New Power Analysis on the Ha-Moon Algorithm and the MIST algorithm

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New power analysis on the Ha-Moon algorithm and the MIST algorithm

Side channel attacks have been attracted by most implementers of cryptographic primitives. And Randomized Exponentiation Algorithm (REA) is believed to be a good countermeasure against them. This paper analyzes the security of the two well-known REAs, the Ha-Moon algorithm and the MIST algorithm. Finding the fact that the intermediate values are variable in two cases, this paper shows that Ha-Moon algorithm is not secure even when it deploys both randomized binary recording technique and branch removing technique for DPA and SPA, respectively. In addition, this paper analyzes the security of the MIST algorithm. Some adaptively chosen ciphertext attacker can lower the security deeply, which can be placed more below than Walter's analysis.X116sciescopu

Key Randomization Countermeasures to Power Analysis Attacks on Elliptic Curve Cryptosystems

It is essential to secure the implementation of cryptosystems in embedded devices agains side-channel attacks. Namely, in order to resist differential (DPA) attacks, randomization techniques should be employed to decorrelate the data processed by the device from secret key parts resulting in the value of this data. Among the countermeasures that appeared in the literature were those that resulted in a random representation of the key known as the binary signed digit representation (BSD). We have discovered some interesting properties related to the number of possible BSD representations for an integer and we have proposed a different randomization algorithm. We have also carried our study to the $\tau$-adic representation of integers which is employed in elliptic curve cryptosystems (ECCs) using Koblitz curves. We have then dealt with another randomization countermeasure which is based on randomly splitting the key. We have investigated the secure employment of this countermeasure in the context of ECCs