Mitosis: Practically Scaling Permissioned Blockchains
Giorgia Azzurra Marson, Sébastien Andreina, Lorenzo Alluminio, Konstantin Munichev, Ghassan Karame · Annual Computer Security Applications Conference · 2021
Scalability remains one of the biggest challenges to the adoption of permissioned blockchain technologies for large-scale deployments. Namely, permissioned blockchains typically exhibit low latencies, compared to permissionless deployments—however at the cost of poor scalability. As a remedy, various solutions were proposed to capture “the best of both worlds”, targeting low latency and high scalability simultaneously. Among these, blockchain sharding emerges as the most prominent technique. Most existing sharding proposals exploit features of the permissionless model and are therefore restricted to cryptocurrency applications. A few permissioned sharding proposals exist, however, they either make strong trust assumptions on the number of faulty nodes or rely on trusted hardware or assume a static participation model where all nodes are expected to be available all the time. In practice, nodes may join and leave the system dynamically, which makes it challenging to establish how to shard and when.