[tor-dev] WTF-PAD and the future

[Tobias Pulls]

On 29/07/18 15:42, George Kadianakis wrote:
>>> 4) They also told me of research by Tobias Pulls which eliminates the
>>>    needs for histograms in WTF-PAD and instead it samples from the
>>>    probability distribution directly. They think that this can simplify
>>>    things somewhat. Any thoughts on this?
>> Yes this is actually exactly what I want to do with the next iteration
>> of WTF-PAD! The question is what form/model to use for these probability
>> distributions. Right now we're encoding inter-burst and inter-packet
>> timings with some weird geometric distribution determining how long
>> these bursts should go on for, when it might be more natural to encode
>> and sample from length-based distributions/histograms.
>>
>> (Histograms vs distribution is not the problem -- its what they encode
>> and how they encode it that matters).
>>
>> I don't see this paper on Tobias's website. Is it up anywhere yet?
>>  
> Hmm. Looking at the README of wtfpad (see the APE section), I think this
> blog post is the best resource we have on this:
>      https://www.cs.kau.se/pulls/hot/thebasketcase-ape/

Hi George and Mike,

You found the main writeup of the hasty work I did in this direction a
while back, also some comments in the source [0]. Unfortunately my
funding took me in other directions and I didn't want to publish any
paper without spending more time on it. As written on the blog post it
looks like a promising direction, but please also note that the attack
implementation of Wa-kNN used has some rough edges for example when it
comes to time-based features (so robustness of the naive distributions
when moving around the PT server far from a given). If someone wants to
collaborate on this I'd be more than happy to contribute, got funding to
work on Tor-related things again starting August.

Best,
Tobias

[0]: https://github.com/pylls/basket2/blob/master/padding_ape.go