eMudhra intermediate keys: CERT-In CIAD-2026-0050 and MeitY special team; company says weak keys from April 2025 ceremony, no end-entity certs issued
Follow-up to the Go/Firefox eMudhra intermediate distrust already on this site. On Oct 21 India's CERT-In published advisory CIAD-2026-0050: eight eMudhra intermediate CA private keys were generated with insufficient randomness (P-384 scalars smaller than 256, recoverable from the public keys); an attacker recovering them could forge TLS certificates. CERT-In says public disclosures do not establish confirmed malicious use as of that date, warns that removing the entire emSign ECC Root CA - G3 can break legitimate chains, and tells admins to update browsers/OS trust stores, replace affected chains, and never disable certificate validation. MeitY formed a special investigation team; officials say CCA-regulated Indian DSC/eSign services are unaffected and that the browser-trusted TLS business is under the global WebPKI framework. eMudhra's Oct 21 statement says the flaw was in a wrap/unwrap step of an April 30, 2025 key-generation ceremony on FIPS HSMs that published a second weak key set; seven of eight intermediates never ran in production, the one that did issued no end-entity certificates (per CT), roots were not compromised, and impact is limited to one US customer ecosystem whose certs are being replaced. Browser/OS distrust of the ECC root remains the practical control for everyone else.
Sources: CERT-In Advisory CIAD-2026-0050 · eMudhra statement (updated Oct 21) · ThePrint: MeitY special team · Mozilla Bug 2083449