3 ms·

Is it possible (in principle) to have an email-like-service with end-to-end encryption so that no one other than the sender and receiver can decipher messages?

• ossreality 11y ago
  Yes?
• chrisper 11y ago
  Yes. Why not? You just have to encrypt the message before sending it and decrypt it after you received it. https://github.com/google/end-to-end https://github.com/google/end-to-end I think the actual challenge is to do it with senders/receivers you do not know. I do not have enough secuirty experience to be able to answer how you can encrypt something on one end but decrypt it on the other hand without knowing the key? I guess something like HTTPS would work.
  • ekianjo 11y ago
    > I do not have enough secuirty experience to be able to answer how you can encrypt something on one end but decrypt it on the other hand without knowing the key? You distribute public keys. That's what people do for PGP nowadays, and you have repositories of public keys you can access.
• e12e 11y ago
  There's a myriad ways to do this. One approach would be "ecc-pub-key-in-hex+user@example.com" as email address, with user@example.com and whatever+user@example.com going to the same mailbox. This is even something gmail hasn't broken (prefix+user@gmail.com goes to user@gmail.com). Why not just pubkey@example.com? Allowing for key rotation. Having the address be (part-of) the key may or may not be a horrible/good idea. It certainly is easy to bootstrap: smart MUAs could encrypt to the key, dumb/old ones could send plaintext, or use S/MIME or GPG). There are plenty of attack-modes: for one - while the key/address need not be kept secret, the sender needs to know that it is corrrect/maps to the right user (eg: key1-e_smith@example.edu vs key2-eve_smith@example.edu).