Study On The Threshold Digital Signature Scheme

Digital signature is one of the main research parts in modern cryptology. Digital signature technology has played an irreplaceable role in identity-authentication, data integrity, and undeniable signature; also has great application in the fields such as military affairs, electronic business affairs, electronic government affairs, etc. Specific digital signature such as Threshold signature, Confirmer signature are applied to meet the needs of specific necessities of given applied environment. In this paper, a double-threshold confirmer digital signature scheme with confirming function was proposed. In the paper not only the ordinary signature was produced by the threshold secret sharing means, but also the confirmer signature was produced by the same means, and threshold means were used to produce the secret key of signer and confirmer twice in this scheme. Therefore, the security level of the system was strengthened to some extend, and in a greater scope, the restrictions and balances of right were realized.The testifying information was publicized when the signer and confirmer secret key were distributed, and prevent the cheating from the secret distributor to secret sharing participants and among the participants. Furthermore, the design of confirmer and deny protocol met the need of zero-knowledge, and the scheme was mainly based on the proved-to-be-correct Shamir threshold secret sharing protocol, at last it was proved that the new scheme was safe, while under the hypothesis that the Discrete logarithm problem and Large integer problem were safe.