Return of the Hidden Number Problem
https://tches.iacr.org/index.php/TCHES/article/view/7337 [tches.iacr.org]
2018-11-16 02:49
Despite these mitigations, this work presents a novel side-channel attack against ECDSA and DSA. The attack targets a common implementation pattern that is found in many cryptographic libraries. In fact, about half of the libraries that were tested exhibited the vulnerable pattern. This pattern is exploited in a full proof of concept attack against OpenSSL, demonstrating that it is possible to extract a 256-bit ECDSA private key using a simple cache attack after observing only a few thousand signatures. The target of this attack is a previously unexplored part of (EC)DSA signature generation, which explains why mitigations are lacking and the issue is so widespread.
source: green