California rooftop code cracks after three-year brain tease
A software engineer solved Adobe’s San Jose Semaphore puzzle, finding a Botticelli rose hidden in the rooftop light code.
By Poppy Nakagawa · Culture Writer
2 min read
A rooftop riddle in downtown San Jose has finally blinked its last secret: the answer was a rose from Sandro Botticelli’s Birth of Venus.
UPI reported that software engineer Brian Vincent solved the San Jose Semaphore puzzle this spring after the coded display ran for three years atop Adobe’s headquarters in California. The puzzle, created by artist Ben Rubin, showed four circles shifting through different positions in a repeating animation.
The display had been running since May 2023, according to UPI. To casual passersby, it looked like abstract motion high above the city. To Vincent, it was a code waiting to be cracked.
Vincent studied the sequence and concluded the changing circle positions corresponded to color information in the pixels of a digital image, UPI reported. That image turned out to be a single rose from Botticelli’s famous painting Birth of Venus.
In a video released by Adobe, Vincent said the challenge hit a sweet spot for puzzle hunters.
“I want to say that the difficulty level on this puzzle is probably perfect,” Vincent said in the Adobe video. “In some ways it seems a little bit simple, but at the same time it takes a lot of work and a lot of effort, and it stands for years before anyone solves it.”
A very public puzzle box
The San Jose Semaphore is not a one-off stunt. UPI reported that the newly solved challenge was the third installment in the series, all designed to turn a building into a public cryptographic playground.
The earlier answers were not exactly small potatoes. According to UPI, the first semaphore, installed about 20 years ago, decoded into the complete text of Thomas Pynchon’s novel The Crying of Lot 49.
The second puzzle had a different flavor: an audio file of Neil Armstrong saying, “One small step for man, one giant leap for mankind,” UPI reported.
That gives the series a neat little résumé: postmodern literature, space history and now Renaissance art, all hidden in plain sight above San Jose.
Another code is coming
Adobe said the rooftop puzzle will not stay quiet for long. The company said a new semaphore challenge is expected to be installed soon.
This time, there is also a prize attached. According to Adobe, the first person to solve the next puzzle will receive a free two-year subscription to Adobe Creative Cloud.
For now, Vincent gets the bragging rights for closing the book on a mystery that had been looping over downtown San Jose since 2023, one circle pattern at a time.
This story draws on original reporting from UPI.