3 ms·
If I encrypt a message and put the secret on an sd-card I hand to my friend at the park, I can mail him encrypted messages over plaintext e-mail and we are safe
by stazz1 7y ago
If I encrypt a message and put the secret on an sd-card I hand to my friend at the park, I can mail him encrypted messages over plaintext e-mail and we are safe.
Most people don't use it this way, but to say it's impossible to secure e-mail is arrogant and not true
- stinky613 7y agoIs the article wrong in saying that the metadata isn't encrypted?
- stazz1 7y agoThe metadata would indeed not be encrypted, how else would the message ever arrive? if the post-man could not make out the address or the sender or if the postage was valid -- it's the same issue.
- tptacek 7y agoSo do you have a point to make that is responsive to the actual article, then?
- tialaramex 7y agoThis is a genuinely interesting problem which Signal put a bunch of work into solving! Sealed Sender lets them arrange that your recipient knows you sent the message, but they (Signal and its servers) don't - https://signal.org/blog/sealed-sender/ https://signal.org/blog/sealed-sender/ is their blog post about this work. Somebody connects to Signal, and hands over a message with a recipient. Signal has an ID for the recipient (you correctly observe there's no way around that) but has no idea who sent it, only that whoever it was can prove they're allowed to send this message. They also don't know in a useful sense who the recipient actually is - you can attach a real name, a photo and so on to a profile but only your trusted contacts can decrypt that profile anyway. It also arranges that by default Sealed Sender only works for sending messages to contacts. If you're a spammer - sending unsolicited messages to people who don't know you - your only way to send messages involves disclosing who you are to Signal, who can choose to rate limit you or block you. Like the rest of Signal's design the sender's identity is deniable - the recipient knows everything needed to produce a fake message from anyone they communicate with and so they can't use real messages as proof to anybody else. Because I'm a nerd I actually have the status indicators described in that blog post switched on, so I know that a few weeks later, in the middle of chatting about RDR2 one of my friends suddenly began using Sealed Sender, and other participants in that group joined in over the next few days. To a normal user nothing changed, their privacy improved significantly without them noticing at all. Anyway, solutions like PGP leak a lot more metadata than just the sender and recipient's identities to every node along the store-and-forward route. And the very existence of the route also leaks data.
- carterehsmith 7y agoOne of the concerns with email that article raised was: the recipient can click on "reply" -- without encrypting the reply message -- which would send the response together with the original message "quoted" - all of that unencrypted. This is apparently common operational mistake. Note that this has nothing to do with key exchange, ie putting it on sd card or whatever, would not change anything about the issue raised above. There is also about a dozen other issues that the article lists, worth reading for sure.
- stazz1 7y agoOh yeah that's a huge flaw in implementation (that probably every main e-mail vendor is guilty of). If it's prevalent enough, then the article is warranted, but the title and the conclusion are still gross simplifications -- it's not like the piping is inherently flawed, it's just that we prefer clear viewing windows to interact with messages, and where these two trains cross is where privacy meets your eyeball and also meets oxygen. Really, all decryption should happen on-device; but we cannot afford to abandon indecipherable messages on a daily or hourly basis in favor of universal privacy. It's somewhat reminiscent of the LOSE_POINTS_TO_LAG flag in quake and setting it to false. Maybe a better title would be Encrypted Email quickly becomes Unencrypted