Rotation due to expired keys should be frequent, enough to pretty much require automated methods to handle the changes. (One of the many great things in LetsEn

Rotation due to expired keys should be frequent, enough to pretty much require automated methods to handle the changes. (One of the many great things in LetsEncrypt.) If it’s a much longer time scale, people start to forget that it’s even possible for stuff to expire. If my fridge filter can display a little reminder light on a timer every few months, cryptography-dependent devices might need something similar. That way, your customers could know in advance and be asking you for an update.