Group-Oriented (t, n) Threshold Digital Signature Schemes with Traceable Signers

In this paper, we propose two group-oriented ) , ( n t threshold digital signature schemes with traceable signers. One needs the assistance of a mutually trusted center, the other does not need the assistance of a mutually trusted center. We also discuss the security and the feature of both schemes and show that the new schemes can withstand conspiracy attacks without attaching a secret number and can avoid to the forgery attacks. In addition, we show that, by the new schemes, any outsider can trace back to find who the signers are.