Security against the business partner

Security research has long focused on protecting against out- side attackers. This was augmented with protection against insider threats, but recently networked business is emerg- ing. With it a new threat is emerging: security against the business partner. A possible solution is secure multi-party computation (SMC) and we give examples of its usefulness. We show with the ex- ample of supply chain optimization that only SMC provides the necessary security guarantees. A major challenge of SMC is its practical realization. We give a detailed study and analysis of multi-party permuta- tion and show the relations of the different theoretical com- plexities in this case. The paper concludes with a comparison of service-oriented architectures and SMC. We show several architectural dif- ferences that need to be overcome.