Tag Archives: 28C3

The best of 28C3

Posted on 2012-01-03 by pappp

I already posted deeper thoughts about some particular talks, but I’ve been watching talks from 28C3 all week, and now that the high-quality permlink videos are up, I want to share some of my favoites. If you would like several hours of background video that will make you a smarter, and possibly better, person, these are excellent.

Roger Dingledine, Jacob Applebaum – How governments have tried to block Tor (Video)
This is the real hacking to change the world for the better situation. These are the hackers who are protecting the people who will get chopped up and mailed to their families for what they say. They deserve all the respect and support in the world. I’m not intellectually equipped to help with Tor, but it is always good to keep humanitarian aspects of engineering in mind – both what you can do to help, and when you may, even inadvertanly, do harm.

Bunnie Huang – Implementation of MITM Attack on HDCP-Secured Links (Video)
I hadn’t really considered the collection of non-infringing desirable things that HDCP ruins (Ever wonderd why Picture-in-Picture stopped being so common? Blame the copyright industry and HDCP.) Bunnie thought about it, and made a consumer-grade product that fixes it. The FPGA crypto+signal work is badass, the hardware platform is awesome, and seeing how it went together as a consumer product is inspiring.

Meredith Patterson – The Science of Insecurity (Video)
Thoughts in a previous post here.

Cory Doctorow – The Coming War on General Compution (Video)
This is why you invite SciFi authors to technical conferences. It lacks the technical depth of most of the other talks I bumped, but it’s insightful and far looking and right.

Evgeny Morozov – Marriage from Hell (video)
This was the keynote, and, unlike most keynotes, really did set the tone for much the conference. The basis of the talk was discussing the issues of large scale surveillance technology, and the role of western companies and governments in creating and perpetuating the industry. A big part of the message is that the technology being paid for for monitoring employees in commercial settings and “lawful intercept” is being sold to authoritarian governments for whom such technologies would otherwise be out of reach, to hunt their citizens.
I thought the Tor talk above actually made a more forceful argument, but this is a better starting point. The hackers have been harping about this for far longer than the rest of the world: these are the people who have been handling the forbidden knowledge computing opens up, and they saw the disaster coming. The freakout isn’t about what large scale surveillance is going to do to hackers – we have the tools to protect ourselves – it’s what it will do to everyone else.

Ang Cui, Jonathan Voris – Print Me If You Dare (Video)
There was some stupid news responses to this (of the “OMG T3H H4XORS WILL BLOW UP YOUR PRINTER” variety) when it was first disclosed, but the hack itself is terribly clever. The reverse engineering foo is tight, the hole they exploit is a classic “I would have done that but … facepalm” kind of hole, and the attacks it enables are a massive evolution of a known mechanism.

Geeks and depression panel(video)
The geek community tends to have depression issues – this isn’t news. The hacker community is an amazing, close, supportive community – this won’t surprise many geeks, but it might surprise others. They talk about this reality. The session is, by the way, really hard to watch. I’m not ashamed to say it made me tear up.

I haven’t seen every session, or even every English session, so I’m no doubt missing some good stuff. There were definitely some other awesome talks; the GSM and USB Reverse Engineering ones were awesome but don’t have quite the same “YOU MUST WATCH THIS” pull to them. I welcome suggestions for other amazing things I may have missed.

Posted in Computers, DIY, Electronics, Entertainment, General | Tagged , | 1 Comment

28C3 The Science of Insecurity

Posted on 2011-12-29 by pappp

This may be the best talk out of 28C3 this year. I was actually more pumped about Cory Doctrow’s “The Coming War on General Computation” 28C3 talk from the previous day, which I shared enthusiastically on G+, but there is more to talk about in this one. It is mostly coached as language/computational theory, but the thesis is that one shouldn’t design protocols in which one is able to construct a message that causes the recipient to perform arbitrary computation in the process decoding of the message. Which is awesome, and their argument for it is convincing. Furthermore, things with the message “Everyone needs to start thinking like language geeks and compiler writers” are bound to appeal to me. That said, I have a couple problems with the talk.

The first problem is purely aesthetic, and mostly unimportant. In terms of presentation, it wasn’t that great a talk. The slides were bland and repetitive, and the speaker kept using problematic mannerisms. The sewearing and such are right in place, but the coughed interjections and such were not good, and the flavoring particles were excessive. I’ve been guilty of most of the above, most of the times I’ve given talks, but the more I teach and speak, the more I become sensitized to presentation, and the internet has made me spoiled on talk quality, with things like fail0verflow’s Console Hacking 2010 at 27C3 last year, or any talk Lawrence Lessig has ever given. On a better note, the Occupy + rage comics visual conceit used throughout is pretty fun.

With that out of the way, on to the techically interesting stuff:

I think they introduce some fundamental problems in demanding context-insensitive protocols. I’m likely misunderstanding, but from working with simple serial protocols, I’m wary of anything that smells like control characters.
Two conceptual problems: indefinite message length, and unwanted control characters. Both arise from the same discussion of automata their thesis is rooted in. The first problem is simple to explain: it is easy to have unbounded input – a message with no stop character will eventually break shit. In practical implementations, message lengths would necessarily be bounded, and part of the problem would go away, but it would still be extremely vulnerable to flooding. They used S-expressions as an example of a reasonable solution – which makes me think “while true; do echo ‘(‘; done”, now you’re DOSed. This could probably be worked around, but it harms the elegance.
As for the second, I don’t see a similar way out. They correctly note that escaping is not a solution, and refer to the delightful field of SQL injection as proof by example. Then they neglect to suggest a different solution, because as far as I am aware, there isn’t one. Given arbitrary data to be transfered, there ARE no delimiters which cannot appear in the data. It’s one of those time-honored intractable problems in CS. The question asked late in the video about badly formed CSV files was poking at the same idea, and they did a great job explaining why field lengths are unsafe, but I’m still unconvinced that there isn’t a fundamental flaw in in-band start/stop characters that is similarly bad. This will require further reading.

My other technical problem: The speakers kept using YACC/BISON as examples of good programming tools in a talk mostly about problems with “leaky” specifications and implementations of things which are fundimentally recognizers. YACC and its ilk are among the worst offenders in this regard. The biggest problem with YACC and imitators is that they require a separate lexer specification, and all kinds of bad things happen when the specifications inevitably don’t quite match. Also, the generated LALR parser breaks when you embed actions, so all your new safety from generating a monolithic parser from a proper language specification goes away. There are better recognizer tools, in terms of ease (and precision) of specification and quality of the generated parser. Personally, I drank the ANTLR cool-aid for that – single specification for the recognizer, no problem with embedding actions (LL(*) instead of LALR), AND spits out parsers in far more languages than any YACC or Bison version I’ve seen.

As an aside, I had independently found and read through the speaker’s old livejournal/blog and some of their research work, without assembling that they were the same interesting person (last paragraph) until now. I also hadn’t associated the identity with her late husband, who was also an interesting person. The computing community is small and close, and it is equal parts amazing and discomfiting.

Now it’s almost 6:30AM localtime, and I haven’t slept because I got interested in something in the middle of the night. What is wrong with me?
EDIT: I noticed that I originally titled this “28C3 Keynote.” It wasn’t. It was the middle of the night. Fixed now.

Posted in Computers, General | Tagged , , | 1 Comment