Hey everyone, I’ve been thinking about a new authentication idea and wanted some feedback. The concept is a dynamic, one-time passcode system where the user supplies a short numeric seed plus a “difference indicator” — basically a small array of numbers they pick each session.

The system is inspired by the Fibonacci sequence, but instead of using the sequence directly, it uses the differences between numbers to generate the code. The user’s difference indicator controls how those differences are applied, and the indicator can change each session. This makes the code easy for the user to calculate but very hard for anyone else to brute-force.

I’m curious if this approach sounds plausible from a cryptography or authentication standpoint, and whether there are obvious pitfalls I might not be seeing. Any thoughts, or has something like this been explored before?