Certificate Transparency

This data is gathered by extracting certificates from Certificate Transparency log servers.

We monitor those logs and filter for certificates matching gov.au domains and have extracted them for analysis by interested parties.

The logs that we monitor are those listed at https://www.certificate-transparency.org/known-logs.

The code we use to generate (and update) this data can be found in our GitHub repository here: https://github.com/govau/certwatch

Under normal operation this dataset is updated live, so we would expect a new certificate to appear within approximately 10 minutes of being included in a new signed tree head published by a log (which is often hourly, sometimes up to daily).

The raw_data field is a base-64 encoding of TLS encoded MerkleTreeLeaf structure as defined in RFC6962 section 3.4. This is what we found in one or more certificate transparency logs, however we reset the timestamp field before storing to de-deduplicate.

The domains column is a list of matching gov.au domains found with the certificate or pre-certificate.

The issuer_cn field is the common name listed in the issuer field of the leaf certificate.

Although data.gov.au may incorrectly show a "Last Modified" date in the past, this dataset is continuously updated as new certificates are issued and found in the certificate transparency logs.