Many individuals would find great use in a self-destructing storage device that vaporises its contents at the first hint of trouble, but good luck getting your hands on one if you don’t work for a three-letter agency. At the very least, we would have declared so had [Walker] not taken the case. He is developing a self-destructing USB flash stick that is open source for journalists, security analysts, informants, and anyone else who values their privacy highly.
Until you knew to wet your fingers before plugging it in, [Walker] simply intended to make the flash drive’s contents hidden when we last reported this project in July. Even while it may sound strange, it’s actually quite intelligent in terms of covert ways to activate anything. However, in response to the reaction he got, he made the bold decision to make the USB drive literally trash itself if it were to be used by someone who didn’t know the secret.
A sophisticated weapon for a more refined era.
But how precisely do you accomplish that? We’d love to see a vial of acid or a little thermite charge put within, but that’s obviously not very feasible. It must be secure enough for you to carry around, and more significantly, it must be unlikely to land you in more difficulty with whoever is going through your possessions. To that end, [Walker] believes he has devised a sophisticated solution.
His flash memory chip’s datasheet states that the measly 4.6 V is the highest voltage it can tolerate before discharging the Magic Smoke. So he reckons running a voltage doubler on the nominal 5 V flowing from a USB port could deactivate the chip perfectly with a minimum of external fuss. Will it be adequate to prevent the data from being recovered forensically? We don’t know, but we’re excited to find out.
In the write-up, [Walker] takes readers through the circuit designs he’s come up thus far, and shows off the source code that will run on the ATtiny25 to calculate when it’s time to toast the flash. He claims by the next article he should have the complete flash drive made and documented, so stay tuned.
