This article applies to 123-reg SSL Certificates
This article will explain what SHA-1 and SHA-2 are, and the differences between them.
SHA stands for Secure Hash Algorithm. These algorithms form part of security applications such as SSL certificates. SHA-1 is the common standard and creates a 40 digit hexadecimal number for use in these security systems. However, it has recently been shown that mathematical weaknesses in the SHA-1 algorithm mean that it is beginning to lose its effectiveness.
To ensure the continued security of the SSL certificates, we will be upgrading to the SHA-2 security algorithm, which has been developed by the National Institute of Standards and Technology to replace SHA-1. This transition will mean that the SSL certificate will continue to perform effectively, and will mean that all SSL certificates will be updated by 1st January 2017, which is when Microsoft will no longer trust SSL Certificates using SHA-1.