A Systematic Approach to Horizontal Clustering Analysis on Embedded RSA Implementation

Side-channel attacks are a threat to cryptographic algorithms running on embedded devices. The exponent blinding is the main countermeasure which resists the classical forms of side-channel attacks. Horizontal side-channel analysis is an effective method to overcome this kind of countermeasures and recover the secret key through the analysis of a single trace. However, it is very difficult to exploit leakage from a single trace in practice, because the segment borders of crucial operation are hard to find and the single execution possibly contains a lot of noise in a real application environment. In this paper, a framework for systematic approach is presented to overcome these drawbacks. Firstly, we propose a method to use the Hilbert-Huang transform for the segment borders detection and the noise reduction. Then, an effective clustering method is used to recover the private key. The proposed horizontal clustering approach is applied to a protected implementation on embedded devices. The results show that the success rate of the key recovery could be up to 98%. Finally, we analyze the mechanism of leakage exploration.