Bitcoin Forum

Investors Beware:  

• Darkcoin is NOT anonymous.  Every transaction can be automatically traced with a Darkcoin de-anonymizer.
• Darkcoin is prone to several cost-less DOS attacks that can destroy the whole network.
• Darkcoin code was written by amateurs who do not properly understand cryptography.

Source: http://www.reddit.com/r/DRKCoin/comments/2nyifp/darkcoin_seriosuly_flawed_zero_anonymity_and/


From reddit:

hello friends,
please do not get confused by the fact, that I am a fresh user. In fact, I am very actively involed in crypto currencies but remaining anonymous requires certain countermeasures.

IN SHORT
It does not require many words to describe the problem. Darkcoin's code base remembers me of my childhood where I started coding on my AMIGA. Functions that easily can be implemented in O(1) are in fact implemented in polynomial complexity (like O(n5) or something). But this is not the problem.

The biggest problem is, that while indeed being savvy the developers have not much background knowledge about crypto and (in general) the very exact details about the bitcoin/darkcoin/whatever protocol.

After excessively revieweing the code and verifying everything on an offline testbox very scary facts popped up:

• Darkcoin is prone to DOS attacks, there are at least 3 (confirmed) ways you can DOS the complete network at no cost at all. You do not even lose your collateral tx.
• More critical: Darkcoin has no anonymity. There is a very easy and reliable way to link inputs to outputs in every single Darksend (as well as automatic denonimating) transaction.

As I know the open source community, I will not get anything from publishing my ideas and helping to fix them. So I want to inform you, that I will shortly setup a "Darkcoin Deanonymizer" which will for every single darksend transaction be able to link incoming and outcoing transactions.

ALRIGHT, DUE TO EXCESSIVE TROLLING ACCUSATIONS I DISCLOSE ONE OF THREE DOS ATTACKS ON DARKCOIN HERE --- just for a start

Alright, I will disclose one of three DOS attacks right now.

Attack: You can destroy all darksend processes by not signing and not losing any of your collaterals ... sabotage for free basically.

Reason: When you push your collateral to the masternode it is incorrectly checked for validity.

Check: IsCollateralValid() in darksend.cpp - line 874ff

It basically checks:

• are all inputs correct
• are all outputs correct
• wtxCollateral.IsAcceptable(true, false)

however, transaction with a nLockTime in the future are also passing "IsAcceptable". So push a collateral with a locktime 10000 blocks ahead, and you will never lose it because it will not make it into any block thus easily can be replaced by another one with a higher nSequence number.

This is SERIOUS and can destroy the whole network.

3 other DOS points are there as well.

Couldn't this be fixed in about 5 minutes?

I would think so. The more interesting question here is the "Darkcoin Deanonymizer". There are several possibilities here:
1) This is pure FUD.
2) The OP actually sets up the "Darkcoin Deanonymizer" and it works.
3) The OP provides the exploit to the Darkcoin developers and they provide a fix that preserves Darkcoin anonymity.
4) The OP provides the exploit to the Darkcoin developers and they cannot provide a fix that preserves Darkcoin anonymity.

Care to bet on "odd" or "even" above?

probably should check with ole BCX ... heard he's in the market to redeem his name and cause some drama.

Interesting developments, will BCX break DarkCoin? I guess only time will sell, price is currently at 0.00612000

https://lynettenoni.files.wordpress.com/2014/05/popcorn.jpg

"If it bleeds, [you] can kill it." Arnold  Schwarzenegger

He is probably being melodramatic about the dead change anonymity issue. See here: https://darkcointalk.org/threads/dead-change-an-anonymity-issue.3019/

It has been discussed at length with the team and a fix posted by DRK dev here: https://darkcointalk.org/threads/change-contracts-using-atomic-transfers.3067/

Nothing to worry about, if there are code bugs, Evan would release a patch within an hour or two. This has happened a few times before.

Pretty much what I said.


~BCX~

You meant "only time will tell", or did you wanted to say it is selling time?

Not sure what you mean by this, are you selling your coins?

