題名: A Multi-policy Threshold Signature Scheme with Traceable Participant Cosigners
作者: Chu, C. H.;Lin, H. F.;Chang, C. C.;Chen, C. Y.
關鍵詞: Cryptography, Group signature;Threshold signature;Traceable threshold signature;Multi-policy threshold signature;Linkage problem
日期: 2008-06
上傳時間: 2009-12-17T06:57:45Z 出版者: Asia University
摘要: In a (t, n) threshold scheme, the secret can be reconstructed by the cooperation
of t or more users. With this basic concept, Lee devised a threshold signature
scheme with multiple signing policies in 2001. His approach still keeps the main benefit,
that is, each member only needs to hold one secret shadow. In Lee?s paper, any verifier
can authenticate the legality of a group signature with the threshold value t. If a dispute
arises, however, no one can trace the cosigners from the group signature.
Therefore, we
present a multi-policy threshold signature with the ability to recover participant cosigners.
In the proposed scheme, different documents can be signed by a suitable threshold value t,
and the cosigners are anonymous when they participate in the (t, n) threshold signature.
If it is necessary to find out the participant cosigners, one can open the group signature
with the help of the system center. Moreover, we also solve the linkage
problem, meaning
that an opened group signature will not disclose the participant cosigners of other group
signatures. In our scheme, each user needs to keep one secret key, one secret shadow
and two secret values.
