Lecture Notes in Computer Science vol:1355 pages:283-294
Cryptography and Coding, 6th IMA International Conference date:December 17-19, 1997
In this paper, we propose a restrictive blind signature scheme with enhanced security for the signer. It is suitable to be used as a basic cryptographic primitive in the design of a privacy protecting off-line electronic payment system. The solution is derived from the transformation of a witness hiding proof of knowledge. In order to blindly sign a message, preserving a certain invariant structure of this message, a proof of knowledge of a representation is diverted. The choice of a witness hiding proof system improves the security and provability of the restrictive blind signature scheme. This is the main contribution of our solution. The cost paid for enhanced security is reasonable with regard to the overall efficiency of the scheme.