November 12, 2018

**<suraeNoether>** howdy everyone!

**<nioc>** meow

**<OpenSorceress>** :D

**<sarang>** hiyo

**<TheFuzzStone[m]>** Sup!

**<rehrar>** hiyo

**<rehrar>** …..to quote sarang

**<suraeNoether>** so, let's flip the usual order of the meeting to allow for questions at the beginning

**<suraeNoether>** i like that

**<suraeNoether>** in fact, i'm going to call THAT the new "usual order"

**<suraeNoether>** so, the agenda today is 1) questions, 2) sarang's research this week and last, 3) mine, and 4) any other project discussion that's remotely relevant to research

**<sarang>** roger

**<suraeNoether>** so, someone give me and sarang your top two questions :D

**<nioc>** any updates on Konferemco preparations?

**<rehrar>** I should have a logo and branding guidelines today

**<rehrar>** in regards to MRL, where are we in the churn and privacy formalizations?

**<rehrar>** although I assume this will be talked about with your report of the week suraeNoether

**<suraeNoether>** that is precisely the case

**<suraeNoether>** i'm in the midst of getting hard numbers for a timing for a practical attack

**<suraeNoether>** sarang and i have discovered an anonymity metric that could give us a guideline for "how rapidly we need to chagne our ring size with respect to blockchain size to maintain our current levels of anonymity."

**<suraeNoether>** this is a very useful metric, but it's dangerous to misinterpret it

**<sarang>** Let us shift that to the later agendum

**<suraeNoether>** so we're avoiding making formal proclamations about it, but we are going to use it as a rough guideline for future ring size increases

**<suraeNoether>** agreed

**<suraeNoether>** nioc our conference organizer has been checking out a few alternative venues, and we have already identified some vendors for things like catering

**<sarang>** I have a question… how the hell do I build the dalek bulletproof rust implementation for timing testing??!?!?!?!

**<sarang>** I know jack shiz about rust

**<suraeNoether>** that's an excellent question that occurred to me yesterday afternoon!

**<sarang>** they claim to be bonkers fast, even compared to libsecp256k1 (which seems nutso to me)

**<suraeNoether>** they are claiming some mad speed gainz on top of your already mad speed gainz

**<sarang>** They don't have batch verification yet tho

**<sarang>** (it's on their issue list)

**<suraeNoether>** jfc

**<sarang>** So I want to run timing tests myself to see

**<suraeNoether>** if that's the case, then… man that implementation is bonker fast like what-what

**<sarang>** I don't think they're lying, but I'm also naturally skeptical

**<sarang>** I don't find it terribly relevant since we're already pretty fast

**<suraeNoether>** i suspect that bulletproofs are going to benefit from 40 years of optimizations in linear algebra and ECC very very quickly

**<sarang>** and any changes specific to underlying curve architecture aren't useful for us ATM

**<rehrar>** sarang: what if it's so fast it can reverse the blackchain continuum?

**<rehrar>** somethign to look into

**<sarang>** Ah yes, the chain shrinks over time

**<sarang>** negachain

**<suraeNoether>** the blackchain continuum hypothesis, by tom clancy

**<suraeNoether>** or dan brown

**<sarang>** Anyway, it won't build for me, but I'll verify timings once I get it figured out

**<rehrar> <sarang>** Ah yes, the chain shrinks over time <– it will give extra space to your computer when it goes negative

**<sarang>** However, they also have ideas for non-power-of-2 stuff, which was on the back burner for me

**<sarang>** if it proves useful for them in a way that translates to us, great

**<suraeNoether>** nioc i believe we already have enough funding availalbe to put a deposit down on a location, and I would like to do that before the end of 2018. email invitations to speakers will be start being setn out this week

**<sarang>** nice

**<sarang>** Also our other conference FFS (Stanford) was funded recently, so many thanks on that front

**<suraeNoether>** in general: thank you to all contributors who make Monero Research Lab a funded thing

**<sarang>** suraeNoether and I will learn next month if either of us will be speaking there

**<sarang>** anyway, other questions for us?

**<rehrar>** ne

**<sarang>** In the absence of further questions, we can talk recent research

**<sarang>** This past week, I did two events in Chicago

**<sarang>** one was a hands-on Monero development workshop

**<sarang>** the other was a more general talk on privacy tech

**<sarang>** both videos are on YouTube, linked from the Monero Moon posting

**<sarang>** thanks to the Chicago Bitcoin and Open Blockchains group for hosting me

**<suraeNoether>** Did you have a good time? think you'll do something like that again?

**<sarang>** Yeah, I think it was very valuable

**<sarang>** They had good turnout and excellent questions

**<sarang>** I really like the workshop idea especially

**<sarang>** Aside from that work, I did a good amount of lit review to support suraeNoether's work (discussed shortly) on graph matchings, which was an extension of some earlier analysis we did on spent output analysis

**<suraeNoether>** what was the demographic of the crowd like?

**<sarang>** The workshop was smaller (due to scheduling shenanigans for some participants) but had folks interested in math/CS/development

