SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
uni-duesseldorf.de
SSL/TLS Certificate
SSL/TLS Certificate for uni-duesseldorf.de
Valid- Issued by (CA)
- Hellenic Academic and Research Institutions CA
- Subject
- hhu.de
- Valid from
- Jan 21, 2026
- Valid until
- Jan 21, 2027 (182 days remaining)
- Public key
- EC 256-bit
- Serial
- 03EFABA88BFF31AF12BCCA78B590CB4C
- SHA-256 fingerprint
- 21:F6:C6:CB:FD:0A:CE:E6:2C:7E:10:F8:F2:92:0E:96:A8:8C:56:CC:00:93:4F:08:A9:9C:C2:03:A3:11:C4:0B
- Chain
- GEANT TLS ECC 1 → HARICA TLS ECC Root CA 2021 → Hellenic Academic and Research Institutions ECC RootCA 2015
Certificate Authority Authorization (CAA)
CAA restricts issuance to harica.gr, pki.dfn.de, sectigo.com, telesec.de; we couldn't map the serving CA (Hellenic Academic and Research Institutions CA) to one of these identifiers.
Never get surprised by uni-duesseldorf.de's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch uni-duesseldorf.de continuously, notifying you the moment anything moves across all three signals:
Uptime
We visit the site from multiple regions worldwide and email you within minutes if it goes down, with a per-region breakdown so a real outage stands out from a regional blip.
DNS changes
We watch NS, MX, CAA, DNSSEC, CNAME and A/AAAA records, and identify the host, network, and ASN behind them, so a real migration or hijack stands out from routine noise.
TLS certificate
We warn you 30, 14, 7, and 1 days before it expires, and flag it if the issuing authority changes or the certificate is unexpectedly replaced.
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