Dnia 19.10.2023 o godz. 09:56:49 Joachim Lindenberg via Postfix-users pisze: > > I disagree.
Of course your points are valid, to some extent: > - without additional authenticated encryption like SMTP-DANE, your > end-to-end encrypted messages are only protected w.r.t. confidentiality > (except sender and recipient addresses), there is no protection w.r.t. > integrity, Usually all end-to-end email encryption solutions also allow for digital signing, so if you both encrypt and sign, you are protected in both aspects. Of course there's the next problem: > - there is no standardized key management (almost nobody uses the > respective RFCs), and https://keys.openpgp.org/ imho has issues, > preventing mass adoption. And if there were mass adoption, we would see > end-to-end encrypted spam that is not caught by spam filters. This can be mitigated to some extent by the fact that you can encrypt/sign not only using PGP, but also using S/MIME, with certificates issued by known CAs - exactly like those used for web servers; most MUAs that support S/MIME recognize them. I regularly get some emails (for example, my bank account statements, or bills from my ISP) signed (but not encrypted) this way. Both MUAs I use (mutt and Evolution) recognize and verify the signature, showing the message as "signed". Thunderbird probably does it too. As I said - these messages are only signed, not encrypted, because that would require from me to have my own certificate and provide my public key to the sender. I fully agree that this isn't something that can be easily done and there are problems with widespread adoption of encryption. The PGP model of trust was basically developed for people who personally know each other, so they can exchange keys in a secure way and know that the key actually belongs to the proper person. On a large scale, S/MIME model is much better suited for end-to-end encryption and signing. However, getting a S/MIME certificate, that can be used to *receive* mail, costs money. You can *send* encrypted mail with no cost if the recipient has a S/MIME certificate and provides it to you. As the certificate is issued by a reputable CA, you have some degree of trust that the recipient is actually who they claim to be - so the certificate can be quite safely sent via email (that's the purpose of certificate after all - that it can be safely presented over an unencrypted channel). > - if you do not trust your administrators, pick a different one service, > at least on your side. The reality contradicts this. A huge number of people use Gmail, while we know for certain that Gmail scans the contents of all emails - this is used for ad profiling and for "smart" functions of Gmail inbox, like automatically putting due dates mentioned in email into your calendar, finding locations mentioned in your travel tickets and showing them on the map etc. Gmail basically wants to be "smarter" than you and suggest you what you can/should do with the email you just received. It can even suggest you what to write when you are writing an email, "based on your writing style". Who knows what are the other purposes Google uses the contents of emails for. And people seem to be completely OK with this, or they don't care. In summary, I think the "old school" approach to email security is still valid and widespread adoption of TLS in mail *transport* didn't change it at all. And that approach is: always assume that email that is not end-to-end encrypted can be read by someone else and if you have something *really sensitive* to send, either take effort to set up end-to-end encryption, or use another method of communication. -- Regards, Jaroslaw Rafa r...@rafa.eu.org -- "In a million years, when kids go to school, they're gonna know: once there was a Hushpuppy, and she lived with her daddy in the Bathtub." _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
