SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
SSL/TLS Certificate for kth.se
Valid- Issued by (CA)
- Hellenic Academic and Research Institutions CA
- Subject
- ns-vip-01.sys.kth.se
- Valid from
- Aug 20, 2025
- Valid until
- Aug 20, 2026 (28 days remaining)
- Public key
- EC 256-bit
- Serial
- 628E4E207D6DE8896AC1C5BF1ACC1519
- SHA-256 fingerprint
- 40:9E:23:60:03:21:3E:77:D8:1D:41:8A:9F:6B:33:BD:BB:7F:C9:48:CC:11:20:4A:D5:02:37:BB:14:1B:3B:1C
- 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 digicert.com, harica.gr, letsencrypt.org, sectigo.com; we couldn't map the serving CA (Hellenic Academic and Research Institutions CA) to one of these identifiers.
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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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