Arkansas deputies mine bitcoins for work

Benton County hopes online currency will help fight crime

Detectives Olin Rankin (left) and Keith Eoff work out of their office in the cybercrime division Friday at the Benton County sheriff’s office in Bentonville. The office hopes mining for Bitcoins will help detectives catch criminals on the dark web.
Detectives Olin Rankin (left) and Keith Eoff work out of their office in the cybercrime division Friday at the Benton County sheriff’s office in Bentonville. The office hopes mining for Bitcoins will help detectives catch criminals on the dark web.

BENTONVILLE — The Benton County sheriff’s office hopes a pilot program in its Cyber Crimes Division will further combat child pornography, child predators and other crimes online.

The pilot program involves acquiring a digital currency, or cryptocurrency, called bitcoin. The currency was created in 2009, and its popularity grew as an alternative to money kept by central banks.

The division intends to use bitcoins for undercover operations in various capacities online, detective Olin Rankin said.

Benton County Sheriff Shawn Holloway said the currency is another tool to keep the community safe. The sexual exploitation of children online and similar crimes are growing concerns in the area, he said at a conference Oct. 17.

As with any new idea, experience most likely will lead to refinement in how the program is run, said Nathan Smith, Benton County prosecuting attorney. He was consulted to see if the program could create cases that his office can prosecute.

“The sheriff’s office deserves credit for creating a pilot program with the goal of depriving criminals of that safe haven,” Smith said. “Ultimately, attacking crime online has a direct impact on the safety of our communities, and I am grateful that our law enforcement officers are being proactive in that effort.”

Many illegal transactions occur in a level of the Internet known as the Deep Web, which is content not indexed by traditional search engines. Examples include commercial databases, password-protected sites and internal networks used by corporations and universities, according to a Congressional Research Service report published in March.

Although the Deep Web is not indexed, it is still accessible through standard Web browsers. The Dark Web, however, has been intentionally concealed and is only accessible through software such as Tor that protects users’ anonymity. The Dark Web may be accessed both for legitimate purposes or to hide criminal activities, according to the report.

Tor estimates that about 1.5 percent of its users visit Dark Web pages, according to the Congressional Research Service report.

Law enforcement’s methods must change as criminals’ methods change, Holloway and cybercrime deputies said. They are going into the Dark Web to start “patrolling the neighborhoods as well as the main highways,” Rankin said as an analogy.

It’s an old-school tactic being used in a relatively new way, the cybercrime detectives explained. These tactics have been used by the U.S. federal government and a few police agencies.

The bitcoin system is peer-to-peer, without an intermediary like a bank. The deputies are earning bitcoins through a process called mining. Miners verify the transactions by running a complex algorithm and are rewarded with a fraction of a bitcoin.

The detectives said they decided to mine bitcoins instead of buying them because it’s cheaper and because they know the money hasn’t been used for illegal purposes. The process will create a slow, daily stream of cryptocurrency that will look less suspicious to other users.

“If you buy $10,000 of bit-coin, someone may see that,” said Zach Steelman, a University of Arkansas, Fayetteville, assistant professor of information systems. “That might not be the same process a criminal would do. Mining the bitcoin is a better way to enter that market without throwing up red flags.”

Rankin said their choice to mine had nothing to do with avoiding suspicion online. He said the average user won’t be able to track where the bitcoins came from.

The cryptocurrency the division accumulates is being put into a hardware wallet, which is like a bank account. They are not trying to accumulate a large sum and have not spent any of the small amount accumulated so far, said Detective David Undiano, a cybercrime detective.

The pilot program began in late April and is in the validation process, Undiano said. The division is working hand-in-hand with the federal government and others on cases that expand outside its jurisdiction and to form a written policy for their use of cryptocurrency, Undiano said.

Rankin said everyone working on the project has directives to follow, and the bitcoin mining process can be easily audited and tracked.


Bitcoins have grown to be a wildly popular payment method for cybercriminals in part because of their perceived anonymity. Europol, the law enforcement agency of the European Union, reported in 2015 that more than 40 percent of online transactions for illegal uses are made with bitcoins.

