Bulletproof TLS Newsletter #47
Attacking cryptography with side channels
29 November 2018
Author: Hanno Böck

This issue was distributed to 48,084 email subscribers.

Bulletproof TLS Newsletter is a free periodic newsletter bringing you commentary and news surrounding SSL/TLS and Internet PKI, designed to keep you informed about the latest developments in this space.

In this issue:

  1. Attacking cryptography with side channels
  2. Short news

Attacking cryptography with side channels

New research shows that cryptographic code often is still vulnerable to side-channel attacks.

An attack called PortSmash shows how to exploit side channels in the hyperthreading functionality of modern CPUs. A proof of concept attack against OpenSSL has been published on GitHub, and a research paper also is available.

The core idea of this attack was published by Colin Percival thirteen years ago. The reason the OpenSSL code is vulnerable is that it has branches based on secrets. OpenSSL has released a security advisory.

Furthermore, a different, unrelated side-channel attack affecting the DSA and ECDSA code in OpenSSL also has been fixed. No details have been published on that attack. OpenSSL has released versions 1.0.2q, 1.1.0j, and 1.1.1a with fixes.

Short news