Flexible and dynamic derivation of permissions

A method for deriving current and maximal permissions for executable content using:

• a. one or more executable content descriptions;
• b. one or more sets of permissions (access rights) that describe the operations that executable content can perform on objects;
• c. one or more permission equations that compute a set of permissions from one or more other sets of permissions;
• d. one or more permission propositions that specify conditions under which associated modifications to permissions apply;
• e. one or more policy graphs that associate permissions, permission equations, and/or permission propositions with graph nodes;
• wherein the method for deriving current and maximal permissions comprises the following steps;
• f. deriving one or more permission equations and one or more permission propositions from policy graphs;
• g. deriving one or more maximal sets of permissions from policy graphs;
• h. selecting granted permissions from within an associated maximal set of permissions;
• i. combining one or more maximal sets of permissions into the maximal permissions using one permission equation and one or more permission propositions;
• j. combining one or more granted permissions into one current set of permissions which are a subset of the maximal permissions using one permission equation and one or more permission propositions.