Logs for the MRL Meeting Held on 2020-04-08

Posted by: asymptotically / Sarang


<sarang> OK, time for the weekly research meeting
<sarang> Let's get started
<sarang> GREETINGS
<sarang> hi
<ArticMine> hi
<atoc> hi
<TheCharlatan> ahoy
<sarang> On to ROUNDTABLE, I suppose
<sarang> I've been working on papers for PoPETs submission, which has been a blast
<binaryFate> hello!
<sarang> As well as some review for a paper on hierarchical one-of-many proofs
<sarang> Finally, plenty of code relating to Triptych
<sarang> Not too much exciting stuff to report overall
<sarang> Any particular questions?
<atoc> hierarchical one-of-many-proofs sounds interesting. can you link the paper?
<sarang> It's not on the IACR yet (and I am not the author)
<sarang> Otherwise, anyone else who wishes to share research topics is welcome to do so
<binaryFate> what are hierarchical one-of-many-proofs?
<sarang> An extension of the Groth proofs used in Triptych and Lelantus that trade size for prover complexity
<sarang> They use a clever layering technique
<binaryFate> smaller size for increased prover complexity?
<sarang> Other way around :)
<binaryFate> ok :)
<sarang> The author thought there could be verification savings in certain cases, but I don't think that's the case if you do batching in the usual way
<sarang> Does anyone else have research topics they'd like to share or discuss here?
<ArticMine> I can give an update on the scaling and fees issue #70
<sarang> Sure!
<ArticMine> I have a solution for the scaling side and minimum relay fee. I am still finalizing the fee ratios
<ArticMine> Basically we can use the long term medium to deal with this
<sarang> Can you summarize?
<ArticMine> Sure
<ArticMine> 1) Put a cap on the rate of fall of the long term medium so that it falls at the same rate it rises
<ArticMine> 2) Make the penalty free zone dynamic as the greater of 300000 bytes and 25% of the log term medium
<sarang> Will that 300K value change with CLSAG?
<ArticMine> No the reference transaction size will to 2100
<sarang> yes
<sarang> But there are no plans to change the fixed-value penalty-free size?
<ArticMine> The minimum relay fee will very close to the old normal fee
<ArticMine> So for the current minimum penalty one the minimum fee will actually go up ~2.5x
<binaryFate> ArticMine what issue/risk is this solution tackling?
<ArticMine> A sudden drop in use followed by a recovery
<ArticMine> In many ways similar to COVID-19
<binaryFate> What would be the shortcomings of the current implementation in that situation?
<ArticMine> https://github.com/monero-project/research-lab/issues/70
<ArticMine> This create the scenario
<binaryFate> Ah, couldn't find issue. Thank you
<ArticMine> The basic problem is a sharp rise in fee that can take months or year to come back to normal
<ArticMine> Also a very sudden drop in the long term medium that also could take months or years to recover
<ArticMine> Issue #70 does not mention COVID-19 but COVID-19 is a very good scenario
<sarang> Will you have specific code or pseudocode soon to allow for simulations prior to any recommended deployment?
<ArticMine> Also there are scenarios where COVID-19 cold lead to a significant demand on the Monero network in terms of transactions
<ArticMine> Yes
<ArticMine> I have all the formulas now except for the fee ratios
<sarang> OK, thanks
<ArticMine> Still working on that
<sarang> I assume you'll post them to the issue you linked?
<ArticMine> Yes that is where I will post this
<sarang> Got it
<sarang> Anything else of note that folks wish to discuss?
<sarang> I know UkoeHB_ recently posted his new version of Zero to Monero
<sarang> not sure if he's around right now
<ArticMine> Yes that is excellent
<sarang> but that's on the getmonero library page, along with a link to the TeX source repo
<sarang> and there was also a suggestion from UkoeHB_ for updating how MLSAG secret data is wiped, which was a great catch (PR now available)
<sarang> Anyone else?
<sarang> Otherwise, we can move on to ACTION ITEMS for the week
<sarang> I will be continuing work on a C++ implementation of Triptych for timing efficiency tests
<sarang> as well as some new material for the multi-signer Triptych variant's security model, prior to the PoPETs submission deadline
<Isthmus> Oops, just got back. Nice work Artic!
<sarang> Isthmus: do you have any research or topics you'd like the group to discuss?
<Isthmus> Ah, I've been neck deep in Zcash all week.
<Isthmus> https://twitter.com/Mitchellpkt0/status/1245769462172745728
