Usable and Efficient Secure Multiparty Computation

In the world of business, several potentially competitive enterprises can share their knowledge and skills to form a temporary alliance, usually called a virtual enterprise (VE), in order to catch new business opportunities. Virtual enterprises can be part of long-term strategic alliances or short-term collaborations. To effectively manage a virtual enterprise, receiving well-founded support from business process engineering techniques is critical. In particular, it is necessary to establish the cross-organizational business process, that is, to identify for each participant what can or is to be performed locally. In other words, one needs to compute the contributing subset of the existing local business process that is consistent with the processes of the other VE~constituents. We refer to this problem as "VE process fusion".

Events and activities of the processes of the two enterprises can be classified as

• internal tasks of the enterprises (e.g. the packaging of goods and the like)
• shared interactions between the two enterprises (e.g. the exchange of electronic documents)
• events observed by one of the enterprises only (e.g. receipt of a payment)
• events observed by both enterprises (e.g. the departure of a carrier from the harbor).

Intuitively, when the process of an enterprise is fused with the process of the partner, it must be updated so as to satisfy the partner's constraints. One of the main obstacles to VE process fusion is the perceived threat to the participants' autonomy. In particular, the participants can be reluctant to expose their internal processes, since this knowledge can be analyzed by the other participants to reveal sensitive information such as efficiency secrets or weaknesses in responding to a market demand. Moreover, the value of confidentiality of business processes is widely recognized, and many enterprises have started to use the patent mechanism to protect the investment required to optimize their workflows.

In this work we consider two mutually distrustful parties, each following a local business process, that wish to compute their local view of the VE process, assuming no trusted third party is available. The VE process are modeled as the synchronous composition of the participant work-flows, and each participant's local view is represented by a process that is trace equivalent to the VE process up to transitions that are not observable by the participant itself. The two parties are reluctant to reveal any information about their own business process that is not strictly deducible from the local view of the other party.

To satisfy these security constraints, we implement a prototype that integrates PROM, a well known business process analysis platform, with Sharemind, the SMC platform used by the UaESMC project.