Abstract: Methods of securely performing online transactions are described which involve two independently controlled web servers. In order to complete a transaction, a user interacts concurrently with each of the two web servers and authentication may occur between the user and each web server and between web servers. Each of the two web servers provide data which is used to complete the transaction and the data provided by the first web server is communicated directly to the second web server for use in the transaction. In an embodiment, the first web server provides a web page which enables a user to specify a variable which is used in the transaction. This is communicated to the second web server which processes the transaction along with an identifier for the message. The identifier may be used in validating the variable before it is used in processing the transaction. Following completion of a transaction this may be reported in real time to the first web server.