A system and method for identity decisions and invalidation. Modified objects (e.g., files, executables, etc.) are flagged for reevaluation. Privileges associated with the object are only persisted if the modifications are determined to be authorized (e.g., updates and patches). In one embodiment, a tagging system registers to be notified of all writes, renames, truncations, moves, deletions, or any other relevant modifications to objects. If the tagging system detects a modification operation targeting the object, it invalidates all identity decisions cached with the object. The next time the object runs, the system does not recognize the object and it is forced to reevaluate its identity. Thus, patching and other write operations are still permitted, but the system detects the changed object and reevaluates the identity.