Can these servers be shut down by governments?

First you say darkcoin uses one server, then you are corrected and told the number is more like 1240 individual servers,
but still the venom splats all over my screen.
Masternodes are hosted on different VPS providers, different locations all around the world and will soon be hosted by individuals!

What has servers being shut down by the government got to do with de-anonymization?
Shutting masternode servers down would not de-anonymize darkcoin? I don't understand what your saying?

I think you are mixing stories here.

You are infact talking about the majority of exit nodes on the tor network being FED controlled, and the parallels between tornodes and Darks masternodes.

Currently

1240 Masternodes
($2,952,000)

To have a 40% chance of de-anonimizing the network with 8 rounds of mixing, you would currently have to hold 90% of the masternodes. This means going into the market and buying 1,120,000 darkcoins.
This would push the price of dark into the billions, market would become bullish, removing coins from the market. I don't think someone could buy that amount of coins in the first place.
Also the price of darkcoin being so high, insentivises new investors to buy and setup more masternodes - further de-centralizing the network.

Put up or shut up, fudder.

You're not worth it.

You cannot shut down an architecture which is decentralised.

I think you're confusing the word "centralised" with the "2-tier" and trying to make out they're the same thing. They are not the same thing.

A "centralised" network is one that has a single central controlling authority. A decentralised one is a network that does not. (The clue is in the word single.)

Nor is it a question of number. There could be only 2 masternodes in the entire world and it still wouldn't be centralised because those 2 masternodes could not prevent another 50,000 from spouting up elsewhere. In other words those 2 masternodes do not constitute a central controlling authority.

As for "buying them all up", if you properly think it through to its ultimate conclusion then even that doesn't work. Although it's a hypothetical possibility, Darkcoin belongs to a technological generation which is characterised by open source reproducibility. Everything can be reproduced: if masternode ownership gets compromised, new ones will appear. If the entire network gets compromised, a new one can just spring up elsewhere.

It isn't a viable proposition because there isn't one aspect of the Darkcoin network - or for any other cryptocurrency network - that can't be extended or reproduced. The reason for that. again, is that there is no single controlling authority (i.e. it's decentralised).

Far from being a weakness, Darkcoin's masternode network gives it massive redundancy because whatever the merits of its particular mixing algos at any given moment, they can be re-applied many times pre-emptively as opposed to having "only one shot at it" when a user performs a transaction.

IMO, Darkcoin stands at the door of very widescale adoption right now because in addition to all the above, it also retains the legacy commercial interface which makes it readily adoptable by new and existing vendors.

All round - it's the business !

That's true. For example quite a lot of masternodes are hosted on Amazon and the government could just instruct Amazon to boot anyone off that's hosting a Darkcoin masternode.

But lets think this through for a minute. For that to happen, Darkcoin would have to have been successful enough to pose a significant threat in one way or another. It's not the type of thing that they could do clandestinely.

Secondly, (and this is where the "decentralised" aspect comes in) masternodes can upped in minutes on any server - it doesn't have to be in any particular country or with a commercial hoster. If you take a look at the current coverage map, they're all over the place - the US, Europe, Asia, Russia, Australia.

Thirdly, you're only addressing the technology the way it's configured at the moment. This is an evolving project. It's already blown way past many of the limitations of only a few months ago - not least the fact that the anonymisation is now done pre-emptively rather than in realtime which makes it almost independent of any weaknesses in whatever mixing algorithm is might use due to massive redundancy.

That ability to make such quantum leap architectural revisions to address emerging issues from trialling is thanks to the 2-tier design which keeps the blockchain integrity solid while allowing for more fundamental development in the masternode network. Whatever limitations are imposed by that design, you can expect them to be addressed with similar success as work goes on.

EDIT: In fact it's being done as we speak: https://darkcointalk.org/threads/instantx-testing-v10-17.3083/page-28#post-31968

I agree that the "buying darkcoin to destroy darkcoin" is laughable, your absolutely correct! It's a ridicules idea that one entity could even buy the amount needed to subvert the network in that way, thanks for supporting that.

