Unattanium: Broken by design. (Status: Proven broken)

[xrobau]

Edit: Attack occurred, and the coin is, indeed, vulnerable. I wrote a small paper on it, that's available here:
    https://docs.google.com/document/d/1d8dwuGznri35uNHDxhUcRDXD0I8afKN9R3G3oPNhBbo

It's only three pages, and contains far too much maths and hypotheticals. However, instructions for taking over the coin yourself are in the last section.

For those that are unaware, Unattanium is a newish limited-number-of-coins SHA coin.

They've recently had to fork the chain, because the difficulty calculations were broken, and it went far too high.  Sadly, they've now broken it in the other direction, and the dev seems intent on ignoring this, and abusing or hand-waving the problems away.

It's now running at an 8 second block time.

Now, for everyone who is NOT facepalming right now, this is faster than blockchain propagation. Basically, it will be amazingly difficulty for the coin to agree on a valid chain, because there will be any number of chains that are almost the same length.

So, After being asked to help out to fix the stuck difficulty, I jumped on their IRC channel and had a discussion with someone called 'Unattanium' who was opped in the channel mentioned on their website.

I phrase that carefully, because I'd hate to slander someone who actually knows what he or she is doing. Because this person didn't.

Anyway, rather than addressing the issue, he (I'm assuming this person is a male. I apologise if you're not) said things like...

<•Unattainium> and who cares about orphans
<•Unattainium> it doesnt break a chain or anything
<•Unattainium> i dont care if it fucks up miner ui or stats
<X-Rob> Well. Everyone who's mining cares about orphan shares.
<X-Rob> uh orphan blocks
<•Unattainium> Everyone will be on the same playing field
<X-Rob> Well no
<•Unattainium> I'll get the same amount of orphans are you
<•Unattainium> as you*

Which is obviously wrong. All I, as a bad guy, need to do is to have more hash rate than you, the innocent miner. At 8 seconds, it's highly unlikely that your block will even have reached me before I mine my next one, leaving me to perform a 51% attack with much less than 51% - it would be (coin hashrate * 0.51)/(average block latency time / coin block time)

Average block latency from bitcoind is around 4 seconds.  Or, basically, I can now perform a 51% attack with only 25% of the coin.

<X-Rob> if your'e going to claim I'm wrong, you'll need to actually back that up.
<•Unattainium> You're spewing nonsense\
<X-Rob> Yet, here I am, saying I'm not.
<•Unattainium> I'm just gonna stop responding
<X-Rob> And you're yet to provide proof that I am
<•Unattainium> Beacuse I think you are either a) ignorant as fuck, or b) trolling hard
<X-Rob> I'm neither
<•Unattainium> there is no option c
<X-Rob> I'm trying to fix a problem that you seem to be deliberately ignoring
<X-Rob> problem is: 8 seconds is far too short.
<•Unattainium> I'm done
<•Unattainium> Not worth my time

So there you go, people.  Fixing a design flaw in the change, that was to FIX a design flaw, is not worth his or her time.

Of course the next design flaw, which will be implemented to fix this design flaw, will be be something awesomely terrible, and I can't wait to see what it is.

Edit: The next design flaw, which was implemented ... for no real reason that I could see, was to randomise the reward, leaving the block times the same, but not giving anyone any notice. So yes. It was awesomely terrible.

Have fun now.

[1714819557]

1714819557

[1714819557]

1714819557

[1714819557]

1714819557

[1714819557]

1714819557

[Chris001]

Yes, it was made not to work. The whole idea make it so no one wanted to go though the trouble to "obtain" it.

[xrobau]

Yes, it was made not to work. The whole idea make it so no one wanted to go though the trouble to "obtain" it.

There's a difference between 'making it hard to obtain' and 'making it amazingly easy to perform a 51% attack and all the bad that that entails'.

[smalltimer]

yawwwn. Just buy or mine the real coin 'unobtanium' ... why do people even bother with this?

[Unattainium]

Nobody from the dev team asked you to fix (or do) anything

[iGotSpots]

Well he's right about orphans. They don't break anything, just mess up stats

All exchanges have to do is set confirms higher. P2P transactions will still be fast even if it takes a few extra mins for an exchange deposit to arrive

[earlz]

Well he's right about orphans. They don't break anything, just mess up stats

All exchanges have to do is set confirms higher. P2P transactions will still be fast even if it takes a few extra mins for an exchange deposit to arrive

Sure, assuming you don't accept any transactions with less than 1000 confirmations

[bitspender]

Well he's right about orphans. They don't break anything, just mess up stats

All exchanges have to do is set confirms higher. P2P transactions will still be fast even if it takes a few extra mins for an exchange deposit to arrive

+1. Really Guy,after fudding the irc All night You come up with This crap?!
You need To stop comparing unat with bitcoin. Now Go play lego.

