Protection boundary for internetwork security

A new protection boundary model for internetwork security is presented, and a security protocol suitable for the model proposed. Intermediate systems of the model do not fulfil security of service or confidentiality but authentication and integrity. The system does not require that the intermediate systems be fully secure. Thus it is practical and can be easily implemented. Data between destination hosts are also protected through the confidentiality service, for which session keys are distributed under the proposed protocol with peer entity authentication