[zzzcpan]

I found some research on fingerprints [1]. At 512 dpi fingerprint sensors have 0.01 bits per pixel of information mutual between samples but still individual, meaning that 160x160 sensors can give 256 bits of information usable for keys. And there are multiple fingers, so it seems enough to derive an encryption key from and even some room for redundancy.

Refreshing it every few years isn't a big deal (as obviously none of it will be used directly as an encryption key for all of your data, but only to encrypt an actual encryption key).

[1] https://backend.orbit.dtu.dk/ws/portalfiles/portal/180163248...

[zaroth]

That paper has absolutely nothing to do with generating keys directly from an image of a finger. They are discussing the lower bounds on how small a fingerprint sensor can get.

It doesn’t seem like you read my reply at all.

It’s not a question of raw entropy from the sensor, which is what the paper is discussing. It’s an issue of repeatability.