A Research Of Side Channel Analysis Method And Countermeasures On Advanced Encryption Standard

Traditional block-cipher cryptanalysis mainly focuses on the mathematical structure of cipher systems, and has not exploited well effectiveness. Recently, much work has been done in cryptanalysis based on the implementation of the cipher systems from the cryptographic community. The side channel analysis, as a newly proposed cryptanalysis technique, is the current hot spot. This paper mainly concentrates on the Power Analysis, Fault Attack on AES, as well as their countermeasures. The main work is listed as follows:Firstly, the S-box's capability index of DPA resistance is studied, and a new lower bound of the S-box's capability of DPA resistance is deduced. Base on this bound, the lower bounds of Boolean functions with different nonlineanty can be calculated. Then the relationship between the nonlinearity and the S-box's capability of DPA resistance is described in detail, and the conclusion that S-box's capability of DPA resistance will grow inversely with the nonlinearity of the cipher system is proposed, which is verified by our simulation.Secondly, fault attack on Advanced Encryption Standard is studied, fault attack on AES through the S-box's nonlinear operation is successfully implemented. And then by using symbolical methods these approaches are systemized, which will provide an effective channel to further research on provable security.Finally, the methods of preventing the power analysis and fault attack are discussed, and a security algorithm against the power analysis and the fault attack is proposed, as well as the timing analysis, on chip cards implementing AES cipher. The defense against side channel analysis can be established.