International Workshop on Public Key Cryptography

PKC 2010: Public Key Cryptography – PKC 2010 pp 384-402

Functional Encryption for Inner Product: Achieving Constant-Size Ciphertexts with Adaptive Security or Support for Negation

  • Nuttapong Attrapadung
  • Benoît Libert
Conference paper

DOI: 10.1007/978-3-642-13013-7_23

Volume 6056 of the book series Lecture Notes in Computer Science (LNCS)

Abstract

In functional encryption (FE) schemes, ciphertexts and private keys are associated with attributes and decryption is possible whenever key and ciphertext attributes are suitably related. It is known that expressive realizations can be obtained from a simple FE flavor called inner product encryption (IPE), where decryption is allowed whenever ciphertext and key attributes form orthogonal vectors. In this paper, we construct (non-anonymous) IPE systems with constant-size ciphertexts for the zero and non-zero evaluations of inner products. These schemes respectively imply an adaptively secure identity-based broadcast encryption scheme and an identity-based revocation mechanism that both feature short ciphertexts and rely on simple assumptions in prime order groups. We also introduce the notion of negated spatial encryption, which subsumes non-zero-mode IPE and can be seen as the revocation analogue of the spatial encryption primitive of Boneh and Hamburg.

Keywords

Functional encryptionidentity-based broadcast encryptionrevocationefficiency
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Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Nuttapong Attrapadung
    • 1
  • Benoît Libert
    • 2
  1. 1.Research Center for Information Security, AISTJapan
  2. 2.Université catholique de Louvain, Crypto GroupBelgium