Editing Premium Bonds (section)

==ERNIE==<!-- This section is linked from [[ERNIE]] -->
[[File:ERNIE1 2012.JPG|thumb|ERNIE 1 on display at the [[Science Museum, London]], 2012|alt=]]
ERNIE - an acronym for "Electronic Random Number Indicator Equipment" - is the name for a series of [[hardware random number generator|hardware random number generators]] developed for this application. There have been five models of ERNIE to date. All of them have generated [[Hardware random number generator|true random numbers]] derived from random [[Fluctuation theorem|statistical fluctuations]] in a variety of physical processes. 

The first ERNIE was built at the [[Post Office Research Station]] by a team led by Sidney Broadhurst. The designers were [[Tommy Flowers]]<ref>{{cite news|url=https://www.bbc.co.uk/insideout/northwest/series6/premium_bonds.shtml |title=BBC Inside Out – Premium Bonds |publisher=BBC |access-date=14 January 2010}}</ref> and [[Harry Fensom]] and it derives from [[Colossus computer|Colossus]], one of the world's first digital computers.<ref>{{cite book|url=https://books.google.com/books?id=NNgzd0xujzsC&q=ernie&pg=PR13 |title=Colossus: the secrets of Bletchley ... – Google Books |date= 23 February 2006|publisher=OUP Oxford |access-date=14 January 2010|isbn=9780192840554 }}</ref><ref name="First ERNIE">{{Cite web|title = First ERNIE computer picked for Science Museum|url = https://www.theguardian.com/technology/blog/2008/jun/13/firsterniecomputerpickedfo|website = The Guardian|access-date = 27 July 2015|first = Jack|last = Schofield|date = 13 June 2008}}</ref> It was introduced in 1957,<ref name="nsandi" /> with the first draw on 1 June, and generated bond numbers from the [[signal noise]] created by [[Gas-filled tube|neon gas discharge tubes]]. ERNIE 1 is in the collections of the [[Science Museum, London|Science Museum]] in London and was on display between 2008 and 2015.<ref name="First ERNIE" />

ERNIE 2 replaced the first ERNIE in 1972.<ref name="nsandi" />

ERNIE 3 in 1988 was the size of a personal computer;<ref name="nsandi" /> at the end of its life it took five and a half hours to complete its monthly draw.

In August 2004, ERNIE 4 was brought into service in anticipation of an increase in prizes each month from September 2004.<ref name="nsandi" /> Developed by [[LogicaCMG]], it was 500 times faster than the original and generated a million numbers an hour; these were checked against a list of valid bonds. By comparison, the original ERNIE generated 2,000 numbers an hour and was the size of a van.<ref name="nsandi" />

ERNIE 4 used [[Johnson–Nyquist noise|thermal noise]] in transistors as its source of randomness to generate true random numbers. ERNIE's output was independently tested each month by the [[Government Actuary's Department]], the draw being valid only if it was certified to be statistically consistent with randomness. At the end of its life it was moved to Bletchley Park's [[The National Museum of Computing|National Museum of Computing]].

ERNIE 5, the latest model, was brought into service in March 2019, and is a [[quantum random number generator]] built by [[ID Quantique]]. It uses quantum technology to produce random numbers through light, replacing the former 'thermal noise' method. Running at speeds 21,000 times faster than the first ERNIE, it can produce 3 million winners in just 12 minutes each month.<ref name="2019-03-01-guardian">{{cite news |last1=Collinson |first1=Patrick |title=Premium bond Ernie takes quantum leap into fifth generation |url=https://www.theguardian.com/money/2019/mar/01/premium-bond-ernie-takes-quantum-leap-into-fifth-generation |access-date=1 March 2019 |work=The Guardian|date=1 March 2019}}</ref>

===In popular culture===
ERNIE, anthropomorphised in early advertising, receives [[Valentine's Day|Valentine]] cards, Christmas cards and letters from the public.<ref name="nsandi" /> It is the subject of the song "E.R.N.I.E." by [[Madness (band)|Madness]], from the 1980 album [[Absolutely (Madness album)|''Absolutely'']]. It is also referenced by [[Jethro Tull (band)|Jethro Tull]] in their album ''[[Thick as a Brick]]''.