Definition-Centralize

concentrate (control of an activity or organization) under a single authority.

Masternodes are not quite centralized, as the majority of nodes are hosted on 2 VPS providers (Amazon/Vultr).
This is a problem i agree, but at this point its more of proof of concept, if MN become more profitable to run,
the incentive will emerge to setup your own mini "datacenter" and host the node from your own home.

I'm already considering this.

Now if at least 10% of the current network did this, 126 individual nodes would be live. The hacker would need to attack each node individually.
And so what if he did? Darksend's process picks a masternode randomly, how would the attacker know which node to attack at a specific time if the selection process isn't already determined?

In relation to your comment's on security, I use at least 8 round's of mixing  8)

OP really does seem to be a fudder... :P

I normally stay well clear of these debates, for obvious reasons, but I do get frustrated when I see well-articulated responses from people who are clearly intelligent advocating this obviously broken architecture, mostly through much hand-waving and placating each other.

Masternodes have to be available and connected to in real time in order to be used. Mixing is based entirely on their availability. Thus, in order to control a substantial number of masternodes one merely has to own a handful, and make the rest of the masternode network unreachable.

For even a script-kiddie-level attacker these techniques and funds are easily found.

Need to render 1100 masternodes unreachable? No problem - SNMP amplification attacks will let you use a handful of boxes to amplify the bandwidth under your control. When a datacenter sees a clear flood of traffic for a particular IP address at the datacenter their response is always automatic and the same - their upstream data provider blackholes that IP address at the upstream bordergate. This means that you can use SNMP or DNS amplification attacks to render a dedicated machine (never mind a VPS) inoperable and unreachable to the outside world.

The most critical take away for you today is that this problem is unsolvable at the userland level. In other words, no matter how much dev worship there is there isn't a magical line of code that can be written that can prevent amplification attacks from devices and servers that are unrelated to and unconnected to the Darkcoin network. It is something that cannot be controlled or influenced.

The solution would literally be for Darkcoin to scrap masternodes and go back to the proverbial drawing board to find an architecture that uses passive blockchain mixing or similar, but I suspect it is too late and there are too many stubborn heads for that.

Drk is weak
Buy ShadowCash the next big thing..

That's true.

Not quite, it only applies if the machine runs a DNS server.
Do Masternodes run BIND or something?

Exactly this.

Especially if coming from somebody promoting or owning the website mymonero.com.
Why don't you just blow it off the table, if its so easy?
Or ask BCX to do it, he seems to be open for good and easy fun.

But its an interesting point.
Hosting masternodes has to be on a level.

I'd suggest to move it into the IP6 address space completely and provide any amount of failover IPs for such scenarios.
Many datacenters offer that already, even in the IP4 space.

I have read little things here and there about DarkCoin not actually being anonymous because you have to create anonymity on the protocol level. Monero/Cryptonote has good anonymity because it splits up all of your blocks over different people when you send the transaction but the drawback to this is that it creates more data on the Blockchain. In DarkCoins case, the mixing nodes would present more of a risk since a script could be run in order to link transactions, plus the nodes can be taken offline and disrupt the network.

Anonymity through obscurity. Unless you can actually prove without a reasonable doubt that Address A paid Address Z with a factor of 3^8 pathways, by all means, knock yourself out. The masternodes used per round are random and only know their inputs and outputs. You would need control over all the masternodes in the chain used (however many rounds the user specifies) to be able to knowingly link A to Z.

Right, the most logical of counter-arguments. That "clay base" you speak of has substantial capital behind it. I'd take this "clay base" over a straw house any day of the week.

I won't even speak at the fud in this thread. I think pointing people to this post made in our most recent testing session might help shed some light on the ds+ process.

https://darkcointalk.org/threads/instantx-testing-v10-17.3083/page-36#post-32290

This is only the first 3 rounds :)

This might help if you can't follow that post. It is Evan's talk from a recent crypto conference.

https://www.youtube.com/watch?v=4Y9wO9v2nMw

This is actually a far better problem for an anonymity coin to have than a protocol weakness.

