Abstract: Methods and systems for exchanging data related to financial transactions utilizing a public network are disclosed. One or more participant computer systems are in communication with the public network. Each participant computer system includes at least one application for performing functions related to a financial transaction, and a gateway providing an interface for sending and receiving data between participant computer systems. At least one directory is used to identify a path for transmitting data between participant computer systems. Upon receiving a message from an application, the gateway accesses the directory to determine a destination address. The gateway then uses the address to open a channel through the public network to send the message to another participant computer system.