I think typically each file would be encrypted with a separate symmetric key. Then you can choose who is able to decrypt it by sticking a header with this key encrypted for various public/private key pairs. Then all you have to do is remove one of the encrypted keys, not re-upload the whole file.

As far as I know asymmetric encryption is never used the way you say in practice. It is too slow. It is used to encrypt a key for a symmetric cipher that is then used to encrypt the actual data. And that "combining your private key and their public key" statement is nonsense. Your private key is useless for securing information originating from you, since your public key is, well, public. It is useful for authenticating that information came from you, which is independent of recipient.

This is all setting aside the fact that once a party has access to some data, "revoking" that access has a sortof squishy meaning because they can just keep a copy of what they retrieved before.

I would expect removing them would be to prevent anyone else being a victim. Rather than marking every page with him on it with a "warning this former faculty was found to have sexually harassed students," the prudent course of action is to shut it all down and sort things out later. While Lewin is no longer active in the courses, they are still active courses and a student might approach him if they didn't know about the issue. There are plenty of other physics faculty at MIT that can fill in the content.

But until recently people usually had equity in their home, so it wasn't a net negative, since the home itself has value and can be sold for more than the cost of paying off the mortgage. But since the financial crisis, there is a decent segment of the population that have negative equity

False equivalency. The latency over satellite internet makes it entirely not equivalent to wired internet.

Well just so you know, I tried DSL via POTS and gave up (with full refund) because I couldn't get more that a few hundred kbps. I have no other cable internet vendor option other than comcast. So I'm in that category of "competition will not decrease" because there currently is no competition. (Actually the FCC probably counts my neighborhood as having DSL access, but it is a fiction.)

Right... transaction reporting. The bitcoin register is public. Everything is reported to everyone. That's how the system works.

Another question you should ask yourself is -- is this legal under educational data privacy laws? The answer is probably not, but as usual with internet things people just ignore the laws.

I have been happily using Friendica for a family network for a while. While quirky, it works, and has a bunch of stuff for interoperating with other sites including facebook and even using RSS feeds. In terms of privacy, development has moved on to redmatrix. The problem being that going to a truly privacy-oriented framework means interoperability is out.

But really it seems like the protocol and the software need to be separated so that different social networking software can interoperate. There is already some of this in friendica for protocols like identi.ca and others. Nominally redmatrix is still largely just a protocol: Zot, but the user interface is progressing.

Sad that neither of these are on this guy's list. I think the wikipedia page on open social networking services is more informative than this article.

If you think this is secure against the FBI you are kidding yourself. Since it is a closed-source app, wickr has control of your private key and they only CHOOSE not to copy it off the device. They can simply be served with a NSL to pull that info from your device. Now if you're only trying to keep things private from criminals and corporations, you're probably good.

Yes the advantage of a multi-party system is that not every policy decision is a nuclear war for control. Parties will ally in different ways on different issues and therefore it is less likely that partisan bickering will hold up general function of government.

But it is perhaps a bigger problem currently the the loudest and most abrasive elements have almost complete control of the public dialog. This is not really a symptom of the two-party system, but of the prevalence and power of advertising-driven media. And, back on topic, data-mining-backed advertising with extensive personal information like facebook can do is frightening.

The linked article is not really even an article, but I think the interesting science topic is that we don't understand where chondrules form. They are somehow formed in the early solar system by melting refrectory elements together. But how and where that melting occurs in not known (http://en.wikipedia.org/wiki/Chondrule#Formation.

It is thought that the formation might be related to dissipation of magnetic fields in the protoplanetary disk or the young sun (so-called magnetic reconnection) but it is not clear. I expect this study is trying to test this type of hypothesis by attempting to ascertain the magnetic field in which the chondrules were formed.

Note that this is NOT the magnetic field causing the formation of the solar system, as stated in the summary. I have no idea where the submitter or editor got that, as it is not in the (non-)article linked. Chondrule formation is a critical process for creating building blocks of planets, but it is pretty tricky to interpret that as the "cause of the formation of the solar system."

So, yes, some of us are a bit irked that the Great Hope passed a conservative health care reform bill.....

Then you are out of touch with reality, since trying to get single-payer through would have provoked a the same sort of overwhelming ad campaign from the insurance companies that it did in the 90s. And the american public is so easily manuplated by this sort of thing that nothing would have happened.

But it probably is a problem if your opponent is a state-level actor. For example, China (and the US probably too) probably monitors connections to known tor entry/exit nodes. Given the attack mentioned, someone using tor in china is safe as long as the server being contacted is known to not be acting in concert with the adversary. However, if the server (or its connection to the tor entry/exit nodes) is also under control of the same adversary, then the connection can be de-anonymized. So this is a problem for chinese bloggers blogging on chinese blogs, but not so much on foreign blogs hosted outside china. Though it appears blog traffic would probably be too small to facilitate a successful attack.

As with another poster, I have learned a whole new meaning to rote memorization. Even in courses in the U.S. that are "just memorization and regurgitation" it is typically not literally word-for-word memorization and regurgitation. I thought that people meant that the tests would be the same problems as the homework, but I didn't imagine it could get to the point where the test was just memorizing and re-writing the solutions, with little regard for correctness. It's like a Brazil-esque caricature of the educational process.

What about RedMatrix and its underlying protocol Zot? (This is what Friendica Red became.) Seems a shame that it isn't even mentioned. But most of the things on the list are oriented toward messaging, not more full-feature peer-to-peer sharing / networking. I think the only downside for Zot is the providor has the key. But you are free to be your own providor or choose one that you trust, and move if that relationship changes.