Smart Contract for Multiparty Fair Certified Notifications

Blockchain can be the base for an evolution in several digital services. Fair Certified Notification is one of these and requires a fair exchange of values: a message and a non-repudiation of origin proof in exchange for a non-repudiation of reception evidence. The main contribution of this paper is the introduction of a blockchain-based Multiparty Fair Certified Notification system allowing the simultaneous fair notification to a set of receivers. We present and evaluate a smart contract for an optimistic multiparty protocol that achieves the properties of confidentiality, fairness and timeliness with a stateless TTP.