The winners of the premium bonds prize draw have been announced for March - and new technology meant the draw took just minutes, instead of nine hours.
Two bondholders from Somerset and Buckinghamshire have won the million-pound jackpot, while millions of lower-value prizes were also awarded.
This prize draw marks a first for an updated version of therandom number generator - known as ERNIE 5 - which has dramatically sped up the process.
Find out who won the major prizes in March, and how the new ERNIE works.
The first overnight millionaire created by ERNIE 5 is a man in Somerset, who holds the winning bond number256SE420168. He holds £50,000 of premium bonds and has held the winning bond since September 2015.
The second £1m prize has gone to a woman in Buckinghamshire, with bond number272TH828201. This lucky winner holds a total of £33,116 in premium bonds and bought the winning bond in May 2016.
While the two jackpots tend to grab the most attention, there were over 3.2m other prizes handed out in March.
A total of five winners took home £100,000 each, while a further 11 were handed £50,000.
You can see the full list of high-value prize winners in the table below.
During the monthly prize draw, every bond number has an equal chance of being selected from the total pool of more than 79bnbonds.
To make the draw truly random - avoiding any type of bias, patterns or predictability - the NS&I uses a random-number generator, known colloquially as ERNIE.
This month, a new evolution of ERNIE was introduced, the fifth since the prize draw debuted in 1956.
ERNIE 5 is able to generate the winning numbers in just a few minutes - down from the nine hours it took ERNIE 4 last month.
For the launch of premium bonds in 1956, the very first ERNIE was built by a former Bletchley Park code-breaker. This machine took 10 days to complete the draw.
The timeframe fell to 5.5 hours with new versions of ERNIE, but increased again when the number of premium bonds on the market exploded in the early 2000s.
The new ERNIE is expected to draw 8.5m numbers in just 12 minutes, revolutionising the process.
You can see the full history of ERNIE below.
|Version||Dates active||Prizes per draw||Time taken to complete final draw||Numbers per hour|
|ERNIE 1||Jun 1957 - Jan 1973||23,142||10 days||2,000|
|ERNIE 2||Feb 1973 - Aug 1988||90,338||5.5 hours||65,000|
|ERNIE 3||Sep 1988 - Mar 2004||191,639||5.5 hours||330,000|
|ERNIE 4||Apr 2004 - Feb 2019||3,223,731||9 hours||1,000,000|
|ERNIE 5||Mar 2019||3,252,781||12 minutes||Not confirmed|
ERNIE is not a computer and doesn't rely on algorithms, which could be tampered with or predicted. It also isn't connected to any type of network, so cannot be hacked.
Instead, it chooses numbers in reference to an unpredictable external factor. Once ERNIE produces a list of numbers, these are then matched against all bond numbers to identify winners.
You might think you detect a pattern in the bond numbers - for example, that specific numbers win more often or that winners are all from the same region - but this is purely coincidence. Every bond is just as likely to win as every other.
Each month, the randomness of the draw is checked by the Government Actuarial Department (GAD), which operates independently from the NS&I.
Of course, the more bonds you hold, the more likely you are to win a prize in any given draw, though there are no guarantees of winning anything at all. So while holding £1,000-worth of bonds gives you a 5% probability of winning any prize over 12 months, holding £10,000-worth ups your probability to 99.99% - though the prize may be as modest as £25.
The NS&I estimates that a person of average luck could have a 1.4% return over the year, though some will see much greater rewards and others nothing at all.