Cryptanalysis of and improvement on the Hwang-Chen multi-proxy multi-signature schemes

Hwang and Chen recently proposed new multi-proxy multi-signature schemes that allow a group of authorized proxy signers to sign messages on behalf of a group of original signers. This paper shows that their schemes are insecure because a malicious proxy signer can forge a signature for a message secretly while participating in the message signing process with the other proxy signers. This paper then proposes a method to remove this weakness with only small computational overheads and without impairing the security of the original schemes.

• Type: Journal
• Year: 2005
• Where: AMC
• Authors: Yuh-Dauh Lyuu, Ming-Luen Wu
• Keywords: AMC 2005, Malicious Proxy Signer, Multi-proxy Multi-signature Schemes, Proxy Signers