A computing device, comprising: a processor configured to provide: a first operating system with access to a first memory; and a second operating system with access to a second memory for secure computing resources, said second memory not accessible by applications in said first operating system; a first software module executable within said first operating system for receiving access requests to access said secure computing resources and passing said access requests to said second operating system after adding access credentials; a second software module executable within said second operating system for receiving said access requests with access credentials and selectively passing said requests to said secure computing resources in dependence on said access credentials; wherein said first operating system defines a rich execution environment and said second operating system defines a trusted execution environment, each as defined by the Global Platform TEE system architecture; wherein, the computing device further comprises: a first data structure containing access credentials corresponding to applications in said first operating system, and wherein said first software module is configured to add access credentials to each one of said access requests, based on an application from which the request originated, by looking up the first data structure; and a second data structure defining access requirements for said secure computing resources, wherein said second software module is configured to compare said access credentials in said access requests to said access requirements, by looking up the second data structure. a processor configured to provide: a first operating system with access to a first memory; and a second operating system with access to a second memory for secure computing resources, said second memory not accessible by applications in said first operating system; a first operating system with access to a first memory; and a second operating system with access to a second memory for secure computing resources, said second memory not accessible by applications in said first operating system; a first software module executable within said first operating system for receiving access requests to access said secure computing resources and passing said access requests to said second operating system after adding access credentials; a second software module executable within said second operating system for receiving said access requests with access credentials and selectively passing said requests to said secure computing resources in dependence on said access credentials; wherein said first operating system defines a rich execution environment and said second operating system defines a trusted execution environment, each as defined by the Global Platform TEE system architecture; wherein, the computing device further comprises: a first data structure containing access credentials corresponding to applications in said first operating system, and wherein said first software module is configured to add access credentials to each one of said access requests, based on an application from which the request originated, by looking up the first data structure; and a second data structure defining access requirements for said secure computing resources, wherein said second software module is configured to compare said access credentials in said access requests to said access requirements, by looking up the second data structure. a first data structure containing access credentials corresponding to applications in said first operating system, and wherein said first software module is configured to add access credentials to each one of said access requests, based on an application from which the request originated, by looking up the first data structure; and a second data structure defining access requirements for said secure computing resources, wherein said second software module is configured to compare said access credentials in said access requests to said access requirements, by looking up the second data structure.