A recent trend in cryptography is to construct cryptosystems that are secure against physical attacks. Such attacks are usually divided into two classes: the leakage attacks in which the adversary obtains some information about the internal state of the machine, and the tampering attacks where the adversary can modify this state. One of the popular tools used to provide tamper-resistance are th...

Non-malleable codes, introduced by Dziembowski, Pietrzak, and Wichs (ICS ’10) provide the guarantee that if a codeword c of a message m, is modified by a tampering function f to c′, then c′ either decodes to m or to “something unrelated” to m. It is known that non-malleable codes cannot exist for the class of all tampering functions and hence a lot of work has focused on explicitly constructing...

In this work, we significantly improve the efficiency of non-malleable codes in the split state model, by constructing a code with codeword length |s|+O(k), where |s| is the length of the message, and k is the security parameter. This is a substantial improvement over previous constructions, both asymptotically and concretely. Our construction relies on a new primitive which we define and study...

Non-malleable codes (NMCs) protect sensitive data against degrees of corruption that prohibit error detection, ensuring instead that a corrupted codeword decodes correctly or to something that bears little relation to the original message. The split-state model, in which codewords consist of two blocks, considers adversaries who tamper with either block arbitrarily but independently of the othe...

We present an information-theoretically secure continuously non-malleable code in the constant split-state model, where there is a self-destruct mechanism which ensures that the adversary loses access to tampering after the first failed decoding. Prior to our result only codes with computational security were known for this model, and it has been an open problem to construct such a code with in...

A (k, ε)-non-malleable extractor is a function nmExt : {0, 1}×{0, 1} → {0, 1} that takes two inputs, a weak source X ∼ {0, 1} of min-entropy k and an independent uniform seed s ∈ {0, 1}, and outputs a bit nmExt(X, s) that is ε-close to uniform, even given the seed s and the value nmExt(X, s′) for an adversarially chosen seed s′ 6= s. Dodis and Wichs (STOC 2009) showed the existence of (k, ε)-no...

Non-malleable codes, introduced as a relaxation of error-correcting codes by Dziembowski, Pietrzak and Wichs (ICS ’10), provide the security guarantee that the message contained in a tampered codeword is either the same as the original message or is set to an unrelated value. Various applications of non-malleable codes have been discovered, and one of the most significant applications among the...

We consider the execution of two-party protocols in the presence of an adversary that has full control of the communication channel between the parties. The adversary has the power to omit, insert or modify messages at its choice. It has also full control over the scheduling of the messages. The honest parties are not necessarily aware to the existence of the adversary, and are not allowed to u...

Dziembowski, Pietrzak, and Wichs (ICS–2010) introduced the notion of non-malleable codes as a useful message integrity assurance for scenarios where error-correction or, even, errordetection is impossible. Intuitively, a non-malleable code ensures that the tampered codeword encodes the original message or a message that is entirely independent of the original message. However, if the family of ...