# What is Certificate Transparency?

> Certificate Transparency is a set of public, append-only logs that record every TLS certificate a trusted authority issues.

Source: https://layerv.ai/glossary/certificate-transparency/

---

[← All Terms](https://layerv.ai/glossary/) 

# What is Certificate Transparency?

Browsers require publicly trusted certificates to appear in Certificate Transparency (CT) logs, so anyone can search them for the hostnames a certificate names. That makes misissued certificates detectable, and it also makes new hostnames public.

Scanners watch the logs: a peer-reviewed study measured first requests arriving on average 5.9 minutes after a certificate was registered. A wildcard certificate, which covers every subdomain of a domain, records only the wildcard name, not each subdomain.

## How LayerV Implements This

The hosts qURL recipients land on are covered by a wildcard certificate, so no per-app or per-link name appears in CT logs.

## Related

[Localhost Tunnel](https://layerv.ai/glossary/localhost-tunnel/) [Attack Surface Reduction](https://layerv.ai/glossary/attack-surface-reduction/)

[The Localhost Exposure Report 2026 →](https://layerv.ai/research/localhost-exposure-2026/) [qURL vs Tailscale Funnel →](https://layerv.ai/compare/qurl-vs-tailscale-funnel/)



---

*This markdown version is auto-generated from [https://layerv.ai/glossary/certificate-transparency/](https://layerv.ai/glossary/certificate-transparency/) for AI agents. Curated agent resources: [llms.txt](https://layerv.ai/llms.txt). For the full interactive experience, visit the HTML version.*