Wildcarded identity-based encryption

Ref: Michel Abdalla, James Birkett, Dario Catalano, Alexander W. Dent, John Malone-Lee, Gregory Neven, Jacob C. N. Schuldt, and Nigel P. Smart. To appear in Journal of Cryptology.

Abstract: In this paper we introduce a new primitive called identity-based encryption with wildcards, or WIBE for short. It allows a sender to encrypt messages to a whole range of receivers whose identities match a certain pattern. This pattern is de ned through a sequence of fixed strings and wildcards, where any string can take the place of a wildcard in a matching identity. Our primitive can be applied to provide an intuitive way to send encrypted email to groups of users in a corporate hierarchy. We propose a full security notion and give efficient implementations meeting this notion under different pairing-related assumptions, both in the random oracle model and in the standard model.