ADFS Servers require Secure Sockets Layer (SSL). Implementers are encouraged to encrypt on-premises Microsoft Dynamics CRM sessions by the use of https and an SSL certificate.
SQL TDE (Transparent Data Encryption) – On-Premises
Microsoft Dynamics CRM on-premises supports the use of SQL TDE to encrypt the SQL Server files which are encrypted when the database is backed up or detached.
Microsoft Dynamics CRM Client for Outlook
It is important to protect the CRM data that has been synchronized to a local store and protect from unauthorized use. This can be accomplished with a combination of BitLocker Drive Encryption and Encrypted File System (EFS) which are included in modern versions of Windows.
BitLocker Drive Encryption –Available with Windows OS and protects the drive from unauthorized access by encrypting its contents.
Encrypting File System (EFS) –Allows for encrypting specific files or directories such as the CRM program files and registry keys.