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How does PUF authentication work?

mx flag

I understand that PUFs (physically unclonable functions) produce unique output based on challenge input because of their sensitivity to manufacturing differences, but not how the actual authentication works. It sounds like one approach is to have a server that keeps a table of known responses to challenges, but wouldn't that table eventually be exhausted?

Can you explain some of the ways that PUFs are used to implement device authentication or cryptography, and how they differ from other methods like a key stored in ROM?

Paul Uszak avatar
cn flag
There's links @ https://crypto.stackexchange.com/a/70062/23115.
mx flag
@PaulUszak I don't think any of those links addressed this question. At best they together describe how one might use a PUF to generate an encryption key, but don't explain how that would differ from a key stored in ROM. Is it because they key is generated directly from the FPGA? (e.g., running fuzzy extractors in multiple places on the FPGA, rather than having a dedicated PUF). I didn't see an explanation of the challenge/response protocol(s) either, just a description on Wikipedia.
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