To mitigate the risk of unauthorized access to confidential information, the Microsoft company issued a non-security update (KB2661254) for all supported Microsoft Windows versions. This update blocks cryptographic keys, whose length is less than 1024 bits. The update is not available for Windows 8 and later or Windows Server 2012 and later, since these systems already can block weak RSA keys of less than 1024 bits in size. For more details about this update, please refer to Microsoft support service website: http://support.microsoft.com/kb/2661254