For this year's DEFCON conference, the Electronic Frontier Foundation released an encryption-puzzle t-shirt (with glow-in-the-dark clues!) designed by EFF Senior Designer Hugh D'Andrade and Staff Technologist Micah Lee. The puzzle was fiendishly clever and made for a beautiful tee, and now it has been cracked by some of DEFCON's intrepid attendees, the first ten of whom stand to win a beautiful, limited edition, signed print.
The binary around the key spells out "violating terms of service is not a crime" in ASCII, a reference to EFF's continuing efforts to reform the Computer Fraud and Abuse Act (CFAA), the draconian US anti-hacking law. (Special thanks to everyone at DEF CON who demanded action from their Congressional representatives at our CFAA DC Dialer phone booth!)
But there's more to the puzzle. Some of the zeroes and ones in the binary block glow in the dark. Converting only the glowing digits to ASCII spells out "d[EFF]con" in recognition of our ongoing work with the community. Note also that the key and red box are surrounded by black ciphertext symmetrically encrypted using GnuPG. Using the passphrase "d[EFF]con" decrypts the ciphertext to reveal the entire US Bill of Rights!
Following a URL at the end would lead you to a brief message from Cyborg Ada Lovelace, with the ultimate passphrase seen under her portrait. (She shares an important lesson: Encryption works, but don't get lazy!)