Finding 1s and 0s with a microscope and computer vision

ROM

One day, [Adam] was asked if he would like to take part in a little project. A mad scientist come engineer at [Adam]‘s job had just removed the plastic casing from a IC, and wanted a little help decoding the information on a masked ROM. These ROMs are basically just data etched directly into silicon, so the only way to actually read the data is with some nitric acid and a microscope. [Adam] was more than up for the challenge, but not wanting to count out thousands of 1s and 0s etched into a chip, he figured out a way to let a computer do it with some clever programming and computer vision.

[Adam] has used OpenCV before, but the macro image of the masked ROM had a lot of extraneous information; there were gaps in the columns of bits, and letting a computer do all the work would result in crap data. His solution was to semi-automate the process of counting 1s and 0s by selecting a grid by hand and letting image processing software do the rest of the work.

This work resulted in rompar, a tool to decode the data on de-packaged ROMs. It works very well – [Adam] was able to successfully decode the ROM and netted the machine codes for the object of his reverse engineering.

18 thoughts on “Finding 1s and 0s with a microscope and computer vision

    1. Not in an automated fashion, but a few chips in MAME were decapped and split into images, then we crowd sourced the typing effort.

    1. You’d be surprised. Old tech is used in new systems all the time. There’s a wise old saying “If it ain’t broke, don’t fix it!”, which, in my experience of the IT Security industry should be amended to: “If it ain’t *very publicly* broke, don’t fix it!”. :P

      That was a good talk though – I’m a big fan of both Chris & Karsten.

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