Thought Leadership
The certificate authority eMudhra is withdrawing from the global SSL/TLS certificate business. The move follows the discovery that the private keys for eight of its intermediate certificates were smaller than 256 and could be calculated almost instantly.
eMudhra’s board has decided to exit the global SSL/TLS business. Affected customers will receive replacement certificates from partner providers at no cost. The Indian company also cites economic reasons for the decision. Its global SSL/TLS business accounts for only about 1 percent of revenue. Data sovereignty and compliance requirements make the business costly and complex to operate, while some major providers issue such certificates for free. The company also says the incident attracted a level of attention on social media that was disproportionate to the importance of this business segment.
“However, the level of social media amplification around this incident has brought scrutiny that is out of proportion to SSL/TLS’s place in our business. In view of this, after detailed deliberations our board has concluded that withdrawing from global SSL/TLS is the right decision for eMudhra and its shareholders.”
eMudhra
What Will Continue
eMudhra is not leaving the digital certificate business altogether. The company will continue to offer digital signature certificates, eSign services and its CertiNext platform. It will also maintain revocation and status services for TLS certificates until every certificate it has issued has expired or been replaced.
Until the transition is complete, customers will continue to be served through eMudhra’s G1-generation RSA root certificates. However, it remains unclear whether Chrome will continue to trust these and the company’s other CA certificates. The announcement makes no mention of InCommon and does not clarify whether new certificates will continue to be issued under G1 until the exit is complete.
The Security Flaw Behind the Decision
The board’s decision followed a security disclosure with significant consequences. A security researcher notified Apple, Google, Microsoft, Mozilla and eMudhra that they had recovered the private keys for eight of eMudhra’s intermediate certificates. Such keys should be extremely large random numbers. In this case, each key was smaller than 256 and could therefore be calculated almost instantly.
Six of the eight certificates were used to issue website certificates. Chrome and Firefox revoked them within hours. According to Google, no website certificates issued from these intermediates had previously been recorded in Certificate Transparency logs, meaning they could not have been used to compromise websites in Chrome. eMudhra says the certificates were never used for customers and rules out a breach of its systems.
Browser vendors nevertheless took further action. On October 20, Mozilla decided to stop trusting the parent ECC Root G3 certificate in Firefox. Chrome is expected to follow soon. This will also invalidate all otherwise valid certificates issued beneath that root.
(Editorial Team)
