In, Microsoft introduced Transparent Data Encryption (TDE) to its Encryption & Key Management for SQL Server - Definitive Guide. MS CRM 2020 Server Side Sync Configuration.
Column-level encryption (aka cell-level encryption) was introduced in SQL Server 2005 and is available in all editions of SQL Server, including the free SQL Server Express edition. To use cell-level encryption (try this site), the schema must be changed to varbinary, then reconverted to the desired data type. This means the application must be changed to support the encryption-decryption operation; in addition, it can affect performance. Encryption of the database occurs at the page level, but when those pages are read to buffer pool, they're decrypted. Data can be encrypted using a passphrase, an asymmetric key, a symmetric key, or a certificate. The supported algorithms for column-level encryption are AES with 128,196,256 bit keys and 3DES.