The "branch history injection" hardware vulnerability

Posted Apr 10, 2024 11:27 UTC (Wed) by rgmoore (✭ supporter ✭, #75)
In reply to: The "branch history injection" hardware vulnerability by snajpa
Parent article: The "branch history injection" hardware vulnerability

Yet it only comes out as we've effectively run out of means to shrink transistors further (aka: means to make more performant chips rather effortlessly).

It's been a long time since chip designers have been able to improve performance "rather effortlessly" just by taking advantage of smaller, faster transistors. Ever since processor clock speeds outran RAM fetch times, processors have depended on cache memory to avoid sitting idle while waiting for memory to load. Those caches provide an opportunity for side channel attacks, and the problem gets worse the greater the difference between clock speed and RAM fetch time.

FWIW, this is not a new problem that just appeared as a convenient excuse to force people to buy new processors. The Spectre and Meltdown paper was published more than 6 years ago, and it was exploiting problems with processors that were designed well before that. Nor were Spectre and Meltdown the first attacks to be published; there's a history of attacks using memory timing side channels going back at least 20 years.