---
title: "Certificate Transparency Monitoring — Lemwatch Help"
description: "Monitor SSL certificate issuance and detect unauthorized certificates."
canonical: "https://lemwatch.com/help/certificate-transparency"
source: "https://lemwatch.com"
---

# Certificate Transparency Monitoring

> Monitor SSL certificate issuance and detect unauthorized certificates.

## Certificate Transparency Monitoring

 Certificate Transparency (CT) logs are a public record of every SSL certificate issued for your domain. LemWatch monitors these logs to detect unauthorized certificate issuance.

### Why It Matters

- Detect unauthorized certificates — If someone obtains a certificate for your domain without your knowledge, it could indicate a security breach or phishing attempt

- Subdomain discovery — CT logs reveal all subdomains that have certificates, including ones you might have forgotten about

- Issuer tracking — See which Certificate Authorities (CAs) have issued certificates for your domain

### What You'll See

- Total certificates found — How many certificates exist for your domain in CT logs

- Certificate issuers — Which CAs issued the certificates (Let's Encrypt, Cloudflare, DigiCert, etc.)

- Subdomains discovered — All subdomains with certificates

- Expired certificates — Certificates that have passed their validity period

- Wildcard certificates — Certificates covering *.yourdomain.com

- New certificates since last check — Alerts on newly issued certificates

### Alerts

 LemWatch alerts you when:

- A new certificate is issued for your domain by an unexpected CA

- A certificate is issued for a subdomain you don't recognise

- The total number of certificates changes unexpectedly

### Limitations

 CT log monitoring is passive — it detects certificates after they're issued, not before. For proactive protection, combine with **CAA DNS records** that restrict which CAs can issue certificates for your domain.


## Related

- [Help centre](https://lemwatch.com/help)
- [SSL Certificate Monitoring](https://lemwatch.com/help/ssl-monitoring)
- [Domain & WHOIS Monitoring](https://lemwatch.com/help/domain-monitoring)
- [Understanding Your Security Grade](https://lemwatch.com/help/security-grade)
- [Exposed Services & Port Scanning](https://lemwatch.com/help/exposed-services)
- [HTML Validation Checks](https://lemwatch.com/help/html-validation)
- [Lemwatch pricing](https://lemwatch.com/pricing)
- [Change Detection & Volatility Alerts](https://lemwatch.com/help/change-detection)