International Association for Cryptologic Research (IACR)
Abstract
A non-malleable encoding scheme is a keyless encoding scheme which is resilient to tampering attacks. Such a scheme
is said to be continuously secure if the scheme is resilient to attacks containing more than one tampering procedure. Also, such a
scheme is said to have tamper-detection property if any kind of
tampering attack is detected. In [S. Faust, et al., Continuous nonmalleable codes, TCC Proc., LNCS Vol. 8349, 2014.] a general
continuous non-malleable encoding scheme based on NIZK is
introduced which is secure in a strong model for which the
adversary receives a no-tamper as a response to its tampering
query if the decoding of the tampered codeword is identical to
the original message.
In this article we introduce a new strongly secure continuous
non-malleable encoding scheme with tamper-detection property
whose security is based on the existence of secure MAC’s. Moreover, we introduce and justify the importance of an intermediate security model called semi-strong continuous non-malleability, while we provide a secure semi-strong continuous non-malleable encoding scheme whose security is based on the existence of CCA-secure public-key encryption.
Considering the area of applications of encoding schemes in
tamper-proof devices, it is instructive to note that our proposed
schemes can be used to implement an algorithmic tamperdetection level as well as maintaining the security conditions