The trend towards common user packet switched networks has increased the need for the provision of adequate end-to-end security techniques in order to protect the data of individual groups of network users. The techniques which can be employed in order to provide adequate end-to-end security measures are considered in this paper frc,mamilitary perspective, where the security requirements are particularly stringent. The paper concludes with a consideration of the practical application of these security techniques in an experimental military packet switched network.