SHA is a popular hashing algorithm used by the majority of SSL certificates. As computing power has increased the feasibility of breaking the SHA1 hash has increased.
A warning is displayed in the Chrome console window regarding your certificate
This usually means the implementation of SSL on your server is not correct. The error is usually caused by a server side problem which the server administrator will need to investigate.
This error message means that the server is returning a certificate for a different common name than that specified in the address bar.
The SSL123 certificate is issued by the Thawte Server CA. This is present in Windows Mobile 5 devices. It is NOT present in Windows Mobile 6.