From cubicles in a nondescript office building in the Denver Tech Center, two of the world’s leading cryptocurrency investigators spend their days trying to unmask people selling drugs, computer viruses and guns in the darkest corners of the internet.
Arran McWhirter and Ryder Wells, special agents in the Denver office of Homeland Security Investigations, work to identify the people using the system for illegal trades. The wide variety of contraband spans the dangerous to the absurd: social security numbers, fake passports, cocaine, dinosaur bones, manuals to build weapons, counterfeit cash, murder-for-hire services, fake Christian Louboutin slippers.
“Whatever your imagination is, it’s there,” Wells said.
When the pair aren’t digging in on an investigation, they’re traveling the world training other law enforcement on their techniques. This month, they traveled to Singapore at the invitation of the United Nations Office on Drugs and Crime. They never planned to specialize in tracking the quicksilver transactions of the dark web, but their work has only become more essential as criminal use of cryptocurrencies such as bitcoin have become more common and online markets for illegal products have proliferated.
“They really became the experts on it,” said Special Agent in Charge Steve Cagen, who leads Homeland Security Investigations for Colorado, Montana, Utah and Wyoming. “Our border that we look at is virtual.”
It’s difficult to track the number of cases that involve cryptocurrency because the money system is often a small piece of a larger investigation, Wells and McWhirter said. But the use of cryptocurrency to commit criminal transactions is becoming more common. Last year, the Denver office of Homeland Security Investigations seized $1.1 million worth of 187 types of cryptocurrency. The Department of Justice even created a prosecutor position to focus entirely on crimes involving digital currency.
Cryptocurrencies are entirely digital money systems that do not rely on banks or any third party to create a transaction, allowing people to remain fairly anonymous and avoid fees. Transactions of such currencies are recorded in a technology called blockchain and are encrypted, which is meant to make them more secure. More than 2,500 types of cryptocurrencies, such as bitcoin, are traded publicly and together are worth approximately $246 billion, according to CoinMarketCap.com, a website that tracks the currencies.
The use and exchange of cryptocurrencies is completely legal, unless they’re used to buy contraband or launder the profits of the sale of illegal items. Many of those transactions happen on the dark web, a part of the internet that is accessible only with certain software or passwords. The organization of many dark web sites mimics eBay. Sellers even have star ratings, except those on the dark web are also rated for their stealth.