Abstract: A secure communication method for allowing a mobile host to communicate with a correspondent host over a Virtual Private Network. The method comprises negotiating one or more Security Associations between the mobile host and a correspondent host of a Virtual Private Network. Subsequently, a communication is initiated between the mobile host and a Security Gateway and an authentication certificate sent to the Security Gateway, the certificate containing at least the identity of a Security Association which will be used for subsequent communication between the mobile host and the correspondent host. Data packets can then be sent from the mobile host to the correspondent host using the identified Security Association, via the Security Gateway. However, the data packets are forwarded by the Security Gateway to the correspondent host only if they are authenticated by the Security Gateway.

Abstract: A method of storing electronic data in a system having a mobile terminal (8) and a remote system (1), the mobile terminal (8) and the remote system (1) interacting with each other to exchange electronic data. In order to prevent data loss at the mobile terminal (8), data storage capacity and storage requirements are monitored at the mobile terminal (8). If a risk exists that the data storage capacity of the mobile terminal (8) is likely to be exceeded, electronic data from the mobile terminal (8) is uploaded to the remote system (1), and stored there. The previously uploaded data is subsequently downloaded from the remote system (1) to the mobile terminal (8) in the event that that data is required by the mobile terminal (8) or a determination is made that the risk of exceeding the data storage capacity of the mobile terminal (8) no longer exists.

Abstract: A secure communication method for allowing a mobile host 1 to communicate with a correspondent host 4 over a Virtual Private Network. The method comprises negotiating one or more Security Associations (SAs) between the mobile host 1 and a correspondent host 4 of a Virtual Private Network (VPN). Subsequently, a communication is initiated between the mobile host 1 and a SG 3 and an authentication certificate sent to the SG 3, the certificate containing at least the identity of a SA which will be used for subsequent communication between the mobile host and the correspondent host. Data packets can then be sent from the mobile host 1 to the correspondent host 4 using the identified SA, via the SG 3. However, the data packets are forwarded by the SG 3 to the correspondent host 4 only if they are authenticated by the SG 3.