[liberationtech] New protocol sacrifices bandwidth for metadata privacy

[Aymeric Vitte]

Hi,

Yes, indeed x the number of keys you hold, 1 billion is exagerated but 
30000 seems small.

I don't know what is the state of the art regarding this but is there 
not a way while parsing the slots to determine that this one might have 
your key so you don't have to decrypt everything and just decrypt the 
slots that might have it? (I have a similar issue with Peersm to check 
the pieces)

Regards

Aymeric

Le 08/08/2014 18:50, Marc W. Abel a écrit :
> On 08/07/2014 05:57 PM, Aymeric Vitte wrote:
>> Because the obvious next question is: if the clique is 1 billion peers,
>> they all keep their time decrypting the 34 slots x 1 billion time every
>> x time to find out who has their keys.
>
>
> Hi Aymeric,
>
> It's worse than you propose.  It's actually 34 slots x 1 billion time 
> x [the number of keys you have on hand to try].  But there are 
> mitigating factors.
>
> 1.  Your machine negotiates bandwidth use with these 1 billion peers. 
> If you've configured it for 50,000 bps total, the fraction you need to 
> decrypt is 95% of that (the remainder is used for discovering peers), 
> so 47500 bps.  There are 4608 bits in one of those packets, so about 
> 10.31 packets per second, or 350 (ish) decryption attempts, per 
> second, per key that you have.  My CPU is an Intel Core 2 Quad Q8200 
> going at 2.33 GHz, and it takes 2.1 microseconds to try a slot.  So 
> CPU use at 50,000 bps is about 0.074% of one core per key that I might 
> have to consider.
>
> 2.  Of course for that size clique, assuming everyone connects at the 
> same speed, it's going to take 37 months to work through everyone one 
> time under these assumptions.
>
> I say a little more about why I don't perceive this as a problem at
>
> http://clique.freeforums.net/thread/5/clique-unscalable-protocol
>
> In a nutshell, Clique is designed to solve a very narrowly defined 
> problem, and does not expand nicely for every communication need. A 
> billion peers aren't going to be coming, at least not with the world 
> anything like we know it today.
>
> Today there are exactly two peers online, so there's ample room for 
> growth.  I hope you might consider trying at least clique-scheduler, 
> as it would be a big first in terms of crossing national boundaries.  
> That much isn't hard to set up; adding the cipherer and deliverer 
> scripts can be done as time and interest permit later.  You can either 
> configure a very low total speed directly
>
>      BitsPerSecond 100
>
> or specify a minimum spacing between packets to any given peer
>
>      MinimumSecondsBetween 3600
>
> so it treads lightly on your Internet connection.
>
> Marc
>

-- 
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