Question: CloudTech Solutions operates a cloud-based document storage service where security assessment reveals the following architecture: a single authentication server handles all login requests for millions of users, one database stores all user credentials and file metadata, a single encryption key encrypts all stored documents, and one administrative interface manages all user accounts and system settings. The system has no backup authentication methods, redundant databases, or alternative administrative access paths. This cloud storage architecture most critically fails to implement which security principle? Need Assignment Help? Question options: Defense-in-depth Economy of mechanism Principle of least privilege Complete mediation