Editing Lavarand

[[File:Lava lamp wall at Cloudflare office -2.jpg|thumb|A wall of lava lamps at the offices of [[Cloudflare]]]]
{{Short description|Random number generator based on lava lamp motion}}
'''Lavarand''', also known as the '''Wall of Entropy''', is a [[hardware random number generator]] designed by [[Silicon Graphics]] that worked by taking pictures of the patterns made by the floating material in [[lava lamp]]s, extracting random data from the pictures allegedly using the result to seed a [[pseudorandom number generator]].<ref>{{cite news | url = https://www.wired.com/wired/archive/11.08/random.html | work = Wired Magazine | title = Totally Random | volume = 11 | issue = 8 | date = August 2003}}</ref>

==Details==
Although the secondary part of the random number generation uses a pseudorandom number generator, the full process essentially qualifies as a "true" random number generator due to the random seed that is used.  However, its applicability is limited by its low bandwidth.

It was covered under the now-expired {{US patent|5732138}}, titled "Method for seeding a pseudo-random number generator with a cryptographic hash of a digitization of a [[Chaos theory|chaotic]] system." by Landon Curt Noll, Robert G. Mende, and Sanjeev Sisodiya.

From 1997 to 2001,<ref>{{cite web
 |url=http://lavarand.sgi.com/ 
 |title=Welcome to Lavarand!
 |accessdate=2010-01-05 
 |url-status=dead 
 |archiveurl=https://web.archive.org/web/19971210213248/http://lavarand.sgi.com/ 
 |archivedate=1997-12-10
}}</ref>
there was a website at lavarand.sgi.com demonstrating the technique. [[Landon Curt Noll]], one of the process's originators, went on to help develop LavaRnd, which does not use lava lamps.<ref>{{cite web|url=http://www.lavarnd.org:80/|title=LavaRnd|archiveurl=https://web.archive.org/web/20040514190302/http://www.lavarnd.org/|archivedate=2004-05-14|url-status=dead}}</ref>  Despite the short life of lavarand.sgi.com, it is often cited as an example of an online random number source.<ref>{{US patent|6889236}}</ref><ref>{{US patent|7,031,991}}</ref><!-- European Patent EP1490752, I think --><!-- other hits on scholar.google.com -->

{{As of|2017}}, [[Cloudflare]] maintains a similar system of lava lamps for securing [[Internet]] traffic, which it also calls the "Wall of Entropy".<ref>{{Cite web |last=Schwab |first=Katharine |date=2017-08-18 |title=The Hardest Working Office Design In America Encrypts Your Data–With Lava Lamps |url=https://www.fastcompany.com/90137157/the-hardest-working-office-design-in-america-encrypts-your-data-with-lava-lamps |access-date=2022-04-16 |website=Fast Company |language=en-US}}</ref>

==References==
{{reflist}}

==External links==
*[https://lavarand.org/ A reincarnation of the original website with source code.]
*[https://web.archive.org/web/20010926221159/http://lavarand.sgi.com/ Archived version of original Lavarand.com from Archive.org] (pictures do not work)
*[https://blog.cloudflare.com/randomness-101-lavarand-in-production/ Cloudflare Blog post - Randomness 101: LavaRand in Production]
*[https://blog.cloudflare.com/lavarand-in-production-the-nitty-gritty-technical-details/ Cloudflare Blog post - LavaRand in Production: The Nitty-Gritty Technical Details]

[[Category:Silicon Graphics]]
[[Category:Random number generation]]