1 .\" Copyright 2007 Jan Glauber (jan.glauber@de.ibm.com)
3 .TH PRANDOM 4 "Jan 2007" "s390-tools"
6 prandom \- kernel pseudo random number generator device for s390
8 The character special file \fI/dev/prandom\fP provides an interface to the
9 pseudo random number generator. The s390 pseudo random number generator uses
10 the hardware accelerated cryptographic assist functions which are integrated
11 in the CPU. \fI/dev/prandom\fP is available starting with the z9 processor.
13 Reading from \fI/dev/prandom\fP is non-blocking. Any amount of data could
14 be read from the device.
16 The s390 pseudo random number generator provides cryptographically secure
17 pseudo random numbers following the algorithm in ANSI X9.17. Entropy is added
18 periodically to the generator to protect against a compromised key.
22 The \fI/dev/prandom\fP device node is generated by udev while loading the corresponding kernel
23 module or while booting a kernel with the generator built-in. By default
24 \fI/dev/prandom\fP is readable only by root. If it should be readable by every user
25 add the following to /etc/rules.d/50-udev.rules:
28 KERNEL=="prandom", MODE="0444", OPTIONS="last_rule"
35 Linux on zSeries: Device Drivers, Features and Commands