The Internet has radically transformed access to and exchange of information, and it plays a fundamental role in today's society and economy. Yet it was difficult to imagine all the services offered today when the first tools necessary for its democratization were introduced thirty years ago. The blockchain, since the publication of the white paper of bitcoin as the first digital asset, has considerably broadened the range of its fields of application and its potential use cases in ten years; it could play, in different forms, a role comparable to that of the Internet in an area that the latter does not cover: trusted IT and legal transactions. Indeed, while the Internet is the privileged vehicle for the exchange of all digitized forms of information, it is not the guarantor, as a network infrastructure, of its uniqueness or its functioning. Blockchain technology has evolved from a niche subject to the hottest tech disruption buzzword, but there is still a lot of confusion about the subject. Without a clear understanding about what Blockchains are, their potential public sector potential impact is sometimes misunderstood or, more often, ignored. Questions related to their technical complexity, risk, security, and appropriateness often serve as obstacles to government officials’ ability to truly engage with this emerging technology. In this article, we consider the key features and types of blockchain technology and describe the potential use of blockchain technology in the public sector. In general, the blockchain can be used in the public sector to address the following tasks: authentication, traceability and uniqueness. We have identified ten potential directions of using blockchain technologies in public sector: self-sovereign identity, contract and vendor management, notarization, aid management, secure data sharing, financial services and banking, voting, verifiable diplomas and certificates, energy utilities, copyrights.