- cross-posted to:
- tech@links.roobre.es
- cross-posted to:
- tech@links.roobre.es
Email is an open system, right? Anyone can send a message to anyone… unless they are on Gmail! School Interviews uses two email servers t…
Email is an open system, right? Anyone can send a message to anyone… unless they are on Gmail! School Interviews uses two email servers t…
IMAP supports TLS, what’s Proton’s excuse for enforcing their own delivery protocol?
Proton is end-to-end encrypted - they don’t have the keys themselves. With TLS, encryption is between you and the server, but the information can be decrypted on the server side.
At least that’s my understanding of it. If you want Proton’s own words, they wrote an explanation on their website. :)
I fail to see how the mails being encrypted stops them from using IMAP(s) like everyone else. IMAP doesn’t care what the contents of the email it’s sending/fetching are, and is perfectly compatible with other E2EE solutions like PGP/GPG which they say their solution is based on.
If IMAP is enabled on a provider, that provider can access your emails, unless you’ve encrypted the content of the email itself (with something like pgp or gpg). Proton only has access to emails in transit and after that, it can no longer access your email as it’s entirely encrypted. Since Proton doesn’t save the emails in transit, it has zero ability to provide those emails even if given an enforceable subpoena. Other providers that use IMAP can and do have access to your emails and can give them to a government authority if given an enforceable request.
The difference is the data at rest protocols on different providers. Proton has zero access encryption for data at rest. It only has access for data in transit and its ephemeral in that once it’s done with that transaction, it no longer has that data.
I presume ProtonMail markets this as a security feature? It guarantees your provider cannot sniff your email content and can’t be compelled to disclose user emails to law enforcement.
They’re not using a different protocol for delivery, they still use IMAP and SMTP, but other mail clients can’t decrypt the message content from Proton because they don’t have the keys (and nor do Proton). Proton do supply a “bridge” app if you want to use your Proton mail with a desktop email client, which handles the decryption between your computer and Proton by accessing the Proton encryption keys on your computer.
TLS is like a padlock on a box, and you have the key. Encrypted content is if the letter in the box is also written in code, needing another key to translate into plain language.
Proton doesn’t use IMAP. Your inbox isn’t quite like other internet mailboxes. You can’t access it with TLS. You access it via normal TCP/IP traffic. The contents are encrypted and can only be decrypted on your device. This is why IMAP doesn’t work. The Bridge acts as a Proton client, decrypts the data and then acts as a local IMAP server so you can connect to it via another IMAP client. Proton cannot read your email at any other time other than ephemerally at the moment it receives the email, which it then encrypts one way into your inbox. It cannot decrypt it. Only your devices can. Your devices get the private key from Proton’s servers, but they’re encrypted with your account password. So you grab the encrypted key and decrypt it locally on your device. It’s not the most secure, but it’s the most secure you can do without having to manage your own keys. It should be noted that you can possibly lose access to your email. This would require losing access to your physical devices and losing your password at the same time. As long as you have a device that has your key, you can restore access to your account which allows it to update the encryption on the key, etc. If you lose your physical devices and lose your password, you can only restore access to your account, but not any of your email up until that point.