Five Level Cryptography in Speech Processing using Multi Hash and Repositioning of Speech Elements

This paper proposes a cryptography technique for audio to increases the security of audio data meant to be transferred on an insecure medium. The audio is recorded in real time using microphone which is applied with five level of encryption which creates a cipher signal which is routed through an insecure line for the recipient who on receiving that signal decrypts the cipher signal in order to retrieve the signal back. The signal achieved in the proposed technique after decryption at the recipient end is a replica of the original signal which was meant for encryption. This cryptography process can take place for varied duration of audio data which can be recorded in real time system. The encrypted signal when played consists of hisses and clicking noise which holds no meaning to the third party who has intercepted that signal. Here encryption and decryption is applied in a sequential manner on the audio file. This technique is reliable in regenerate the audio data, which was previously encrypted by the sender. The proposed technique hides the audio data such that even if one level of encryption is broken the rest of the levels will still be there to prevent the actual audio data getting discovered by a third party. In the proposed technique two processes take place -encryption and decryption. This proposed technique is capable to regenerate the audio which is encrypted. It guarantees a highly accurate communication between the sender and receiver. Keywords— Cipher text, Cryptography, Decryption, Encryption, Key tables, Plain text, Speech processing.