>How could I check my environment noise is enough? $ cat /proc/sys/kernel/random/entropy_avail will give you current available entropy on the system. This number drops when you read from any of these devices(random/urandom).
Please refer : http://vinitsworld.blogspot.com/2008/10/difference-between-devrandom-and.html -Vinit On Fri, Aug 28, 2009 at 1:17 PM, loody <[email protected]> wrote: > Hi: > > 2009/8/28 Martin Møller Skarbiniks Pedersen <[email protected]>: > > 2009/8/28 loody <[email protected]>: > >> Dear all: > >> I made linux running on Mips machine. > >> Right now I found the /dev/random doesn't work properly, since I use > >> "dd if=/dev/random of=/tmp/random.txt", it stops working. > >> If I use "cat /dev/random", it will not pop out anything. > >> > > > > You can't except to read a lot of data from a /dev/random file > > From the man-page: > > > > " > > When read, the /dev/random device will only return random bytes > > within the estimated number of bits of noise in the entropy pool. > > /dev/random should be suitable for uses that need very high quality > > randomness such as one-time pad or key generation. > > When the entropy pool is empty, reads from /dev/random will block > > until additional environmental noise is gathered. > > " > > > > Use /dev/urandom instead. > thanks for your kind help :) > after reading your suggestion, I guess maybe the problem comes my > environment noise. > Since the document says the /dev/random use environment noise to > generate random number. > How could I check my environment noise is enough? > appreciate your help, > miloody > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [email protected] > Please read the FAQ at http://kernelnewbies.org/FAQ > >
