BANGALORE
eMudhra, an India-based certificate authority, is exiting the global SSL/TLS business following discovery of eight intermediate TLS credentials with severely compromised private encryption keys.
The company's board concluded the exit was justified by three factors: mounting regulatory compliance costs, the TLS business generating only 1 percent of total revenue, and the proliferation of free certificate providers eroding returns. V. Srinivasan, chairman of eMudhra Limited, said the reputational damage from the incident—amplified across social media—exceeded the business unit's strategic value.
The scale of the cryptographic failure is striking. The eight compromised certificates used NIST P-384 elliptic curve keys, which should contain approximately 384 bits of entropy. Instead, the actual keys ranged from 3 to 8 bits—meaning the strongest key offered only 256 possibilities, crackable in milliseconds. The specific weak keys identified were 4, 56, 66, 115, 155, 156, 230, and 237. A 4-bit key offers just 16 possibilities.
Attackers could forge TLS certificates trusted by major browsers, email servers, and IoT devices. Browser makers blocked the vulnerable certificates within one to two days of discovery. eMudhra faces likely revocation of its certificate authority status by the CA/Browser Forum, the industry body that sets TLS program rules.
eMudhra traced the flaw to April 30, 2025, during a Key Generation Ceremony using FIPS 140-2 Level 3 Hardware Security Modules. The company said a defect in the HSM's wrap/unwrap cryptographic step generated a second set of weak keys alongside the intended strong ones. Those weak keys were then published to browser root stores. eMudhra is investigating the root cause of the HSM flaw.
