A Secret Sharing Scheme with the Changeable Threshold Value

In this paper, we investigate the problem of increasing the threshold value of the Shamir's (t, n)-threshold scheme without the dealer's helps, and present a new secret sharing scheme with the threshold value increasing. In this scheme, the dealer needs not to pre-compute or publish any information in advance, all participants cooperate to take on the dealer's role and to complete the share renewing, and each participant only stores one share as the same size of the secret. The results of analysis show that the proposed scheme is secure, and it is perfect and ideal.