A Secure Improved Multi-signature Scheme

摘要

The multisignature scheme is a signaturescheme;in which plural signer jointly generate a signature for a message or several messages. Reentry, based on RSA and discrete logarithm with composite modulus, Huang and Chang proposed two multisignature schemes with distinguished signing authority and claimed that their schemes can resist forgery attack. Unfortunately, in this works, we show that their schemes are universally forgeable by security analysis on Huang-Chang multi-signature schemes. Given a multisignature of a certain document, arbitrary one can forge a multisignature on the document. To overcome the weakness of the schemes, we proposed an improved scheme and show that the scheme is proven secure in random oracle model.