Paper Title
Design of Channel Encoder With Security

Error control and security are prominent functions in digital communication systems. Reliability, security and efficient in digital data transmission systems having more demand in high speed communication networks. To protect against the error free data transmission to the varying channel conditions channel encoding schemes are used. In this paper puncturing and trellis pruning as new coding concepts, we provide security to the channel encoders based on turbo codes and to achieve reliability as well. Puncturing is employed to decrease the performance of the code and thus increase the error probability experienced by an eavesdropper at a given SNR. The cryptanalytic attacks will become impossible because of puncturing due to whose complexity depends on the error probability. The trellis pruning, is enable the legitimate users communicate reliably in a secret fashion. The legitimate users has superior performance , in terms of bit error rate than the eavesdropper, which depends on puncturing and pruning rates. In this paper an algorithm is proposed to compute the puncturing and pruning rates based on EXIT charts. We will analytically show their EXIT charts as a function of the EXIT charts associated with underlying turbo code for a transmission over a AWGN channel. Keywords— Turbo codes, puncturing, trellis pruning, cryptanalytic attacks , EXIT charts.