/dev/random: providing random numbers
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Purpose
The /dev/random file provides random data from the Linux kernel random number generator. Typically /dev/urandom is the preferred source for random data.
This file on Linux is a filesystem interface to an operating system device driver of type character.
File permissions
The file permissions of the /dev/random file are usually 666 (rw-rw-rw-), meaning user, group, and others can read and write.
Notes
Usually /dev/random is created during the boot cycle using the mknod command. The random numbers provided are generated from an entropy pool that is filled using noise such as from device drivers. The underlying random functions also track the number of bits in the entropy pool, and may give a warning if it is not sufficient.
More information and usage of /dev/random
The following articles have a reference to /dev/random and might be worth reading to learn more.
