Questions and discussions related to the FRESCO project (https://github.com/aicis/fresco)
I already wrote the sample programs required (https://github.com/aicis/fresco-samples), but for some reason did not submit it yet. I think there was some issue with mascot or something.
Did he bring FRESCO stickers? 😋
Bar-Ilan will be covered in FRESCO stickers by the end of the week
In your opinion
Hey, I've been playing around with your framework but I am generally new to MPC.
I have currently built a test program with numerical advanced numerical and comparison operations using spdz.
Yesterday I also managed to integrate the SpdzMascotDataSupplier, which obviously slowed down my code.
After some analysis I found out that 90% of the additional time is due to the Comparison operation compareLEQ.
I just wondered if this is to be suspected, if I am doing something wrong or if there is a way around it?
I have currently built a test program with numerical advanced numerical and comparison operations using spdz.
Yesterday I also managed to integrate the SpdzMascotDataSupplier, which obviously slowed down my code.
After some analysis I found out that 90% of the additional time is due to the Comparison operation compareLEQ.
I just wondered if this is to be suspected, if I am doing something wrong or if there is a way around it?
One thing that comes to mind is reducing the modulus bit length and max bit length to 128 and 64 respectively. That should noticeably speed up your overall application. It may or may not give you enough precision (depending on your concrete computation). If you start seeing incorrect outputs as a result it means that your modulus does have to be bigger. The modulus bit length and max bit length are set on the
SpdzResourcePool class.
Ah thanks for the input, I am actually already setting those values over command line trying to figure out what the best configurations are!
Another question then came up: Does decreasing the mod bit length impact the overall security of the protocol or is it just some internal setting?
Another question then came up: Does decreasing the mod bit length impact the overall security of the protocol or is it just some internal setting?
Yep, it does also affect security. If you are using comparisons (or other computations based on bit decomposition), you get 64 for the computational security parameter and 60 (need to double-check that) for the stat. security parameter when you set mod bit length to 128. These are accepted as sufficiently large in the current MPC literature. If you go lower with the mod. bit length however your computational and statistical security params also decrease (because their sum is >= mod. bit length), so things get controversial.
I totally support that point
@rw0x0 hey! sorry for the late reply. there isn't an "out-of-the-box" way to measure offline and online times separately, however there are two things you could do: 1) run the application you want to benchmark with mascot pre-processing and then with dummy pre-processing. the difference in runtime will roughly correspond to the overhead introduced by mascot. 2) you could figure out how much pre-processing material (e.g., multiplication triples) your application needs and measure the time it takes to generate the required amount with Mascot by using the Mascot class (https://github.com/aicis/fresco/blob/master/tools/mascot/src/main/java/dk/alexandra/fresco/tools/mascot/Mascot.java#L27) directly. hope this helps!
hi, thank you for your reply. I thought that I would need some kind of workaround, what i did in the end was, that i added some functions to the spdzmascotdatasupplier, which allowed me to produce a number of triples (and randomelements, etc.) beforehand.
Something like:
public void produceTriples(int el) {
ensureInitialized();
triples.addAll(mascot.getTriples(el));
}
Calling this function before the actual computation had the result, that during the online phase no triples had to be produced. Maybe something like this could be added to the main project? :)
Hi, just wanted to let you know: I was asked by Marcella from the MPC-SoK project to add the FRESCO sample programs I wrote last year to the MPC-SoK repo. Which I did in this PR MPC-SoK/frameworks#21
I hope that is fine with everyone. I didn't really do much to validate that the old code is working an so on, and it might be out of date with recent FRESCO versions (it uses 1.1.2). If she has problems with it I hope you can help her out.
Is there built in functionality to help calculate the communication costs involved while executing a FRESCO app?
Hi, you might want to take a look at the networkloggingdecorator class which can be found in core/logging.
Using this in addition to the socket network tracks all network traffic one party receives over the network is tracked. This can then be analyzed using the getLoggedValues function.
Using this in addition to the socket network tracks all network traffic one party receives over the network is tracked. This can then be analyzed using the getLoggedValues function.
Hi, is there an easy way to run the examples in https://github.com/aicis/fresco-samples with proper preprocessing?
Oh no! The logo is no longer available at https://alexandra.dk/logo/fresco-logo-artwork.svg ... this messes up the README.md! Someone save the logo!
Bumping the version in https://github.com/aicis/fresco-samples gives loads of errors. Are there any plans to update the examples?
@mkskeller Sure -- let me just check how much work it is.
because of this, you can no longer access library functions directly through the ProtocolBuilder, but need to create ComputationDirectories as you need them. This is done using the syntax "AdvancedNumeric.using(builder)"