The criticism above is fair enough as far as network serviceability goes, but if it doesn't have any impact on the anonymity of historical transactions in the blockchain and they remain safe, then the job is more or less done.

All networks are subject to DOS attacks, whatever their nature. It's not a significant criticism of an anon-coin to say that it may be exposed to DOS attacks - who cares as long as the blockchain's safe ? Websites get DOS'd, eMail gets DOS'd, everything gets DOS'd. You just mitigate it, setup nodes elsewhere and carry on. The technology and the whole approach evolve to become progressively more optimal and resistant to serviceability attacks.

On the other hand, networks that rely on purely protocol based anonymisation are a ticking time bomb because if a crack emerges then you've got a potential can opener for the whole blockchain's worth of historical data.

That's why I think Darkcoin's got the right approach. If I want to make an anonymous transaction today, I don't give a sh*t about whether it can be DOS attacked tomorrow. But I DO care about my historical transaction staying anonymous.

The other blatant flaw in the "it's vulnerable to DOS attacks" critiscism is that it assumes a static network. The masternode network is not static, it's constantly moving. A masternode can be setup and hosted in minutes and then moved in minutes if need be. It's a moving target "cloud" that is not stuck behind a fixed DOS'able firewall in the way fluffypony alludes to.

So all in all, I think this post, far from exposing any weaknesses, only goes to demonstrate its fundemantal strength of approach in offering massive redundancy and pre-emptive anonymisation using the 2-tier system.

to OP

- pls stop hiding behind fake accounts like Iranianfromhell666 on reddit and now this account on BTC, its just getting a bit sad really.
- thanks for giving Darkcoin some well-deserved attention, 1473 views for a post on BCT is impressive .. since most people in this Altcoin
Discussion Forum are used to trolls creating new accounts and attacking coins i trust most of these readers to prick right through this
post and form their own opinion about Darkcoin and maybe even get a bit more intrigued by it.

Maybe those people will start asking themself questions like : what is Darkcoin about? what does Darksend mean and what does it do exactly ?
what are Masternodes ? how many Masternodes are there and why do they keep growing so fast ? why is Darkcoin getting in the news more and more
lately ? why is it being attacked so much by trolls lately ? What is that Darkcoin InstantX i keep hearing about ?

Find answers to those questions and you my dear readers may have found more wisdom. To help you get started i will provide you with a link to the developer
of Darkcoin explaining some of those questions himself : https://www.youtube.com/watch?v=l1J5iYBpwNY

qwizzie



        

No it isn't - AT ALL - it would be a good idea to read up on terms you are unfamiliar with. An amplification attack uses other devices on the Internet with open SNMP or DNS servers to amplify the attack and flood the target machine with packets so that the data centre is forced to null-route the traffic. It has nothing to do with the target machine - in fact, even if the machine has no services running you can still run this attack, as the routers in the data centre will still route traffic to it.

I have no desire to do that, but that does not mean I won't engage in debate.

A fundamental architectural failure betrays critically flawed thinking on the part of its creators. In fact, such open exposure to Sybil attacks indicates a lack of understanding of the fundamentals of network security - these attacks are so well known that it is as fundamental to the architecture of distributed systems as salted passwords are to the architecture of authentication systems. At this stage arguing that it doesn't have a protocol weakness is nonsensical - it merely doesn't have a protocol weakness that you know of.


A DDoS attack can be rerouted in seconds. Since every node knows every masternode this becomes a non-trivial problem to solve.

Furthermore, masternodes can and will be malicious against other masternodes when the time is right. This is already happening with mining pools in Bitcoin (http://blog.fairlay.com/2014/12/has-cannibalizing-pools-lead-to-latest-decline-in-difficulty/), what makes everyone think masternode operators will be any less aggressive?

lol, if you insist... How's Monero and the inflation working out for you? As your investment dwindles away into nothingness from the nonstop dumps.

And I should clarify, I have no issues with CN or the Monero dev team. Each coin does privacy in its own way. I do have a problem with bullshit being thrown by both sides (and yes, you kazuki, are part of the problem).

