In 2012, OAuth 2.0 was introduced as a major overhaul to OAuth 1.0. The changes made to this version of OAuth were significant enough that versions 2.0 and 1.0 are not compatible. OAuth 2.0 was designed to address a session fixation security flaw in the OAuth authorization flow. Although this issue has been resolved with OAuth 2.0, the new version intentionally does not define or support encryption, signature, client verification, or channel binding, but instead requires that implementers use a different security protocol like HTTPS/TLS for that purpose.