Transport Layer Security (TLS), is a technology used to encrypt sensitive information sent via the Internet. Authorize.net plans to disable TLS 1.0 and TLS 1.1 on February 28, 2018. If you are a hosting customer with us, the newer TLS version 1.2 is already enabled. To see if the new version of TLS is supported on your site, please visit https://www.ssllabs.com/ssltest/