SSL (Secure Sockets Layer) is a method of encrypting your connections on the Internet, so that your connections are still safe if they are being "eavesdropped" on.
Rizon also supports Nickserv identification via SSL certificates with CertFP.
Setting up your client for SSL
mIRC's official documentation can be found here.
SSL can be used via Mibbit by clicking on the "Server" link on the connection dialogue and by using "+6697" as the port.
Rizon's QWebIRC automatically uses SSL when connecting via https.
IRCCloud is using a secure connection by default. You can verify this by editing the network - the checkbox named Secure Port has to be enabled and the port has to be 6697 or 9999
By default HexChat should connect using a secure connection. To ensure that you are connecting via SSL you can enable the checkbox named Use SSL for all the servers on this network by editing the network details in the network list.
To make sure Irssi verifies the authenticity of the certificate you need to enable certificate verification. You can do this by connecting using the
-ssl_verify flag. Users of version Irssi >= 0.8.21 are encouraged to use
Connecting with SSL
Typically, your client will have a connection dialogue which may ask you if you wish to connect with SSL as one of the options, allow you to pass a -ssl argument as part of the connect command, or use a "+" in front of the port number. (i.e. "/server irc.rizon.net +6697", "/connect -ssl irc.rizon.net 6697")
Currently all Rizon servers have SSL support on port 6697 and 9999.
RizonBNC allows SSL connections via port 12345 only.