Interdomain security issues for IN based services

Current IN services are usually within the controlled, secure domain of a single operator. Future services may operate over several networks where information about users and their actions may be shared by several parties. A user will have a lower level of trust for a foreign operator, they must be protected from security threats. Conversely, the network operator must maintain the security of their system when it is open to both external users and other networks. The most obvious threat is of revealing information over a bearer channel; however, the opening of signaling networks leads to further threats to security. This article examines these threats in the context of some example services