> leaking AM emissions from a computer by twiddling the memory bus This technique is as old as computers themselves, it's well-known back to the mainframe and minicomputer era. For example, here's a video of a DEC PDP-8 (LAB-8/e) minicomputer (1971) playing music using the same technique [0], the software was Richard Wilson's "Music Compiler" written back in 1975, you should watch it. Later it was also rediscovered by the microcomputer hackers, members of the Homebrew Computer Club played Beatles on the Altair 8800. Acoustic leakage is also possible. Here [1] is a program that runs on a Thinkpad, and here's the video [2]. It changes the Intel CPU P-state to induce a coil whine at a specific frequency, and it plays PC Speaker music via the inductor coil on the switched-mode power supply of the CPU. On one hand, we can say it's a time-honored tradition in computing and hacking, on the other hand, it means the same huge side-channel exploit is still here despite that it has been half-a-century already... [0] ▶ this video [1] [link] [2] [link]
in “Finding Radio Frequency Side Channels” · View on HN