Encryption

We have several HL7 interfaces that we manage over TCP sockets that currently run across a dedicated fiber pair to a hospital partner of ours.  We are moving, and need to rework this.  There is a a city owned fiber optic ring that we could use as a transport medium, problem is, the data would have to be encrypted to pass over it using TCP sockets.  The other choice is VPN using standard encryption.  Does anyone have any experience  encrypting within Cloverleaf?  We are running 5.3 on a Windows 2003 platform.