Moglen on Freedom Box and making a free net [LWN.net]

Moglen on Freedom Box and making a free net

Posted Feb 9, 2011 1:38 UTC (Wed) by imitev (guest, #60045)
In reply to: Moglen on Freedom Box and making a free net by kleptog
Parent article: Moglen on Freedom Box and making a free net

Well, there's already a lot of research done in this area, just do a google query for "routing in ad-hoc networks". For instance:

http://en.wikipedia.org/wiki/List_of_ad_hoc_routing_proto...

I worked on routing and security in ad-hoc network 10 years ago, when it was still "academic bleeding-edge" (but was a technology already well known to military: I remember one application where they would drop many sensors from a plane and these sensors would manage to communicate with each other and route back data to a central station).

The key thing is that nodes do not know the full network topology, only their first neighbors (ie, in the radio range perimeter). Then, if you want to add efficiency to the routing protocol, nodes can also discover 2nd range neighbors (neighbors of your neighbors), and even 3rd range but then it's not very efficient: you begin to have a lot of traffic only to update each node database when nodes move in and out of radio ranges.

Then, routing has a lot to do with graph theory, only that you just know your neighbors. So based on some logic you decide to send to the neighbor you think is the best, this neighbor does the same, etc. You have to record the path in the packet, to avoid loops, and know which nodes to avoid if the packet gets back to you. There's also a handful of other problems (eg. rogue nodes dropping packets, ...) that makes all of this a poor-performance network.
However, for "static" networks with no moving nodes like sensors, alarm transmitters, ... it works much better since you can learn a lot more about network topology (Xth range neighbors) and just do path discovery when your didn't receive ACK your packet reached destination (in a very dynamic network you would do it almost for each packet).

For sure a lot has changed since 10 years, but by that time, "real-world" application that would Just Work were with static ad-hoc networks, while dynamic ones were just a geek/academic research area with too many shortcomings. So, yes, a static ad-hoc network could be used in a city, but then you still need to get "out" of the city and for that you'll need uplinks to internet, and these can be switched off (not so easily if - say - you use several satellite uplinks).

to post comments

Moglen on Freedom Box and making a free net

Posted Feb 9, 2011 6:32 UTC (Wed) by jmorris42 (guest, #2203) [Link] (4 responses)

> but was a technology already well known to military

Were any of those (or any since) designed to work in an environment where all of the nodes weren't ultimately under one command and control authority? As in, sure you can airdrop a load of self organizing sensors or repeaters IF they are all equipped with common keys. But what if the op force gets their mitts on one for a few days? Detecting a node sending bogus (hacked or just malfunctioning) route information doesn't sound easy even in a controlled situation like an airdropped network, doing it in a 'download this .deb and install it on your plug computer' setting is a nightmare.

Making a network of semi-reliable links work isn't that hard, see FTN networks from the pre-Internet BBS world for just one example. Making them work in a real time Internet like environment is a little harder. Making them work without any central authority (even IANA can become a central Internet chokepoint in any situation longer than a few weeks) at all hasn't been done yet. Then add the design requirement that it stand up to rogue nodes, spam gangs, criminal organizations trying to hijack the network and/or individual nodes for identity theft, credit card harvest, etc. and finally the dedicated physical and R&D might of nation state actors is asking a bit much of a rag tag band of hackers. A way needs to be found to level the field a bit. We probably need a nation state or other similar empowered actor involved in the design, they have the resources.

> these can be switched off (not so easily if - say - you use several
> satellite uplinks).

I can't believe anyone clueful enough to have written the rest of the post added that. Sat links are the easy chokepoint if one of the very few nation states that operate the birds become involved. For example, just how many ground control stations are responsible for every sat with a footprint covering Egypt? In the case of the US I'd bet ~100% of Internet or video capable birds with a footprint on the US are ground controlled from CONUS.

Yes it would work in the current case of Egypt since one could probably find a bird willing to sell you airtime as all of the other Middle Eastern despot regimes haven't circled their wagons and there are probably a couple operated from Europe, Israel, India or the US with footprints covering some or all of Egypt. But depending on them is only a false sense of security since if the poo were ever truly in the fan, the exact sort of situation this sort of planning is intended for, it will fail.

Moglen on Freedom Box and making a free net

Posted Feb 9, 2011 7:11 UTC (Wed) by imitev (guest, #60045) [Link]

> I can't believe anyone clueful enough to have written the rest of the post added that

I still don't think that was a clueless example.

How to cross international borders: cables, or radio (or people moving their arms with pre-agreed movements, or sending Morse code, but let's say that's not convenient). Forget about cables since they're so easily cut/switched off by any government with any decent control of their borders. That leaves us with radio, which is (just) a bit harder to cut off. But, either you have a PtP wifi link crossing the border from one country to the other, or you have full ad-hoc connectivity, meaning a very dense node network even up to the border, or, you use satellite links. All examples assume that the other side of the link is in a friendly country.
Because of geographic reasons, any city closer than a few miles from the border can't have PtP links. It's also not realistic to think you can go "ad-hoc" all the way through a country's border. That's why I mentioned having satellite uplinks.

