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"Touch ID does not store any images of your fingerprint. It stores only a mathematical representation of your fingerprint. It isn't possible for your actual fin
by softbuilder 13y ago
"Touch ID does not store any images of your fingerprint. It stores only a mathematical representation of your fingerprint. It isn't possible for your actual fingerprint image to be reverse-engineered from this mathematical representation."
This is a tad disingenuous.
Fingerprint 101:
Fingerprint databases don't search images of your fingerprints. They search mathematical representations of your fingerprints.
To uniquely identify your fingerprint an image is scanned for unique features called "minutia points"[1]. The spacing and orientation of those points is what is stored and later searched for.
Fingerprint matching isn't boolean. When you do a database search you get a list of high probability matches. There are no perfect matches, even between two different images of the exact same finger. Everything is based on probability. For law enforcement purposes, strong matches result in a technician reviewing actual images and making comparisons. For biometric security like this (which is not my area) I expect that there is a threshold percentage match that must be met.
The reason this quote concerns me is that while the actual image can't be reproduced, the image isn't the part that matters! The "mathematical representation" is what counts.
Whether or not that information is actually secure onboard the phone, I don't know.
[0] I have worked with fingerprint processing systems.
[1] http://en.wikipedia.org/wiki/Fingerprint_recognition#Minutia_features http://en.wikipedia.org/wiki/Fingerprint_recognition#Minutia...
- Axsuul 13y agoSo it's essentially a md5 hash and the only way someone can determine what your actual fingerprint looks like is from a rainbow table of fingerprints.
- jdiez17 13y agoDid you read the comment you just replied to? Do you understand how a hash function works? In particular, the avalanche effect[1] prevents MD5 (or any other cryptographic hash) from being useful in this scenario, since fingerprints are matched fuzzily. Hashing functions are only useful when the input data doesn't change. [1] http://en.wikipedia.org/wiki/Avalanche_effect http://en.wikipedia.org/wiki/Avalanche_effect
- jnardiello 13y agoNobody knows where the model is stored. Considering the records and recent history, very likely finger prints models will be used for further intelligence analysis.
- numbsafari 13y agoIt's stored inside a portion of the A7 chip that accepts writes, but apparently not direct reads. Further analysis will hopefully show whether this was successfully implemented or not.