diff --git a/_posts/2019-03-11-logs-for-the-Monero-Research-Lab-meeting-held-on-2019-03-11.md b/_posts/2019-03-11-logs-for-the-Monero-Research-Lab-meeting-held-on-2019-03-11.md new file mode 100644 index 00000000..8c619d0e --- /dev/null +++ b/_posts/2019-03-11-logs-for-the-Monero-Research-Lab-meeting-held-on-2019-03-11.md @@ -0,0 +1,198 @@ +--- +layout: post +title: Logs for the Monero Research Lab Meeting Held on 2019-03-11 +summary: Network upgrade, Point release discussions, MRL work, and miscellaneous +tags: [community, crypto, research] +author: el00ruobuob / sarang +--- + +# Logs + +**\** Our meeting begins presently +**\** Let's go ahead and get started. Agenda is here: https://github.com/monero-project/meta/issues/314 +**\** howdy everyone +**\** 1. GREETINGS +**\** hi +**\ \** Hello! Biking, in soon. +**\** hello! +**\** Let's recap 2. NETWORK UPGRADE +**\** Kudos to everyone for a successful first upgrade +**\** I don't recall when the second was slated to occur, since block arrival was stunted +**\** Any thoughts on the upgrade after the fact? +**\ \** Hi +**\** I believe it was dEBRUYNE who wanted an upcoming meeting specifically to talk more deeply about the future of PoW +**\** anyone monitored the "old chain"? if there have been this large amount of asics on there, and not turned off it should be visible +**\** I believe sgp\_ ran some blackball numbers on it +**\** and found essentially nothing of interest +**\** but as far as hashrate, I am not sure +**\** yeah, no chain reactions so far, very few known spent outputs through reused key images +**\** impact on network privacy so far is essentially 0 +**\** sgp\_: were the key image reuse numbers for only v9 and v10? +**\** yes, just those two +**\** great, thanks +**\** Relating to this, we can also introduce 3. NEXT POINT RELEASE +**\** Not all desired non-consensus changes made it in to this release, so Sometime Soon (tm) will be a point release +**\** BP optimizations will be one nice addition +**\** I would like output selection to also be included... we talked about it at length at an earlier meeting +**\** sarang: Correct. It's a topic with a lot of depth that requires an extensive discussion imo +**\** suraeNoether: do you have a current recommendation for output selection? +**\** i'm running into problems testing the matching code, based on this problem too +**\** Here is a discussion of the different algorithms: https://github.com/monero-project/meta/issues/307#issuecomment-466514757 +**\** iirc the output lineup method performs quite well +**\** I prefer it among the others that were tested +**\** But it's a change that deserves more than two thumbs-up :) +**\** there is no optimal solution, but some solutions are better than others and the output lineup method is more reasonable than the other proposals, and i have no new proposals to make (yet) +**\** I updated the sim code (link in agenda) to examine the output weighting in more details +**\** Hopefully the BP optimizations are less contenious +**\** uhm i think i have one possible proposal that i want to chat about with you by side channel to hash out some details +**\** sure +**\** We should have a formal recommendation before whatever date is set for the point release code freeze +**\** Anything else relating to the point upgrade that ought to be discussed? +**\** ping moneromooo perhaps +**\ \** I just want timelines. Nothing to say on content. +**\** hi +**\** What's the question ? :) +**\** I don't know about any date. Depends when we get all the stuff on master ready really. +**\** Anything relating to the next point release you'd like us to discuss? +**\** None that come to mind right now. +**\** ty +**\** In that case, let's move to 4. ROUNDTABLE +**\** suraeNoether: care to go first? +**\** OK, I can go first instead +**\** ok +**\** aha, go ehead +**\** heh +**\** Well, my simulations for the matching code are to the point where i'm running a matching on some test data now to generate a confusion matrix. +**\** i'm also editing the manuscript describing the whole process +**\** one of the problems i'm running into is actually simulating our output selection in part because it's not clear which direction we are going yet +**\** and it occurred to me that this could help inform our choice of output selection by seeing if one of these possibilities makes matching easier or harder +**\** IMO matching expect spend with proper weighting seems optimal enough from a purely timing perspective +**\** (leaving out questions of binning etc) +**\** when i say easy or hard i don't mean in terms of time, because as we've seen matching is essentially super duper fast +**\** i mean in terms of false negative and false positive rates +**\** but you are 100% on that +**\** aw shucks +**\** i'm working on a variety of other side things but i'm shooting for this matching paper to be complete and published some time in the next 2 months +**\** Excellent +**\** if we get more speakers for the konferenco, then i won't be speaking, but otherwise i will probably be presenting on this at the konferenco +**\** Neat; anything else of interest to share? +**\** that's all i have