The Umbrella security mechanism implements a combination of process-based Mandatory Access Control (MAC) and authentication of files through Digital Signed Binaries (DSB) for Linux based consumer electronics devices ranging from mobile phones to settop boxes. Umbrella is implemented on top of the Linux Security Modules (LSM) framework. The MAC scheme is enforced by a set of restrictions on each process. This policy is distributed with a binary in form of execute restrictions (in the file signature) and within the program, where the developer has the opportunity of making a restricted fork.
faeb10d56d1de90fdbbed7805e978845fdc3ef6a6b662e432333a84ad68f04aa