Two Level Security Implementation for Voice Data Transmission

This paper addresses two security challenges faced by many while transmitting confidential voice message. First, how to protect confidential message content against unauthorized access and second, how to protect information about the speakers personality. Presented work provides solution to these issues using hybrid approach. The former issue is handled by speech watermarking while speaker normalization deals with latter. The method initially normalizes speech signal containing secret information by modifying the speaker voice acoustic characteristics which is further processed to incorporate additional security measure and then it is embedded in high frequency components of the host signal using the human auditory system (HAS) properties and concept of blind, invisible watermarking approach. Reverse practice is followed to get the intended confidential message. This scheme has been evaluated and results of test shows that the approach does not degrade the quality of host signal and ensures reasonably excellent security. Technique can be used in any domain where secure transmission of the information is important.