GoKawiilChip-puzzle contest reveals mystery ASIC was a Star Battle solver checker
A chip-design puzzle published in August challenged readers to reverse-engineer a small chip's function from only its raw GDS layout, with no netlist or signal names provided. The organizers have now revealed the chip validates solutions to an 11x11 'Two Not Touch' Star Battle puzzle, using row, column and region counters plus a delay line to prevent adjacent stars, and an LFSR-obfuscated ROM to reveal the solution text once all checks pass.
GoKawiil's interpretation of the reporting above, not reported fact.
The roughly 400 submissions from over 30 countries, using tools like KLayout, Yosys and Z3 alongside custom-built analyzers, suggest a broad and technically diverse community interested in hardware reverse engineering as a hobby or skill-building exercise. The variety of approaches, including some entrants attacking the LFSR obfuscation directly, indicates that puzzles like this can surface creative analysis techniques that might inform both security research and chip-design education.
- The mystery chip implements a checker for an 11x11 'Two Not Touch' Star Battle puzzle.
- About 400 people from 30+ countries submitted solutions using tools like KLayout, Yosys, Z3 and custom-built software.
- The chip obfuscates its output string with an LFSR tied to the game board, which some solvers attempted to break directly.
FPGA Development Board Kit — If you enjoyed reverse-engineering this ASIC's GDS layout, an FPGA board lets you design and test your own digital logic puzzles and checkers hands-on. It's a perfect way to experiment with Yosys and other open-source toolchains mentioned in the article. Great for hobbyists wanting to go from chip-reading to chip-building.
See FPGA Development Board Kit on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: blog.janestreet.com, 2026-10-02
Published there as: “Results from the ASIC puzzle”
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