A blind source separation based cryptography scheme for mobile military communication applications

Security in digital transmission is an increasingly interesting topic in a number of fields. In many cases however, the need for security is forfeited due to the high complexity of commonly used cryptosystems. The use of the underdetermined source separation problem as a basis for a cryptographic mechanism has recently been proposed. Many cryptographic algorithms, such as public key algorithms which based a common military application, use as a basis intractable number theory problems (such as integer factorization and exponentiation). Underdetermined blind source separation is also shown to have the potential to serve this purpose, as the difficulties of deriving an analytic solution to this problem have been extensively documented. This paper presents a study of blind source separation based encryption, proposes some further improvements in approaches that have already been presented and illustrates the application of the improved algorithms in the paradigm of secure speech communication. The proposed scheme is related to Independent Component Analysis Concepts. A preliminary cryptanalysis study is presented that verifies the adequacy of the new scheme for use in mobile military communication units and other applications where security is critical. The proposed scheme is also shown to be immune to some of the attacks to which existing methods were believed to be vulnerable.