On 22/03/14 14:13, Tom Sparks wrote:
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>> On Friday, 21 March 2014 9:55 PM, Matthew Toseland 
>> <[email protected]> wrote:
>>> On 21/03/14 04:42, Steve Dougherty wrote:
>>>   On Tuesday - March 25th - I have a meeting scheduled with Professor J.
>>>   Alex Halderman [0] to talk about security and Freenet. He is one of the
>>>   people behind such research as Green Dam arbitrary code execution, [1]
>>>   cold boot attacks on disk encryption, [2] and insufficient entropy on
>>>   embedded systems leading to weak encryption keys. [3]
>> Nice.
>>>   What should I say? I'm planning to mention:
>> Bear in mind that nobody, no matter how brilliant, is an expert in
>> everything.
> that I do agree with
>
>>>   2) Would it be possible to run a seed node on campus?
> your campus IT people well want to terminate the node unless you can prove 
> that you run it for legal research reasons
>
>> The only solution other than darknet AFAICS is charging people real
>> money (possibly BTC) to join opennet. This would require a much greater
>> appeal to start with, and more reliable software. In BTC, the funds (or
>> a large part of the funds) would be provably destroyed, possibly with
>> the rest going to FPI or a charity chosen from a list (need to make sure
>> it doesn't go straight back to the guy trying to exploit announcement!).
> paying to access freenet doesn't make sense unless it a private mesh network 
> and you are paying for the hardware
>
> I could see a kevin bacon[1] like people becoming Certificate authority
That's called darknet. We want people to use darknet. It is dramatically
more secure today, much harder to block or identify (especially with
steganography), and with some work could provide a really interesting
level of security (using the social network to build tunnels). The key
point here is your friends don't have to be ultimately trustworthy: On
opennet, the attacker can see everyone and choose who to connect to, and
can quickly approach a specific target location (a key step in some
really hideously bad attacks). On darknet, they have to social engineer
you. Which is doable, but it's more costly.

The point is the most powerful known attacks on opennet rely on "Sybil
attacks", that is, creating lots of (malicious) nodes, or exploiting
announcement protocols to move easily to a targeted location on the network.

The best way to beat this is darknet - a friend-to-friend network.

If you want a secure opennet, you need some sort of scarce commodity: IP
addresses, bandwidth, CPU time, CAPTCHAs, ... And all of these are far
cheaper for an attacker than for a normal user. For example, CAPTCHAs
can be bought (using human beings to solve them!) for $3 per 1000. CPU
time can be obtained very cheaply for an attacker (think GPU mining),
but long calculations prior to getting onto Freenet would be a big
problem for anyone with a slower computer (which could still run
Freenet). Bandwidth is very cheap in bulk; even if you have a really big
network, connecting to every node will be cost effective for a
semi-serious attacker; and it would be rather complex to use scarcity of
IP addresses, and probably to little benefit, as it's likely a serious
attacker can get them fairly easily. And so on. The only way to square
this circle, apart from darknet, is to charge users real money (possibly
as bitcoins) to join the network. But clearly we can't do that just yet.

Anyway if you have a proposal for a certificate authority that isn't
trivial to exploit and doesn't involve either darknet (connecting to
your friends) or spending money, lets hear it. Going to conferences for
keysigning etc counts as spending money, and is much less convenient.
IMHO short of payment or something even more inconvenient the problem is
intractable, if you can solve it you can solve many of the problems with
SSL ... cacert.org??

(Actually, if you consider the broader picture, it's worse than that.
Most of the plausible attackers in the West beyond the bored student
level are already in bed with the NSA, which passes information to
regular law enforcement and presumably to corporations, since we know it
does economic espionage, and which has hundreds of documented internal
abuses, so presumably corporate-level PIs can sometimes get favours ...
and we know the NSA can crack almost anything, are more likely to target
people using obscure tools, and are willing to attack relatively obscure
systems ... there is no hope ... :| And China, Iran, etc, will just
block it, even if they have to do traffic flow analysis and accept some
collateral damage...)

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