What are the key components of a secure cloud architecture?
Represent the answer as a validation task: verify that all required security components exist and that their dependency graph is acyclic. A dependency pair [component, prerequisite] means the prerequisite must be established before the component.
validate_secure_architecture(components, dependencies) returns {secure, missing, cycle, order}. order is a deterministic topological ordering of the supplied components, or [] when a cycle exists.
def validate_secure_architecture(components, dependencies):