of encryption, in particular to a double-line mapping-based encryption system and digital signature method with anti-repudiation capability. Background technique [0002] Compared with PKI (Public Key Infrastructure) which uses digital certificate technology, Identity Based Cryptography (IBC) saves the troublesome link of obtaining the public key digital certificate of the private key owner, and the technology is simple to implement. People's attention, has broad application prospects. [0003] Identity passwords can be used for both data encryption (called Identity Based Encryption, IBE) and digital signatures (called Identity Based Signature, IBS). Most of the current identification encryption algorithms are based on bilinear mapping (bilinear mapping, also known as pairing operation, Pairing) algorithm, wherein the bilinear mapping (pairing operation) is: [0004] e:G 1 ×G 2 →G T , where G 1 , G 2 ...

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Problems solved by technology

[0011] The identification password is easy to use. However, when the identification password is used for digital signatures, since the private key is generated by the user's previous private key generation system (private key generator) and not generated at the user end, this will cause repudiation problems: electronic orders, The signer of the electronic contract can say that the signature of the electronic order and electronic contract is not generated by himself, because the operator of the private key generation system can use the private key generation system to generate the private key of the signer, and then use the generated private key to impersonate the signer Signed electronic orders and electronic contracts

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