资 源 简 介
snd-egd has moved to GitHub.
snd-egd can convert analog sound signals into a source of entropy for the Linux kernel random number device. The quality of entropy generated is dependent on the input signal. White noise from radio signals between broadcast radio stations (atmospheric noise) would be ideal, but just a simple disconnected microphone or line input connector on a sound card with sufficiently high gain will generate thermal noise.
The input data is not merely fed into the KRNG without any transformations; whitening of the input data is first performed. The whitening method is simple
and relatively fast.
A configurable number of frames is sampled from both the left and right input channels. The stream of input frames is transformed into the absolute value of its derivative. This process effectively discards one frame.
Each bit from the frame is treated as a unique bitst
