[Cryptography] Photon beam splitters for "true" random number generation ?

[Ron Garret]

On Dec 27, 2015, at 6:54 AM, ianG <iang at iang.org> wrote:

> The process we developed at CAcert was:
> 
> 1.  Everyone brings their favourite RNG on their laptop.  I used laptop photos of a white card in lowlight, similar to above, and hashed every photo.  One person used John Denker's audio device.  Another used the OpenSSL RNG ;-)
> 
> 2.  Each feed was then transferred on USB stick to a single offline computer.
> 
> 3.  All feeds were then combined (XOR'd together and hashed) by a 1 page C program.  Result was fed into the key generation process.

Concatenation would be more secure than XOR.  XOR can actually lose entropy if two of your sources are correlated.  Concatenation (followed by a hash) doesn’t have that problem.

rg