# System.Net.Security

``` diff
 namespace System.Net.Security {
     public class SslStream : AuthenticatedStream {
-        public Task AuthenticateAsClientAsync(SslClientAuthenticationOptions sslClientAuthenticationOptions, CancellationToken cancellationToken);
+        public Task AuthenticateAsClientAsync(SslClientAuthenticationOptions sslClientAuthenticationOptions, CancellationToken cancellationToken = default(CancellationToken));
-        public Task AuthenticateAsServerAsync(SslServerAuthenticationOptions sslServerAuthenticationOptions, CancellationToken cancellationToken);
+        public Task AuthenticateAsServerAsync(SslServerAuthenticationOptions sslServerAuthenticationOptions, CancellationToken cancellationToken = default(CancellationToken));
     }
 }
```

