Refining the Pattern-Based Reference Model for Electronic Invoices by Incorporating Threats

Almost every company needs to process invoices to either claim money from their customers or to pay for products or services. Although companies are allowed to electronically process their invoices, most of them still rely on the paper-based invoice process. Within this paper we built upon existing work to develop a methodology for defining a reference model for the electronic invoice based on security patterns. This paper identifies threats of the e-invoice process in order to create a context for the security problem, which allows us to refine our methodology.