  Non-malleable code is a relaxed version of error-correction codes and the
decoding of modified codewords results in the original message or a completely
unrelated value. Thus, if an adversary corrupts a codeword then he cannot get
any information from the codeword. This means that non-malleable codes are
useful to provide a security guarantee in such situations that the adversary
can overwrite the encoded message. In 2010, Dziembowski et al. showed a
construction for non-malleable codes against the adversary who can falsify
codewords bitwise independently. In this paper, we consider an extended
adversarial model (affine error model) where the adversary can falsify
codewords bitwise independently or replace some bit with the value obtained by
applying an affine map over a limited number of bits. We prove that the
non-malleable codes (for the bitwise error model) provided by Dziembowski et
al. are still non-malleable against the adversary in the affine error model.
