Abstract: We present a standardized method of security protocol design through composition,define the concepts of the base case and the component in the protocol,analyze the security attributes on the components,and design the single-step protocols which can implement the special security goals based on the components.The combination of several single-step protocols part into a complicated protocol without destroying the security properties established by each independent part.Then it can design security protocol by the context of specific applications based on the choice of the single-step protocols.In other words,the composition framework permits the specification of a complex protocol to be decomposed into the specifications of simpler single-step protocols based on the components,and thus makes the design and verification of the protocol easier to handle.