Simple Secrecy: Analog Stream Cipher for Secure Voice Communication
John M. Campbell · Digital Commons (Liberty University) · 2015
Voice signals are inherently analog, and some voice communication systems still utilize analog signals. Existing analog cryptographic methods do not satisfactorily provide cryptosecurity for communication systems due to several limitations. This paper proposes a novel means of provided cryptosecurity for analog signals without digitization; thereby avoiding the latency which results from ADC/DAC conversions. This method utilizes the principles of the digital stream cipher, generating instead a continuous pseudorandom analog key stream signal which is transformed with the original analog signal to create an encrypted ciphertext signal which is statistically independent of the original signal and the key stream signal. The transform is then inverted with the ciphertext signal and the same key stream signal to recover the original signal. The performance and characteristics of such a system has been measured and demonstrated through modeling and simulation.