
Ask HN: Approximate encryption - mdpopescu
(Apologies if I get things incorrectly, I&#x27;m just a layman.)<p>Is there an encryption method that can work if you only have, say, 90% of the key? (Work = the ciphertext is decrypted perfectly, as if you had the whole key.)<p>Rationale:<p>I was thinking about biometric authentication; as far as I can tell, a &quot;detector&quot; device compares the fingerprint &#x2F; retina &#x2F; whatever with a database of known biometrics and sends an &quot;ok &#x2F; not ok&quot; signal to another system which actually grants access to a resource.<p>This enables two methods of attack: 1) add a fake record to the database and 2) do a MITM and send an &quot;ok&quot; signal no matter what the biometric detector says.<p>To combat that, we could encrypt the secret with the actual biometric; this way, unless you have the fingerprint &#x2F; retina you can&#x27;t get to the information and faking one doesn&#x27;t help. Of course, given that you can&#x27;t get the same reading from a fingerprint &#x2F; retinal scanner, conventional encryption would be useless - hence my question.
======
pizza
This will be of interest:
[https://blog.cryptographyengineering.com/2017/07/02/beyond-p...](https://blog.cryptographyengineering.com/2017/07/02/beyond-
public-key-encryption/) \- talks about numerous approaches beyond a single
all-or-nothing key

~~~
mdpopescu
"Attribute Based Encryption" seems to be what I was looking for, thank you!

