Stuart Schechter, a computer scientist at the University of California, Berkeley, is launching DiceKeys, a simple kit for physically generating a single super-secure key that can serve as the basis for creating all the most important passwords in your life for years or even decades to come. Wired reports: With little more than a plastic contraption that looks a bit like a Boggle set and an accompanying web app to scan the resulting dice roll, DiceKeys creates a highly random, mathematically unguessable key. You can then use that key to derive master passwords for password managers, as the seed to create a U2F key for two-factor authentication, or even as the secret key for cryptocurrency wallets. Perhaps most importantly, the box of dice is designed to serve as a permanent, offline key to regenerate that master password, crypto key, or U2F token if it gets lost, forgotten, or broken. Schechter intends for most DiceKeys users to only ever roll their set once. After shaking the keys in a bag, the user dumps them into their plastic box, then snaps the lid closed to permanently lock them into place. The user then scans the dice box with the DiceKeys app — currently a web app hosted at DiceKeys.app — that accesses their laptop, phone, or iPad camera. That app generates a cryptographic key based on the dice, checking the barcode-like symbols on the faces to ensure it interpreted the dice’s characters and orientation correctly. Despite the current version of the DiceKeys app being hosted on the web, Schechter says that it’s designed so that no data ever leaves the user’s device. Thanks to the different numbers and letters on each key face as well as the dices’ orientations, the resulting arrangement has around 196 bits of entropy, Schechter says, meaning there are 296 different possibilities for how the dice could be positioned. Schechter estimates that’s roughly as many possibilities as there are atoms in four or five thousand solar systems. Read more of this story at Slashdot.