Timeline for Securing privacy of "who communicates with whom" under Orwell-like conditions
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
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| Oct 30, 2013 at 18:08 | comment | added | Stefan Kohl♦ | @HenryCohn: In that you are obviously right -- and this is also the main reason why I said that it is still quite a way to go to get to anything practical. | |
| Oct 30, 2013 at 14:45 | comment | added | Henry Cohn | If you have a small group of friends, you can certainly use this approach to maintain privacy within that group, but scaling is a problem if you want to keep the secret service from knowing who your friends are. (If you expand the group to the size of the internet, then you'll end up downloading encrypted versions of every e-mail in the world to find yours. You'd need an NSA-scale server to handle that.) | |
| Oct 30, 2013 at 13:49 | history | edited | Goldstern | CC BY-SA 3.0 |
Improvement, I hope
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| Oct 30, 2013 at 2:54 | comment | added | François G. Dorais | @paulgarrett: Would it be? I think that the flow of intended email messages is already extremely low with the weight of spam. (Which gets sent, no matter how much you flush it away or ignore it.) Would it be different in such a broadcast scheme? | |
| Oct 30, 2013 at 0:35 | comment | added | paul garrett | And if A sends email to B but B never sends email to A, the all-knowing snoops realize that there's something fishy. And, yes, as Waldemar comments, identifying a group of 100 or 1000 emailers emailing each other en masse, possibly as a pseudo-privacy ploy, would be an obvious traffic pattern. | |
| Oct 30, 2013 at 0:28 | comment | added | Waldemar | I think that for a sender privacy broadcasting dummy messages is necessary. Without a sender privacy, it can be much easier to infer e.g. who is the boss in the group sending orders down through the hierarchy. It makes the system more expensive: if e.g. I want to send just one true message to someone I have to broadcast $n$ messages with $n-1$ being dummy ones. Moreover, if I don’t want to send any true message I should also broadcast $n$ messages in order to protect sender privacy of the others in the group. | |
| Oct 30, 2013 at 0:28 | comment | added | Waldemar | If the system is not applied widely but only by some people, the government can be interested in knowing the group of “common friends” listed as receivers by many senders in this broadcasting scheme. It’d give a clue that they form a group which is very much interested in protecting their privacy. This could signal that they are potentially bad guys. (see Henry Cohn's meta-questions) | |
| Oct 29, 2013 at 23:57 | comment | added | paul garrett | And one can pad the mailing list by consistently spamming a few hundred people one doesn't know. However, if the spying-filter is at the other end, they'll know when you email the known bad-guy email-box. Unless there is powerful precedent that people do spam bad-guy mailboxes as well as everything else, catching things at a conspicuous recipient's end would still be revealing. | |
| Oct 29, 2013 at 23:57 | comment | added | Stefan Kohl♦ | Thank you! -- I think of the 5 answers given so far, this is the best. | |
| Oct 29, 2013 at 23:53 | comment | added | François G. Dorais | This scheme could also provide some sender privacy by broadcasting messages encrypted for a (securely) randomly generated key at random intervals so that Big Brother doesn't know when you actually intend to send a message. | |
| Oct 29, 2013 at 23:30 | history | answered | Goldstern | CC BY-SA 3.0 |