Interesting. Reminds me of the times long ago when pocket calculators were a new thing and I was also owning an AM/FM radio and held it close to the calculators

Interesting. Reminds me of the times long ago when pocket calculators were a new thing and I was also owning an AM/FM radio and held it close to the calculators to listen to what they were "doing". You would hear a lot more in the radio than the bit of whining and buzzing that you can hear acoustically from nowaday's computers. So, I was wondering, what about the FM radio built into many (if not most) mobile phones? Connected my earbuds (they also function as antenna), turned on the phone loudspeaker, laid the earbud cable over my laptop, tuned the FM radio to some frequency where there is no radio station (thus statics playing), and voilà, I can clearly hear correlation between noise and activity. Even when I'm placing my earbuds/phone a foot away from the laptop I can still clearly hear when I'm opening some new window. The sounds are not as 'colorful' as they were on an AM radio when listening to calculators, but I'd wager a guess that it's better than an acoustic attack. So much for thinking that making acoustic noise like playing music would dwarf the attack vector "mobile phone". PS: what might prevent this attack is that on some (most?) phones the output of the FM radio can't be captured directly. It could be played through the speaker and recorded through the mic, though. The attack as carried out by Genkin/Shamir/Tromer is sending tons of encrypted emails and would probably arouse suspicion anyway if the computer was attended, thus this indirection may not pose a problem.