Reed-Solomon

In 1994, Masahiro Hara faced a problem at Denso Wave, a Toyota subsidiary. Manufacturing plants were drowning in barcodes—each component required multiple labels, scanned one at a time, with workers manually tracking which code corresponded to which part. The existing barcodes could only store about 20 characters. What they needed was something that could hold thousands of characters and be read from any angle, in under a second. The solution Hara’s team developed became the QR code—a matrix of black and white modules that would eventually spread far beyond automotive manufacturing. By 2022, 89 million Americans were scanning QR codes on their phones. But the technical architecture that makes this possible—the Reed-Solomon error correction, the masking patterns, the carefully structured grid—remains largely invisible to the billions of people who scan them daily. ...

In 1947, a mathematician at Bell Labs faced a frustrating problem. Richard Hamming was using the Model V relay computer to perform calculations, and every weekend the machine would grind to a halt when it encountered an error. The computer would simply stop, flashing its error lights, and Hamming would have to wait until Monday for the operators to reload his program. One Friday evening, staring at the silent machine, he asked himself a question that would change computing forever: “Why can’t the computer correct its own mistakes?” ...