International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Boneh-Franklin Identity Based Encryption Revisited

David Galindo
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Abstract: The first practical identity based encryption (IBE) scheme was proposed by Boneh and Franklin. In this work we point out that there is a flawed step in the security reduction exhibited by the authors. Fortunately, it is possible to fix it without changing the scheme or the underlying assumption. In the second place, we introduce a variant of the seminal IBE scheme which allows a more efficient security reduction. The new scheme is simpler, and has more compact ciphertexts than Boneh-Franklin's proposal, while keeping the computational cost. Finally, we observe that the flawed step pointed out here is present in several works, and that our techniques can be applied to obtain tighter reductions for previous relevant schemes.
  title={Boneh-Franklin Identity Based Encryption Revisited},
  booktitle={IACR Eprint archive},
  keywords={public-key cryptography / provable security, identity-based encryption, exact security, bilinear maps},
  note={An extended abstract has been accepted for ICALP 2005. 12894 received 21 Apr 2005},
  author={David Galindo},