Abstract: Certain methods and systems are described to provide security for sending and receiving data over unsecured networks. In an example a security broker (260) is provided between a first network (210) and a second network (220) where the security level of the first network is different from the security level of the second network. A user in the first network is given control over the level of security to be applied to data being supplied to an application (240) in the second network. The security broker (260) is arranged to supply data encrypted using a security scheme to the application (240) in the second network (220) and to supply decrypted data using the security scheme to a computing device associated with the first network (210).