Random 1 to 1 webcam
From the cryptographic side, I wouldn't use MD5 for this, but a newer hash function like one of the SHA-2 family.While the broken collision resistance of MD5 is not a problem here, other then when your adversary can plug in its own device and feed arbitrary bits instead of the images, it is just bad for your reputation to use MD5 for anything security-relevant. commented, there is still missing quite some analysis (how much entropy do we actually get from the differences?Computers are deterministic, in that if you repeat the same experience under the same environment, the same result will be achieved.What you get with computers are pseudo-random numbers, mostly depending on current circumstances: date, time, other variables like memory being used, network traffic at the moment, etc.
As a matter of fact, most hardware random number generators are designed to feed /dev/random, through the kernel (or the Windows equivalent), to deal with this bias/entropy issue.
I don't want to know about PRNGs that are good enough for practical applications. Of course, generating true random numbers will require hardware devices.
That's why I tagged this with The random number generator gathers environmental noise from device drivers and other sources into an entropy pool. Written in Perl and hence portable across many platforms.
I have read from a real random number generator, based on a webcam ("randcam").
My problem is, that I do not really understand how the generation of the random numbers works.