If all this is true, then why would someone hiding behind a new account? After all, it is clear that someone wants to knock down the price to buy cheaper ..

wow.....Really Really interesting read. Darkcoin is even scammier than i thought, and thats why I support it 100%!!

Nice trust (https://bitcointalk.org/index.php?action=trust;u=255566) btw, I especially liked this one: "Blatant scammer"

'shocking'... NOT.  No one should ever expect to be completely hidden.  Only way to stop from being caught electronically is to stay completely off the grid... and even then I'm not so sure you couldn't be hunted down if someone wants you bad enough.

Darkcoin is my favorite coin. Have a lot in common

i agree that darkcoin can be easily crashed
someone can destroy it if he got a lot of mining power, and it won't cost a lot of money to do so

anon coins.. uhm no.

unless its so good you don't even know if you have your own coins lol....

check this video out for an idea how easy it can be with the right analysis to see right through mixing and obfuscation.

A Quantitative Analysis of Altcoins — Princeton Bitcoin seminar final project http://youtu.be/x23C1sQg6wQ

And so begins the promised barrage of FUD about Darkcoin that has been seen being planned in various IRC channels for the past few weeks.  Question is, why did ***** ***** choose 25th Feb for it to start?  And if you coin is better than Darkcoin then why not just win out by, er, being the better coin?

If the best software won in life Windows wouldn't exist today unfortunately.

The problem I see with this is.

Say there are 1,240 master nodes on the network. Lets say they are each feeding off a 1Gb pipe

In order to take out 1,240 masternodes you would need at least 1,240Gbps sustained ddos attack. Pretty hard to pull off

You would also have to own a few masternodes to pull off the attack. Therefore making an sizeable investment. And then attempting to destory the value of that investment

Your essentially saying the bitcoin network is just as vulnerable. If thats the case you could ddos 1,240 pools and gain 51% hashing power. Its just not as easy as your making it seem I dont think

Quite simply, unless the BTC price falls to 0.0001 and the cost of spinning up enough fire power to destroy the network becomes negligible, this simply wont happen.

The cost currently and probably alway will outweigh the benefits. If you wish to argue anonymity and some of the bad decisions , then yeah maybe you could prove something. The rest is just nonsense. 

do you really think so? If someone wanted to destroy darkcoin's anonymity to say, catch someone whos engaging in illegal activity, then they(law enforcement) would probably have no issue ddosing all the masternodes, and what makes it even easier is that all the masternode's ip's are in the open.

If its true do it and I'll pay you. I hold a certain interest in dark coin competition. Also it would be better for everyone involved if this monster was killed before it becomes any bigger and hurts even more people. But lets just say ill believe its THIS easy when i see it myself.

There are currently too many barriers for this kind of attack to even make sense. Even governments have spending oversight (lax as it is)
I'd like to see the agent in charge try to explain expenditure in the 10 million range , just to catch one or three traders of 50k worth of DRK.  

Really? 10million dollars is pocket change to a government that "controls" a country with a GDP of 17 trillion(America), and yearly budgets in the high multi- billions. I have no doubt in my mind that they would ddos darkcoin's masternodes if it meant that they could catch a serious drugdealer or terrorist for example. The difference between ddosing darkcoin and bitcoins nodes, is that darkcoin's masternodes is what gives darkcoin its "anonymity", and when those nodes are gone or limited(not a lot of nodes), its anonymity is gone as well.

Darkcoin is such a scam. I never put a penny into it.

Cool, hiring someone to do criminal activities for your benefit - check with your momma first if she thinks it's a good idea.

Problem for trying to deanonymize DRK by ddos'ing is that the coins are pre-anonymized before they can be used.

So people will have anonymous coins in their wallet, and someone starts the attack and manages to take out every masternode except their own. People will send their anonymous coins to purchase whatever, and the attacker will be none the wiser as the coins and transactions are already anonymous. At that point people would notice the number of masternodes dropping from > 2000 to 20 for example, and realize what's going on, and wouldn't try to anonymize their standard coins. I've suggested earlier that the wallet would automatically detect this and prevent the user from mixing their coins while the attack is going on, and I believe it's a feature that will come at some point. So, the outcome would be that someone has just spent a lot of time and resources for no gain.

