Abstract: Methods and systems are provided for secure transaction processing. A secure processor may include an integrated wireless card reader and optionally a secure memory. When a request for payment information associated with an on-line transaction is received, the integrated wireless card reader reads data from the payment card. The secure processor may retrieve a set of transaction identifiers from the payment card issuer or optionally a trusted third party. The secure processor transmits one of the retrieve transaction identifiers to the on-line merchant instead of payment card data. The on-line merchant communicates the transaction identifier to the payment card issuer or the trusted third party for validation. Alternatively, the secure processor may encrypt the read payment card data utilizing the payment card number as the shared secret required by the cryptographic algorithm. The secure processor then forwards the encrypted payment card data to the on-line merchant.