Universitaet Bremen TZI Cisco This document specifies "XTLS", a protocol for end-to-end encryption of Extensible Messaging and Presence Protocol (XMPP) traffic. XTLS is an application-level usage of Transport Layer Security (TLS) that is set up using the XMPP Jingle extension for session negotiation and transported using any streaming transport as the data delivery mechanism. Thus XTLS treats the end-to-end exchange of XML stanzas as a virtual transport and uses TLS to secure that transport, enabling XMPP entities to communicate in a way that is designed to ensure the confidentiality and integrity XML stanzas. The protocol can be used for secure end-to-end messaging as well as other XMPP applications, such as file transfer.