Distributed Systems Security Questions

Security considerations and patterns for distributed systems and multi service environments. Topics include service to service authentication and authorization, key management and secret rotation at scale, implications of eventual consistency for access control decisions, securing inter service communication, distributed logging and auditing, handling security during partial failures and partitioning, Byzantine fault tolerant scenarios and consensus impacts on security, tradeoffs between availability confidentiality and integrity across regions, and designing resilient defenses for systems spanning multiple data centers or organizational boundaries.