ISO 27001 A.5.23: Information security for use of cloud services

Write a cloud security policy covering: which cloud service models and deployment types are approved, security criteria for selecting providers, data classification restrictions for cloud environments, shared responsibility requirements, and exit strategy expectations. Set up a proper provider evaluation process. Assess against: certifications (SOC 2 Type II, ISO 27001, CSA STAR), data protection capabilities (encryption, key management, data residency), IAM features, logging and monitoring, incident response and breach notification, and data portability support. Implement your side of the shared responsibility model thoroughly. For each cloud service, document who owns what. Harden configurations using CIS benchmarks or equivalent baselines. Set up strong IAM with MFA, RBAC, and just-in-time access for admin functions. Do not rely on default settings. Deploy cloud security monitoring. Use cloud-native tools (AWS Security Hub, Azure Security Center, GCP Security Command Center) and consider CSPM tools if you are running multi-cloud. Watch for misconfigurations, overly broad permissions, unencrypted data, and publicly exposed resources. Add workload protection for compute resources. Plan your exit strategy from day one. Understand data export options, formats, and migration paths before you are locked in. Include exit clauses in agreements covering data return, deletion confirmation, and transition support. Test data export and recovery periodically. Avoid deep vendor lock-in by using portable standards and abstraction layers where practical.