Let’s Encrypt will be reducing the validity period of the certificates we issue. We currently issue certificates valid for 90 days, which will be cut in half to 45 days by 2028.
This change is being made along with the rest of the industry, as required by the CA/Browser Forum Baseline Requirements, which set the technical requirements that we must follow. All publicly-trusted Certificate Authorities like Let’s Encrypt will be making similar changes. Reducing how long certificates are valid for helps improve the security of the internet, by limiting the scope of compromise, and making certificate revocation technologies more efficient.
So what’s the floor here realistically, are they going to lower it to 30 days, then 14, then 2, then 1? Will we need to log in every morning and expect to refresh every damn site cert we connect to soon?
It is ignoring the elephant in the room – the central root CA system. What if that is ever compromised?
Certificate pinning was a good idea IMO, giving end-users control over trust without these top-down mandated cert update schedules. Don’t get me wrong, LetsEncrypt has done and is doing a great service within the current infrastructure we have, but …
I kind of wish we could just partition the entire internet into the current “commercial public internet” and a new (old, redux) “hobbyist private internet” where we didn’t have to assume every single god-damned connection was a hostile entity. I miss the comraderie, the shared vibe, the trust. Yeah I’m old.
Will we need to log in every morning and expect to refresh every damn site cert we connect to soon?
Automate your certificate renewals. You should be automating updates for security anyway.
This is one of the reasons they’re reducing the validity - to try and convince people to automate the renewal process.
That and there’s issues with the current revocation process (for incorrectly issued certificates, or certificates where the private key was leaked or stored insecurely), and the most effective way to reduce the risk is to reduce how long any one certificate can be valid for.
A leaked key is far less useful if it’s only valid or 47 days from issuance, compared to three years. (note that the max duration was reduced from 3 years to 398 days earlier this year).
From https://www.digicert.com/blog/tls-certificate-lifetimes-will-officially-reduce-to-47-days:
In the ballot, Apple makes many arguments in favor of the moves, one of which is most worth calling out. They state that the CA/B Forum has been telling the world for years, by steadily shortening maximum lifetimes, that automation is essentially mandatory for effective certificate lifecycle management.
The ballot argues that shorter lifetimes are necessary for many reasons, the most prominent being this: The information in certificates is becoming steadily less trustworthy over time, a problem that can only be mitigated by frequently revalidating the information.
The ballot also argues that the revocation system using CRLs and OCSP is unreliable. Indeed, browsers often ignore these features. The ballot has a long section on the failings of the certificate revocation system. Shorter lifetimes mitigate the effects of using potentially revoked certificates. In 2023, CA/B Forum took this philosophy to another level by approving short-lived certificates, which expire within 7 days, and which do not require CRL or OCSP support.





