Concept and Construction of Group Signature with self-proof capacity for confirming and denying

With privacy-preserving and traceability properties, group signature is a cryptosystem with central role in cryptography. And there are lots of application scenarios. A new extension concept of group signature is presented, namely group signature with self-proof capacity. For a legitimate group signature, the real signer can prove that the signature is indeed signed by him/her. While for the other members of the group, they can prove that the signature is not signed by him/her. The former can be used for claiming money reward from the police, while the latter can be used for proving one's innocent in a criminal investigation

Better Quantum Seal Schemes based on Trapdoor Claw-Free Functions

Seal in classical information is simply impossible. Since classical information can be easily copied any number of times. Based on quantum information, esp. quantum unclonable theorem, quantum seal maybe constructed perfectly. But it is shown that perfect quantum seal is impossible, and the success probability is bounded. In this paper, we show how to exceed the optimal bound by using the TCF (Trapdoor Claw Free) functions, which can be constructed based on LWE assumption. Hence it is post-quantum secure