US Patent 7917765 Modular signature verification architecture

It is difficult to provide a mechanism that is able to verify electronic signatures of different types in a simple and cost-effective manner. This is achieved by using a signature verification engine with an interface enabling signature modules to be removably plugged in. Each signature module has information about a particular signature type and functionality for verifying signatures of that type. The signature verification engine receives requests to verify signatures. It identifies a suitable signature module and works with that module to verify the signature. An enterprise who acquires equipment incorporating the signature verification engine is able to plug in its own signature module giving versatility whilst retaining security.