A spokeswoman says the PINs are "strongly encrypted" and can only be decrypted with a key held by an independent payment processor. Target says the key was not stolen in the breach.
The news comes just one day after the company said PIN numbers were not compromised.
This is the latest update following the breach that left 40 million customers' payment info in the wrong hands. Target says law enforcement officials have launched a forensic and criminal investigation into the breach.