Memorize one TOTP key for a cloud offering; then store the rest in it. 1password, Lastpass, etc. It’s not that much longer than a Windows product key, and I still know one of those.
The secret key is just an RNG output so you could also take it in 4 byte chunks and memorize 16 PRNG inputs that generate each the 4 bytes.
Or you could memorize a passphrase, take a sha2 hash of it, and then memorize a single PRNG input that spits out the bitstring diff between the hash output and the TOTP key. That way you aren’t wholly dependent on memorizing numbers and you can still safely use a more predictable and weak ‘PRNG’ that can amplify the bitstring salt out of an input.
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Memorize one TOTP key for a cloud offering; then store the rest in it. 1password, Lastpass, etc. It’s not that much longer than a Windows product key, and I still know one of those.
The secret key is just an RNG output so you could also take it in 4 byte chunks and memorize 16 PRNG inputs that generate each the 4 bytes.
Or you could memorize a passphrase, take a sha2 hash of it, and then memorize a single PRNG input that spits out the bitstring diff between the hash output and the TOTP key. That way you aren’t wholly dependent on memorizing numbers and you can still safely use a more predictable and weak ‘PRNG’ that can amplify the bitstring salt out of an input.
etc.