2 research outputs found
IA-CCF: Individual accountability for permissioned ledgers
Permissioned ledger systems allow a consortium of members that do not trust one another to execute transactions safely on a set of replicas. Such systems typically use Byzantine fault tolerance (BFT) protocols to distribute trust, which only ensures safety when fewer than 1/3 of the replicas misbehave. Providing guarantees beyond this threshold is a challenge: current systems assume that the ledger is corrupt and fail to identify misbehaving replicas or hold the members that operate them accountable—instead all members share the blame. We describe IA-CCF, a new permissioned ledger system that provides individual accountability. It can assign blame to the individual members that operate misbehaving replicas regardless of the number of misbehaving replicas or members. IA-CCF achieves this by signing and logging BFT protocol messages in the ledger, and by using Merkle trees to provide clients with succinct, universally-verifiable receipts as evidence of successful transaction execution. Anyone can audit the ledger against a set of receipts to discover inconsistencies and identify replicas that signed contradictory statements. IACCF also supports changes to consortium membership and replicas by tracking signing keys using a sub-ledger of governance transactions. IA-CCF provides strong disincentives to misbehavior with low overhead: it executes 47,000 tx/s while providing clients with receipts in two network round trips
Confidential Consortium Framework: Secure Multiparty Applications with Confidentiality, Integrity, and High Availability
Confidentiality, integrity protection, and high availability, abbreviated to
CIA, are essential properties for trustworthy data systems. The rise of cloud
computing and the growing demand for multiparty applications however means that
building modern CIA systems is more challenging than ever. In response, we
present the Confidential Consortium Framework (CCF), a general-purpose
foundation for developing secure stateful CIA applications. CCF combines
centralized compute with decentralized trust, supporting deployment on
untrusted cloud infrastructure and transparent governance by mutually untrusted
parties. CCF leverages hardware-based trusted execution environments for
remotely verifiable confidentiality and code integrity. This is coupled with
state machine replication backed by an auditable immutable ledger for data
integrity and high availability. CCF enables each service to bring its own
application logic, custom multiparty governance model, and deployment scenario,
decoupling the operators of nodes from the consortium that governs them. CCF is
open-source and available now at https://github.com/microsoft/CCF.Comment: 16 pages, 9 figures. To appear in the Proceedings of the VLDB
Endowment, Volume 1