International audienceIdentity systems today link users to all of their actions and serve as centralized points of control and data collection. NEXTLEAP proposes an alternative decentralized and privacy-enhanced architecture. First, NEXTLEAP is building privacy-enhanced federated identity systems, using blind signatures based on Algebraic MACs to improve OpenID Connect. Second, secure messaging applications ranging from Signal to WhatsApp may deliver the content in an encrypted form, but they do not protect the metadata of the message and they rely on centralized servers. e EC Project NEXTLEAP is focussed on xing these two problems by decentralizing traditional identities onto a privacy-enhanced based blockchain that can then be used to build access control lists in a decentralized manner, similar to SDSI. Furthermore, we improve on secure mes-saging by then using this notion of decentralized identity to build in group messaging, allowing messaging between diierent servers. NEXTLEAP is also working with the PANORAMIX EC project to use a generic mix networking infrastructure to hide the metadata of the messages themselves and plans to add privacy-enhanced data analytics that work in a decentralized manner
