International Association for Cryptologic Research (IACR)
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 \u2706). 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 \u2707).
Our construction departs from the oft-used paradigm of re-encrypting the same
message with different keys and then proving consistency of encryption.
Instead, we encrypt an encoding of the message; the encoding is based on an
error-correcting code with certain properties of reconstruction and secrecy
from partial views, satisfied, e.g., by a Reed-Solomon code
