4 ms·

Thumbprints on the seller's machine would be useless; they could just save the data. What we really need is the buyer authenticating and somehow notifying the m

• teilo 17y ago
  Just about as useless as, say, a signature? You are making an incorrect assumption about signatures: They are there to verify or dispute that you authorized a purchase, if necessary, after the fact. The whole point is that the vendor saves the data, because it is his proof that you were there. Signatures are about managing by exception, because it is impractical to do anything else. Biometric signing, properly implemented, is far more secure than a signature. Consider: * POS system grabs biometric data and encodes it. * POS system transmits the biometric data to the bank, who returns a cryptographically signed timestamp. * Biometric signature, authorization, and timestamp are then bundled together and cryptographically signed by the vendor. This becomes the receipt. * Vendor stores the result locally as proof of sale. Customer receive the same as proof of sale. Thus, the bank, for the first time, has actual proof of the presence of a customer. This makes the signature stronger. Also, vendor and customer both have much stronger proof of transaction to dispute / verify same. No system is impossible to subvert. Low-level man-in-the-middle hardware/firmware hacks are always possible. But with some variant of the above, the buying process can be both swift, and much more secure than it is now.