- Aug 17, 2017
- 1,609
A newly discovered vulnerability baked into Apple’s M-series chips allows attackers to extract secret keys from Macs when they perform widely used cryptographic operations. The flaw—a side channel allowing end-to-end key extractions when Apple chips run implementations of widely used cryptographic protocols—can’t be patched directly because it stems from the microarchitectural design of the silicon itself. Instead, it can only be mitigated by building defenses into third-party cryptographic software that could drastically degrade M-series performance when executing cryptographic operations.
The attack, which the researchers have named GoFetch, uses an application that doesn’t require root access, only the same user privileges needed by most third-party applications installed on a macOS. M-series chips are divided into what are known as clusters. The M1, for example, has two clusters: one containing four efficiency cores and the other four performance cores. As long as the GoFetch app and the targeted cryptography app are running on the same performance cluster—even when on separate cores within that cluster—GoFetch can mine enough secrets to leak encryption keys.
The attack works against both classical encryption algorithms and a newer generation of encryption that has been hardened to withstand anticipated attacks from quantum computers.
Unpatchable vulnerability in Apple chip leaks secret encryption keys
Fixing newly discovered side channel will likely take a major toll on performance.
arstechnica.com