Absolutely not true. Please dont tell lies in an attempt to invalidate my words. This "pre-anonymization" is mixing, and mixing takes time(Ive used darksend before). If darkcoins anonymity was cut off, youd see all "premixed"(coins that havent been mixed yet) darkcoins, and be able to trace back all premixed darkcoins through the blockchain.

So again, you can end darkcoins "anonymity" and trace back the coins on the blockchain.

Ok, let's see..



Yes, true so far..



Still true..



Now this doesn't even make any sense. First of all, "premixed" coins are not "coins that havent been mixed yet". Second, if "anonymity was cut off" (I guess you mean the masternodes were all ddos'ed), that wouldn't help you to interpret the blockchain at all. The anonymous transactions that have already happened, stay anonymous. And the anonymous coins you already have, will be anonymous even if you send them while all the masternodes (except for the attacker's) are down.

Criminal? How? I mean if its some sort of crime than never mind. What law are you referencing?

Why do all accusative topics have to be self-moderated? I'm feeling like this is going to be like the "ltc is dead" topic where darkota deletes everything positive about litecoin.

This thread is gold to be honest.  I'll bump this in 6 months if nobody else has and we'll see what is what.

Most of the FUD is out of date, incorrect or just lies.  Why not pick on the real shortcomings of DRK?  Dark supporters discuss these issues openly and the dev team to do list gives a few more pointers towards real (fixable) problems.

Problem is that the truth is not inflammatory if everybody agrees with it and the issues are being dealt with.

Amen to that.

The biggest weakness of Darkcoin I think is if the regime decides that coin tumbling is illegal and akin to money laundering and all it will take is a quick court order to go yank all those Amazon cloud servers hosting the Masternodes real fast.

...and the biggest strength is that masternodes are decentralised so they can be set up in 5 minutes on any other of 1-2 billion computing units around the world. The critical thing that secures a masternode isn't a poxy Amazon cloud server, it's a blockchain address containing 1000 coins (which isn't hosted on a cloud server  ;) ).

So, the actual capacity of DRK to fill these computing units is .0011% as an absolute maximum of number of computing units (2 billion) that will be a masternode.

Your argument would have better off just mentioning that there are 1-2 billion units capable of decentralizing the network, if we were to agree on the fact that likely 90% of those 1-2 billion computing units are easily compromised by air gaps, numerous hardware backdoors, and then even more software vulnerabilities and backdoors.

So really, the critical thing is that theres a blockchain hosted by a node...because the actual chances of a single masternode ending up on non compromized software based on chance would be 10% x .0011% I'd wager. So .00011% of all masternodes, which are fairish odds of about 1 in 91k masternodes would end up on noncompromised hardware and software with 1-2 billion users and other numbers pulled totally out of my ass.

I mean if 1-2 billion people were to use darkcoin, they're just not all gonna host masternodes. It would probably be from them that the network remained decentralized, rather than a few ten thousand masternodes at that point.

The theoretical limit to the number of DRK masternodes at this point in time is 5157 and then there would only be 101 DRK in total left to be used as a currency. http://coinmarketcap.com/currencies/ (http://coinmarketcap.com/currencies/)/ I fail to see where people are getting a few ten thousand masternodes from.

estimated coins max, is 22,000,000 at some unknown point in the future.

Obviously if all of them were in use for masternodes, it likely wouldn't be a currency at that point, but I'd say it's still a maximum.

So, maybe, an estimated maximum of 22k masternodes then?

add: the odds I was referring to were just that, odds. We can imagine that there are "one in a trillion odds" for someone, though there are not that many people in the world. sorry if that was taken to indicate there would be >90k masternodes ever, because there won't.

In my country it's called "telecommunication interference" (word-for-word translation), which is a crime. Depends on the country where the affected party is I suppose.

