tevador <tevador@gmail.com> writes:
Hi all,
Hello tevador, thanks so much for your work here and for the great simulation. Also for the hybrid attack which was definitely missing from the puzzle. I've been working on a further revision of the proposal based on your comments. I have just one small question I would like your feedback on.
3.4.3. PoW effort estimation [EFFORT_ESTIMATION] {XXX: BLOCKER: Figure out of this system makes sense}
I wrote a simple simulation in Python to test different ways of adjusting the suggested effort. The results are here: https://github.com/tevador/scratchpad/blob/master/tor-pow/effort_sim.md
In summary, I suggest to use MIN_EFFORT = 1000 and the following algorithm to calculate the suggested effort:
1. Sum the effort of all valid requests that have been received since the last HS descriptor update. This includes all handled requests, trimmed requests and requests still in the queue. 2. Divide the sum by the max. number of requests that the service could have handled during that time (SVC_BOTTOM_CAPACITY * HS_UPDATE_PERIOD). 3. Suggested effort = max(MIN_EFFORT, result)
This algorithm can both increase and reduce the suggested effort.
I like the above logic but I'm wondering of how we can get the real SVC_BOTTOM_CAPACITY for every scenario. In particular, the SVC_BOTTOM_CAPACITY=180 value from 6.2.2 might have been true for David's testing but it will not be true for every computer and every network. I wonder if we can adapt the above effort estimation algorithm to use an initial SVC_BOTTOM_CAPACITY magic value for the first run (let's say 180), but then derive the real SVC_BOTTOM_CAPACITY of the host in runtime and use that for subsequent runs of the algorithm. Do you think this is possible?