Act as a Senior Systems Architect. Design a distributed ledger system intended for global financial transactions capable of processing 10,000 transactions per second. Your design must address the following points without using code: 1. Define the consensus algorithm, explaining why you chose Byzantine Fault Tolerance over Proof of Work. 2. Detail the sharding strategy to ensure data availability and partition tolerance. 3. Explain how the system handles network latency and Byzantine nodes during the consensus phase. 4. Describe the security measures to prevent double-spending and Sybil attacks.