PEORIA — A McLean County man has been sentenced to four years in federal prison for operating an unlicensed bitcoin exchange.

PEORIA — A McLean County man has been sentenced to four years in federal prison for operating an unlicensed bitcoin exchange.

The U.S. Attorney's Office in central Illinois says 55-year-old John D. Powell was sentenced on Dec. 4 by Chief U.S. District Judge James Shadid. Powell pleaded guilty in July to two counts of operating an unlicensed money service business.

Bitcoins are virtual currency used to buy and sell some goods and services without government-issued money. The cyber currency also allows people to conduct transactions anonymously.

Prosecutors say Powell's exchange allowed people even more anonymity by exchanging cash anonymously for bitcoins.

They say Powell received more than $3 million during an 18-month period even though he hadn't registered his business with the state of Illinois or the federal government.