Let's Encrypt Oak Logs going Read-Only

[Matthew McPherrin]

As previously announced, Let's Encrypt plans to mark our Oak Logs read only this week.

We will keep them online as read-only RFC6962 logs, and are investigating archiving them as static-ct logs per Filippo's previous email to this list.

Our new logs, Sycamore and Willow, are now usable. I see many CAs are obtaining SCTs from them. We encourage everyone to switch using those logs.

For more information, see our previously posted blog post,

https://letsencrypt.org/2025/08/14/rfc-6962-logs-eol

Thanks,

Matthew McPherrin

Let's Encrypt

[Matthew McPherrin]

The Let's Encrypt Oak log are now read-only. We'll keep them online as RFC6962 logs until the previously communicated date.

We are currently planning to make archives of the log data available as discussed in the Archiving Certificate Transparency Logs thread on ct-policy.