We are building a Malleable Interactive Software Toolkit (MIST), a tool set and infrastructure to simplify the design and construction of dynamically-reconfigurable (malleable) interactive software. Malleable software offers the end-user powerful tools to reshape their interactive environment on the fly. We aim to make the construction of such software straightforward, and to make reconfigurati...

We explore a new man-in-the-middle adversarial model for multi-prover interactive proofs (MIPs), and construct round-optimal, unconditionally secure, non-malleable MIPs. We compile from a large sub-class of Σ-protocols to a non-malleable MIP, avoiding the use of expensive NP-reductions to Graph Hamiltonicity or other NP-complete problems. Our compiler makes novel use of non-malleable codes – in...

Nowadays, achieving cryptosystems secure in an asynchronous network like the Internet is demanded to be necessary, where concurrent non-malleable proof-of-knowledge and universal composability are among the most powerful and fundamental security properties. But, when achieving more and more complex cryptosystems secure in an open network like the Internet, it is often the case that generic solu...

Non-malleable codes are a generalization of classical errorcorrecting codes where the act of “corrupting” a codeword is replaced by a “tampering” adversary. Non-malleable codes guarantee that the message contained in the tampered codeword is either the original messagem, or a completely unrelated one. In the common split-state model, the codeword consists of multiple blocks (or states) and each...

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...

Non-Malleable Codes for the split state model allow to encode a message into two parts such that arbitrary independent tampering on the parts either destroys completely the content or maintains the message untouched. If the code is also leakage resilient it allows limited independent leakage from the two parts. We propose a model where the two parts can be refreshed independently. We give an ab...

The notion of Zero Knowledge introduced by Goldwasser, Micali and Rackoff in STOC 1985 is fundamental in Cryptography. Motivated by conceptual and practical reasons, this notion has been explored under stronger definitions. We will consider the following two main strengthened notions. Statistical Zero Knowledge: here the zero-knowledge property will last forever, even in case in future the adve...

Non-malleable codes—introduced by Dziembowski, Pietrzak and Wichs at ICS 2010— are key-less coding schemes in which mauling attempts to an encoding of a given message, w.r.t. some class of tampering adversaries, result in a decoded value that is either identical or unrelated to the original message. Such codes are very useful for protecting arbitrary cryptographic primitives against tampering a...

We construct efficient, unconditional non-malleable codes that are secure against tampering functions computed by small-depth circuits. For constant-depth circuits of polynomial size (i.e. AC tampering functions), our codes have codeword length n = k for a k-bit message. This is an exponential improvement of the previous best construction due to Chattopadhyay and Li (STOC 2017), which had codew...

We describe efficient protocols for non-malleable (interactive) proofs of plaintext knowledge for the RSA, Rabin, Paillier, and El Gamal encryption schemes. We also highlight some important applications of these protocols: – Chosen-ciphertext-secure, interactive encryption. In settings where both parties are on-line, an interactive encryption protocol may be used. We construct chosen-ciphertext...