SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
sekiguchi-holdings.com
SSL/TLS Certificate
SSL/TLS Certificate for sekiguchi-holdings.com
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- sekiguchi-holdings.com
- Valid from
- Aug 16, 2026
- Valid until
- Nov 14, 2026 (62 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 05E765CD91CB2AE06A8F9F40748B1832120B
- SHA-256 fingerprint
- FA:85:2C:58:09:F6:C8:85:6B:5A:76:DE:B8:C4:2D:2A:66:0C:2C:27:D4:BB:18:92:2E:75:E9:AE:D5:2F:08:24
- Chain
- YR2 → Root YR → ISRG Root X1
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
We've observed 1 previous certificate for this host. This certificate has been served since Aug 21, 2026.
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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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