SecurityProtocolType SecurityProtocolType SecurityProtocolType SecurityProtocolType Enum


Specifies the security protocols that are supported by the Schannel security package.

This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.

public enum class SecurityProtocolType
public enum SecurityProtocolType
type SecurityProtocolType = 
Public Enum SecurityProtocolType


Ssl3 Ssl3 Ssl3 Ssl3 48

Specifies the Secure Socket Layer (SSL) 3.0 security protocol.

SystemDefault SystemDefault SystemDefault SystemDefault 0

Allows the operating system to choose the best protocol to use, and to block protocols that are not secure. Unless your app has a specific reason not to, you should use this value.

Tls Tls Tls Tls 192

Specifies the Transport Layer Security (TLS) 1.0 security protocol.

Tls11 Tls11 Tls11 Tls11 768

Specifies the Transport Layer Security (TLS) 1.1 security protocol.

Tls12 Tls12 Tls12 Tls12 3072

Specifies the Transport Layer Security (TLS) 1.2 security protocol.

Tls13 Tls13 Tls13 Tls13 12288


This enumeration defines the set of values that you can use to specify which transport security protocol to use. It is the enumerated type for the SecurityProtocol property. Use this enumeration to determine your transport security protocol policy when you're using HTTP APIs in the .NET Framework such as WebClient, HttpWebRequest, HttpClient, and SmtpClient (when using TLS/SSL).

Applies to