Opening the stick

Because the stick doesn't do anything on the USB-port when the correct fingerprint isn't detected, a software hack to get to the data of a 'found' USB-stick is out of the question: there's just no software to hack. I had delve into the hardware of the stick if I wanted the chance to get to the data it stores.

Cracking the case of the stick doesn't prove that difficult: there are no screws anywhere and the case appears to be glued shut, but inserting a flat screwdriver into the crack between the USB-plug and the casing gives enough leverage to crack the case without damaging it too badly. Once inside, the stick seems to be made of two PCBs connected to eachother by means of two pin-headers. The type of the chips arem't visible: Ritech seems to have smeared some kind of epoxy over the important ICs and their pins.

First of all, I decided to get these two PCBs apart, so I could inspect all sides of them. I used a rotating tool to saw through the headers and re-connected the pins with thin wire. As you can see in the picture, that made the USB-stick more like an USB-credit-card. A quick test revealed it still worked, in spite of its radically changed form factor.

To get access to the chips and te signals on their pins, I still had to remove the epoxy-like goob that sat on Luckily for us, Ritech seems to have used a thermoplast-type of material to seal the pins away from us: when heated, it becomes rubber-y and breaks off easily. I used a toothpick and a heat-gun to get the epoxy off everything.

As all the goop was removed, the way the chip worked was revealed by a quick look at the previously-obscured type-numbers of the ICs. These were the main ones:

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