Music cryptography based on carnatic music

Abstract

Music and cryptography have been linked to one another since ancient times. The idea of replacing plaintext letters with music notes and sending the music file to receiver, is not new. But such replacements sometimes result in music clips which are not pleasant to listeners and thereby leading to the music clip gaining unnecessary extra attention. Most of the works done in this area, fail to ensure the generation of a music clip that invariably conforms to any particular form of music. Melody of the music clip is neglected. In order to address this issue, current paper proposes a novel approach for sharing a secret message based on concepts of Carnatic Classical Music. The method proposed here aims at converting a message in textual format to a music clip before sending it to the receiver. Receiver can then decrypt that message using the knowledge of range of frequency values associated with each musical note also called as 'swara' in Carnatic Classical Music. Each plaintext character from English alphabet is replaced by different combinations of swaras. The set of swaras mapped to each plaintext character is so chosen that the final music file produced as the output of encryption always conforms to a melodic form ('Raga') governed by the framework of Carnatic Classical Music. Ten subject matter experts in the field of Carnatic music have given their opinion about the conformance of these music clips to specified ragas. Also, Mean Opinion Score (MOS) of 25 listeners has been tabulated to test and verify the melodic aspect of these music clips. BEIESP.