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Re:RSA is a fragile cryptosystem by jancsika on Monday July 08, 2019 @03:29PM (#20385929)
Not hard at all. I send my public key over gmail. Recipient adds it to authorized_keys. I answer "yes" to whatever partially human-readable question ssh asks me to trust the server's key on first use. Now I'm in.

The difficulty you are describing assumes a user base of crypography pedants who make assumptions about third parties that don't matter to 99% of non-technical users (nor even technical users in many cases).

Re:RSA is a fragile cryptosystem by loup-vaillant on Monday July 08, 2019 @06:02PM (#20387205)
But when it matters, boy are the consequences dire.

One example: you work for the American government, and you witness something very wrong, very illegal going on. You'd better be sure, when contacting Laura Poitras, that you are indeed contacting Laura Poitras, and not some counter-intelligence operative from the NSA.

And it has to work even if you don't have Ed Snowden's skills. Without reliable crypto the rest of us can use, people will get caught, arrested, tortured, killed blackmailed… just for speaking up.

Maybe we don't want reliable crypto to be widely available. Maybe we want to have mass surveillance. But that's another debate. (Personally, I'd rather have everyone to have reliable crypto, and I'm willing to make wiretapping impossible in the process.)

Re:RSA is a fragile cryptosystem by maxerickson on Monday July 08, 2019 @09:44PM (#20388334)
Your comment sort of implies that there are complicated solutions to the key finding problem that are better than the simple ones. But then it doesn't bother establishing that argument.

How to beat Laura Poitras publishing a public key all over the place?

Re:RSA is a fragile cryptosystem by loup-vaillant on Tuesday July 09, 2019 @06:44AM (#20390501)
I swept a whole host of issues under the rug, not all of which are related to key finding. Let's see forward secrecy (one of the bigger ones). The internet works this way: when you send a message, it gets delivered to the recipient, and a copy is sent to the NSA.

Without forward secrecy, getting Laura Poitras' key will enable the NSA to read all past communications. They only have to seize her computer when it's still on, and the key is still in memory somewhere, or compel the poor journalist to give up here keys (possibly using that "non invasive" waterboarding torture, and justifying it with suspicion of helping terrorists).

Now if Laura kept the decrypted messages in her laptop, forward secrecy wouldn't do anything, but if she properly deleted them, it would be a shame if the messages were nevertheless at the mercy of the attacker.

---

As for key finding, well… the simple solutions do work pretty well. Snowden for instance didn't find Poitras' keys lying around on the internet. He asked someone he trusted would give him the right key.

Re:RSA is a fragile cryptosystem by rakoo on Tuesday July 09, 2019 @04:06AM (#20389811)
How are you sure it's her key ? That's the real problem
Re:RSA is a fragile cryptosystem by maxerickson on Tuesday July 09, 2019 @07:55AM (#20390869)
The one that gets published on multiple social media accounts, a personal website and in the New York Times?

It isn't real ambiguous.

For instance, Snowden had someone tweet a key fingerprint: https://theintercept.com/2014/10/28/smuggling-snowden-secret...

Re:RSA is a fragile cryptosystem by rakoo on Tuesday July 09, 2019 @09:23AM (#20391418)
That's a pretty good way of making sure, because you defer trust to the intermediaries. While it definitely works for high profiles like this, it is obviously not scalable for larger audiences
Re:RSA is a fragile cryptosystem by sk5t on Monday July 08, 2019 @09:30PM (#20388266)
Maybe we shouldn't take security advice from folks with no need for security that is obvious to them.
Re:RSA is a fragile cryptosystem by jancsika on Tuesday July 09, 2019 @11:17PM (#20398911)
Ok. Take if from the maintainer of GPG:

https://lwn.net/Articles/464137/

Hint: TOFC is a lot like what I described above, with the added usability that you don't have to type "yes" every time like a chump.