Date: Mon, 30 Oct 1995 21:59:14 -0500 From: "Josh M. Osborne" <stripes@va.pubnix.com> When /dev/random doesn't have "enough" enthropy left does reading from it return an error, or block? I would strongly suggest blocking, as the non-blocking behavur is not really all that useful. It acts like many character devices and named pipes in that if there is no entropy available at all, it blocks. If there is some entropy available, but not enough, it returns what is available. (A subsequent read will then block, since no entropy will then be available.) Actually, what's currently in Linux doesn't work precisely like this, but it will soon. After talking a number of people on both sides of the block vs. non-blocking camp, this seemed to be a suitable compromise. At least one Major Workstation Vendor is planning on using this behavior for their /dev/random, to appear in a future OS release. If we all can standardize on this behavior, it'll make application writer's jobs that much easier. - Ted