I got an email from Authorize.net about "Security Certificate Upgrades to api.authorize.net". The email is below. Does this change affect my Cart (Professional Version 2.2.5)?
Security Certificate Upgrades to api.authorize.net
As part of our continuous upgrades to enhance system performance and security, on September 21, 2015, we are upgrading api.authorize.net to new security certificates, which are signed using Security Hash Algorithm 2 (SHA-2) and 2048-bit signatures.
These upgrades were already completed on secure.authorize.net in May. If your website or payment solution connects to api.authorize.net and any updates are necessary to use the new certificates, please refer to this blog post in our Developer Community, which has all of the certificate information you and your developer will need for this update. Our sandbox environment has already been updated so that you can validate that your solution will continue to work using SHA-2 signed certificates, prior to September 21st.
After the update is complete on September 21st, any website or payment solution that connects via api.authorize.net that cannot validate SHA-2 signed certificates will fail to connect to Authorize.Net's servers.