Article URL: https://blog.janestreet.com/can-you-reverse-engineer-an-asic/ Comments URL: https://news.ycombinator.com/item?id=49200933 Points: 29 # Comments: 3

Earlier this year we published a puzzle that handed you a complete neural network and asked you to figure out what it did. The response was great, so we’ve made another one! This time, we’re going much deeper down the tech stack. Modern chips start life as code. A hardware designer describes a circuit in a hardware description language like Verilog, which gets synthesized into a netlist of logic gates—NANDs, NORs, XORs, flip-flops. Then electronic design automation tools place and route those gates: they pick a physical location for every gate on the die and draw the metal wires that connect them, across many stacked routing layers connected by vias. The end result is a GDS file: a geometric description of every polygon on every layer of the chip, from the transistors that do the actual logic to all the metal on top of them. That’s the file a foundry such as Intel or TSMC uses to fabricate the physical silicon. The GDS is, in a very real sense, the chip. Everything the circuit does is in there. The tricky part: nothing is labeled! We’ve designed an ASIC, and we’re giving you its final mask: all of its metal, routing, and active transistor layers, along with some sample inputs and outputs. Your job is to reverse engineer it. First, recover a netlist from the layout. Then figure out the circuit’s true purpose. And then comes the puzzle within the puzzle: once you understand what the chip does, use it to tease out the output it’s looking for, and find the string value that’s your final answer. Once you figure it out, submit your answer here along with a brief description of how you did it. Submissions close on September 4th, 2026. Feel free to collaborate with friends on the puzzle, but please refrain from posting spoilers (or a full writeup) online until the submissions are closed. If you do publish your solution (on a personal blog or repository) after submissions are closed, email us and we may include the link in our follow-up post! Please don’t feed the puzzle files directly into an AI tool, nor use it to generate your writeups. Feel free to use AI for writing any scripts or code you may need as part of solving the puzzle, though! It’s also fair game to use AI to work through the warm-up puzzle, see below.