Convenient End-To-End Encryption for E-Mail
Unpopular but very probably true fact: email can't practicably be made secure, and people should stop trying. Email is itself archaic, and there aren't good reasons people should use it for routine peer-to-peer communications that need secrecy.Why? Because:* It's default-plaintext. We don't generally love the way websites ensure they're viewed securely, but email doesn't even have the basic mechanisms HTTP has to prevent secrets from accidentally being sent in the clear.* Email encryption is never forward-secure. The most popular standard, OpenPGP, involves a long-term key that is the root of secrecy for all messages from a particular person. Lose that key, ever, and not only is every message you send in the future unsafe, but every message you've ever sent in the past is too. That's a terrible property for a secure messaging system.* Email leaks metadata. In fact, some of what we call email "metadata" isn't even metadata --- stuff like subject lines are simply content. They're sent in plaintext. We would never accept a new secure messaging system that behaved like that.* Most email users get their email from a website. Unless you make them install something on all their computers --- and at that point, just get them to install Signal, WhatsApp, or Wire --- "encrypting" their email involves schemes in which those websites can get their plaintext mail.* Most email clients are searchable-archive-by-default. Again, if you're using a secure messaging system to keep secrets from a state-level adversary, that's exactly what you don't want. And again, what matters here is the behavior of the overwhelming majority of clients. If you can stipulate a special mail client that is extra-careful, why not stipulate a forward-secure advanced messaging system and stop bothering with email?Everything that makes email effective in the real world makes it inhospitable to secure messaging. We should stop trying to push this particular boulder up this particular mountain and instead just get people to adopt serious secure messengers.