An apparatus and method provide a controlled, dynamically loaded, modular, cryptographic implementation for integration of flexible policy implementations on policy engines, and the like, into a base executable having at least one slot. The base executable may rely on an integrated loader to control loading and linking of fillers and submodules. A policy module may be included for use in limiting each module's function, access, and potential for modification or substitution. The policy may be implemented organically within a manager layer or may be modularized further in an underlying engine layer as an independent policy, or as a policy created by a policy engine existing in an engine layer. The policy module is subordinate to the manager module in the manager layer in that the manager module calls the policy module when it is needed by the manager module. The policy module is preferably dynamically linkable, providing flexibility, and is layered deeper within the filler module than the manager module.