“People are selling child pornography on the Dark Web and on the Internet. They are accepting bitcoins, not payments,” Undiano said, referring to deals made with U.S. currency.

Bitcoin is one of more than 1,000 cryptocurrencies but is by far the most popular and is at its highest valuation ever, Steelman said. Microsoft and accept bitcoins directly, and eGifter lets users buy gift cards to Amazon and other retailers with bitcoins.

A Bitcoin was worth about $6,187 as of Sunday afternoon — more than 20 times the value of the second-highest cryptocurrency on the market, according to

The website says the daily trading volume in bitcoins is running at about $1.8 billion.

“That’s not $1.8 billion of child pornography and drugs,” Steelman said. “Lots of these are companies that send money across borders or selling assets that are real things. People are buying houses now with bit-coin they invested in five years ago.”

Steelman and others in his department are working to incorporate Blockchain into their teaching. All bitcoin transactions are recorded on Blockchain, which is the public online ledger. Every transaction ever done with bitcoin is publicly available, Steelman said, and they can be viewed from outside the network.

Anyone using the currency has a long digit of random numbers assigned to his account. It might not make sense to the human eye, but it’s essentially a bank account number, he said.

“When it first came out, it was assumed to be anonymous. People thought, ‘I can buy whatever I want. No one is going to be able to trace me, because I’m not using cash or my bank account,’” Steelman said. “What ends up happening is your personal information may not be tied to your bitcoin account, but what law enforcement tries to do is find the crumbs that people have left in other places on the Internet.”

Not every criminal will leave crumbs, and the percentage of bitcoin transactions for illegal purposes is very small, but it’s still a worthwhile endeavor, Steelman said.

“There is still going to be potential to catch people. I definitely think there will be positive results,” he said. “It’s always a cat-and-mouse game. Law enforcement is always trying to catch up, but they are getting better at it and getting better tools.”


The sheriff and cybercrime detectives said they want to be transparent but also “don’t want to give out the playbook,” Rankin said.

Bitcoin mining has become increasingly specialized over the years and is now mostly done by dedicated professionals with specialized hardware, cheap electricity and, usually, big data centers, according to Bitcoin Magazine.

Glenn Latham, a former law enforcement officer who plans to challenge Holloway in the 2018 election, has concerns about the new program.

“These machines that they have to use draw a huge amount of power, and cooling costs will go up. That’s at the taxpayers’ expense,” Latham said. “If they can prove that it is cost-effective, OK, fine. But every taxpayer has the right to know what is going on.”

Benton County Cyber Crimes Division is not trying to rake in the big bucks by mining, the detectives said. They are using one computer, which is stored in a data center already designed to keep the hardware cool, Rankin said.

The electricity bill increase for mining would be marginal at best when compared to the cost of running the whole facility, he said, comparing it to plugging in another PC.

The project is in its early stages, and the detectives said there is plenty of room to adjust. Undiano said they need to finish collecting and then review the data and consult with officials and experts on how much currency they need.

Privacy and potential system hacking is a concern about law enforcement in general mining bitcoin and interacting on the Dark Web. The Cyber Crimes Division does not think this will be an issue after consulting with experts.

The division is part of a mining pool, which combines different miners’ resources to share their processing power over a network. The miners in the pool split the reward according to the amount of work they contributed. Rankin attempted to identify the other users in the mining pool and has not been able to, which he said demonstrates the security on the sheriff’s office’s end as well.

Latham said he is not an expert on the bitcoin mining process or the Dark Web, but said the sheriff’s office should go after what he called the large amount of low-hanging fruit online instead of diving into something he believes will not lead to many, if any, arrests.

“No question whatsoever that those activities are happening, and criminals are using bitcoin,” he said. “The problem with it is the anonymity behind the Tor network and the expense we will go through to reach a dead end. There are easier ways of catching people who are actively hunting children.”

Undiano said the use of bit-coins and Dark Web activities are prevalent in Northwest Arkansas.

“It’s becoming mainstream everywhere except with law enforcement agencies,” he said.

Rankin said about the pilot program: “I’ll be the first to say that if it doesn’t work, I’ll shut it down.”

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