Breaking a real life signature scheme with only 20 signature queries

Thursday, October 30, 2014 - 4:00pm to 5:30pm
Light Refreshments
Special Location: D463, Star Room
Nigel Smart, Professor, Dept. of Computer Science, Univ. of Bristol, UK

Abstract: I will discuss recent joint work with Uni. Adelaide on
applying the Flush+Reload side channel to the OpenSSL implementation
of EC-DSA. The attacks require side-channel analysis as well as
the lattice based cryptanalysis of DSA nonces introduced by
Howgrave-Graham and Smart (later refined by Nguyen and Shparlinkski).
Unlike previous attacks which requires almost as many signatures
as the number of bits in the underlying secret key, I will show
how the choice of "special" primes in the standardized elliptic
curves allows one to reduce this number by an order of magnitude.