Cryptology ePrint Archive: Report 2019/1299

A constant-rate non-malleable code in the split-state model.

Divesh Aggarwal and Maciej Obremski

Abstract: Non-malleable codes, introduced by Dziembowski, Pietrzak and Wichs in ICS 2010, have emerged in the last few years as a fundamental object at the intersection of cryptography and coding theory. Non-malleable codes provide a useful message integrity guarantee in situations where traditional error-correction (and even error-detection) is impossible; for example, when the attacker can completely overwrite the encoded message. Informally, a code is non-malleable if the message contained in a modified codeword is either the original message, or a completely "unrelated value''.

The family which received the most attention is the family of tampering functions in the so called (2-part) split-state model: here the message x is encoded into two shares L and R, and the attacker is allowed to arbitrarily tamper with each L and R individually.

In this work, we give a constant rate non-malleable code from the tampering family containing so called 2-lookahead functions and forgetful functions, and combined with the work of Dodis, Kazana and the authors from STOC 2015, this gives the first constant rate non-malleable code in the split-state model with negligible error.

Category / Keywords: foundations /

Date: received 7 Nov 2019

Contact author: dcsdiva at nus edu sg,obremski math@gmail com

Available format(s): PDF | BibTeX Citation

Version: 20191111:210231 (All versions of this report)

Short URL: ia.cr/2019/1299


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