Cryptology ePrint Archive: Report 2019/055

Rate-Optimizing Compilers for Continuously Non-Malleable Codes

Sandro Coretti and Antonio Faonio and Daniele Venturi

Abstract: We study the *rate* of so-called *continuously* non-malleable codes, which allow to encode a message in such a way that (possibly adaptive) continuous tampering attacks on the codeword yield a decoded value that is unrelated to the original message. Our results are as follows:

-) For the case of bit-wise independent tampering, we establish the existence of rate-one continuously non-malleable codes with information-theoretic security, in the plain model.

-) For the case of split-state tampering, we establish the existence of rate-one continuously non-malleable codes with computational security, in the (non-programmable) random oracle model. We further exhibit a rate-1/2 code and a rate-one code in the common reference string model, but the latter only withstands *non-adaptive* tampering.

It is well known that computational security is inherent for achieving continuous non-malleability in the split-state model (even in the presence of non-adaptive tampering).

Continuously non-malleable codes are useful for protecting *arbitrary* cryptographic primitives against related-key attacks, as well as for constructing non-malleable public-key encryption schemes. Our results directly improve the efficiency of these applications.

Category / Keywords: foundations / non-malleable codes, tamper-proof security

Date: received 18 Jan 2019, last revised 29 Jan 2019

Contact author: corettis at nyu edu,antonio faonio@imdea org,venturi@di uniroma1 it

Available format(s): PDF | BibTeX Citation

Version: 20190129:142412 (All versions of this report)

Short URL: ia.cr/2019/055


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