Statistical analysis of error patterns in block ciphered crypto-system

Abstract

In the presence of channel errors, the error pattern in decrypted plaintexts in block-ciphered systems demonstrates certain burst features. In this paper, we provide a rigorous study of error properties of block-ciphered cryptosystems operating in either ECB or CFB mode. By analyzing the relationship between bits within and across adjacent output blocks, we obtain the resulting equivalent channel transitional probabilities for each case. Our statistical characterization of the underlying burst patterns is of great importance to designing powerful error correcting codes that can enhance a legitimate system's throughput under channel distortions.