Feedback in Joint Channel Coding and Cryptography

This paper presents further research based on the idea of Soft Input Decryption (SID). The approach, which integrates decryption into the decoding process, is now enhanced by feedback from the decryptor to the channel decoder, which leads to an iterative application of Soft input Decryption. The enhanced coding gain of the subsequent channel decoding can be exploited by longer Soft Input Decryption blocks or results in reduction of the BER of the final output. Results of analytical calculations of BER as well as simulations represent the coding gains.