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Comment on Speculative Dereferencing of Registers: Reviving Foreshadow [pdf]parent

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Interesting! I have always seen timing attacks cited as originating in Kocher (1994), but I suppose this is some bias towards the current Unix / PC / crypto world away from mainframe development. The 1991 paper is quite clear, though the 1977 paper it cites just kind of punts on the issue (end of section 3.6):

Hence, it will not be possible to transmit information over a covert communication channel at a high enough bandwidth to make such attempts worthwhile.

Skimming the citations though, I'm not 100% sure it's the same thing as Kocher (1994) which has a more direct line to Meltdown/Spectre. The idea that intervals of high-precision clocks could carry information is the same, but especially the KVM/370 paper seems concerned with it being used for unmonitored communication between two malicious actors, or as a tool to learn something generally about what other users of the system are doing, not exfiltration of the the stored data itself across a security boundary with an oblivious user. The 1991 paper seems to sit somewhere in the middle.

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