Cryptanalysis of Two Provably Secure Short Signature Schemes
Yumin Wang · Jisuanji gongcheng · 2007
Digital signature schemes provably secure in the standard model attract a great interest,since a proof in the random oracle model can only serve as heuristic argument and can not imply the security in the implementation.This paper shows that the two short signature schemes provably secure in the standard model are all insecure against key substitution attacks under the multi-user setting,namely an adversary can generate a new public key satisfying legitimate signatures created by the legitimate signer.