  In this paper, a multilayer perceptron guided key generation for
encryption/decryption (MLPKG) has been proposed through recursive replacement
using mutated character code generation for wireless communication of
data/information. Multilayer perceptron transmitting systems at both ends
accept an identical input vector, generate an output bit and the network are
trained based on the output bit which is used to form a protected variable
length secret-key. For each session, different hidden layer of multilayer
neural network is selected randomly and weights or hidden units of this
selected hidden layer help to form a secret session key. The plain text is
encrypted using mutated character code table. Intermediate cipher text is yet
again encrypted through recursive replacement technique to from next
intermediate encrypted text which is again encrypted to form the final cipher
text through chaining, cascaded xoring of multilayer perceptron generated
session key. If size of the final block of intermediate cipher text is less
than the size of the key then this block is kept unaltered. Receiver will use
identical multilayer perceptron generated session key for performing
deciphering process for getting the recursive replacement encrypted cipher text
and then mutated character code table is used for decoding. Parametric tests
have been done and results are compared in terms of Chi-Square test, response
time in transmission with some existing classical techniques, which shows
comparable results for the proposed technique.
