Non-Malleable Codes

We introduce the notion of "non-malleable codes" which relaxes the notion of error-correction and errordetection. Informally, a code is non-malleable if the message contained in a modified codeword is either the original message, or a completely unrelated value. In contrast to error-correction and error-detection, nonmalleability can be achieved for very rich classes of modifications. We construct an efficient code that is non-malleable with respect to modifications that effect each bit of the codeword arbitrarily (i.e. leave it untouched, flip it or set it to either 0 or 1), but independently of the value of the other bits of the codeword. Using the probabilistic method, we also show a very strong and general statement: there exists a non-malleable code for every "small enough" family F of functions via which codewords can be modified. Although this probabilistic method argument does not directly yield efficient constructions, it gives us efficient non-malleable c...

• Type: Conference
• Year: 2010
• Where: ICS
• Authors: Stefan Dziembowski, Krzysztof Pietrzak, Daniel Wichs
• Keywords: ICS 2010, Theoritical Computer Science