Retail giant, Target has said that hackers were able to steal debit-card PINs from millions of customers who shopped from its stores a month earlier.

hackers who breached the retailer's network were also able to steal encrypted personal identification numbers (PINs) of the shoppers. Minneapolis-based discounter, Target Corporation has said that it will offer discounts to customers shopping in its stores on 21 and 22 December.

The massive security breach was revealed on Thursday in which hackers were able to access credit and debit card information of over 40 million target customers who shopped in stores between 27 November and 15 December. Target Corporation and law enforcement agencies are currently investigating the breach nationwide.

The information stolen by the hackers were posted on the Target Corporation website and included Customer names, credit and debit card numbers including valid upto dates and three digit security codes. The entire breach has affected customer confidence on the discount chain at this key holiday shopping season. Several customers of the company tried to contact the company through its website or call centres to report activity on their credit cards.

Spokeswoman Molly Snyder said in an emailed statement Friday said, "We remain confident that PIN numbers are safe and secure. The PIN information was fully encrypted at the keypad, remained encrypted within our system, and remained encrypted when it was removed from our systems."