[Cryptography] Generate Random Data From Sound Card

[Patrick Chkoreff]

On 3/6/26 11:38 PM, Kent Borg wrote:

> Ted's code is quite happy to have you feed in additional entropy 
> sources. Write new data into /dev/urandom.

Glad you brought that up.  I had long suspected that I could seed the 
core /dev/random itself with something like:

$ echo cf684beeebbe >/dev/random

I searched around yesterday for confirmation and I saw a mention that 
one must be "authorized", so I assumed they meant use sudo:

$ sudo echo cf684beeebbe >/dev/random

I don't think it makes sense to have to be superuser, so I doubt that's 
necessary.


You bring up an interesting point about seeding /dev/urandom instead of 
/dev/random.  I think that makes sense because the effect on 
/dev/urandom would be more direct and immediate.  Directly seeding 
/dev/random might take a while to percolate into /dev/urandom, which is 
what we actually use.


-- Patrick