<monerobux> [ Mitchell P. Krawiec-Thayer on Twitter: "Several unique phenomena in the #Zcash transaction lock_time field. Most make sense: 0, block heights, unix timestamps, delayed broadcast. Still trying to under ] - twitter.com
<Isthmus> We did find that funny transaction over in NRL
<Isthmus> Probably more of a novelty than anything else
<Isthmus> Lemme grab the link
<sarang> Anything relating to the Zcash lock times that's been observed in the Monero network too?
<Isthmus> https://gist.github.com/noncesense-research-lab/a90b8bc5f57ffa9fff1a22d1323e5c2c
<sarang> Or any lessons to learn from the Zcash work?
<Isthmus> Monero's lock times look very similar
<Isthmus> Actually there's also 4 bands
<Isthmus> Like this:
<Isthmus> 0
<Isthmus> {1,3,8,10,12}
<Isthmus> {block heights ~ 1xxxxxx}
<Isthmus> and then UTC timestamps
<Isthmus> It's all over the place, and I don't think any of it is enforced, so the lock_time field is really just an arbitrary memo xD
<sarang> In Zcash too?
<TheCharlatan> Did you analyze the distribution of the UTC timestamps as well?
<Isthmus> Lemme try to find that notebook
<Isthmus> Shoot, I don't have it on this computer
<sarang> No worries
<sarang> Any other action items for the week?
<TheCharlatan> So what's up with duplicate subaddresses?
<sarang> Isthmus: were those the only two such examples?
<sarang> You suggested "novelty", heh
<Isthmus> No, there were several, But all very similar, that one is representative
<sarang> hmm
<sarang> Along those lines, it was suggested (last week, IIRC) to move some of the more standardized tx fields out of extra
<sarang> Which wouldn't eliminate strange behavior, of course
<sarang> but could help with distinguishing factors like ordering etc.
<sarang> Any further thoughts on that?
<Isthmus> I'm working on it a bit, but need to move ideas from my head into diagrams. Will share here in a week or two.
<Isthmus> Might have a new approach, but tbd
<sarang> New approach to what exactly?
<sarang> Transaction structure?
<Isthmus> Nah, mental models that more accurately describe information leaks
<Isthmus> But it doesn't all fit together yet.
<Isthmus> My action item is making it into something comprehensible by next week xD
<sarang> ah ok
<sarang> Neat!
<sarang> We're coming up on the end of the hour
<sarang> Any last questions, topics, action items, etc.?
<binaryFate> Just curious what's your perception of relevant research over the next 6 months. Everything staled? Business almost as usual?
<binaryFate> Conferences and events are mostly canceled or moved to remote?
<sarang> Oh you mean in the broader research community?
<sarang> Seems that some conferences planned for later in the year are playing it by ear for now
<binaryFate> Yeah, anything relevant to MRL and Monero, how do you see things going?
<sarang> The cancellation of the Konferenco was unfortunate, but necessary
<sarang> Otherwise, calls for papers seem to be mostly continuing as normal, which is great to see
<binaryFate> ok good to know thank you
<sarang> Perhaps bored academics stuck at home will be more eager to read and review new research too
<binaryFate> and go straight for journals :)
<Isthmus> Oh interesting question @binaryFate
<Isthmus> That reminds me, when do we want to research quantum-resistant PoW and/or quantum-resistant cryptography?
<Isthmus> Note that pqPoW isn't super important in the short term
<binaryFate> "before it's too late"
<Isthmus> However it is unfortunate that the Monero transaction I make tomorrow will most likely be decrypted by a quantum computer during my life time.
<sarang> I know that suraeNoether had taken a particular interest recently in post-quantum signature constructions, but I don't know of any relevant efficient results at this point
<Isthmus> It might be nice to have somebody put together a survey of (1) Exactly which pieces of Monero will be broken by quantum computers (2) Potentially Monero-compatible solutions
<sarang> The reliance on discrete log hardness is the kicker
<Isthmus> Yep, it's gonna be tricky.
<Isthmus> But, I believe we can do it! If not, Monero has a very limited shelf-life :- P
<atoc> I feel like the bipartite graph matching project that suraeNoether is verifying will be one of the most vulnerable
<sarang> Graph matching is already parallelizable without a quantum computer
<sarang> It's just a very large search space in general
<sarang> On that happy note, let's go ahead and adjourn!
<sarang> Thanks to everyone for participating
<sarang> Logs will be posted shortly to the agenda GitHub issue

Post tags : Dev Diaries, Cryptography, Monero Research Lab