Chapter

Theory of Cryptography

Volume 4948 of the series Lecture Notes in Computer Science pp 427-444

Black-Box Construction of a Non-malleable Encryption Scheme from Any Semantically Secure One

  • Seung Geol ChoiAffiliated withColumbia University
  • , Dana Dachman-SoledAffiliated withColumbia University
  • , Tal MalkinAffiliated withColumbia University
  • , Hoeteck WeeAffiliated withColumbia University

Abstract

We show how to transform any semantically secure encryption scheme into a non-malleable one, with a black-box construction that achieves a quasi-linear blow-up in the size of the ciphertext. This improves upon the previous non-black-box construction of Pass, Shelat and Vaikuntanathan (Crypto ’06). Our construction also extends readily to guarantee non-malleability under a bounded-CCA2 attack, thereby simultaneously improving on both results in the work of Cramer et al. (Asiacrypt ’07).

Our construction departs from the oft-used paradigm of re-encrypting the same message with different keys and then proving consistency of encryptions; instead, we encrypt an encoding of the message with certain locally testable and self-correcting properties. We exploit the fact that low-degree polynomials are simultaneously good error-correcting codes and a secret-sharing scheme.

Keywords

Public-key encryption semantic security non-malleability black-box constructions