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, wherein the plurality of secure domains (142-1, 142-2) comprises a target domain different from the current domain, wherein the resources of the current domain 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, to the target domain resources based on the policy associated with the current domain, the policy associated with the target domain, 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 resources and the resources of the target domain. 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, wherein the plurality of secure domains (142-1, 142-2) comprises a target domain different from the current domain, wherein the resources of the current domain 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, to the target domain resources based on the policy associated with the current domain, the policy associated with the target domain, and an execution context identifier associated with the process based on the UID of the application (150-1, 152),