Group delegation computing method

A group delegation computing method, wherein the method comprises the following steps:

• receiving a security parameter and a number of group members, and inputting the security parameter and the number of group members into a pre-established trusted third-party operation initialization algorithm model, to obtain a public parameter and an initialized revocation list;
• inputting the public parameter and a delegation function into a pre-established key generation algorithm model, to obtain a group administrator secret key, a group administrator public key, a trace secret key, a trace public key, a pair of a public key and a secret key of a group member, a group public key, a secret key for delegation computing, and a public key for delegation computing;
• inputting the public parameter, the group administrator secret key, and the group public key into a pre-established member joining algorithm model, generating a digital signature by using a key pair registered in PKI, verifying whether the digital signature is registered, and if the digital signature is registered, terminating joining, or if the digital signature is not registered, computing a revocation token and a group member certificate;
• inputting a delegation public key, a delegation secret key, the group public key, a group member secret key, a group member certificate, and a delegation input into a pre-established question generation algorithm model, to obtain an encrypted delegation input, a verification key, a computing key, a recovery key, and a group signature issued by a group member;
• inputting the group public key, the revocation list, the delegation input, and the group signature into a pre-established signature verification algorithm model, performing signature verification on the group signature issued by the group member, to output a verification result, and if the signature is legal, returning 1, or if the signature is illegal, returning 0;
• inputting the computing key, the encrypted delegation input, and the verification result into a computing algorithm model, and if the signature verification is illegal, skipping performing computing, or if the signature verification is legal, computing, by the cloud server, a computing result and a correctness proof;
• inputting the delegation public key, the verification key, the computing result, and the correctness proof into a pre-established blind verification algorithm model, to obtain a blind verification result, and if the computing result is correct, returning acceptance, or if the computing result is incorrect, returning rejection;
• inputting the recovery key, the blind verification result, and the computing result into a pre-established recovery algorithm model, and if an output of the blind verification result is acceptance, outputting a real function result, or if the output is rejection, terminating the algorithm;
• inputting the group public key, the group administrator secret key, a revocation token of a group member, and a revocation list into a pre-established member revocation algorithm model, adding the revocation token of the group member to the revocation list to perform a revocation function of the group member, and if the revocation succeeds, returning 1, or if the revocation fails, returning 0;
• and
• inputting the group public key, a trace key, the delegation input, and the group signature into a pre-established signature opening algorithm model, to obtain an opening result, and determining an identity of a specific member of the delegation computing.