**<sarang>** The talk had a good mix of technical folks and well-wishers

**<sarang>** It'd be cool to find a way to host an interactive online workshop

**<OpenSorceress>** what would that entail?

**<sarang>** Well, one set of tasks I had them do was use a simple Python ed25519 library to build some constructions

**<sarang>** like Pedersen commitments and Schnorr sigs

**<rehrar>** lol, love the name OpenSorceress. That's funny.

**<sarang>** So being able to do video w/ slides for introductory work would be good

**<sarang>** as well as interactive stuff to help the participants write code

**<sarang>** Then we did some basic RPC stuff

**<OpenSorceress>** like remote pairing?

**<sarang>** OpenSorceress: some situation where the workshoppers could do in-browser code, perhaps, and then let me assist interactively if needed

**<sarang>** I don't know if there is such a thing already

**<sarang>** just spitballing here

**<suraeNoether>** that is pretty awesome, sarang! i'm glad it's online.

**<OpenSorceress>** there is

**<sarang>** orly

**<OpenSorceress>** yeppers

**<OpenSorceress>** -> floobits pops to mind

**<sarang>** Cool, let's discuss after meeting

**<OpenSorceress>** :) ok

**<sarang>** I've also been working to integrate stealth addresses into the RTRSRingStringRuffCT optimizations

**<sarang>** and other minor tasks, etc

**<suraeNoether>** allrighty

**<sarang>** How about you suraeNoether? The graph matching, perhaps

**<suraeNoether>** well, i've been doing the churn and graph theoretic stuff

**<suraeNoether>** as I mentioned earlier, sarang and I have stumbled upon a class of anonymity metrics for graphs such as ours, and this will give us a quantitative basis for maintaining at least our current levels of anonymity as the blockchain gets larger

**<sarang>** It's worth noting that this isn't even new analysis

**<sarang>** But a really clever interpretation of older stuff that suraeNoether came up with

**<sarang>** which is always great in math

**<suraeNoether>** correct, in fact several of these were proposed right around the time Bitcoin was proposed, which amuses me

**<suraeNoether>** 2007, 2008, 2009

**<rehrar>** so are you saying that as the blockchain gets larger, anonymity decreases?

**<suraeNoether>** well, consider the following situation

**<suraeNoether>** let's say something ridiculous like "tomororw Monero goes back to ring size 1"

**<sarang>** It's important to note that "anonymity" here means "anonymity according to a very specific metric formulation that may or may not correspond to a particular threat model"

**<suraeNoether>** what happens? a bunch of blocks are added to the monero blockchain, all of which are totally linkable

**<suraeNoether>** this is an edge case of the following idea:

**<notmike>** Even I could link them!

**<suraeNoether>** heh

**<suraeNoether>** if we take our present system and add a bunch of non-anonymous stuff, we aren't improving our anonymity

**<suraeNoether>** in fact, we are decreasing our anonymity, by essentially diluting our nice big fat blockchain filled with fat ring sigs with non-anonymous data

**<sarang>** At their heart, these metrics use numbers of matchings to relate to some idea of anonymity

**<sarang>** a graph matching is a possible global spend history, of which there will be many

**<sarang>** Think of it as being a guess about true spends that's at least _consistent_, but of course not provable

**<sarang>** My current view of this type of analysis is that, being only a heuristic that could be combined with things like output age, it provides the same types of plausible deniability that ring sigs have always offered

**<sarang>** however

**<sarang>** what suraeNoether was saying about it being useful to examine proposed changes is a good idea

**<sarang>** So you can say "if we increase ring size to X given usage patterns Y, this metric implies that anonymity gets better"

**<sarang>** it's not possible to say things like "anonymity gets Z% better" though

**<suraeNoether>** so, to answer your question rehrar: the Edman anonymity level is *negatively* related to overall graph size and *positively* related to ring size. so we can say "okay, if our blockchain was *this* big, how big of a ring size would we need to have similar EAL to today?"

**<suraeNoether>** the fact of the matter is, though, it very slowly changes with respect to graph size at these levels

**<rehrar>** got it

**<suraeNoether>** to maintain an EAL similar ot what we have today, the blockchain could be 10x larger

**<suraeNoether>** and we might need a ring size of like 15 at that point, or something like that, to make it equal exactly

**<sarang>** I have the same types of broad, non-mathematical questions about global anonymity that I do about rings in general

**<sarang>** If there are 2^64 possible spend histories, is that good enough for our threat models? What if there were only 2^4? I don't know

**<suraeNoether>** sarang actually we can sort of answer that question quantitatively

**<sarang>** Well, for some threat models, "good enough" means "enough reasonable doubt to avoid someone getting in trouble for a spend history they weren't actually involved in"

**<sarang>** and that depends on how your legal system works

**<sarang>** What types were you considering?

**<suraeNoether>** the question an attacker needs to answer is "out of all possible spend histories with a likelihood greater than some C of being the true spend history, what % of these is a specific edge traced?" for example, if in 95% of all plausible and likely histories, edge e sending monero from address X to address Y is included in the matching, we conclude that edge e is the true spender.

