Extending the Liaison Workflow model and engine to support different signature purposes

Currently, many software systems are developed in offices geographically distributed in different locations. Furthermore, it is also common for a software system development project to contract to different software houses. These contracted software development projects, very often, are further sub-contracted to some other software houses. These software development modes can be supported and managed by good distributed workflow systems. Signatures play an important role in these software development modes. Most workflow systems, at best, can only support digital signatures. Digital signatures with public key cryptosystem are limited to authentication, integrity, confidentiality and non-repudiation. The wide variety of signature purposes such as authorization or multiple signatures in group decision making are not supported explicitly by most workflow systems. We have studied different kinds of signature in software development and workflow systems. The paper discusses the problems and solutions of incorporating these signatures in a distributed workflow engine, in particular, the Liaison Workflow Engine, to support the contemporary modes of software developments.