[tor-talk] hidden services and stream isolation (file transfer over Tor HS speedup?)

Fabio Pietrosanti (naif) lists at infosecurity.ch
Sat Sep 8 17:59:03 UTC 2012


On 9/7/12 6:13 PM, Nick Mathewson wrote:
> So, if i would do a piece of code that want to "benchmark" the
> performance of different full-circuit to a tor-hs, i may just:
> - setup two Socks port 9050,9051, 9052, 9053, 9054,9055
> For certain values of two, sure.
:P
>> - create 5 connections using different socks port
>> - exchange traffic to benchmark bandwidth and latency
>> - pick-up the faster one
> I was with you to this part.  I thought you were trying to benchmark
> performance, not pick the fastest one at the expense of hosing the
> network.
mmm, well this questions didn't come exactly from that need.

Let me explain.

That step come while brainstorming with hellais and vecna about a file
upload system for big files that should try to optimize at maximum the
transfer over a TorHS with Javascript /web browser.

While making big files transfer over a TorHS, there is the risk to went
into very low-bandwidth circuit or even unstable circuits due to the
length of a TorHS connection path (7 hops right?).

The idea is:
- to split the files that need to be transferred in chunk of fixed size
- then send that chunks over multiple sockets
- every new chunk has to be sent, open a new socket trough a different
Socks port (so trough a different tor circuit)

That way each chunk would have a different circuit established,
bandwidth be shared among more nodes, reducing the likelihood to
encounter a low-bandwidth circuit.

The chunk maybe something like 1Mb sized and the parallel channels maybe
5 or 10.
Does it may provide good benefit to file transfer process over Tor HS

-naif


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