Black-Box Construction of a Non-malleable Encryption Scheme from Any Semantically Secure One
- Cite this paper as:
- Choi S.G., Dachman-Soled D., Malkin T., Wee H. (2008) Black-Box Construction of a Non-malleable Encryption Scheme from Any Semantically Secure One. In: Canetti R. (eds) Theory of Cryptography. TCC 2008. Lecture Notes in Computer Science, vol 4948. Springer, Berlin, Heidelberg
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.