Fairbrix fiasco

[dayfall]

One of these altcurrencies needs to attempt to implement a forked chain detection algorithm.

[thirdlight]

I have a connect of 3, 2300 blocks but doesn't seem to increase further.  Is it normal or is there any issues?  I have opened the port.

That was the old version. Count is now 2303. Someone somewhere is still mining...

[michaelmclees]

I don't know why anyone would mine that.  For all I know, it's still producing blocks with 0 coins.

If you wish to mine Fairbrix, https://github.com/coblee/Fairbrix is the one to use.

[Red]

Why don't you add in a rolling block lock. Say locking blocks 1 hour old. That would limit any CPU attack to the ability to only erase transactions less than an hour old.

I know about the chicken and egg problem. How do anonymous peers know which block to lock? But in this case there is one known "non-anonymous" peer that is implicitly trusted. It is owned and operated by "michaelmclees".

When you reach critical mass and add an exchange to the fairbrix network. That adds a second non-anonymous peer. Though no one will "implicitly" trust the exchange, if miners go with a fork unsupported by the exchange there will be no place to reap their rewards.

If an exchange changes forks, it would result in brix they sold to customers for dollars disappearing. Since the exchange is non-anonymous actual police are likely to show up and arrest them for fraud. I presume exchanges will be monitoring any chain swap attacks closely.

[Lolcust]

Exchanges already have just such a mechanism (though timestamp-based locking holds promise too... anyone willing to try thing out on GeistGeld ?)

[Red]

Exchanges already have just such a mechanism (though timestamp-based locking holds promise too... anyone willing to try thing out on GeistGeld ?)

Just curious, what mechanisms to the mechanisms to the exchanges currently use?

[Lolcust]

Exchanges already have just such a mechanism (though timestamp-based locking holds promise too... anyone willing to try thing out on GeistGeld ?)

Just curious, what mechanisms to the mechanisms to the exchanges currently use?

Basically, they watch out for reorgs that affect more than their "confirmation horizon" and shut trades down. Recent fairly cunning i0coin run-in managed to get around that, though (don't recall the details) so those mechanisms might need some refining.

For all practical intents and purposes that is "kinda lock-in"

[Red]

For all practical intents and purposes that is "kinda lock-in"

Yes, I completely agree. I've been away from the *coin world for about a year. Just trying to get the lay of the land.

I always thought the original bitcoin philosophy, of defending everyone's shared history based on the implausibility of >51% CPU power attacks, died when coders put in the first hard coded block lock. Since then the question has been, "How much history can we leave at risk?" What you call a "confirmation horizon" is exactly what I am suggesting. Otherwise, the definition of "confirmed" becomes non-sensical.

I figured exchanged must have long ago solved this problem. It simply doesn't make any sense for multiple exchanges to trade on different branches. The notion of, "Everyone stop trading, while we (exchanges) discuss this among ourselves." makes perfect sense.

[Lolcust]

It's not so much "discuss among ourselves" as "A girl in Brazil is reorging the blockchain! SHUT ! DOWN ! EVERYTHING !!!"

[Red]

LOL!  New meme for me. Woot!

[iopq]

Basically, they watch out for reorgs that affect more than their "confirmation horizon" and shut trades down. Recent fairly cunning i0coin run-in managed to get around that, though

well, first the guy got the bitcoins and THEN revealed his longer chain that invalidated the older spends

so it doesn't help

[doublec]

well, first the guy got the bitcoins and THEN revealed his longer chain that invalidated the older spends
so it doesn't help

Right, this is what happened. If you want to centralize around the exchange one thought I posted in another thread is have the exchange broadcast to the network the checkpoint for blocks when it confirms a deposit to the exchange database. Nodes then accept this message as a 'lockin' checkpoint. Expanding this to multiple exchanges might be wanted but in the 'one true exchange' case it'd work.

[Lolcust]

I am far from being a Real Programmer, but I have a sort of hunch that various "dynamic lockins" (be they timestamp-based or "magical transaction" based) could open a rather large can of net-scale DoS worms.

Just a bellyfeel, unsupported with code or evidence.

[doublec]

I am far from being a Real Programmer, but I have a sort of hunch that various "dynamic lockins" (be they timestamp-based or "magical transaction" based) could open a rather large can of net-scale DoS worms.

I don't see how an exchange sending out a signed transaction containing a checkpoint to nodes is any different from a coin creator regularly updating the client with a checkpoint and asking for clients to upgrade. The advantage with the former is it's automatic and nodes upgrade automatically.

[OneMINER]

I think that is a very bad idea. Why should I trust exchange operators? Because they are in business and hold coins? That doesn't qualify them to control an aspect of a crypto coin. Which exchange operators would we trust? What if the exchange got hacked and the key stolen? A thief would know who to target to get the key and exchanges are already juicy targets. What if an exchange is sold? Then the buyer(s) gets to do what they want with the chain?

No thank you sir.

I mean no offence by this.

[doublec]

I think that is a very bad idea. Why should I trust exchange operators? Because they are in business and hold coins? That doesn't qualify them to control an aspect of a crypto coin. Which exchange operators would we trust? What if the exchange got hacked and the key stolen? A thief would know who to target to get the key and exchanges are already juicy targets. What if an exchange is sold? Then the buyer(s) gets to do what they want with the chain?

Right, there are problems to resolve. But this is for the specific case of low hash rate chains. It's trust the central authority to provide lockins or have coins stolen by block chain rewriters.

[2112]

Which exchange operators would we trust? What if the exchange got hacked and the key stolen?

It would need to work like the current "certificate storage" in the web browsers. You would put the "public key" for the exchange that holds your coins into your client. If they get hacked you could read about it in the news and remove the key manually, without having to wait for the developer to change anything.

The main obstracle is that this would be a rather complex piece of software, with nontrivial effort required to develop it. But I think this will need to be developed sooner or later, probably as an offshot of libbitcoin.

[OneMINER]

I'd like to see merged mining in both GPU and CPU chains. You don't have to trust anybody and your hash rate goes through the roof. It will mess with the exchange rates but that will get ironed out in the end.

I really see merged mining as a win win.

[Red]

Why should I trust exchange operators?

Which exchange operators would we trust?

What if the exchange got hacked and the key stolen?

Understandably, from the point of view of *coins as crypto-anarchist currencies, this would seem initially distasteful.

However, it is important to note that it *never* makes sense for two different exchanges to trade on different forks. They will always have to take a break from trading to determine which is the correct fork to continue trading on.

Otherwise, forking effectively doubles the number of coins in existence. Bitcoin hoarders pray for that to happen. It never will. Imagine if the chain forked and Euros traded on one branch and Dollars on the other. I could sell my pre-fork coins once for Dollars and again for Euros. Woot!

Not going to happen.

So the reality is, if you chose to continue the fork without the exchanges. You are in the same boat. You have just create a new currency pre-distributed to everyone who also owned *coins before the fork. That is just bad business. You would deserve what you get.

If an exchange got hacked and tried to fork the chain, all the other exchanges would notice, stop, and gather together to repeat the above exercise. Most likely the hacked exchange would be forced back to the consensus branch and be required to repair any client damage. Otherwise they would be bankrupted and sued.

It is an ironic fact, that even in crypto-anarchist currencies, there is a center of the universe. For Fairbrix at this moment, it is michaelmclees. Later it will be the exchanges.

[michaelmclees]

I am not the center of the Fairbrix universe in any way that I'm aware of.