Ovrdrive Is a 16GB USB Drive That Protects Your Data By Destroying Itself When Inserted Wrong
There is a lite mode that just hides the data, but that's less fun.
One way to keep data safe is to store it offline on media like a USB flash drive. But, if you lose control of the drive, you lose control of the data. Fortunately, Ryan Walker of Interrupt Labs has a solution. The Ovrdrive USB flash destroys itself and the stored data unless you insert it into the computer correctly.
From the outside, Ovrdrive appears like any other USB-based flash drive. Inside are a 16 GB flash memory chip, a USB 2.0 interface controller, and a Microchip ATtiny24A microcontroller. However, the ATtiny24A is not related to USB. Instead, it has two other, far more exciting purposes.
Ovdrive protects your data with two different methods. First, the MCU inhibits the flash device's chip select signal in its default light mode. This action effectively hides the stored data from the host computer without erasing anything.
The other method results in Full Self Destruct (FSD). One of Walker's goals was to make the FSD safe for the user but effective as destroying the data. So, a voltage doubling circuit charges a couple of capacitors and over-volts the flash device's voltage rail. Once this event occurs, the flash chip is no longer functional.
For both methods, if you insert the drive once, it engages its protection mode. However, inserting three times in a row results in a fully functional flash drive.
Since FSD results in a dead flash chip, switching from Lite mode to FSD mode requires a minor hardware modification. That change requires opening the enclosure and physically cutting a PCB trace. This feature means you can practice many times before going for full protection.
Interrupt Labs open sourced the design and encourages hacking Ovrdrive. For example, there is an unpopulated (1.27mm pitched) in-circuit programming header so that you can re-flash the microcontroller. This GitHub repo contains the firmware, mechanical, and electrical design files.
Check out the Ovrdrive Crowd Supply page if you want to buy one. There you can sign up for notifications when the campaign goes live.