4 ms·
That's not how it works. The process of reading your retina / fingerprint is error prone. You can't take hash out of error-prone data blob! My understanding is
by majke 9y ago
That's not how it works. The process of reading your retina / fingerprint is error prone. You can't take hash out of error-prone data blob!
My understanding is that matching the pre-saved template against a fresh scan is a process similar to measuring Levenshtein distance. There is some threshold, and sample with smaller error are accepted. This does imply that the iphone has somewhere stored your _unencrypted_, _unhashed_ template of your fingerprint.
But this is not my area of expertise. Perhaps a subject matter expert can comment.
- NwmG 9y agoYeah, pretty much. It compares the minutiae[1] from the new scan against that from one, or multiple saved scans from registration. [1]https://www.wikiwand.com/en/Minutiae https://www.wikiwand.com/en/Minutiae
- tdist 9y agoI addressed this when this study was discussed last week, but it's worth reminding that minutiae comparing is not the only technique used for fingerprint matching. [1] (possible corporate bias) [1] https://corporate.fingerprints.com/en/newsroom/faq-regarding-fingerprints-information-disclosure-and-product-launches/current-questions-answers/ https://corporate.fingerprints.com/en/newsroom/faq-regarding...
- NwmG 9y agoThanks for the link! Yes there are many ways, I always thought minutiae was most common/simplest. There are some interesting advancements also occuring in the optical tomography. [1] http://ieeexplore.ieee.org/document/7110228/?reload=true http://ieeexplore.ieee.org/document/7110228/?reload=true
- out_of_protocol 9y agoIndeed it is, inside a sensor (that's why so much trouble replacing one on iphone), gladly raw data never leaves it (same goes for Android as well, except really really old versions, like 4-)
- majke 9y ago"data never leaves it" reference please?
- H4CK3RM4N 9y agohttps://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf You're looking for the bit on the "Secure Enclave".
- delinka 9y agohttps://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf Find the section titled "Secure Enclave." When the SE needs to store data on the filesystem, it's encrypted with a key that never leaves the SE. Effectively, assuming the encryption is implemented correctly, data 'owned' by the SE is never available to any other part of the system.
- theoh 9y agoI'm not an expert, but I remember getting an impression of a very principled approach to biometrics from John Daugman. This article is about iris recognition and I'm pretty sure it is worth posting in this context: https://www.cl.cam.ac.uk/~jgd1000/csvt.pdf https://www.cl.cam.ac.uk/~jgd1000/csvt.pdf
- wlesieutre 9y agoNot cryptographic hashing functions, definitely. What about locality-sensitive hashing? https://en.wikipedia.org/wiki/Locality-sensitive_hashing https://en.wikipedia.org/wiki/Locality-sensitive_hashing
- deleted 9y ago[deleted]