Functional Encryption for Regular Languages

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Functional Encryption for Regular Languages
We provide a functional encryption system that supports functionality for regular languages. In our system a secret key is associated with a Deterministic Finite Automata (DFA) M. A ciphertext CT encrypts a message m and is associated with an arbitrary length string w. A user is able to decrypt the ciphertext CT if and only if the DFA M associated with his private key accepts the string w. Compared with other known functional encryption systems, this is the first system where the functionality is capable of recognizing an unbounded language. For example, in (Key-Policy) Attribute-Based Encryption (ABE) a private key SK is associated with a single boolean formula φ which operates over a fixed number of boolean variables from the ciphertext. In contrast, in our system a DFA M will meaningfully operate over an arbitrary length input w. We propose a system that utilizes bilinear groups. Our solution is a “public index” system, where the message m is hidden, but the string w is not....
Brent Waters
Added 28 Sep 2012
Updated 28 Sep 2012
Type Journal
Year 2012
Authors Brent Waters
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