[bitspender]

And most important, why are You still mining It??!??!
Wrong coin Pall, NO panic sales here.

[Dutchmining]

And most important, why are You still mining It??!??!
Wrong coin Pall, NO panic sales here.

U better pay me back my btc scammer... (bitspender) Angry Instead of posting here on bctalk, w8tch out people.. this guy is bad news...

[xrobau]

U better pay me back my btc scammer... (bitspender) Angry Instead of posting here on bctalk, w8tch out people.. this guy is bad news...

You know, I'm kind of unsurprised that he's being accused of being a scammer.  Their behaviour in IRC is .. odd, to put it mildly.

<•Unattainium> If you had any idea who you were talking to, you would know I definitely know what I'm doing

And yet, he/she is not saying who he/she is? 

<X-Rob> There is a bug. I see and understand the bug. You don't, or claim not to understand the bug.  That's.. pretty much it. You're the one with access to the code, so, i fyou want to leave it broken, there's not much I can do about it, apart from warn other people.
<•Unattainium> Ok, give me the bug
<•Unattainium> "I don't like fast block times"
<X-Rob> I have. Several times.
<X-Rob> No, that's not the bug
<•Unattainium> Not a bug
<•Unattainium> Ok
<•Unattainium> I'm like
← You were kicked by Unattainium (175c3d62@gateway/web/freenode/ip.23.92.61.98): wibble
→ X-Rob joined (X-Rob@gateway/web/irccloud.com/x-boeazzlbzlokrgfu)
Channel mode is +cnt
<X-Rob> Heh
<X-Rob> So
<X-Rob> here's the bug
<X-Rob> '8 second block times are insecure'
<•Unattainium> Meant to ignore not kick
<•Unattainium> That was my bad
<X-Rob> now, you can either claim it's not a bug, which is factually false
<X-Rob> or, you can say that you're aware of the issue, and it's fixed because of xyz.
<X-Rob> or, you can say something else.
<•Unattainium> For the record, I can't see what you're typing anymore. I'll just wait until you crawl to the forums to try and get someone as equally ill informed to agree with you

I have an 8 year old son who does that. Puts his hands over his ears and goes 'LALALALA I CAN'T HEAR YOU' when you're saying something he doesn't want to hear.

<X-Rob> And.. he -still- hasn't adressed the latency issue.

This is amazingly hilarious.

[moko666]

what is link to ann thread for this coin or website?

[Nxtblg]

Well he's right about orphans. They don't break anything, just mess up stats

All exchanges have to do is set confirms higher. P2P transactions will still be fast even if it takes a few extra mins for an exchange deposit to arrive

Sure, assuming you don't accept any transactions with less than 1000 confirmations

As Cryptsy did with Reddcoin?

[iGotSpots]

Well he's right about orphans. They don't break anything, just mess up stats

All exchanges have to do is set confirms higher. P2P transactions will still be fast even if it takes a few extra mins for an exchange deposit to arrive

Sure, assuming you don't accept any transactions with less than 1000 confirmations

As Cryptsy did with Reddcoin?

And as Poloniex did with several coins

[xrobau]

The number of confirmations you have to wait for is not relevant.  As I pointed out above, by having a block time that is so short, it's amazingly easy to do a 51% attack, without actually having 51% of the coin's hashrate.

I did explain this to the dev, but he said that he knew better, and he was right, and I was wrong.

Here's how it works.

There is the public 'good' chain. It is mining along at.. let's say (for ease of counting) 12TH.  It's split up amongst 3 pools, and each of them have 4TH each (That means that the coin will be asking for difficulty 30000-ish blocks, btw)

We live in a universe where there is a finite speed of light. There is an amount of time it takes for Pool A (that mined the coin) to send it to the other pools, and other coinds.  This is the network latency time. In bitcoind it takes, on average, 4 seconds (and that's an average, not a mean. Mean is much higher) for a block to propogate to 90% of the nodes.  (These numbers are from memory. They're roughly accurate, but not exact. They won't be an order of magnitude out). Whatever the time in una is, it's an amount.. I'm going to keep on at 4 seconds, because the exact number doesn't actually matter.

If we work on 4 seconds, then roughly -half- of the blocks that are mined, will be mined within the same window. There will be two valid blocks, and only one of them will be accepted by the blockchain. 

So that brings the -effective- hashing rate of the coin down to 6TH. Everyone's hashes who mined the rejected coins were wasted.

Along comes Mr 'I actually HAVE a clue' who understands this.  He goes and rents 4TH of SHA mining, and sets up his own coind.  He's going to solomine, to his own pool. His own pool isn't GOING to have any orphans, because he's always going to mine to his chain. He'll never accept a block mined by someone else.

He is, however, going to spam his blocks out, so that everyone else must discard what they're doing (on the non-evil chain), and start working on the new (evil) block.

Now, we have 4TH of 100% guaranteed never-gunna-orphan, and 6TH of 25% chance of orphaning (we still have network latency, but now it's only half as likely).

