On Symmetric Encryption and Point Obfuscation

  • Ran Canetti
  • Yael Tauman Kalai
  • Mayank Varia
  • Daniel Wichs
Conference paper

DOI: 10.1007/978-3-642-11799-2_4

Part of the Lecture Notes in Computer Science book series (LNCS, volume 5978)
Cite this paper as:
Canetti R., Tauman Kalai Y., Varia M., Wichs D. (2010) On Symmetric Encryption and Point Obfuscation. In: Micciancio D. (eds) Theory of Cryptography. TCC 2010. Lecture Notes in Computer Science, vol 5978. Springer, Berlin, Heidelberg

Abstract

We show tight connections between several cryptographic primitives, namely encryption with weakly random keys, encryption with key-dependent messages (KDM), and obfuscation of point functions with multi-bit output (which we call multi-bit point functions, or MBPFs, for short). These primitives, which have been studied mostly separately in recent works, bear some apparent similarities, both in the flavor of their security requirements and in the flavor of their constructions and assumptions. Still, rigorous connections have not been drawn.

Our results can be interpreted as indicating that MBPF obfuscators imply a very strong form of encryption that simultaneously achieves security for weakly-random keys and key-dependent messages as special cases. Similarly, each one of the other primitives implies a certain restricted form of MBPF obfuscation. Our results carry both constructions and impossibility results from one primitive to others. In particular:

  • The recent impossibility result for KDM security of Haitner and Holenstein (TCC ’09) carries over to MBPF obfuscators.

  • The Canetti-Dakdouk construction of MBPF obfuscators based on a strong variant of the DDH assumption (EC ’08) gives an encryption scheme which is secure w.r.t. any weak key distribution of super-logarithmic min-entropy (and in particular, also has very strong leakage resilient properties).

  • All the recent constructions of encryption schemes that are secure w.r.t. weak keys imply a weak form of MBPF obfuscators.

Copyright information

© IFIP International Federation for Information Processing 2010

Authors and Affiliations

  • Ran Canetti
    • 1
  • Yael Tauman Kalai
    • 2
  • Mayank Varia
    • 3
  • Daniel Wichs
    • 4
  1. 1.School of Computer ScienceTel Aviv UniversityIsrael
  2. 2.Microsoft Research New EnglandUSA
  3. 3.Massachusetts Institute of TechnologyUSA
  4. 4.New York UniversityUSA

Personalised recommendations