today, thanks! +**\** Righto +**\** I have a few things +**\ \** The line up is looking great btw! Fantastic effort for a first konferenco +**\** catching up on lots of reaidng in algebraic geometry :D +**\** First, my next FFS/CCS will be posted soon +**\** As was discussed here, in -community, and elsewhere, the request will be for immediate payout +**\** This means both donors and I know the actual value of the donations +**\** Since this is a big change, any questions or comments on it? +**\** (presumably suraeNoether will be doing the same arrangement) +**\** i'm in support of this, and i will indeed be mimicking this +**\** Folks who do not trust us to run with the money should, of course, not donate +**\** But my hope is that our records have shown we're good for it :D +**\** happy we came to that solution eventually, hopefully will be better for your guys +**\** Thanks to binaryFate and others for agreeing to this change +**\** yes the idea is that donors being careful should discourage randomers to do the same +**\** The CCS posting will \_very\_ clearly state the arrangement, so there is no confusion +**\** If you figure out the markdown +**\** Yes indeed +**\** Technically, it's within the existing rules as stated: one milestone, which consists of "sarang starts working" :) +**\** Second, the paper that suraeNoether and I have been collaborating with external researchers on (DLSAG et al.) is in final review now +**\** We've been asked not to share it before it's released as a preprint, as a courtesy to all authors +**\** \*nod\* +**\** It has some great details on useful constructions that I'm sure we'll discuss at length after the preprint goes to IACR +**\** it'll be submitted for a conference as well +**\** Third, I wrote up some additional tests and code for Bulletproofs MPC +**\** sarang: How does this work if the proposal is not fully funded yet when your period starts? +**\** Two options: either the bulk is paid out and it stays open until filled +**\** or it all sits there until fully funded +**\** I prefer the first, but am open to discussion +**\** Regarding Bulletproofs MPC, real\_or\_random had some great thoughts on this before the meeting (but I won't put him on the spot) +**\** i imagine that the important part is laying out which way it goes in the proposal +**\** the question has to do with what a malicious player can do +**\** We chatted about the fact that an evil player could try to pull what amounts to a cancellation of partial proof elements, effectively setting the inputs to the hash that generates a F-S challenge +**\** I couldn't find a way that this could be used as an exploit, aside from obviously generated an invalid proof +**\** but the security proofs for BPs do require that F-S challenges are uniform +**\** I had neglected that point when I had thought about this earlier +**\** My strong suspicion is that proof elements are still uniformly distributed in the presence of a dishonest challenge due to the prover's randomness, and that you still get zk in this case (but not provably) +**\** Moral: if we do anything in the future that requires/desires this scheme, these things would need to be considered +**\** Any questions/comments relating to this? +**\** allrightythen +**\** i think we should continue to ponder it and write something up formally about the BP MPC schemes +**\** Well that's the thing... there's really nothing to write formally +**\** You can probably solve all the theoretical woes by having all players commit to their proof elements before multicasting them +**\** then an honest prover is guaranteed uniform F-S challenges +**\ \** Sorry but I'm a little out of the loop here. What exactly are BP MPC for? something to do with multisig with BP? +**\** it's nice to think about collectively computing BP range proofs, but I'm still v curious about the coinjoin approach that we are considering on the larger scale. +**\** Ideally, untrusted parties could generate single BPs for outputs +**\** after all, it's hard to even think about threat models unless we know how these things will be used in practice +**\** Sure, this is all pie-in-the-sky right now +**\** learninandlurkin: collaborating with friends to compute a range proof for a coinjoin style transaction, so that the participants don't reveal their amounts to each other +**\** But yes, the threat model would be very different depending on how the rounds go +**\** Finally, suraeNoether had shown me this a while back: https://lelantus.io/lelantus.pdf +**\** agreed on the commit-and-reveal; expensive but usually does the trick to ensure participants can't be rewound inappropriately +**\** An interesting application of some of the fundamentals behind Bulletproofs and the old StringCT scheme +**\ \** So... allowing multi-input transactions where each user doesn't know the amounts of the other inputs? Sounds useful +**\** learninandlurkin hence our interest in nailing down threat models \*nod\* +**\** I've been playing around with some of the math in that paper to see what nuggets could be extracted +**\** oh i had a brief thing to point out: isthmus and n3ptune at noncesense-research-lab answered one of my requests