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 polyu.hk
Valid- Issued by (CA)
- DigiCert Inc
- Subject
- polyu.hk
- Valid from
- Jul 21, 2026
- Valid until
- Feb 4, 2027 (176 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 06379D9CD3751F51501D888BCA6125E9
- SHA-256 fingerprint
- 86:82:87:35:DE:2E:C5:A4:B5:8E:90:EE:82:00:11:AA:94:0B:E3:63:BE:2B:55:C2:A6:AB:15:C3:C7:CB:AB:2B
- Chain
- DigiCert Global G2 TLS RSA SHA256 2020 CA1 → DigiCert Global Root G2
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
This certificate has been served since Jul 20, 2026.
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This is today's certificate. Turn on monitoring and we'll watch polyu.hk continuously, notifying you the moment anything moves across all three signals:
Uptime
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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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