Specifies whether to require the use of a specific encryption level to secure communications between client computers and RD Session Host servers during Remote Desktop Protocol (RDP) connections. This policy only applies when you are using native RDP encryption. However, native RDP encryption (as opposed to SSL encryption) is not recommended. This policy does not apply to SSL encryption. If you enable this policy setting, all communications between clients and RD Session Host servers during remote connections must use the encryption method specified in this setting. By default, the encryption level is set to High. The following encryption methods are available: * High: The High setting encrypts data sent from the client to the server and from the server to the client by using strong 128-bit encryption. Use this encryption level in environments that contain only 128-bit clients (for example, clients that run Remote Desktop Connection). Clients that do not support this encryption level cannot connect to RD Session Host servers. * Client Compatible: The Client Compatible setting encrypts data sent between the client and the server at the maximum key strength supported by the client. Use this encryption level in environments that include clients that do not support 128-bit encryption. * Low: The Low setting encrypts only data sent from the client to the server by using 56-bit encryption. If you disable or do not configure this setting, the encryption level to be used for remote connections to RD Session Host servers is not enforced through Group Policy. Important FIPS compliance can be configured through the System cryptography. Use FIPS compliant algorithms for encryption, hashing, and signing settings in Group Policy (under Computer ConfigurationWindows SettingsSecurity SettingsLocal PoliciesSecurity Options.) The FIPS compliant setting encrypts and decrypts data sent from the client to the server and from the server to the client, with the Federal Information Processing Standard (FIPS) 140 encryption algorithms, by using Microsoft cryptographic modules. Use this encryption level when communications between clients and RD Session Host servers requires the highest level of encryption. Countermeasure: Configure the Set Client Connection Encryption Level setting to High Level. Potential Impact: Clients that do not support 128-bit encryption will be unable to establish Terminal Server sessions.

[low level/client compatible/high level/disabled]

(1) GPO: Computer Configuration\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Security\Set client connection encryption level (2) REG: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services!MinEncryptionLevel