and we now have a complete empirical distribution of number of inputs and outputs per transaction +**\** forgot to mention this: +**\** Neato, where is this distribution to be found? +**\** https://github.com/noncesense-research-lab/tx\_in\_out\_distribution +**\** the data surprised me +**\ \** I prefer the first, but am open to discussion <= I'd be OK with the first, but perhaps it would be most convenient to use a rounded number +**\** e.g. if 211 XMR is funded, pay out 200 +**\** You won't believe what's in tx\_distribution\_in.csv! +**\** Mebbe malware +**\** :P +**\** super heavy tails for one thing, and a rootkit for another +**\** dEBRUYNE: perhaps a full payout at date X, and then a second payout at either date Y or completion, whichever comes first +**\ \** I prefer the first, but am open to discussion <-- donors will have no incentive to fund in time, it will drag till the end of the period +**\** binaryFate: how would you do it? +**\** I like the incentive to donors of you proposing something and getting to work on it only if funded +**\ \** I imagine coinjoining going on would really complicate output selection. Or is there some idea where they work off each other to get rid of heuristics? +**\** Depends on how timely it is +**\** learningandlurkin coinjoin brings a whole new nightmare to the party. does everyone bring their own mix-ins? certainly nothing is to stop a malicious party from coinjoining with a bunch of badly selected mix-ins +**\** A ring is one person only. Fake output selection is untouched. +**\** Well each input signs with its own ring +**\** ^ +**\** That person makes their own ring, yes. Otherwise others would know which is the real out. +**\** The benefit is breaking the assumption of one-party control of outputs and the link to the input rings +**\** What about simple attack of using the same 10 decoys as one of the other participants? +**\** ^ +**\** Is parasew, nevvton, or txmr in the channel? +**\** mmm you don't know which are decoys, nevermind ^^ +**\** If this moves forward, hopefully we can determine the necessary practical security for BPs +**\** If we can't aggregate, they'd have to be separate for each output +**\** my beard is getting very thoroughly stroked this morning. much to think about... +**\** I believe we'd get practical security without player commitments, but not provable +**\** Anyway: does anyone else wish to share interesting research before we close? +**\ \** Yes it sounds like the interplay between coinjoin and ringsigs will require some diagrams for me to ever understand. Could get complicated. +**\** i think you would want a commit-and-reveal stage for everyone to see the ring members to prevent malicious ring intersection in the coinjoin +**\** MoneroCoinJoin: an easy 14-round process! +**\** isthmus and i have been chatting about methods of extracting the true spend-time distribution from the monero blockchain without knowing exactly which outputs have been spent +**\** that's a very nascent conversation, though I think it'll end up being a very straightforward project +**\** Discussions in #noncesense-research-lab I presume? +**\ \** so, truish spend-time distribution +**\** Are there regular meetings on this or just continuous discussion? I had been working on this at some point and have some code around aiming to graphically show the real spend distribution +**\** I've seen a few informal conversations in #noncesense-research-lab but didn't know if suraeNoether had something more formal +**\** binaryFate: ah, no, this has been a casual conversation by side channel, but there is clearly interest +**\** i'll start blabbing about it in here more publicly +**\** In the interest of time, let's review 6. ACTION ITEMS and then close to continue discussion afterword +**\** Ok don't hesitate to ping me on this +**\** I will be posting my CCS request soon, tidying up the output selection stuff for a recommendation, getting the DLSAG application paper reviewed and out the door, and playing around with that Lelantus paper when/if I get a chance +**\** suraeNoether: ? +**\** CCS request, working on simulations and measurable numbers for matching, and looking into using our matching code to answer questions about output selection +**\** excellent +**\** also casual github maintenance +**\** Any final questions or remarks before we adjourn? +**\ \** once you guys have made a recommendation for output selection +**\ \** and it gets implemented, what's the next big focus? +**\** There will be much to consider in the realm of refund and payment channels +**\ \** Ooh yes the refund ideas from a while back were really interesting +**\** and some aspects of output selection, like linking spends across rings in txns, is not solved yet +**\ \** Seems like a logical next area of research +**\** and if coinjoin works out, there will be a lot to consider with that +**\** Also transaction relay and network-level anonymity stuff that's still in progress +**\** To quote the Simpsons: "like the cleaning of a house... IT NEVER ENDS" +**\** But on that note, our meeting does end +**\** Thanks to everyone for attending. We're adjourned; let the conversations continue