Authentication Protocol
Object i authenticates itself as follows:
- when it claims to be object i, it sends its identifier i to a verifier who retrieves the data (Vi,Wi) from a trusted database. Alternatively i could provide the verifier with this data (Vi,Wi) together with a certificate that this data is correct.
- Object i allows the verifier to take a noisy measurement Y = X + N of its physical properties X.
- The verifier applies operation G(W,Y) to the helper data W and to the measured signal Y. This results in signal Z = G(W,Y)
- This is fed into a cryptographic hash function F(Z). Note that during authentication, Z is the estimate of the S that was chosen during enrollment.
- The output U = F(Z) is compared with an authentication code V. If U = V, the authentication is successful.
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In some applications it is useful to extract further cryptographic keys from Z.