You understood that, since you mention you have to rely on an operator covering many countries which are not necessarily so easily shut down by request of a single country (see for instance [1] for the whole Europe). And yes, you're right it's not suitable for large countries like US, Russia, ..., but they're not the only countries out here.

Maybe your post and mine differ in that you're thinking about a 100% failsafe network, while I'm only looking at how to use existing and available technology to mitigate the risk of a global government "switch".

[1] - http://www.tooway.com

Moglen on Freedom Box and making a free net

Posted Feb 9, 2011 8:44 UTC (Wed) by elanthis (guest, #6227) [Link] (2 responses)

"A way needs to be found to level the field a bit. We probably need a nation state or other similar empowered actor involved in the design, they have the resources."

Not necessary. That's the thing about software. Or math. You don't need lots of expensive resources. You just need a sharp mind and some inexpensive commodity resources.

Remember, all software can be "executed" by a human with pencil and paper. Even full .h264 movie decoding could be done by hand on paper, if you give a human the algorithm in English, a stream of paper tape with the raw digits of the encoded movie, and a stream of paper tape to write the decoded frame color values to. It'll be god-awful slow, but it's 100% possible.

Wireless networks can be replaced with people using mechanical means of communication. Displays can be replaced with paint and canvas. Input devices can be replaced with vocal cues or hand gestures. Storage can be replaced with paper or stone. Compases and gyroscopes can be replaced with simple mechanical devices. Even complex electronic interfaces like a GPS can be replaced by an external GPS unit with a digital display read by the human "interpreter" of the code.

This is different than physics, in which the laws and math we are given come not from thought but from observation, with increasingly accurate physics formulas requiring increasing intricate and expensive equipment (like the LHC) to observe things we can't otherwise see.

It's also different than engineering, in which the thoughts cannot be executed by a human. Even if you think up the perfect catapult design, at some point you need to gather the wood and metal and stone to actually build a catapult if you want to launch rocks.

When it comes to software, resources have always been pretty much irrelevant. All you need is the right brilliant person trying to solve the right problem. Software is just math, and like math, the big breakthroughs in software almost never come from governments or megacorps. They come from universities or often even just independent minds working towards an interesting problem that piqued their interest.

When it comes to manufacturing chips and devices that encode software, you need resources. That ceases to be pure CS/math and becomes engineering. If the world simply needs new algorithms and protocols and designs that run over existing wireless hardware to get these new mesh networks, though, then the engineers don't need to get involved, nothing but commodity hardware needs to be paid for, and big resources cease to be relevant.

Moglen on Freedom Box and making a free net

Posted Feb 9, 2011 19:27 UTC (Wed) by martinfick (subscriber, #4455) [Link]

Projects requiring large resources do not require nation states either, that is what the concept of a corporation is for, to pool together resources. It's just a lot easier to waste money on something that costs more than it returns indefinitely with a nation state (so we, naturally see more large projects for vague things such as: "for the good of mankind, for everyone, ...", than we do in the commercial world), since a nation state's projects do not have to be sustainable (for real, not via propaganda) since you can always tax more.

Moglen on Freedom Box and making a free net

Posted Feb 15, 2011 5:37 UTC (Tue) by jmorris42 (guest, #2203) [Link]

> nothing but commodity hardware needs to be paid for,
> and big resources cease to be relevant.

Really. Creating Linux/GNU/X/etc was basically a rewrite project for the first decade, even now most of the work is more improving the existing codebase than inventing major new things. Yes some major new things do happen these days but it isn't the majority of the effort.

Now compare to this proposed 'Internet as it was supposed to be, nuke proof, private, perfected' idea. There aren't even any good theories in the academic world to take and run with. So phase one isn't even something for code monkeys, it if for math geeks, network and game theory nerds, etc. And remember that the final product has to withstand active attack by the almost limitless resources and manpower of nation state actors.

So what is the biggest Free Software organization currently. Does it have the resources to build thousand node test networks and then fund thousands of man hours by 'the best of the best' to trying to break it? If any did is it not reasonable to assume they might would have made such a hardening effort at things like Firefox, Glibc, Apache, BIND, etc. already?

That is the big problem with this notion, it not only requires a new breakthrough in network design it will almost certainly require a level of software reliability in the face of an unprecedented level of active attack that has never been achieved to date. Children break Windows and IE, serious Black Hats break LAMP servers. Is there anything the NSA couldn't break if they were desperate? Or the Chinese intelligence agencies? If the final proposed system can't, with a high confidence backed with hard maths, claim to be resistant to such determined attackers then it isn't worth a damn.

To deploy a system as is under discussion that isn't secure will only get a lot of people killed when they foolishly rely upon it and at the critical juncture the secret police round them all up. So either the required miracle in design has to also be a design that can be 100% private, untracable and yet verifiable regardless of implementation bugs or compromised communications links or the fielded implmementation has to prove 100% reliable when the day comes.... and it will probably be put to the ultimate test at most one or two times.