(D)TLS 1.3 support for 0.5-RTT (round trip time) data has been introduced to wolfSSL in the latest release (5.6.6). 0.5-RTT data is an optimization in (D)TLS 1.3 that significantly reduces latency and improves overall performance of application data. The full handshake requires two full round trips to start sending data while this functionality allows the server to send application data along with its final flight of handshake messages. This new addition works well with our support for early data (also known as 0-RTT data). An embedded device is able to resume a connection, send early data with its connection request, and receive a response immediately within one RTT.

	Client                                           	Server

	ClientHello         	-------->
                                                	ServerHello
                                      	EncryptedExtensions
                                      	CertificateRequest
                                             	Certificate
                                       	CertificateVerify
                                                 	Finished
                        	
	Application Data  	    	Application Data

Diagram showing 0.5-RTT data in a full TLS 1.3 handshake If you would like to learn more about (D)TLS 1.3 in wolfSSL, please contact us at facts@wolfSSL.com or call us at +1 425 245 8247. Download wolfSSL Now