1. Comodo Group. Mar. 31 2011 update; https://www.comodo.com/Comodo-Fraud-Incident-2011-03-23.html. Comodo Group. Mar. 31 2011 update; https://www.comodo.com/Comodo-Fraud-Incident-2011-03-23.html.
2. Langley A. Enhancing digital certificate security. Google Online Security Blog 2013; http://googleonlinesecurity.blogspot.de/2013/01/enhancingdigital-certificate-security.html. Langley A. Enhancing digital certificate security. Google Online Security Blog 2013; http://googleonlinesecurity.blogspot.de/2013/01/enhancingdigital-certificate-security.html.
3. Langley A. Further improving digital certificate security. Google Online Security Blog 2013; http://googleonlinesecurity.blogspot.co.uk/2013/12/further-improving-digital-certificate.html. Langley A. Further improving digital certificate security. Google Online Security Blog 2013; http://googleonlinesecurity.blogspot.co.uk/2013/12/further-improving-digital-certificate.html.
4. Laurie B. Improving SSL certificate security. Google Online Security Blog 2011; http://googleonlinesecurity.blogspot.co.uk/2011/04/improving-ssl-certificate-security.html. Laurie B. Improving SSL certificate security. Google Online Security Blog 2011; http://googleonlinesecurity.blogspot.co.uk/2011/04/improving-ssl-certificate-security.html.