Secure Storage for Identification

Abstract

Ahlswede and Dueck introduced identification via channels as a new paradigm in information theory. They showed that the number of messages that can reliably be identified over a noisy channel grows doubly exponentially with the block length. In this work we also consider identification, but we assume that messages are stored on a database such that they can be identified. Additionally the legitimate users have access to the output of a source. This source allows us to store messages securely. It is also used to increase the number of messages that can be stored securely on the database and identified reliably. We define a protocol for secure storage for identification such that the number of stored messages that can be identified grows doubly exponentially with the number of symbols read from the source and the number of storage cells available respectively. We also consider the privacy leakage of the protocols used for identification. As a by-product we also get new results on common randomness generation.