TY - CONF AB - Sharding, or partitioning the system’s state so that different subsets of participants handle it, is a proven approach to building distributed systems whose total capacity scales horizontally with the number of participants. Many distributed ledgers have adopted this approach to increase their performance, however, they focus on the permissionless setting that assumes the existence of a strong adversary. In this paper, we deploy channels for permissioned blockchains. Our first contribution is to adapt sharding on asset-management applications for the permissioned setting, while preserving liveness and safety even on transactions spanning across-channels. Our second contribution is to leverage channels as a confidentiality boundary, enabling different organizations and consortia to preserve their privacy within their channels and still be part of a bigger collaborative ecosystem. To make our system concrete we map it on top of Hyperledger Fabric. AU - Androulaki, Elli AU - Cachin, Christian AU - De Caro, Angelo AU - Kokoris Kogias, Eleftherios ID - 8298 SN - 0302-9743 T2 - Computer Security TI - Channels: Horizontal scaling and confidentiality on permissioned blockchains VL - 11098 ER -