BOSTON — A federal judge in Boston has sentenced a computer hacker to 20 years in prison in the last of three cases that prosecutors say involved one of the largest thefts of credit and debit card numbers in U.S. history.

The sentence imposed today on Albert Gonzalez will run concurrently with a 20-year sentence he received Thursday in two other cases. That means the 28-year-old Miami man will not have to serve any more than 20 years.

The one-time federal informant pleaded guilty in all three cases last fall. Today’s sentence involved the theft of card numbers from Hannaford Bros. supermarket chain, 7-Eleven, and Heartland.

Prosecutors said Gonzalez led a group of professional hackers and identity thieves who sold stolen numbers and withdrew other people’s money from ATMs.