I'm Building a Self-Destructing USB Drive Part 2 - Page 1
Forum section: electronics / projects

author: machinehum
author_rank: Contributor
timestamp: September 19, 2022, 05:18:22 pm
content: https://interruptlabs.ca/2022/08/31/I-m-Building-a-Self-Destructing-USB-Drive-Part-2/Comments, suggestions and critique welcome

author: Hydron
author_rank: Super Contributor
timestamp: September 20, 2022, 01:30:56 pm
content: Have you proved the overvoltage destruction method btw? It sounds safe to assume that a ~2x overvoltage will make it pop, but will it work on every single chip? And will it actually kill the whole die, or just fuse a bondwire or something (which could in theory be fixed by someone determined enough).

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 20, 2022, 01:46:24 pm
content: Put a bit of PhotonicInduction into it.It can easily be done with a modified camera flash.

author: CaptDon
author_rank: Super Contributor
timestamp: September 20, 2022, 01:49:13 pm
content: Use a hammer, Use a hacksaw, Throw into fire, Put a couple ounces of vinegar into an old blender and throw the USB drive in and set to high speed. There must be a million ways to destroy a USB drive, but why not just use Norton Wipe Info?? After the passes with 00, FF, 55, AA and then the final pass there is no way in hell old data can be extracted unlike the claims of reconstructing data from a wiped hard drive which is also impossible after running Wipe Info twice. Don't know if Wipe Info will correctly work on 'wear leveling' devices?

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 20, 2022, 04:38:10 pm
content: Quote from: NiHaoMike on September 20, 2022, 01:46:24 pmthere corrected for you. btw.. regardless if it can work or not, if everybody on earth is like me, nobody will touch that self destruct drive with barge pole, risk of accidentally loose my hardwork data only by just forgetting to lick finger. there are other safer ways of avoiding prying eyes.

author: machinehum
author_rank: Contributor
timestamp: September 20, 2022, 07:23:58 pm
content: Quote from: Hydron on September 20, 2022, 01:30:56 pmI have not. This is certainly an open question. The first revision is mainly to answer some of these questions. I might have to double the doubler, or use another method all together.

author: ajb
author_rank: Super Contributor
timestamp: September 20, 2022, 08:22:02 pm
content: What's your threat model? "Beyond repair" is not a hard line, it depends on the level of resources your opponent is willing to throw at getting whatever's on the drive. If it's the NSA, then, well, you better completely vaporize the die.I have a hard time imagining that the overvoltage method will be reliable enough for any real level of security. Just increasing the voltage isn't necessarily going to improve your chances, at least until you get to the point where the whole die is vaporized, but that doesn't really meet your requirement for discretion. You can't really know how effective it is without trying it, and then decapping the flash IC to inspect the damage and see if it's sufficient--but even then a different part, or even a different revision of the same part, may not exhibit the same behavior when overvolted due to differences in internal circuitry and even in the way it's packaged.If you were to put a suitable FPGA/MCU between the flash IC and the USB connector you could encrypt the contents of the flash, and then destroying the contents is as simple as erasing the encryption key. This is what a lot of commercial devices, including phones, do, and is more likely to be reliable--given sufficiently strong encryption. This opens up other options for things like hidden sectors or external password requirements, and as a bonus, you could include a method to reinstall the key from an offline backup and recover the data if you wanted. That's obviously more complicated than just throwing a voltage doubler at a flash IC, though.From your website:QuoteReally? Those are, uhhh, kind of important values to know about...