Well in that case what do we even need byzantine fault tolerance for? Lets just make it illegal to interfere with the network! That's got to be cheaper than all this "mining" nonsense. :D

No but seriously legality aside, if it really was easy to destroy the network it would be in everyone's best interest for someone to do this. That would make w/e value it had bubble value and its better to pop a small bubble than a big one.

I always thought Darkcoin is a good one.

Yes, I agree - obviously a coin should be tolerant even to illegal attacks.

OP's original claim that "Darkcoin is prone to several cost-less DOS attacks that can destroy the whole network" is not true though. I don't know if it was true back when the claim was made, but I know that after OP was posted the dev team went bug hunting and fixed several bugs that could've been used to stall some of the functionality or game the masternode payments to benefit a dishonest masternode. When developing new technology problems are bound to happen, and that has been priced in as we can remember from the fork issues and the subsequent price drop last summer. Nevertheless, it was a good thing that the OP was posted back then as it motivated the team to set developing new features aside for a moment and go through the codebase and clean out all bugs they could find.

A better way to phrase my point

If this attack were this easy. Would you rather....

1. Attack bitcoin nodes and double spend for profit

2. Attack darkcoin nodes to unmask masked transactions

Just a quick note on the usage of AWS for masternodes.  AWS accounts for less than half of masternode hosting now.  The community started to branch out some months ago.

You are incorrect for several reasons.

Firstly, when a server is DDoS'd the reaction of the data centre is almost always to block all data destined for the server's IP at the upstream data provider. Normally this is done on a BGP level. The thing with these BGP requests is that they cannot happen on a minute-by-minute basis, because massive routing changes are potentially dangerous and normally go through a change control process. Typically speaking, a dedicated server would be blackholed upstream on a BGP-level for ~4 hours. A VPS maybe longer by virtue of how cheap it is.

Thus if a sustained attack of 10 minutes is required to shut down a server for 4 hours, how much simultaneous bandwidth is required to kill your proverbial 1 240 masternodes? Well, basically it means you have to attack ~52 servers simultaneously. Now bear in mind that there are plenty of VPS and dedicated hosts that have 100mbps limits, I'd hazard less than 40% have 1gbps on tap, and fewer still with unmetered ports. In the VPS space especially bandwidth is shared between all guests on the host machine, so the actual available bandwidth is far from promised. Thus we can't take your 1gbps theoretical as being valid for all but a handful of masternodes. But let's be generous and pretend that 50% have unmetered 1gbps ports, and 50% have unmetered 100mbps ports, which means the total bandwidth required to knock the 52 servers off the grid is 28.6gbps.

Assuming you're Joe Scriptkiddie and don't have access to a botnet, how much would it cost to launch such an attack? Well I used Str3ssed (https://str3ssed.me/#s3) (one of the many so-called "booter" or "stresser", basically a DDoS-on-demand service pretending to be a network stress tester) to price it out. With their 250gbps of "stresser" capacity a 28.6gbps requirement is trivial. So if we just wanted to attack the network once we'd need to use their "1 Month Ultimate" package, which allows us to attack 1 target at a time for a total of 60 minutes within the month (of course you can change targets and start/stop attacks whenever you want, it's just a total of 60 minutes in the month). Because of that restriction we have to attack 207 masternodes simultaneously for 10 minutes, and then switch to the next group of 207 masternodes, and so on for an hour. After an hour we will have knocked the masternode network offline at least for the following 3 hours, some for even longer. The total cost of doing this once-off attack would be 207 x $50 = $10 350. Not cheap, but certainly not out of reach.

The larger problem is that an attacker only slightly more sophisticated or enabled than Joe Scriptkiddie can pull off a sustained attack without spending a cent. SNMP amplification attacks, for instance, are no longer uncommon (http://www.pcworld.com/article/2159060/ddos-attacks-using-snmp-amplification-on-the-rise.html). Since SNMP provides a ~650x amplification, it means that a savvy attacker can turn a 1gbps VPS into a 650gbps DDoS device.

