OpenBSD Disables Intel Hyper-Threading to Prevent Spectre-Class Attacks
Jun 20, 2018
Security-oriented BSD operating system OpenBSD has decided to disable support for Intel's hyper-threading performance-boosting feature, citing security concerns over Spectre-style timing attacks . Introduced in 2002, Hyper-threading is Intel's implementation of Simultaneous Multi-Threading (SMT) that allows the operating system to use a virtual core for each physical core present in processors in order to improve performance. The Hyper-threading feature comes enabled on computers by default for performance boosting, but in a detailed post published Tuesday, OpenBSD maintainer Mark Kettenis said such processor implementations could lead to Spectre-style timing attacks. "SMT (Simultaneous multithreading) implementations typically share TLBs and L1 caches between threads," Kettenis wrote. "This can make cache timing attacks a lot easier, and we strongly suspect that this will make several Spectre-class bugs exploitable." In cryptography, side-channe