Date Added: Jan 2012
Signals are any time varying quantity having lot of Information and have its own frequency. Signal can be classified into random signal, periodic signals, and non-periodic signals, discrete or digital signal. Signal may contain various data like audio, video, or in text format. Signal also has information like images. But question arises of security of signal. So, Signals can be making secure by using the different Security techniques such as encryption and decryption by using RSA algorithm, Stegnography, Digital watermarking techniques.