A Java']Java API for historical ciphers: An object-oriented design project

This paper describes a project suitable for a software engineering or object-oriented design course. The project consists of asking students to design an application programming interface (API) for a particular range of applications. An API-design project has several features not always found in application-design projects: It forces students to focus carefully on the distinction between the programming and the user interfaces; it provides a good justification for studying existing APIs as model code; it provides a natural way to divide tasks between different groups of designers/programmers; and, the final product can be used as the basis for programming projects in other courses. In this case the particular project we describe is the design of an API for implementing Historical Cipher algorithms.