Introducing TesseraCT Alpha

[Philippe Boneff]

Hi everyone,

We are really excited to announce that the alpha of our tile-based CT log implementation, TesseraCT, is now officially ready! Read up on details in our announcement blog post about it, and please do give it a try and let us know what you think and what could be improved.

In addition to the alpha being ready for Log operators to begin playing with, we are running TesseraCT test logs, which we'd love for monitors and CAs to use in order to test their robustness.

The whole team is on the transparency.dev slack, so reach out to us there with any questions, feedback or if you need any help getting TesseraCT up and running.

Philippe and the TrustFabric team

[Pim van Pelt]

Hoi,

Congratulations on the delivery of TesseraCT Alpha! I've been toying with this for a few weeks now, and wrote up two findings - one on the performance of the S3/MySQL and POSIX variants of TesseraCT, and the other on a TesseraCT log that I'll be running. A full description for these are on https://ct.ipng.ch/ but a quick link:

Loadtests for Tessera: https://ipng.ch/s/articles/2025/07/26/certificate-transparency-part-1-tesseract/

Operational Notes for TesseraCT: https://ipng.ch/s/articles/2025/08/24/certificate-transparency-part-3-operations/

You can find our TesseraCT Static Logs here:

• A staging log called [Lipase], incepted 2025-08-22, starting from temporal shared lipase2025h2.
• A production log called [Halloumi], incepted 2025-08-24, starting from temporal shared halloumi2025h2.

Many thanks to Philippe, Al, Martin and the Google team for your help (and code changes!) figuring this out. Perhaps the extra configuration tooling I wrote will motivate others to operate a log as well.

groet,

Pim