International Conference on the Theory and Application of Cryptology and Information Security

ASIACRYPT 2009: Advances in Cryptology – ASIACRYPT 2009 pp 287-302

Improved Non-committing Encryption with Applications to Adaptively Secure Protocols

  • Seung Geol Choi
  • Dana Dachman-Soled
  • Tal Malkin
  • Hoeteck Wee
Conference paper

DOI: 10.1007/978-3-642-10366-7_17

Volume 5912 of the book series Lecture Notes in Computer Science (LNCS)
Cite this paper as:
Choi S.G., Dachman-Soled D., Malkin T., Wee H. (2009) Improved Non-committing Encryption with Applications to Adaptively Secure Protocols. In: Matsui M. (eds) Advances in Cryptology – ASIACRYPT 2009. ASIACRYPT 2009. Lecture Notes in Computer Science, vol 5912. Springer, Berlin, Heidelberg

Abstract

We present a new construction of non-committing encryption schemes. Unlike the previous constructions of Canetti et al. (STOC ’96) and of Damgård and Nielsen (Crypto ’00), our construction achieves all of the following properties:
  • Optimal round complexity. Our encryption scheme is a 2-round protocol, matching the round complexity of Canetti et al. and improving upon that in Damgård and Nielsen.

  • Weaker assumptions. Our construction is based on trapdoor simulatable cryptosystems, a new primitive that we introduce as a relaxation of those used in previous works. We also show how to realize this primitive based on hardness of factoring.

  • Improved efficiency. The amortized complexity of encrypting a single bit is O(1) public key operations on a constant-sized plaintext in the underlying cryptosystem.

As a result, we obtain the first non-committing public-key encryption schemes under hardness of factoring and worst-case lattice assumptions; previously, such schemes were only known under the CDH and RSA assumptions. Combined with existing work on secure multi-party computation, we obtain protocols for multi-party computation secure against a malicious adversary that may adaptively corrupt an arbitrary number of parties under weaker assumptions than were previously known. Specifically, we obtain the first adaptively secure multi-party protocols based on hardness of factoring in both the stand-alone setting and the UC setting with a common reference string.

Keywords

public-key encryptionadaptive corruptionnon-committing encryptionsecure multi-party computation
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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Seung Geol Choi
    • 1
  • Dana Dachman-Soled
    • 1
  • Tal Malkin
    • 1
  • Hoeteck Wee
    • 2
  1. 1.Columbia University 
  2. 2.Queens College, CUNY