Multi-cloud architectures promise resilience, cost control, and vendor freedom. They also multiply the attack surface. Each provider ships its own security model, IAM syntax, encryption defaults, and monitoring stack. Misalignment between them is the fracture point attackers wait for.
A proper multi-cloud security review starts with identity. Role-based access control must be unified across providers. Map every permission and close gaps where a user or service has more power in one environment than another. Enforce MFA everywhere. Rotate keys with automated processes.
Next, harden the network layer. Disable open ingress by default. Use private links and VPC peering where possible. Segment workloads so that a breach in one region or provider cannot pivot to another.
For data security, verify encryption in transit and at rest for all storage classes, backups, and message queues. Compare cipher strength and key management practices between clouds. Bring central control to customer-managed keys with tight audit logging.