Network security: Minimum session security for NTLM SSP based (including secure RPC) clients This policy setting determines which behaviors are allowed for applications using the NTLM Security Support Provider (SSP). The SSP Interface (SSPI) is used by applications that need authentication services. The setting does not modify how the authentication sequence works but instead require certain behaviors in applications that use the SSPI. The possible values for the Network security: Minimum session security for NTLM SSP based (including secure RPC) clients setting are: - Require message confidentiality. This option is only available in Windows XP and Windows Server 2003, the connection will fail if encryption is not negotiated. Encryption converts data into a form that is not readable until decrypted. - Require message integrity. This option is only available in Windows XP and Windows Server 2003, the connection will fail if message integrity is not negotiated. The integrity of a message can be assessed through message signing. Message signing proves that the message has not been tampered with; it attaches a cryptographic signature that identifies the sender and is a numeric representation of the contents of the message. - Require 128-bit encryption. The connection will fail if strong encryption (128-bit) is not negotiated. - Require NTLMv2 session security. The connection will fail if the NTLMv2 protocol is not negotiated. - Not Defined.

[none/require_message_integrity/require_message_confidentiality/require_NTLMv2_session_security]

(1) GPO: Computer ConfigurationWindows SettingsSecurity SettingsLocal PoliciesSecurity Options!Network security: Minimum session security for NTLM SSP based (including secure RPC) clients (2) REG: HKEY_LOCAL_MACHINESystemCurrentControlSetControlLsaMSV1_0!NTLMMinClientSec