| From: William Muriithi <william.muriithi@gmail.com> [Your MUA seems to muck up linebreaks in quoting. It also converted some of what I typed to non-ASCII. I've tried to fix that.] | >Adversaries can easily break your cryptosystem if | >you don't have sufficient entropy. It's that bad. | | >What sources do you use? /dev/random and | >/dev/urandom are the Linux | >channel for entropy. There are various sources | >that can be pooled by the kernel: | | | /dev/urandom does not generate entropy I think. It depends on | /dev/random. The firmer just stretch the later entropy. Neither generates entropy. That's why I described them as channels. I tried to be fairly careful in what I said. You are right that /dev/random only yields as many bytes as the kernel estimates there are bytes of entropy in the pool and that /dev/urandom will give as many bytes as you ask for, even if the entropy estimate says that there is none remaining. Entropy is a tricky topic. Maybe this talk next Monday will be enlightening: <http://www.fields.utoronto.ca/programs/scientific/fieldsmedalsym/14-15/Images/fms_po_final.pdf> I'm thinking of going. | The problem is more acute with servers though unfortunately as most run | on virtualized environment these day and since there is no console, they | gave little entropy during start up. Good point: virtual servers are even worse off than real servers.