Blind Identity-Based Encryption and Simulatable Oblivious Transfer

An extended abstract of this paper appears in Kaoru Kurosawa (Ed.): Advances in Cryptology ASIACRYPT 2007, volume 4833 of Lecture Notes in Computer Science, pages 265–282, Springer-Verlag, 2007. This is the full version. In an identity-based encryption (IBE) scheme, there is a key extraction protocol where a user submits an identity string to a master authority who then returns the corresponding secret key for that identity. In this work, we describe how this protocol can be performed efficiently and in a blind fashion for several known IBE schemes; that is, a user can obtain a secret key for an identity without the master authority learning anything about this identity. We formalize this notion as blind IBE and discuss its many practical applications. In particular, we build upon the recent work of Camenisch, Neven, and shelat [CNS07] to construct oblivious transfer (OT) schemes which achieve full simulatability for both sender and receiver. OT constructions with comparable efficie...

• Type: Conference
• Year: 2007
• Where: ASIACRYPT
• Authors: Matthew Green, Susan Hohenberger
• Keywords: ASIACRYPT 2007, Blind Ibe, Cryptology, IBE Schemes, Secret Key