Attribute Based Encryption with Direct Efficiency Tradeoff

  • Nuttapong Attrapadung
  • Goichiro Hanaoka
  • Tsutomu Matsumoto
  • Tadanori Teruya
  • Shota Yamada
Conference paper

DOI: 10.1007/978-3-319-39555-5_14

Volume 9696 of the book series Lecture Notes in Computer Science (LNCS)
Cite this paper as:
Attrapadung N., Hanaoka G., Matsumoto T., Teruya T., Yamada S. (2016) Attribute Based Encryption with Direct Efficiency Tradeoff. In: Manulis M., Sadeghi AR., Schneider S. (eds) Applied Cryptography and Network Security. ACNS 2016. Lecture Notes in Computer Science, vol 9696. Springer, Cham

Abstract

We propose the first fully secure unbounded Attribute-Based Encryption (ABE) scheme such that the key size and ciphertext size can be directly traded off. Our proposed scheme is parameterized by a positive integer d, which can be arbitrarily chosen at setup. In our scheme, the ciphertext size is O(t/d), the private key size is O(md), and the public key size is O(d), where tm are the sizes of attribute sets and policies corresponding to ciphertext and private key, respectively.

Our scheme can be considered as a generalization that includes two of the state-of-the-art ABE instantiations, namely, the unbounded ABE scheme and the ABE scheme with constant-size ciphertexts proposed by Attrapadung (Eurocrypt 2014). Indeed, these two schemes correspond to the two extreme cases of our scheme, that is, when setting \(d=1\) and when setting d as the maximum size of allowed attribute sets, respectively. Furthermore, our scheme also yields a tradeoff between encryption and decryption time. Interestingly, when estimating efficiency using numerical parameters, the decryption time is minimized at d being somewhere in the middle of the spectrum.

We believe that this tradeoff can provide advantages in applications where size and/or time resources are concretely fixed in advance, as we can flexibly adjust d to match available resources and thus make the most of them. Such situations include, but are not limited to, implementations of ABE in tiny hardware tokens.

Keywords

Attribute-based encryption Efficiency tradeoff Unbounded Short ciphertext Full security 

Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Nuttapong Attrapadung
    • 1
  • Goichiro Hanaoka
    • 1
  • Tsutomu Matsumoto
    • 2
  • Tadanori Teruya
    • 1
  • Shota Yamada
    • 1
  1. 1.National Institute of Advanced Industrial Science and Technology (AIST)TokyoJapan
  2. 2.Yokohama National UniversityYokohamaJapan