A Bengaluru company that the world’s major browsers trust to vouch for websites generated the secret keys for eight of its security certificates so poorly that anyone could have worked them out in seconds. Google, Mozilla, Apple and Microsoft have blocked the certificates, the Union government has set up a special team to investigate, and security experts are warning that the clean-up will be long and difficult.
It asked government departments, internet service providers, software vendors and website administrators to update their systems and their lists of trusted certificates.
It said the keys “were generated with insufficient cryptographic randomness” and “could be recovered almost instantly”. The agency’s tone was markedly different from the ministry’s, warning that attackers could use them to intercept or alter communications, “potentially resulting in credential theft, unauthorised disclosure of sensitive information and financial fraud”. “Do not bypass certificate-validation warnings or disable certificate verification,” it said.
The Indian Computer Emergency Response Team (CERT-In), the national cybersecurity agency, issued an advisory only on Wednesday afternoon.
The clean-up could be enormous and slow, they warned, and hardest for the routers, payment terminals and ageing software that are seldom updated. The cleanup could be enormous, particularly for devices and software that cannot be easily updated. Because a certificate authority, a company that checks who controls a website, has signed it, the browser trusts the certificate.
There is no evidence yet that the keys were misused, and the major browsers had a safeguard that would have exposed any attempt against their users. Keys this flimsy, which no standard tool would have produced, could give phishing gangs and eavesdroppers the kind of opening they rarely get. “This isn’t just about eight compromised keys. “A single authority’s failure can undermine authentication for organisations that have never dealt with it. To take a hypothetical example, the certificate for sbi.co.in lets a browser confirm that the site is run by the State Bank of India before it shows a padlock and encrypts what the user sends. Browsers and operating systems each keep a list of the several dozen authorities they trust, and eMudhra is on the lists kept by Google, Mozilla, Apple and Microsoft. Authorities keep their top-level root certificates for signing intermediate certificates, and the intermediates sign certificates for individual websites. All eight of eMudhra’s compromised certificates were intermediates. Six were for websites, and two were for code signing, which software makers use to prove a program is genuine. If a website’s certificate is an identity card, an intermediate is the office that issues the cards, and whoever holds its private key, the secret number used for signing, can issue a card in any name.
But security experts said they were alarmed at the lapse, describing it as a blow to “the global internet’s chain of trust”. Any trusted authority can vouch for any website, they said, so one company’s failure can expose organisations that have never dealt with it. It’s about the global internet’s chain of trust,” said Yash Kadakia, founder and chief technology officer of cybersecurity firm Security Brigade. Every website whose address begins with “https” presents a certificate to prove its identity.
“As this incident enables even technically unsophisticated individuals to easily recover the private keys for these intermediates, the impact of this incident could not be higher,” Mozilla, which makes the Firefox browser, wrote in its incident report. In a statement on Wednesday, eMudhra said that “a flaw in the KGC caused a wrap/unwrap step to produce a second set of weak keys alongside the original strong keys”, referring to the key generation ceremony at which it created the bad keys on April 30, 2025. “The weak keys were the ones published to the browser root stores,” it said.
