A fully dynamic multi-secret sharing scheme with redundant authorization

Based on Shamir’s threshold scheme and Elliptic curve cryptography, a fully dynamic multi-secret sharing scheme with redundant authorization is proposed for the general access structure. In the proposed scheme, during the secret recovery phase, each participant who recovers the shared secrets must obtain the redundant authorization, which is constructed by the secret dealer. The access structure can be changed and the number of participants can be increased (decreased) when the shared secrets are changed, while the share of each participant does not need to change. In addition, multiple secrets (s secrets) can be securely shared when each participant needs to hold only one share, and the s secrets can be recovered based on the threshold k. Moreover, compared with the existing dynamic schemes, our scheme has the following characteristics: 1) It is fully dynamic; 2) When the number of shared secrets satisfies the condition \(s>k+5\), each shared secret requires less average storage space; 3) It can ensure that the secret dealer knows the status of secret sharing.