Home / bulletins Microsoft Security Advisory (2661254): Update For Minimum Certificate Key Length - Version: 1.2
Posted on 11 September 2012
Revision Note: V1.2 (September 11, 2012): Clarified that applications and services that use RSA keys for cryptography and call into the CertGetCertificateChain function could be impacted by this update. Examples of these applications and services include but are not limited to encrypted email, SSL/TLS encryption channels, signed applications, and private PKI environments.
Summary: Microsoft is announcing the availability of an update to Windows that restricts the use of certificates with RSA keys less than 1024 bits in length. The private keys used in these certificates can be derived and could allow an attacker to duplicate the certificates and use them fraudulently to spoof content, perform phishing attacks, or perform man-in-the-middle attacks.
