Protocol Labs Research
2020-04-27 /
Merkle-CRDTs: Merkle-DAGs meet CRDTs
Hector Sanjuan, Samuli Poyhtari, Pedro Teixeira, Yiannis Psaras


We study Merkle-DAGs as a transport and persistence layer for Conflict-Free Replicated Data Types (CRDTs), coining the term Merkle-CRDTs and providing an overview of the different concepts, properties, advantages and limitations involved. We show how Merkle-DAGs can act as logical clocks giving Merkle-CRDTs the potential to greatly simplify the design and implementation of convergent data types in systems with weak messaging layer guarantees and a very large number of replicas. Merkle-CRDTs can leverage highly scalable distributed technologies like DHTs and PubSub algorithms running underneath to take advantage of the security and de-duplication properties of content-addressing. Examples of such contentoriented systems could include peer-to-peer content exchange and synchronisation applications between opportunistically connected mobile devices, IoT devices or user applications running in a web browser.