A method performed by a processor of a computing device to provide a plurality of secure domains (142-1, 142-2) in an Android operating system of the computing device, the method comprising: a) for each secure domain (142-1, 142-2): a1) associating resources of the secure domain (142-1, 142-2) with a unique domain identifier, the resources comprising at least one data file or at least one application (150-1, 150-2, 152, 154); and a2) storing a policy in association with the unique domain identifier, the policy comprising a rule set for controlling access to the resources; characterized in that : the method further comprises: b) receiving a selection of one of the plurality of secure domains (142-1, 142-2) as a current domain (142-1), wherein the plurality of secure domains (142-1, 142-2) comprises a target domain (142-2) different from the current domain (142-1), wherein the resources of the current domain (142-1) comprise an application (150-1, 152) associated with a unique application identifier comprising a Unix-type user identifier, UID, assigned to the application (150-1, 152) on installation; and c) controlling access by a process, generated by execution of the application (150-1,152) of the current domain (142-1), to the target domain (144-2) resources based on the policy associated with the current domain (142-1), the policy associated with the target domain (144-2), and an execution context identifier associated with the process based on the UID of the application (150-1, 152), the execution context identifier further comprises the unique domain identifier contained in reserved bits of the UID, and the Android operating system provides a user interface providing concurrent access to the resources of the current domain (142-1) resources and the resources of the target domain (142-2). a) for each secure domain (142-1, 142-2): a1) associating resources of the secure domain (142-1, 142-2) with a unique domain identifier, the resources comprising at least one data file or at least one application (150-1, 150-2, 152, 154); and a2) storing a policy in association with the unique domain identifier, the policy comprising a rule set for controlling access to the resources; characterized in that : the method further comprises: a1) associating resources of the secure domain (142-1, 142-2) with a unique domain identifier, the resources comprising at least one data file or at least one application (150-1, 150-2, 152, 154); and a2) storing a policy in association with the unique domain identifier, the policy comprising a rule set for controlling access to the resources; b) receiving a selection of one of the plurality of secure domains (142-1, 142-2) as a current domain (142-1), wherein the plurality of secure domains (142-1, 142-2) comprises a target domain (142-2) different from the current domain (142-1), wherein the resources of the current domain (142-1) comprise an application (150-1, 152) associated with a unique application identifier comprising a Unix-type user identifier, UID, assigned to the application (150-1, 152) on installation; and c) controlling access by a process, generated by execution of the application (150-1,152) of the current domain (142-1), to the target domain (144-2) resources based on the policy associated with the current domain (142-1), the policy associated with the target domain (144-2), and an execution context identifier associated with the process based on the UID of the application (150-1, 152), <EOS>