Abstract : At ACISP 2004, Giraud and Knudsen presented the first fault analysis of DSA, ECDSA, XTR-DSA, Schnorr and ElGamal signatures schemes that considered faults affecting one byte. They showed that 2304 faulty signatures would be expected to reduce the number of possible keys to 240, allowing a 160-bit private key to be recovered. In this paper we show that Giraud and Knudsen's fault attack is much more efficient than originally claimed. We prove that 34.3% less faulty signatures are required to recover a private key using the same fault model. We also show that their original way of expressing the fault model under a system of equations can be improved. A more precise expression allows us to obtain another improvement of up to 47.1%, depending on the values of the key byte affected.
https://hal.inria.fr/hal-01056107 Contributor : Hal IfipConnect in order to contact the contributor Submitted on : Thursday, August 14, 2014 - 6:25:15 PM Last modification on : Friday, June 5, 2020 - 6:54:05 AM Long-term archiving on: : Thursday, November 27, 2014 - 1:47:26 AM
Christophe Giraud, Erik W. Knudsen, Michael Tunstall. Improved Fault Analysis of Signature Schemes. 9th IFIP WG 8.8/11.2 International Conference on Smart Card Research and Advanced Applications (CARDIS), Apr 2010, Passau, Germany. pp.164-181, ⟨10.1007/978-3-642-12510-2_12⟩. ⟨hal-01056107⟩