Hackers are taking aim at the security of fundamental Internet infrastructure technologies such the domain name system (DNS), SSL and digital certificates. Several high-profile hacks of leading CAs such as Comodo, GlobalSign and DigiNotar reinforced the need to protect these assurance tokens that validate the authenticity of online transactions and messaging. Microsoft announced in June its intention to no longer support certificate key lengths shorter than 1024; that requirement happens Oct. 9 when Microsoft releases an automated tool that will check for RSA key lengths and revoke any not meeting the 1024 minimum.
Source: https://threatpost.com/ssl-digital-certificate-security-issues-put-cas-notice-091912/77028/