Code book cipher system

A new system is proposed to enhance the security of a stream ciphering algorithm that is based on non-linear J-K flip flop networks (Pless´s system). The new system incorporates a multiplexing algorithm with a Pseudorandom Number Generator (PNG) to generate a random sequence that is totally independent of the corresponding input sequence. This multiplexing algorithm can be achieved by using a 32 MByte Random Access Memory (RAM) code book filled with random sequences where the (25 bit) input sequence will specify the address of the output bytes. Although the RAM code book algorithm is very secure, another level of complexity is added using a non-linear arithmetic operation at the output stage where the message text (400 bits) will be added to a (320 bits) random key and then evaluated for a (320 bits) random base. Both, key and base, are generated by the code book which has a period of 10E110. The overall system is considered an NP-complete problem and it is very secure under plain-text attack