Overview#

Schannel SSP (also referred to by Microsoft as Secure Channel or Schannel) is a Security Support Provider (SSP) as used in the Microsoft Windows through the Security Support Provider Interface that provide identity authentication and Secure connections, private communication through encryptionSchannel SSP is used for access to web-enabled services, such as mail or personal information served on Web pages and secure Netlogon Remote Protocol

Schannel SSP, which includes a suite of four authentication protocols, uses Public Key certificates to authenticate parties. When authenticating parties, Schannel SSP selects one of the four protocols in the following order of preference:

• Transport Layer Security (TLS).
• Secure Socket Layer (SSL) version 3.0.
• Private Communications Technology (PCT) which is disabled by default in Windows Server 2003.
• SSLv2 version 2.0.

The protocol that is selected is the preferred authentication protocol that both parties can support. For example, if a server supports all four Schannel protocols and the client supports only SSL 3.0 and SSL 2.0, the Schannel SSP will use SSL 3.0.

More Information#

There might be more information for this subject on one of the following:

• Netlogon Remote Protocol
• Private Communications Technology
• Schannel
• Secure Channel
• Security Support Provider
• Security Support Provider Interface
• Windows Authentication Package

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• [#1] - TLS/SSL overview (Schannel SSP) - based on information obtained 2019-04-08