Rate-distortion theory for the Shannon cipher system

Rate-distortion theory is considered for the Shannon cipher system (SCS). The admissible region of cryptogram rateR, key rate Rk, legitimate receiver’s distortion D, and wiretapper’s uncertainty h is determined for the SCS with a noisy channel. Furthermore, inner and outer bounds of the admissible region of R, Rk, D, and wiretapper’s attainable minimum distortion ~ D are derived for the SCS with a finite discrete source and a noiseless channel.