Certificate Transparency

In order to provide encrypted traffic to users, a site must first apply for a certificate from a trusted Certificate Authority (CA). This certificate is then presented to the browser to authenticate the site the user is trying to access.

In recent years, due to structural flaws in the HTTPS certificate system, certificates and issuing CAs have proven vulnerable to compromise and manipulation. Google's Certificate Transparency project aims to safeguard the certificate issuance process by providing an open framework for monitoring and auditing HTTPS certificates.

Google encourages all CAs to write the certificates they issue to publicly verifiable, append-only, tamper-proof logs. In the future, Chrome and other browsers may decide not to accept certificates that have not been written to such logs.

As of 2015-01-01T12:34, there have been 32,341,621 entries made to the set of Certificate Transparency logs that Google monitors.

More information about the Certificate Transparency project: https://www.certificate-transparency.org/

Look Up Certificates by Hostname

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Issuing Certificate Authorities

Certificates

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Issuer (Filtered)

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# Issued

The number of matching certificates issued by this Certificate Authority.

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Subject

Only the Common Name part of the Subject is shown.

# DNS Names

The number of hostnames included in this certificate.

Issuer

Only the Common Name part of the Issuer is shown.

All Certificate Authorities that issued certificates matching the search query. Click Filter to drill down to a single issuer.

Valid From

The earliest date on which this certificate is valid.

Valid To

The last date on which this certificate is valid.

# CT Logs

The number of Certificate Transparency Logs that have logged this certificate.

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Certificate Details

Serial Number

Validity

Matching DNS Names

These hostnames are included in the certificate in its Subject or Subject Alternative Name. The certificate can be used on any of those domains. Wildcard names (those starting *) match any subdomain.

Log

The Certificate Transparency Logs that have logged this certificate.

Index

The position in each Certificate Transparency Log where the certificate is logged.

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Transparency Report

Certificate Transparency

Look Up Certificates by Hostname

At Google

On Top Sites

HTTPS Usage

FAQ

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