2026-10-11T18:26:16Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:11765 2024-03-06T09:48:39Z ddc:004 open_access

Limits to Non-Malleability Ball, Marshall Dachman-Soled, Dana Kulkarni, Mukul Malkin, Tal non-malleable codes black-box impossibility tamper-resilient cryptogtaphy average-case hardness There have been many successes in constructing explicit non-malleable codes for various classes of tampering functions in recent years, and strong existential results are also known. In this work we ask the following question: When can we rule out the existence of a non-malleable code for a tampering class ℱ? First, we start with some classes where positive results are well-known, and show that when these classes are extended in a natural way, non-malleable codes are no longer possible. Specifically, we show that no non-malleable codes exist for any of the following tampering classes: - Functions that change d/2 symbols, where d is the distance of the code; - Functions where each input symbol affects only a single output symbol; - Functions where each of the n output bits is a function of n-log n input bits. Furthermore, we rule out constructions of non-malleable codes for certain classes ℱ via reductions to the assumption that a distributional problem is hard for ℱ, that make black-box use of the tampering functions in the proof. In particular, this yields concrete obstacles for the construction of efficient codes for NC, even assuming average-case variants of P ⊈ NC. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Marshall Ball and Dana Dachman-Soled and Mukul Kulkarni and Tal Malkin 2020 Is Part Of LIPIcs, Volume 151, 11th Innovations in Theoretical Computer Science Conference (ITCS 2020) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ITCS.2020.80 urn:nbn:de:0030-drops-117657 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITCS.2020.80 eng https://creativecommons.org/licenses/by/3.0/legalcode