Speaker: Dr. Yuval Yarom University of Adelaide Title: A Side-channel Attack on the OpenSSL Implementation of the Bitcoin Elliptic Curve Digital Signature Date: Wednesday, May 27, 2015 Time: 1:30 p.m. Room: E-Quad, Room B205 Host: Prof. Ruby Lee

Abstract: Side-channel attacks aim to break cryptosystems by exploiting information leaked through the interaction of the cryptosystem's Implementation with its environment. This talk presents some recent advances in side-channel analysis. It demonstrates how to combine a new side channel, a recently discovered property of many standard elliptic curves and an improved lattice technique in order to break the OpenSSL implementation of the Elliptic Curves Digital Signature Algorithm (ECDSA). When used against the secp256k1 curve, employed in the Bitcoin protocol, an attacker can break the cryptosystem by observing as little as 25 signatures.

The talk is based on a joint work with Naomi Benger, Joop van de Pol and Nigel Smart.

Biography: Yuval Yarom is a Research Associate in the School of Computer Science at the University of Adelaide. His main research interests are computer security and cryptography, with a current focus on side-channel attacks and defences. He obtained his BSc and MSc from the Hebrew University, Jerusalem and a PhD in Computer Science from the University of Adelaide. Prior to resuming his academic interests he has spent several years in the industry, doing computer security research at Memco Software and co-founding Girafa.com.