NEW YORK — Off-price retailer TJX Cos Inc. said that information from about 45.7 million credit and debit cards was stolen in a computer data security breach over an 18-month period. The operator of the T.J. Maxx and Marshall’s chains also said that personal information — including names, addresses and personal ID numbers — of about 451,000 people who returned merchandise without a receipt was stolen, adding to the 3,600 it had previously identified. The company gave the numbers in a regulatory filing late on Wednesday, more than two months after first disclosing that its computer system had been compromised by hackers. Data from about 75 percent of cards was either expired or had masked data, meaning that the card numbers were not readable, the company said in the filing. The company said it believes its computer system was accessed by an unauthorized user in July 2005, then on subsequent dates in 2005 and from mid-May 2006 to mid-January 2007. It added that no customer data was stolen after December 18, 2006. Last week six people in the Miami, Florida area were arrested in connection with the purchase of hundreds of thousands of dollars worth […]