As part of our ongoing efforts to maintain a robust security posture and comply with industry best practices, we have implemented Transparent Data Encryption (TDE) in our SQL Server environment. In this response, we will provide comprehensive details regarding the TDE architecture, key hierarchy, key rotation processes, and supporting evidence.1. TDE Architecture and Key Hierarchy:The TDE architecture in SQL Server follows a hierarchical encryption model, where each level of encryption keys secures the next level. This layered approach ensures that the encryption keys themselves are protected by higher-level keys, providing a strong security foundation.At the top of the hierarchy, the Data Protection API (DPAPI), a built-in component of the Windows Operating System, encrypts the Service Master Key (SMK). The SMK is a symmetric key created during the SQL Server setup process and serves as the root key for the entire SQL Server instance.The SMK, in turn, encrypts the Database Master Key (DMK) for the master database. Each database, including the master database, has its own unique DMK, which is a symmetric key created using the `CREATE MASTER KEY` statement.The DMK of the master database plays a crucial role in securing other keys within the SQL Server instance. It creates a certificate in the master database, which is then used to encrypt the Database Encryption Key (DEK) in user databases.The DEK is a symmetric key specific to each user database and is created using the `CREATE DATABASE ENCRYPTION KEY` statement. This key is responsible for encrypting and decrypting the actual data within the user database.Finally, the entire user database is secured by its DEK through the `ALTER DATABASE ... SET ENCRYPTION ON` statement, which enables TDE for that database.