Literally the only reason that ludicrous amateur cryptography like this survives is because of the vast technical incompetence of many altcoin proponents. The time will come when someone more proficient sees an opportunity to short a coin or stands to benefit from a downturn, and they will decimate the house-of-cards infrastructure that has been built up.

Oh and your last point is, unfortunately, also not true: if you DDoS all the pools difficulty would not retarget quickly enough for you to have 51% of the hashing power, as the majority of miners have a fallback, sometimes to private pools etc. Also, things like p2pool and solo miners make an attack like this unreliable.

No, you're misunderstanding what a DDoS attack is. DDoS attacks are tangential to the software running on the server.

I can DDoS a server that has every port closed off to the outside world; the minute I send enough multi-packet traffic bound for that IP that the server / router / bordergate / network appliance has to reassemble packets I'm going to cause devastating congestion, forcing the datacenter to block packets bound for that IP at their upstream data provider.

This has nothing to do with the very excellent Bitcoin software or any cryptocurrency cloned from it, it is merely the nature of IP traffic routing. No amount of "bug fixing" in the software can prevent these attacks since the attack doesn't even require the software to be running.

I've already pointed out that 1. is nonsensical and not possible, and 2. makes the assumption that deobfuscation is the aim.

The third option that you're missing is: continuously attack Darkcoin masternodes in order to increase the profit of my masternode. Malice doesn't need to come from law enforcement, nor does it have to care about the longevity of the network.

Masternode gaming was identified as a risk in a security review and a lot of strengthening against this was done.

However, its virtually impossible to attack the masternode network to increase payments to your node.  Thats just not how payment selection works.

He said DOS, not DDoS. When he said DOS, he meant stuff like agreeing to participate in mixing, and then stalling the process by not signing, and so on. Bugs that allowed that sort of DOS attacks were fixed.

Wrt DDoS however, I posted this earlier:


And there are plans to hide the masternode IPs so you can't find them and DDoS them (this will also help the masternode owners stay anonymous if they so prefer) - the development is still going on. What we have now doesn't mean it's what we'll have in a year or two. The fact that Darkcoin is not fully complete and perfected yet is priced in by the markets, otherwise it would have 10x to 100x the market cap it has now. ;)

I'd also like everyone to know the truth about the best scam ever made.

truth is out there. this cryptoshit is scam haven 101.

Seems to be the truth

Darkcoin is such a shitty fake-anon coin and blatantly illegal HYIP scheme.

No wonder they want desperately to steal Dash's name for their rebrand.

Hey icebreaker, i just fixed your post and wrote what you actually meant to say.  Maybe your words got a bit muddled as you typed?!

oh, incase anyone missed it, Darkcoin/DASH hit 0.0249 today....what did the other 'anonymous' crypto currencies today?

Darkcoin/DASH continues to grow because it is the only genuine privacy-centric digital currency in the marketplace that actually works and has not been exploited.

Lies.

wow darkcoin stole another coin name dash, took that name DASH and had a instamine. wow but i love it

Quick hand me another eye patch, shes sprung another leak cap'n.

http://img4.wikia.nocookie.net/__cb20131014045404/adventuretimewithfinnandjake/images/8/89/Jiggler_fit_to_burst.png

DASH Last Price?  0.0124   ;D

The rebranding pump was just a blow-off top and an opportunity for THE DARKCOIN FOUNDATION INC to dump more of its massive insta-mine on you true-believing cargo cult losers.

Thanks to the leveraged shorts now offered by Poloniex, not even otoh can prop up the price.   :)

Too bad DASH volume in Poloniex is so low that you can't short any meaningful amount without suffering huge financial losses in the process. And why would any privacy aware person surrender himself to Poloniex and its KYC policies in the first place.

Only if your sh*tcoin can't get listed anywhere else, and even when it does, no one will touch it with a ten foot poll ;)

I don't get this concern--unless you are trying to hide the buying or selling of Monero, this doesn't break your privacy. You can still spend it privately, so what's the concern? Your are certainly capable of using shapeshift or an exchange that doesn't follow KYC if laundering funds is your objective (not that I'm condoning that behavior).