On The Impossibility of Basing Identity Based Encryption on Trapdoor Permutations

CitationIn proceedings of FOCS 2008, pp. 283-292
AuthorsD. Boneh
A. Papakonstantinou
C. Rackoff
Y. Vahlis
B. Waters


We ask whether an Identity Based Encryption (IBE) system can be built from simpler public-key primitives. We show that there is no black-box construction for IBE from Trapdoor Permutations (TDP) or even from Chosen Ciphertext Secure Public Key Encryption (CCA-PKE). These black-box separation results are based on an essential property of IBE, namely that an IBE system is able to compress exponentially many public-keys into a short public parameters string.

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