Certificates signed with SHA-256
Most of SSL certificates are signed, by default, with a sha1WithRSAEncryptio method, meaning with a SHA1 based hash algorithm.
SHA256 (sha256WithRSAEncryption) has been implemented to enhance the certificates security level.
Get prepared for this unavoidable transition and begin now!
See the compatible software:
In order to completely forget SHA-1, you also need to use SHA-256 in the SSL session. It requires compatible cipher and TLS 1.2 protocol. This protocol is not widely used on server (see IIS and Apache situations) and on browsers (IE 8+ (except XP), and Opera 10+) The feature is available in Firefox and Chrome since 2013 see here).