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>anyone can code up a system that uses a fingerprint as a username Really? Please describe such a system. Will it use a photograph of the fingerprint? A hash v

by xoa 8y ago

>anyone can code up a system that uses a fingerprint as a username Really? Please describe such a system. Will it use a photograph of the fingerprint? A hash value? What hash? How do you deterministically arrive at the exact same one each time, or do you plan to "change the user name every single time" and in that case what is the actual persistent pointer to the account/person? Do you expect people to then use that name in conversation or when they think about it? See, this makes no sense. That's not what "user names" are, it doesn't have any of the properties humans ascribe to them. >similarly, lots of applications use the fingerprint as both username and password Name them. Name one, for that matter. You seem very, very confused about all this but at this point I really don't know how to make it any clearer for you.

modzu 8y ago
im sorry it doesnt make sense to you. when you said, "thats's not what usernames are" it became clear it's a linguistic issue. you are defining terms one way and i have defined them another way (that's fine) so that is why we cannot come to agreement on any corollary. the distinction is that you are sticking to the "formal" definitions, while i am using "functional" definitions. we agree (troll test #1) that auth factors can come in 3 flavors (for the 100th time): something you know, something you have, and something you are. according to this definition, a fingerprint goes into one bucket ("are") and a password goes into another bucket ("know"). peachy. BUT, fingerprints are also something else: GREASE. grease left on a handrail doesnt fit into any of these buckets. that doesnt mean its not a fingerprint! do you see the point? if you can appreciate that, and look at my comments through this lens, they might make sense. functionally, programmers are free to use "usernames" QUA "passwords" if they want to -- we can't just define that out of existence.
Phemist 8y ago
Re the hash value. Are you aware of fuzzy commitment[1]? It is a crypto scheme for protecting and/or deriving encryption keys from data that is subject to noise (such as in biometrics). If you can derive encryption keys, you can also derive hashes. [1] https://dl.acm.org/citation.cfm?id=319714 https://dl.acm.org/citation.cfm?id=319714

by xoa 8y ago

modzu 8y ago

im sorry it doesnt make sense to you. when you said, "thats's not what usernames are" it became clear it's a linguistic issue. you are defining terms one way and i have defined them another way (that's fine) so that is why we cannot come to agreement on any corollary. the distinction is that you are sticking to the "formal" definitions, while i am using "functional" definitions. we agree (troll test #1) that auth factors can come in 3 flavors (for the 100th time): something you know, something you have, and something you are. according to this definition, a fingerprint goes into one bucket ("are") and a password goes into another bucket ("know"). peachy. BUT, fingerprints are also something else: GREASE. grease left on a handrail doesnt fit into any of these buckets. that doesnt mean its not a fingerprint! do you see the point? if you can appreciate that, and look at my comments through this lens, they might make sense. functionally, programmers are free to use "usernames" QUA "passwords" if they want to -- we can't just define that out of existence.

Phemist 8y ago

Re the hash value. Are you aware of fuzzy commitment[1]? It is a crypto scheme for protecting and/or deriving encryption keys from data that is subject to noise (such as in biometrics). If you can derive encryption keys, you can also derive hashes. [1] https://dl.acm.org/citation.cfm?id=319714 https://dl.acm.org/citation.cfm?id=319714