eMudhra ends SSL/TLS certificate issuance after keys cracked in under a second

Certificate authority eMudhra announced Thursday it will stop issuing SSL/TLS certificates.

The company’s board decided that withdrawing from global SSL/TLS serves the company and its shareholders. Chairman V. Srinivasan pointed to rising data sovereignty and compliance costs and competition from large providers offering free certificates. Chairman V. Srinivasan said SSL/TLS generated just 1 percent of eMudhra’s revenue. The company said social media amplification brought scrutiny out of proportion to SSL/TLS’s role in its business.

eMudhra acknowledged reputational risks it cannot quantify. Digital signature and enterprise security services continue to operate normally alongside other eMudhra businesses.

The company said its infrastructure was not compromised and that no data was breached and none of the eight intermediates had issued end-entity certificates. Security researcher Scott Helme said he recovered all eight private keys in under a second using a laptop.

The compromised keys were the integers 4, 56, 66, 115, 155, 156, 230 and 237. Each key was a whole number below 256, with sizes ranging from 3 to 8 bits. Researchers said the private keys were easily guessed integers rather than strong 384-bit random numbers.

The standard NIST P-384 keys should contain about 384 bits of entropy. eMudhra blamed the flaw on an error during an April 2025 key generation ceremony. A publishing error replaced the intended keys with a weak set on browser trust lists.

A Mozilla bug ticket indicates eMudhra blamed a key-setup script bug, according to Helme. On Oct. 17, a researcher named Wayne told Apple, Google, Microsoft and Mozilla that anyone could derive the keys from public certificates.

Browser makers blocked the certificates quickly, with Chrome and Firefox acting within hours. Apple blocked the certificates on Oct. 19 and Microsoft on Oct. 20. Mozilla took eMudhra’s root certificate off its trusted list.

Google said an update expected next week will remove the root from Chrome as the company reviews its remaining certificate. Major browser vendors including Chrome, Firefox, Apple and Microsoft revoked trust within days.

PKI underpins HTTPS, code signing and enterprise identity. Anyone could use the defective keys to generate TLS certificates trusted by major browsers, email servers, IoT devices, Docker containers and unmaintained tools.

Mozilla warned that fraudulent certificates could let interceptors impersonate trusted sites and alter data. Testing found that curl, Python, Node, Go and Java accepted a forged Stripe API certificate. Nonbrowser software that does not check revocation may stay vulnerable.

Go, Node.js, Python’s certifi bundle, Rust’s webpki-roots and several Linux distributions shipped updates. Node.js was still pending a fix when last checked. eMudhra revoked the eight intermediate certificates. The company said no breach occurred, its infrastructure was not compromised and the eight intermediates issued no end-entity certificates.

No attacks linked to the keys have been reported. Whether anyone used the weak keys is not known. CERT-In reported no malicious use of the keys through Wednesday. The Register reported that eMudhra issued more than 60 million certificates.

The company’s stock dropped 40% within two days of the disclosure. Browser vendors are accelerating CA accountability enforcement and regulators are expanding PKI oversight. AI tools are able to crack weak keys using one prompt. Organizations using third-party certificate authorities face pressure to audit supply chains for cryptographic hygiene.