Attack Based Research On Security Analysis Of Digital Signature

Digital signatures can solve many problems such as forgery, tamper and repudiation and are important in information security. Security is the inherent requirement of digital signatures. The primary approach of evaluating the security of digital signatures is analysis. This thesis introduces several methods of analysis such as security evaluation and attack and the master study is attack analysis of digital signature schemes. In this thesis, a universal attack analysis model is presented for the lack of methodological study at the moment; Six flawed digital signature schemes are analyzed with the model and two of them are repaired. The following items show the innovation:(1)Proposing an identity-based threshold undeniable signature scheme. The scheme is the maiden attempt to the identity-based threshold undeniable signature and has a non-interactive, bi-proof confirmation-disavowal protocol.(2) Proposing a model for attack analysis of digital signature schemes. The model presents a general method of attack analysis.(3)Demonstrating two attacks on Xie-Yu group signature scheme. We point out that the scheme does not measure up with the definition of a standard group signature and show that two group members can generate a signature that cannot be opened and frame other group members.(4)Demonstrating four attacks on WCF dynamic threshold group signature scheme. We detect the redundancy of the scheme and show that it does not satisfy any security requirement.(5)We show that two signature schemes based on double hard problems of Laih and Kuo are both based on only single hard problem.(6)Demonstrating two attacks on GMD forward-secure signature scheme. We show that the scheme is not forward-secure and present an improved version of the scheme.(7)Demonstrating two attacks on GMD (N-1,N) key-insulated signature scheme. We show that the scheme is (1, N) key-insulated and improve it.In this paper, the attack analysis model introduces a general method. The attack analysis and improvement on some signature schemes enhance the security of signatures and can be used as reference in the research after. This thesis shows that many digital signature schemes may be flawed and security analysis should be an important work in the construction of signature schemes.