**<suraeNoether>** we may be able to quantify our security on an individual level that way, and see how it is sensitive to game parameters

**<suraeNoether>** anyway, 100% of my MRL attention is on this paper right now

**<sarang>** A lot of this (not just graph metrics) seems to be chasing after specific heuristics (some unknown) without a real fundamental idea of what guarantees we want to be able to offer

**<sarang>** Subtly moving from "not provable spending" to "not heuristically-guessable spending" seems like a generally good idea, but it's like swiss cheese

**<suraeNoether>** all of my work so far is highlighting, essentially, the urgency with which we need to replace ring signatures

**<sarang>** true

**<suraeNoether>** and the fundamental problem with using KYC exchanges

**<sarang>** Well, those aren't going anywhere

**<sarang>** and if anything, more people will move to them

**<hyc>** as opposed to DEXs?

**<sarang>** Do you know of any usable ones?

**<hyc>** I assume Bisq works

**<gingeropolous>** bisq .. ?

**<hyc>** haven't used it

**<rehrar>** question on replacing ring signatures…is there any sort of tech (eevn un battle tested) that exists at the moment?

**<sarang>** nor have I

**<sarang>** rehrar: no

**<suraeNoether>** i hear bisq is good, but i haven't used it yet

**<suraeNoether>** rehrar: yes and no

**<sarang>** not without sacrificing trust

**<suraeNoether>** or speed/efficiency

**<sarang>** correct

**<suraeNoether>** there are some trustless set-ups that are unreasonably slow

**<hyc>** if we could do cross-chain atomic swaps with BTC that would eliminate a huge chunk of exchange usecases

**<suraeNoether>** or big

**<sarang>** IMO the goal of the graph matching analysis should be to at least get an order-of-magnitude estimate on Monero global spend histories

**<suraeNoether>** hyc that is 100% correct, and we have all the theoretical framework for that except SPV at this point, but the recent nipopow paper and another recent paper may fix that too

**<sarang>** I'm not convinced this provides an adversary with remarkably more actionable data than existing heuristics

**<OpenSorceress>** how would you go about sussing that out?

**<sarang>** And while it should push us toward better non-ring-sig solutions, I also don't want to FUD our users in the same way that all the other Monero tracking papers have

**<suraeNoether>** it should provide literally the same amount of data, just one is a global approach and one is a txn-by-txn approach

**<sarang>** OpenSorceress: run the analysis on at least a portion of the chain

**<sarang>** suraeNoether: implementing nipopow is a huge undertaking

**<suraeNoether>** yes

**<sarang>** suraeNoether: what do you see as the goal of the analysis?

**<suraeNoether>** provide actionable advice for the monero community on how to mitigate the worst known traceability chainalsysis attack. ultimately

**<sarang>** in terms of ring size specifically?

**<sarang>** given that the EAL is sensitive to it?

**<suraeNoether>** not necessarily, although that is presently a facet of the analysis, yeah.

**<suraeNoether>** i mean, at this point, I think that further increases in ring size without order-of-magnitude increases… i'm not convinced of their efficacy, but i can't say either way at this point

**<sarang>** What's the takeaway from all of this, for the folks in this meeting?

**<suraeNoether>** research is ongoing into the matter

**<suraeNoether>** progress is being made in terms of making actionable recommendations to the community

**<suraeNoether>** but we aren't announcing them yet, until after more consideration

**<suraeNoether>** i'm not sure what you mean

**<rehrar>** good enough for me

**<sarang>** Do you view this a fundamentally new form of analysis that provides adversaries with a lot of new damaging information?

**<sarang>** (as opposed to, for example, the closed-set attack, which really gave marginal information)

**<suraeNoether>** there is no practical way i can answer that question, sarang

**<sarang>** ok

**<suraeNoether>** i'm telling you it's the worst-known traceability attack

**<suraeNoether>** i'm estimating how bad it is

**<suraeNoether>** that's my job right now

**<sarang>** ok

**<sarang>** Anything else of note to share from your side regarding recent stuff?

**<suraeNoether>** not with respeect to MRL, no

**<sarang>** kk

**<suraeNoether>** and i have an appointment i need to get to you guys, so.. peach out

**<suraeNoether>** imagine whirled peas

**<suraeNoether>** etc

**<sarang>** np

**<suraeNoether>** love you guys *smooches*

**<sarang>** Anyone else wish to bring up something they've been working on?

**<sarang>** crickets!

**<hyc>** if you're bothered by blockchain sync speed, get your hands on Optane SSDs

**<sarang>** yeah?

**<OpenSorceress>** Optane SSDs?

**<endogenic>** SSDs?

**<sarang>** Ds?

**<endogenic>** ??

**<OpenSorceress>**

**<sarang>** I store the chain in RAM

**<hyc>** yeah http://www.lmdb.tech/bench/optanessd

**<endogenic>** LOL

**<sarang>** I build a new ASIC for each block that gets added

**<hyc>** Real Men store the blockchain in RAM :P

**<sarang>** Well, I'll officially adjourn today's meeting; thanks to all for attending

**<sarang>** Next week, same bat-time, same bat-channel

**<hyc>** ttyl

**<rehrar>** bai

Post tags : Community, Cryptography, Monero Research Lab