What went wrong with eMudhra's digital certificates? In April 2025, a flaw during a key-generation ceremony caused weak cryptographic keys to be created alongside strong ones. These weak keys were published to browser root stores, exposing eight intermediate certificates to potential misuse. Attackers could use these keys to issue fake website certificates or make malicious software appear trusted.
- Weak cryptographic keys exposed in eMudhra's global TLS certificates.
- Private keys for six TLS and two code-signing certificates were vulnerable.
- Attackers could issue fraudulent certificates or sign malicious software.
- Indian Digital Signature Certificate (DSC) and eSign services remain unaffected.
- Mozilla and Google blocked affected certificates in their browsers.
- eMudhra is replacing certificates and investigating the root cause.
- CERT-In advises updating browsers and monitoring for unauthorized certificates.
What caused the security issue with eMudhra's certificates?
The problem originated during a key-generation ceremony on April 30, 2025. A flaw in the process caused a wrap-and-unwrap step to produce a second set of weak cryptographic keys alongside the intended strong keys. These weak keys were mistakenly published to browser root stores, making them vulnerable to reverse engineering, possibly with AI-assisted techniques.
What risks do the weak keys pose to users?
Attackers who obtain these private keys could issue fraudulent TLS certificates for domains they do not control. This means they could impersonate legitimate websites, potentially tricking users into sharing sensitive information. Additionally, the weak code-signing keys could allow malicious software to appear as if it was signed by a trusted publisher, increasing the risk of malware infections.
How has the Indian government responded to this incident?
The Ministry of Electronics and Information Technology (MeitY) formed a special team to investigate the incident. The Indian Computer Emergency Response Team (CERT-In) issued an advisory warning about the risks and recommended steps to mitigate them. MeitY clarified that the impact on Indian websites and applications was very limited and short-lived. They also emphasized that India's regulated digital signature and eSign services were not affected.
What actions have browser vendors taken?
Mozilla blocked the six affected TLS intermediate certificates through its OneCRL certificate block list and updated Firefox and its extended support releases. Google blocked the affected public keys in Chrome and planned to remove the emSign ECC Root CA - G3 certificate from its Chrome Root Store on October 27, 2026. These measures prevent browsers from trusting certificates linked to the compromised keys, protecting users from potential attacks.
Is eMudhra’s Indian digital signature business affected?
No. eMudhra confirmed that its Indian Digital Signature Certificate (DSC) and eSign businesses operate on separate infrastructure from the global TLS business. These Indian services continue to run normally and have not been compromised.
What should users and organizations do to stay safe?
CERT-In recommends updating browsers and certificate trust stores promptly. Organizations should review services that rely on the affected certificates and replace any vulnerable certificates. Monitoring for unauthorized certificate issuance is also important. Software vendors and administrators should verify code-signing certificate chains and avoid bypassing certificate-validation warnings to maintain security.
What is eMudhra doing to resolve the issue?
eMudhra is working directly with potentially affected customers to provide replacement certificates and avoid service disruptions. The company is cooperating with browser root programs and continuing its investigation to establish the root cause. Despite the incident affecting only about 1% of eMudhra's revenue, the company acknowledges potential reputational risks.
