> I have dealt with banking environment when they required SSL with at least 1-year validity on the callback API URL. Which excluded Let's Encrypt.
I wonder if this would be an opportunity for revenue for Let's Encrypt? "We do 90-day automated-renewal certificates for free for everyone. If you're in an unusual environment where you need certificates with longer validity, we offer paid services you can use."
Probably better to keep LE / ISRG completely non-profit. Adding a profit motive has too big of a chance to end with actually security-relevant features being gated behind payment eventually.
It's less about the profit motive, and more about removing the remaining incentives to stay outside the ACME ecosystem. The funding would be to provide additional infrastructure (e.g. revocation servers for longer-lasting certificates), and to fund new such efforts.
But once there is an income stream from issuing certificates there is an incentive to increase it which will quickly find itself at odds with the primary missions of providing secure connections to as many people as possible. Making infrastructure depend on that income stream only increases that incentive. Perhaps you trust the ISRG to resist the temptaton but as far as I know they are run by humans.
There are many, many opportunities in both the business and non-profit world to make more money by screwing your customers/users, and despite that, it does not always happen. Businesses and non-profits are built on the trust of users (or built in spite of the utter lack of it, e.g. Comcast). I don't think they should be afraid to provide things users need. It is, in fact, possible to choose and keep choosing to maintain the trust of your users.
I think there's still incentive alignment here. Getting people moved from the "purchase 1 year certificate" world (which is apparently still required in some financial contexts) into the ACME-based world provides a path for making a regulatory argument that it'd be easy for such entities to switch over to shorter-lived certificates because the ACME infrastructure is right there.
I wonder if this would be an opportunity for revenue for Let's Encrypt? "We do 90-day automated-renewal certificates for free for everyone. If you're in an unusual environment where you need certificates with longer validity, we offer paid services you can use."