Platform security

The exemplary aspects of the invention can be performed by at least a method, apparatus and computer program. The exemplary aspects include receiving from a source a package including a binary file representing an application software and an associated resource declaration indicating resources required by the application software, extracting the resource declaration from the package, forming an intersection of the extracted resource declaration and a set of allowable resources, for the source of the package, obtained from a software sources ranking and resources usage policy, granting the application software resources based on the result of the formed intersection, installing the application software, and storing an indication of the granted resources in a resource possession list. Further, the aspects include calculating, at a device, a cryptographic hash of an executable, signing the cryptographic hash, and storing a resulting reference signed cryptographic hash in a protected storage, prior to executing t