Fibonacci Based Position Substitution (FBPS) Encoder for Secured Message Transmission

The technique considers a message as binary string on which the Fibonacci based position substitution (FBPS) method is applied. A block of n bits is taken as an input stream from a continuous stream of bits. The decimal equivalent value of a source block is obtain and finds its position on the Fibonacci series, on a number or in between two numbers. The source value is mapped on a previous number of the series called target number. For proper one-one mapping a scheme is applied on the target number. This target number is again projected on a previous number and so on until the target number reached in a 0 or 1. Each time of the projection a 0 or 1 is produced. Plain text is encrypted for different block sizes as per the specification of a session key of a session to generate the final encrypted stream. Comparisons of the proposed technique with existing and industrially accepted RSA and triple DES have also been done in terms of frequency distribution and chi-square value. Test of avalanche and bit ratio have also been performed for the proposed technique.