Saint VoltJockey, Who Rode the Voltage

Patron of CPUs with voltage scaling, TrustZone secure worlds, and those who play with millivolts.

Life

In 2019 the researchers behind VoltJockey showed that lowering the processor's voltage a little, through the software interface that tunes its frequency and voltage, could make it miscalculate at just the right moment. With these controlled faults they extracted cryptographic keys and broke the integrity of secure worlds like TrustZone and, in parallel variants, SGX. Intel and others fixed it by restricting access to voltage control (CVE-2019-11157).

Prayer

O Saint VoltJockey, who bends the voltage to the point of error, let our processors always compute at honest voltage. Amen.

How to celebrate

Celebrated by updating BIOS and microcode to lock voltage control away from software.

Lower the voltage and you harvest errors.