This letter was originally published in our 2024 Annual Report.
The past year at ISRG has been a great one and I couldn’t be more proud of our staff, community, funders, and other partners that made it happen. Let’s Encrypt continues to thrive, serving more websites around the world than ever before with excellent security and stability. Our understanding of what it will take to make more privacy-preserving metrics more mainstream via our Divvi Up project is evolving in important ways.
Don’t certs just create an ephemeral key pair that disappears after the session anyhow? What does cert validity period have to do with “This is a big upgrade for the security of the TLS ecosystem because it minimizes exposure time during a key compromise event.”
I mean, it’s LE so I’m sure they know what their talking about. But…?
compromising a keypair is a huge win. lets you impersonate the domain. shorter validation periods = smaller windows of compromised situations.
basically the smaller you make the window the less manual intervention and the less complicated infrastructure gets. currently TLS systems need a way to invalidate certificates. get them down to a day and suddenly that need just disappears. vastly simplifying the code and the system. 6 days is a huge improvement over 90 days.
The key pair you’re thinking of is just a singular key for a block cipher. That key needs to be generated/transmitted in a secure manner. Meaning that its security is dependent on the cert. The expiration time of that cert is what they’re aiming at.
Don’t certs just create an ephemeral key pair that disappears after the session anyhow? What does cert validity period have to do with “This is a big upgrade for the security of the TLS ecosystem because it minimizes exposure time during a key compromise event.”
I mean, it’s LE so I’m sure they know what their talking about. But…?
compromising a keypair is a huge win. lets you impersonate the domain. shorter validation periods = smaller windows of compromised situations.
basically the smaller you make the window the less manual intervention and the less complicated infrastructure gets. currently TLS systems need a way to invalidate certificates. get them down to a day and suddenly that need just disappears. vastly simplifying the code and the system. 6 days is a huge improvement over 90 days.
Ok, I slid right by the “compromised” word. Makes sense now.
you mean you slid right on by an understanding of how security infrastructure works. since one always assumes credentials will be compromised.
I mean I just missed that part.
The key pair you’re thinking of is just a singular key for a block cipher. That key needs to be generated/transmitted in a secure manner. Meaning that its security is dependent on the cert. The expiration time of that cert is what they’re aiming at.