The sys admin’s daily grind: haveged Random Release

Random Release

Article from Issue 131/2011
Author(s):

Practical cryptography is often an encounter with many random numbers in just a few moments. Entropy is the raw material that gives birth to the random number, but it’s harder to come by than you might think.

Creating havoc with a computer is an easy thing to do, but today, I need a more ordered kind of chaos: entropy. I need to generate high-quality random numbers with minimal predictability. Anybody who plumbs the depths of cryptographic functions will need a good and fast entropy generator at some time, say, to make sure that keys really are generated from genuinely random data, rather than predictable numbers.

You need to be creative to achieve high-quality entropy. Creative people have invented methods for generating random numbers from the bubbles in a lava lamp, the noise generated by feedback from a microphone input, and the luminance values of a camera sensor in a closed black box. All of these work really well, but they’re slow.

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

SINGLE ISSUES
 
SUBSCRIPTIONS
 
TABLET & SMARTPHONE APPS
Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • Charly’s Column: OpenNetAdmin

    Last month, the Havege daemon helped organize the chaos in this column. Today, Charly attempts to organize the network – a tale of suffering in three chapters.

  • Deleting Data

    Backups are a common topic, but you’ll hardly hear anyone mention safe data deletion.

  • Kernel News

    This month we discuss replacing the random number generator, checking when a process dumps core, fixing filesystem security issues, and adding build dependencies to clean the source tree.

  • Rasp Pi Generates Weak SSH Keys

    The Pi's popular Raspbian OS pursues secrecy without entropy.

  • Kernel News

    This month in Kernel News: Opening a Random Can of Worms and Out with the Old.

comments powered by Disqus
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters

Support Our Work

Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

Learn More

News