So there's your first 51% attack. It's pretty visible though, as people watching the blockchain will notice.

The second one is much sneakier, and kinda awesome. Basically, the second one runs his own parallel blockchain. Same deal, it'll never orphan (so you only need 25%-ish), BUT, he doesn't send his blockchain out until AFTER his double spend is completed.   

This one is much easier to manage, as you can control the hashrate exactly to encourage more blocks to be mined than the public chain.

I am, admittedly, glossing over the hard-er bits. I encourage anyone who's actually interested in this to watch the upcoming Dogecoin double spend attack, which is going to be using option 1 I believe, from what I've read.

[Nyterax]

This is hilarious. The number of extremely arrogant, incompetent developers is going through the roof lately. *grabs popcorn*

[Viper1]

yawwwn. Just buy or mine the real coin 'unobtanium' ... why do people even bother with this?

Was going to say the same thing.. The Unobtanium guys actually increased their block time a month or so ago in order to slow down mining and put things back in order.. And it's gone from something like 0.003 to 0.005 I think in the last couple weeks. Sounds like the Unattanium guys need to do more reading on the forum about what works and what doesn't lol

[nutildah]

They should have just let the block time remain around 8 hours... Who cares if its not instantly transferrable to the exchanges, it would have retained its uniqueness and functionality.

[Nxtblg]

I am, admittedly, glossing over the hard-er bits. I encourage anyone who's actually interested in this to watch the upcoming Dogecoin double spend attack, which is going to be using option 1 I believe, from what I've read.

What upcoming attack? Have you got a link?

[bitspender]

They've recently had to fork the chain, because the difficulty calculations were broken, and it went far too high.  Sadly, they've now broken it in the other direction, and the dev seems intent on ignoring this, and abusing or hand-waving the problems away.

Wrong.
The community voted to fork the chain to avoid denials from bigger exchanges as they would have to many support tickets from users asking why coins dont confirm.
Nothing was broken.

It's now running at an 8 second block time.

Wrong.
Some day it will run at 8 seconds block time. Not now. It slowly decreases to avoid forks.

So, After being asked to help out to fix the stuck difficulty, I jumped on their IRC channel and had a discussion with someone called 'Unattanium' who was opped in the channel mentioned on their website.

Wrong again.
Nobody asked you anything. You just happened to pop up, because a miner pointed his rental to this pool.
I told you to go away, since all you did was causing FUD.

Enter FUD:

* X-Rob (X-Rob@gateway/web/irccloud.com/x-boeazzlbzlokrgfu) has joined #Unattainium
<DoubleDD> I won't be able to help as I paid almost 0.5 btc to mine for 2 days
<X-Rob> Uh. So who's bright idea was it to set the block time to 8 seconds?
<X-Rob> that's un-mineable
<Bitspender_> X-Rob what?
<X-Rob> all it's going to do is cause massive, huge, orphan trees

Where is this guy coming from:

<X-Rob> DoubleDD: Someone rented my rig, and pointed it at a pool with this coin, and I hadn't heard of it before
<X-Rob> I have ~13TH availabel for rent
<X-Rob> so I read the thread and went 'aah, you guys need some help', so I left my rig mining on this coin

Strange for a coin so bad as you make it appear:

<X-Rob> I can spare a couple of hundred TH to free the chain up in a couple of hours
<X-Rob> well
<X-Rob> probably 140 or so TH

And suddenly his hundreds of Th drops down to 13..

<X-Rob> I'm intrigued
<DoubleDD_> awesome
<DoubleDD_> what pool will you be mining?
<X-Rob> DoubleDD_: Oh, I'll just solo
<DoubleDD_> nice
<Bitspender_> yeah, i'm solo for 750 Petahash to
<Bitspender_> to bad i cant prove it
<DoubleDD_> I've had 10TH on for last 24 hrs and got another 24 hrs on 10TH.
<DoubleDD_> X-Rob: how much hash and for how long will you help out. trying to keep track of how it will affect diff
<X-Rob> Bitspender_: Amusingly, I -can- prove it. https://bitcointalk.org/index.php?topic=513500.0
<X-Rob> DoubleDD_: I'll hash until the difficulty comes down to a reasonable rate
<Bitspender_> 13Th is not 150Th
<X-Rob> I didn't say it was all mine.

And on his way to getting kickbanned after FUDDING all night long:

<X-Rob> Right. 100TH is all I've been able to scrounge up
<X-Rob> best share 67M.

So the guy who has hundreds of Th, who discovered this awfull bad coin, has been solomining it all night, RENTING 90Th extra than what he owns, and still is mining when i check network hashrate.

If this coin is really that bad, why are you still solo mining it as we speak?
Already told you. Wrong coin, no panic sells here. And that's the only thing you try to accomplish.

Go home rob, your drunk.