--- layout: post title: Logs for the MRL Meeting Held on 2020-04-08 tags: [dev diaries, crypto, research] author: asymptotically / Sarang --- # Logs **\<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