[tor-dev] Hidden Service Scaling

[Michael Rogers]

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On 06/05/14 22:17, Christopher Baines wrote:
> On 06/05/14 22:07, Christopher Baines wrote:
>> On 06/05/14 15:29, Michael Rogers wrote:
>>> I'm interested in your work because the hidden service
>>> protocol doesn't seem to perform very well for hidden services
>>> running on mobile devices, which frequently lose network
>>> connectivity. I wonder if the situation can be improved by
>>> choosing introduction points deterministically.
>> 
>> Unfortunately, I don't really see how anything I have done could
>> have helped with this. Assuming that the mobile device has
>> maintained connectivity during the connection phase, and you now
>> have the 6 hop circuit through the RP, the behaviour from then on
>> is unchanged, and this is where I assume the problems with
>> loosing connectivity occur?
> 
> Right, attempt two, I think I may have misinterpreted what you
> said. The above response relates to client behaviour for hidden
> services. Am I correct in saying that you actually mean hosting the
> hidden service from a mobile device?

That's right.

> If so, then yes. When I implemented the deterministic selection of 
> introduction points, I had to implement a reconnection mechanism
> to ensure that the introduction point would only be changed if it
> had failed, and not in the case of intermittent network issues (the
> degree to which I have actually done this might vary).

Is it necessary to know why the circuit broke, or is it sufficient to
try rebuilding the circuit, and pick a new IP if the old one isn't
reachable?

What about the attack suggested by waldo, where a malicious IP
repeatedly breaks the circuit until it's rebuilt through a malicious
middle node? Are entry guards enough to protect the service's
anonymity in that case?

Cheers,
Michael
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