Abstract: A system and method of authorizing an electronic commerce transaction between a purchaser using a credit card, an on-line merchant, and a credit card company. A server associated with the merchant receives a purchase request from the purchaser that includes a purchase amount and the purchaser's credit card information. A SIP multi-party conference is established, and information is shared among the three parties through a multicast procedure. A Web camera may take an image of the purchaser when the purchaser sends the purchase request to the merchant. A whiteboard application is used to capture an image of the purchaser's signature. The credit card company verifies the credit card information, authorizes the purchase amount, and validates the purchaser's image and signature utilizing an image recognition program and a database of valid cardholder images and signatures.