Abstract: A location-limited channel is implemented using physical exchanges of physical tokens. The physical tokens are implemented using writeable or re-writeable storage media. Location-limited channels, when used to implement pre-authentication protocols, provide demonstrative identification and authenticity. A group originator loads pre-authentication information and a network location from a communication device onto the location-limited physical token channel. The location-limited physical token channel is passed to another participant, who copies the originator's pre-authentication information and location onto that participant's communication device. That participant then adds that participant's own pre-authentication information and network location onto the location-limited physical token channel. This is repeated until the last participant passes the location-limited physical token channel back to the group originator.