Topic: XMR vs DRK - page 39. (Read 69755 times)

Let us say I face an attack that will work against 1 round of Darksend but will fail against 2 rounds of Darksend. This could be the Sybil example I quoted above. If the attacker has also partially compromised the masternode network, then I need a sequence of 2 un-compromised Darksend rounds for protection from this attack. In this example sequence 1 will not work

1) Honest Malicious Honest Malicious Honest Malicious

but sequence 2 will work

2) Malicious Honest Honest Malicious Malicious Honest

because of the bold part. So it is the probability of the sequence of n honest masternodes in the chain that matters, and this is much lower than the probability of a single honest masternode in the chain.

That probability depends on every transaction using 4 rounds of mixing (not likely), as well as assembling a 100% complete transaction, which isn't necessary for an attacker to draw hasty conclusions.

It would be nice to know what are the average or most comonly used mixing rounds in a darksend, and calculate probability based on that. Or, even better, calculate attacker probability based on the minimum allowable amount of mixing, to establish a "worst case scenario" or baseline probability.

I'm trying to get my head round this

While I keep trying, maybe you could illustrate with an example of some kind.

For the level of privacy / fungibility desired by the user. For example in his paper http://cdn.anonymousbitcoinbook.com/darkcoin/darksend-paper/Atlas_Darksend-Analysis-v001.pdf Kristov proposes using multiple levels of Darksend to mitigate the impact of a Sybil attack.
One of the problems with the probability arguments that have been made by many Darkcoin/Dash proponents is that they only apply for the most basic level of protection. When one starts to combine attacks then these arguments break down. For multiple rounds of Darksend to provided additional protection one needs a sequence of un-compromised masternodes. So it is not for example the probability of getting a single Darksend round that is un-compromised, with a partially compromised masternode network, it is the probability of getting for example 4 Darksend rounds in sequence out of a 20 round Darksend with a partially compromised masternode network that matters.

Edit: With Monero I can increase my privacy /  fungibility by increasing the mixing level. The equivalent in Darkcoin/Dash to a large degree is to increase the number of rounds of Darksend. The problem is that this will not work with a partially compromised masternode network. I could very likely still end up with and effective Darksend of 1 round. One the Monero side MRL0004 provided an excellent discussion of some of these risks. https://lab.getmonero.org/pubs/MRL-0004.pdf

But if DRK goes to the moon and loads of people dump MNs, it will come back down from the moon as 1000s of coins flood the market.

Question is, I suppose, who snaps up the coins and what do they do with them?

The whole concept is flawed to the core. I have thought about it for lengths and the conclusion was that the only viable solution for anonymity right now is Cryptonote. Nothing comes close to the ease of the blockchain doing the whole work without fuss or uncertainties

What about miners? How are they compensated compared to masternodes?

Well, because this is where the conversation is happening, maybe FINALLY i can get some input to a point I raised in another version of this thread.

The coupling of darkcoin privacy tech to the currency value.

If DRK goes to the moon, as it were, this could lead to an increasingly small number of masternodes - people cashing out. The ridiculous MN rewards may be enough to keep people in, maybe not.

Or, it will lead to a centralization of masternodes to people that can afford the price. And guess who those people usually are?

oh yeah the banks we were trying to get away from, or the governments that can just print money to entice anyone.



and what happens if, to mitigate this, it is proposed to decrease the stake required to 500 drk? forking.

its crazy - the cheaper DRK is, the more secure the privacy tech because anyone can provide the resource to the network..... because thats the whole point of decentralization.........

Enough for what? Could you elaborate please?

Of course the story is not true, that wasn't my point. "Coffee shop owner" doesn't give a damn, he just wants to be paid promptly and efficiently.  DASH payments using darksend (rename coming soon I hope) and instantx produce an untraceable transaction in 5 seconds.  If the coffee shop owner keeps books listing his customers, he can check this transaction off as "paid".  If he doesn't need to know who gave him payment...

This assumes that one un-compromised round of Darksend is enough.

Lets kill this false tale starting now

http://www.scientificamerican.com/article/fact-or-fiction-nasa-spen/

I agree with this wholeheartedly and have listened to fluffy, but he hasn't given any solid reasons why DASH is not fit-for-purpose. He was also wrong about Darksend.

