MADISON, Wis. (WMTV) -- Jeremy Ryan used bitcoin and a hidden service website to attempt to purchase radioactive material, according to an affidavit.
In the affidavit, Ryan is reported as having used a "hidden service website" that requires a username and password, and "contains subsections advertising the sale of various illegal products, including drugs, counterfeit goods, and weapons."
He then used bitcoin, and "placed an order for the radioactive substance," according to the affidavit.
But just how easy is it to access the dark web, and to use bitcoin to purchase illegal goods from it?
Purchasing bitcoin itself is fairly easy, said Bob Turner, Chief Information Security Officer at UW Madison.
"Sometimes all you need is a credit card, and you can buy the bitcoin," he said.
Turner said that one of the simplest ways to understand bitcoin is seeing it as a mode of barter. Bitcoin is a cryptocurrency, and the price is set by those who use it in transactions.
"The true value is in the negotiation," he said. "I have this good or service, you have three and a half bitcoins. I'll give you this much of the good or service for those bitcoins. So it's an on the spot transaction."
That ultimately means that the price can easily fluctuate, and could potentially change value from transaction to transaction.
While bitcoin can have a number of legal uses, it can also be used in illegal transactions, like the one Ryan participated in, because it is not as easily traced as traditional exchange routes.
"You also don't have the international regulations on banking and transactions," Turner said. "You can make the transaction and it kind of goes unrecorded because eventually that block in the beginning of the chain in the bitcoin will be meaningless in a bitcoin transaction."
Ryan was able to find radioactive material on a hidden service website, also known as the dark web. But what is the dark web?
"What it means is websites that aren't generally known to the public," said Chief Information Security Officer for the UW System Nicholas Davis. "Websites that aren't easily visible within search engines, websites that aren't assigned to specific domain names, websites that are hidden but people who have credentials or know the addresses of those websites can visit them."
Davis said that the "surface web," or the internet most people use on a daily basis, is much smaller than the dark web.
"The dark web is about four to five times larger than the internet that the rest of us are able to access publicly," Davis said.
He said this makes it more difficult for law enforcement to track down and stop negative websites.
"You've got millions and millions of sites on the dark web, you've got millions and millions of people who are interested in these things," he said. Davis said that when one site gets shut down, it is easy for another to pop up, like a game of "whack-a-mole."
Those sites offer a spectrum of illicit goods and services.
"It's not just limited to the radioactive materials that you're hearing about in the current case," he said. "You can buy weaponry, you can buy illegal drugs, you can even buy human organs if you need a transplant out on the dark web. It's really really a scary, frightening place to be."
Davis said that the best way to stay out of trouble on the internet is to avoid the dark web, and to not go looking for it. He also said accessing those sites could leave your computer vulnerable to viruses.