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 ...

In this paper we introduce two notions of security: multi-user indistinguishability and multi-user non-malleability. We believe that they encompass the correct requirements for public key encryption schemes in the context of multicast communications. A precise and non-trivial analysis proves that they are equivalent to the former single-user notions, provided the number of participants is polyn...

The problem of the malleability rhenium at room temperature is discussed. It has shown that manufactured by mean electron beam melting able to mechanical treatment rolling temperature. primary condition for minor share tensile stress in processing scheme. suppresses grain boundary sliding a coarse-grained workpiece this refractory HCP-metal.

The Internet enables concurrent executions of cryptographic protocols. This concurrent setting, however, also brings forth new types of coordinated attacks in which an adversary controls many parties, interleaving the executions of the various protocol instances, and attempts to ”maul” messages from one execution to use in another. In this talk, we will survey some recent methods for achieving ...

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...

A malleable coding scheme considers not only compression efficiency but also the ease of alteration, thus encouraging some form of recycling of an old compressed version in the formation of a new one. Malleability cost is the difficulty of synchronizing compressed versions, and malleable codes are of particular interest when representing information and modifying the representation are both exp...