Abstract: Steganography relies on hiding covert message in unsuspected multimedia data and is generally used in secret communication between acknowledged parties. Steganography works by replacing bits of useless or unused data in regular computer files (such as graphics, sound, text, HTML, or even floppy disks) with bits of different, invisible information. This hidden information can be plain text, cipher text, or even images. Audio steganography is a young branch of this discipline. An encoding mechanism is used for embedding the message into the audio file. In this paper we used the 4th Bit LSB method to do it. The quality of the audio file after encoding remains unaffected. A public key cryptographic algorithm, RSA is also used to ensure greater security

Keywords: Steganography, Audio Data Hiding, LSB Algorithm, Cryptography, RSA, EASS.