How RANDOM.ORG's Journey From Radio Static to True Randomness Generates Reliable Results for Games, Security, and Clinical Trials

RANDOM.ORG: Radios to Generating Truly Random & Reliable Numbers

TL; DR: In the early days of the web, Mads Haahr and his friends knew online gambling would take off — they were just a decade too early. Although their startup never got off the ground, an improved method to generating true random numbers emerged and still thrives today. RANDOM.ORG uses atmospheric noise to generate numbers for lottery drawings, games, security, as well as art and music. Mads prides himself on rigorous statistical standards and shared with us how the popular service grew from a $10 radio to more than 1.38 trillion randomly generated bits.

Fresh off a master’s degree in computer science, Mads Haahr and three friends set out to build an online gambling engine. It was 1997, and they thought online games were going to be a big deal.

Mads’s job was to build a better random number generator than what currently existed — with real money at stake, the gaming results had to be truly random.

Instead of relying on algorithms, which didn’t generate the quality of randomness needed, Mads wanted to use atmospheric noise to gather statistically random numbers. To gather atmospheric noise — essentially the radio static caused by lightning — Mads and his friends went to a nearby Radio Shack to buy the cheapest radio they could find.

“We got the guy in the store to take it out of the box and put batteries in so we could see that it didn’t have a noise filter,” Mads said of the $10 radio. “We got really excited when we heard the noise and started geekily jumping up and down. He must have thought we were off our rockers.”

Mads wrote software to process the noise into a stream of bits that would translate into the random numbers that would determine how dice would roll or cards would shuffle. Alas, nothing came of the online gambling business.

“We were much too early,” Mads said. “It took about 10 years longer than we expected for online gambling to take off.”

The random number generator survived, however. Mads was so excited about randomness he bought a domain name and put his generator online for anyone to use.

Now, RANDOM.ORG has created 1.38 trillion bits and has evolved from a hobby into a business — providing true random numbers for everything from lottery drawings and games to art and baseball card trading.

More Complex Than You Think: Methods and Importance of Randomness

Only one other true random number generator existed when RANDOM.ORG came about. Instead of algorithms or atmospheric noise, they used radioactive decay and Geiger counters.

“It’s very good-quality noise, but it’s hard to get radioactive decay to happen quickly,” Mads said. “It’s hard to generate many random numbers per second with that approach.”

Algorithms vs. Atmospheric Noise: Getting True Randomness

When Mads was creating the RANDOM.ORG engine, most random number generators relied on algorithms that would fail statistical tests and produce deterministic, pseudo-random results — if you have the same algorithms and styling parameters, you eventually get the same numbers.

While not random in quite the way people often expect, algorithm-driven random number generators are very useful and much faster than generators producing true randomness, according to Mads. “It’s math, which computers are excellent at,” he said.

Mads posing with the original radio

Mads with the original radio that powered RANDOM.ORG from 1998 to 2001.

Pseudo-random numbers are perfectly suitable for lighthearted games or entertainment, along with modeling and simulations, according to Mads. True randomness, however, becomes important when money or people’s livelihoods are at stake.

For that, true random number generators extract randomness from physical phenomena, such as lightning or radioactive decay, and feed it into a computer. A computer hardware company once made a number generator using pictures of lava lamps, while another company supplements their random bits with the rate of page views coming to their own server.

Public Perception vs. Reality: Finding the Right Balance of Patterns

Mads and his team routinely test their generators to ensure pure randomness. They even expect to fail some of the time.

“If you have a proper random number generator, it will fail statistical tests every once in a while because it will generate sequences of numbers that don’t look random,” he said. “If your random number generator is excellent, it will generate all combinations of numbers with equal probability.”

After all, a string of consecutive numbers is just as likely as any other combination. If you flip a coin 100 times, Mads said you’ll be surprised by how many streaks of heads or tails you’ll see.

“People are expecting fewer patterns in randomness than there actually are,” he said. “Our brains are so great at finding patterns. We find patterns anywhere, even if they appear randomly and don’t mean anything.”

How Atmospheric Noise Powers RANDOM.ORG and Turns Into Numbers

From the original $10 radio, Mads graduated to a free radio with a broken cassette tape player for the first few years of RANDOM.ORG. He slowly upgraded and added radios, computers, and hard drives. The radios, located in different countries, are tuned between stations to pick up the atmospheric noise. The computer collects the data and distills it into bits, or single binary values — either zeros or ones.

Graphs showing RANDOM.ORG source purity

RANDOM.ORG gathers data from Copenhagen, Dublin, and Ballsbridge with typically greater than 99% purity.

Because physical sources of randomness may bias toward zeros instead of ones, the data goes through a skew correction algorithm to ensure source purity. RANDOM.ORG includes statistics that show the reliability of their raw data.

“It shows how good-quality randomness comes out of each of the raw sources of noise we have,” Mads said. “It’s pretty close to 100%.”

This process produces a long stream of zeros and ones in roughly equal measure. All RANDOM.ORG generators hook into the stream to gather the bits that determine the random number or result given to users. For example, producing a random number between one and eight requires three bits. The random number depends on the quantity and order of zeros and ones returned from the bit stream.

“The coin flip is probably the simplest one to understand because there are only two outcomes,” Mads said. “That’s one bit. A zero might be heads, and a one could be tails.”

More Than Coin Flips: Uses for Randomness Include Music and Medicine

From setting fantasy football draft orders to deciding where to go for dinner, RANDOM.ORG appeals to a wide range of users and applications:

  • Employee drug testing
  • Clinical trials
  • Trading baseball cards
  • Calling on students
  • Random sampling for audits
  • Generating passwords
  • Composing music
  • Painting
  • Knitting patterns
  • Learning French

While RANDOM.ORG analytics will show which services are the most popular, Mads relies on feedback to learn how RANDOM.ORG is being used. Many of the notes are published on the site as testimonials.

“I really rely on people who email me and tell me their stories,” he said. “I try to be responsive and add new features they request. That makes people happy and makes the services more useful.”

RANDOM.ORG became more than a fun side project or public service when a company contacted Mads in 2007 asking for a service that would help them randomly select drawing winners.

“They wanted something that would create records of everything so they could show auditors that winners were selected properly, in an unbiased fashion, and without tampering,” Mads said. “Gradually, other people started using it and were willing to pay some money for it.”

Similar gambling and lottery programs are major users of RANDOM.ORG, but Mads has also heard of businesses using the services to randomly select employees for drug testing.

“Randomness really matters when there’s a lot at stake,” he said. “The intention from the very beginning with us was that we needed absolute, top-notch randomness.”

Tuned for the Future: RANDOM.ORG Focuses on New Website

The original $10 radio is long gone, but Mads still has the free, broken cassette player radio in his kitchen in Dublin.

“Today, we’re using some much better sources for our atmospheric noise,” he said with a laugh.

As the technology behind RANDOM.ORG improves, so do the services and platforms. The current undertaking is updating the core website, which looks “like the web used to look maybe 10 years ago,” Mads said. “We’re working on new features all the time, probably every single day. It’s not something that’s just sitting there. We’re actively developing it.”

Laura Stamey

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