Non-malleability of a cryptographic primitive is a fundamental security property which ensures some sort of independence of cryptographic values. The notion has been extensively studied for commitments, encryption and zero-knowledge proofs, but it was not until recently that the notion—and its peculiarities— have been considered for hash functions by Boldyreva et al. (Asiacrypt 2009). They give...

Non-malleable code is a relaxed version of errorcorrection codes and the decoding of modified codewords results in the original message or a completely unrelated value. Thus, if an adversary corrupts a codeword then he cannot get any information from the codeword. This means that non-malleable codes are useful to provide a security guarantee in such situations that the adversary can overwrite t...

Existing de nitions of program obfuscation do not rule out malleability attacks, where an adversary that sees an obfuscated program is able to generate another (potentially obfuscated) program that is related to the original one in some way. We formulate two natural avors of non-malleability requirements for program obfuscation, and show that they are incomparable in general. We also construct ...

The round complexity of non-malleable commitments and non-malleable zero knowledge arguments has been an open question for long time. Very recent results of Pass [TCC 2013] and of Goyal et al. [FOCS 2014, STOC 2016], gave almost definitive answers. In this work we show how to construct round-efficient non-malleable protocols via compilers. Starting from protocols enjoying limited non-malleabili...

Currently, there has been substantial interest, in Australia and internationally, in policy activities related to outcomes-based educational performance indicators and their link with growing demands for accountability of teachers and schools. In order to achieve a fair comparison between schools, it is commonly agreed that a correction should be made for lack of equity. It is argued that stude...

A non-malleable code protects messages against various classes of tampering. Informally, a code is non-malleable if the message contained in a tampered codeword is either the original message, or a completely unrelated one. Although existence of such codes for various rich classes of tampering functions is known, explicit constructions exist only for “compartmentalized” tampering functions: i.e...

Non-malleable Codes (NMCs), introduced by Dziembowski, Peitrzak and Wichs (ITCS 2010), serve the purpose of preventing “related tampering” of encoded messages. The most popular tampering model considered is the 2-split-state model where a codeword consists of 2 states, each of which can be tampered independently. While NMCs in the 2-split state model provide the strongest security guarantee, de...

The notion of non-malleable cryptography, an extension of semantically secure cryptography , is deened. Informally, the additional requirement is that given the ciphertext it is impossible to generate a diierent ciphertext so that the respective plaintexts are related. The same concept makes sense in the contexts of string commitment and zero-knowledge proofs of possession of knowledge. Non-mal...

Non-malleability is an important security property of commitment schemes. The property means security against the man-in-the-middle attack, and it is defined and proved in the simulation paradigm using the corresponding simulator. Many known non-malleable commitment schemes have the common drawback that their corresponding simulators do not work in a straight-line manner, requires rewinding of ...