5 research outputs found
Biometric and Physical Identifiers with Correlated Noise for Controllable Private Authentication
The problem of secret-key based authentication under privacy and storage
constraints on the source sequence is considered. The identifier measurement
channels during authentication are assumed to be controllable via a
cost-constrained action sequence. Single-letter inner and outer bounds for the
key-leakage-storage-cost regions are derived for a generalization of a classic
two-terminal key agreement model with an eavesdropper that observes a sequence
that is correlated with the sequences observed by the legitimate terminals. The
additions to the model are that the encoder observes a noisy version of a
remote source, and the noisy output and the remote source output together with
an action sequence are given as inputs to the measurement channel at the
decoder. Thus, correlation is introduced between the noise components on the
encoder and decoder measurements. The model with a secret key generated by an
encoder is extended to the randomized models, where a secret-key is embedded to
the encoder. The results are relevant for several user and device
authentication scenarios including physical and biometric identifiers with
multiple measurements that provide diversity and multiplexing gains. To
illustrate the behavior of the rate region, achievable (secret-key rate,
storage-rate, cost) tuples are given for binary identifiers and measurement
channels that can be represented as a mixture of binary symmetric subchannels.
The gains from using an action sequence such as a large secret-key rate at a
significantly small hardware cost, are illustrated to motivate the use of
low-complexity transform-coding algorithms with cost-constrained actions.Comment: Shorter version to appear in the IEEE International Symposium on
Information Theory 202