RC4 will no longer be supported in Microsoft Edge and IE11 beginning in April By Microsoft Edge Team March 16, 2016 10:00 am In September 2015, Microsoft announced the end-of-support of the RC4 cipher in Microsoft Edge and Internet Explorer 11 in early 2016. We plan to release this change with April’s cumulative security updates on April 12th, 2016. With this update, the RC4 cipher will be disabled by default and will not be used during TLS fallback negotiations. There is consensus across the industry that RC4 is no longer cryptographically secure. With this change, Microsoft Edge and IE11 are aligned with the most recent versions of Google Chrome and Mozilla Firefox.