Patent ID: 7200576

Claim:
A computer-readable medium whose contents cause a computing system to: receive a request from a client to perform a transaction; and in response to receiving the request: identify a user requesting the transaction; identify the user's secure device; determine an alpha-numeric string that should be being currently generated by the user's secure device; create a captcha image using the alpha-numeric string; create a transaction verification page comprising the captcha image of the alpha-numeric string as a visible watermark, the transaction verification page requesting a next alpha-numeric string to be generated by the user's secure device to verify the transaction; transmit the transaction verification page to the client; receive from the client a second alpha-numeric string, the second alpha-numeric string being input to the transaction verification page by the user; determine a confirmation alpha-numeric string for confirming the transaction represented by the transaction verification page, the confirmation alpha-numeric string generated by the secure device immediately after the captcha image alpha-numeric string used as the visual watermark; compare the second alpha-numeric string to the confirmation alpha-numeric string being currently generated by the secure device; in response to the second alpha-numeric string matching the confirmation alpha-numeric string, commit the transaction represented by the transaction verification page; and in response to the second alpha-numeric string not matching the confirmation alpha-numeric string, abort the transaction represented by the transaction verification page.