Simon Willison’s Weblog

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However, six digits is a very small space to search through when you are a computer. The biggest problem is going to be getting lucky, it's quite literally a one-in-a-million shot. Turns out you can brute force a TOTP code in about 2 hours if you are careful and the remote service doesn't have throttling or rate limiting of authentication attempts.

Push notification two-factor auth considered harmful