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arXiv · 2202.04896

Faulty isogenies: a new kind of leakage

Gora Adj·Jesús-Javier Chi-Domínguez·Víctor Mateu·Francisco Rodríguez-Henríquez
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Abstract

In SIDH and SIKE protocols, public keys are defined over quadratic extensions of prime fields. We present in this work a projective invariant property characterizing affine Montgomery curves defined over prime fields. We then force a secret 3-isogeny chain to repeatedly pass through a curve defined over a prime field in order to exploit the new property and inject zeros in the A-coefficient of an intermediate curve to successfully recover the isogeny chain one step at a time. Our results introduce a new kind of fault attacks applicable to SIDH and SIKE.

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Gora Adj, Jesús-Javier Chi-Domínguez, Víctor Mateu, Francisco Rodríguez-Henríquez. 2022-02-10. Faulty isogenies: a new kind of leakage. https://arxiv.org/abs/2202.04896

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