Blockchain and satisfiability modulo theories for tender systems

A tender process consists in competing offers from different candidate suppliers or contractors. The tender winner is supposed to supply or provide a service in better conditions than competitors. Tenders are developed using centralized unverified systems, which reduce transparency, fairness and trust on the process, it also reduces the ability to detect malicious attempts to manipulate the process. Systems that provide formal verification, decentralization, authentication, trust and transparency can mitigate these risks. Satisfiability Modulo Theories provides a formal analysis to prove correctness of tender offers properties, verified properties ensures system reliability. In addition, one technology that claims to provide decentralization is Blockchain, a chain of distributed and decentralized records linked in a way such that integrity is ensured. This paper presents a formal verified and decentralized proposal system, based on Satisfiability Modulo Theories and Blockchain technology, to make electronic procurement tenders more reliable, transparent and fair.