Group signature method suitable for large groups

Abstract

The invention discloses a group signature method suitable for large groups, which comprises the following steps: generating system parameters, adding new members, generating a group signature, and verifying the group signature, wherein a group trusted center selects a group private key and a group public key for a group administrator; when a new member joins in the group, the new member randomly selects (xA, z), stores xA as the private key thereof and transmits z to the group administrator, the group administrator signs z by using the private key thereof, the signature result is (r, s, w), and the group administrator stores the member identity information (w, z) and transmits the (r, s, w) to the new member; after receiving the (r, s, w), the new member verifies whether the (r, s, w) is valid by using the group public key (e, n), and if so, the new member accepts (s, w) as the member certificate and joins successfully; any member in the group can generate a group signature (u, t, s1, s2) for the message m of a signature requester according to the signature algorithm by utilizing the member certificate and the private key xA; and after obtaining the signature the (u, t, s1, s2), a verifier calculates a verification equation. When a new member joins in, the invention does not need to update the group public key and the member private keys, thereby saving time; and when opening the signature, the identity of a signer can be traced.

Description

technical field [0001] The invention relates to a digital signature method in e-commerce / government affairs, in particular to a group signature method suitable for a large group with a large number of group members. Background technique [0002] With the development of network technology and e-commerce, digital signature technology has been deeply studied, and many new application environments require digital signature to support some special functions. Group signature means that all signers form a group (group for short), and each member in the group can sign anonymously on behalf of the group. Each group is managed by a trusted group authority, which is responsible for the Composition and update, and in the event of a dispute, the identity verification of the signer can be performed according to some pre-set agreements, and the person in this authority is usually called the manager of the group. Group signatures can be publicly verified. Anyone who holds the group public ...

AI Technical Summary

Problems solved by technology

However, the ACJT method is not suitable for large groups in terms of signature speed, calculation amount, communication volume and efficiency, so the researchers proposed a group signature method that does not rely on knowledge signatures and is suitable for large groups. The efficiency of signing, verifying signature calculation speed and new members joining the group has been greatly improved, but this method has problems when opening the signature to track the identity of the signer

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