That's a lot of presumptions based off minuscule data. I wasn't disputing the chart--I just had a hunch that the infographic and chart was disingenuous and didn't include all the variables to conclude that dark was as anonymous as Monero (or good enough), and my hunch was proved correct by Fluffy.

Now, if I entertained the idea that it was legitimate and dark was indeed every bit as secure and anonymous as Monero (notice no one in drk land ever makes this claim, but Bitcoin devs praise Monero's anonymity while never mentioning drk--just funny, thought I'd twist the knife a bit), but again I'll play fool to your sales pitch and for the sake of argument say drk is as anonymous as Monero, what then? Well, since i'm an investor, I say, "Hmmm, since anonymity is an even trait, lets go to trait two: leadership. On one hand I have a dev team respected by their peers, with a clear goal, and is open and honest from everything to development to the chance of failure (not only of their coin, but all cryptos) and treats peers whom they respect and who are working on rival technologies with kindness and openness (see G. Maxwell). Now on the other hand I have a dev who lied about when he was going to launch his coin, then proceeds to mine it an incredible speed, locks it to only Linux, and manages to get 1.5 million coins in 8 hours and then claims it was a mistake--cool, did he own it? No, he said it was an accident and then didn't relaunch the coin. So what am I to think? Is he bad with his own project or is he a bold face liar? Doesn't matter--because if he fast mined it and "owned-it", I'd at least know he was ballsy. And if he made a mistake with his code and said "whoops, happens, sorry guys, deepest apologies,"  all would be forgiven once he fixed the code and did a relaunch."

Except that's not what happened. He either lied which means he can't own up to his actions, or he made a mistake and compounded it with an even bigger mistake that was more easily avoidable and would have done much to restore faith in his project. Now compound that with buzz words, fantastic promises, name changes, and little to no respect from well-known devs and you get me saying I'll go with Monero if all things are equal. You guys have terrible leadership and there isn't a gimmick in the world that can fix that.

And yes, I'm not a scientist or cryptographer, but I know who the smartest person in the room is, and when it's not me, I listen. So drowning Fluffy out with claims of you haven't proved it beyond my impossible standard of doubt is like congressman holding up a snowball and claiming, "See, no global warming!"

When NASA first started sending up astronauts, they quickly discovered that ballpoint pens would not work in zero gravity. To combat the problem, NASA scientists spent a decade and $12 billion to develop a pen that writes in zero gravity, upside down, underwater, on almost any surface, and at temperatures ranging from below freezing to 300 degrees Celsius.

The Russians used a pencil.

I would appreciate it too.

I know I've nitpicked at fluffy, but I respect his knowledge and would love to see him properly review DASH. The more I learn about the Monero project the more it interests me, so to see a fair (and I stress fair) review of DASH by fluffy would be very interesting for me as an investor.

OK, let's see. 

(DISCLAIMER: I'm not a mathematician, I just fucked around in a spreadsheet....feel free to rip this to shreds and I will eat humble pie)

If I fire a gun into a crowd the probability of hitting someone is either 1, as you suggest, or very close to 1.

If I compromise 15% of the masternode network (per your example) and, for the sake of argument, everyone is mixing with 4 rounds of Darksend, the probability of tracing a transaction - i.e. having a complete set of data for a transaction is:

1.22265E-66

Let's say there are 1 million transactions in 24 hours, so multiply that figure by 1 million and we get:

0.00000000000000000000000000000000000000000000000000000000000122265

This is how many complete transactions we are likely to sample in one day at 1m tx/day. So divide that into 1 to find out how many days are required to (probably) assemble a complete transaction:

817898000000000000000000000000000000000000000000000000000000

Assuming my calculations are correct (see disclaimer) and I was a betting man, I'd go with firing the gun into a crowd

Of course this doesn't take into account possible extrapolation techniques that fluffy referred to, but does address your point on probability (probably, again see disclaimer )

I knew about that one, but thank you for the links.

Mr. Atlas is an individual, not a group, and I do not know his educational credentials, and they are not listed in the paper nor on his website.
That is not to say that he not intelligent and well-versed in many things crypto-related.

One so far by Kristov Atlas

http://blog.anonymousbitcoinbook.com/2014/09/paper-an-analysis-of-darkcoins-blockchain-privacy-via-darksend/

Paper of the review

https://dashtalk.org/threads/reply-to-kristovs-paper.2325/

Imho to be also considered it was reviewed back in sept 2014 and darksend has been improved several times since then (i.e. masternode blinding)