Quantum secure non-malleable codes in the split-state model

Abstract: Non-malleable-codes introduced by Dziembowski, Pietrzak and Wichs [DPW18] encode a classical message $S$ in a manner such that tampering the codeword results in the decoder either outputting the original message $S$ or a message that is unrelated/independent of $S$. Providing such non-malleable security for various tampering function families has received significant attention in recent years. We consider the well-studied (2-part) split-state model, in which the message $S$ is encoded into two parts $X$ and $Y$, and the adversary is allowed to arbitrarily tamper with each $X$ and $Y$ individually. We consider the security of non-malleable-codes in the split-state model when the adversary is allowed to make use of arbitrary entanglement to tamper the parts $X$ and $Y$. We construct explicit quantum secure non-malleable-codes in the split-state model. Our construction of quantum secure non-malleable-codes is based on the recent construction of quantum secure $2$-source non-malleable-extractors by Boddu, Jain and Kapshikar [BJK21].