Comment by smtddr | Hacker News Reader

Comment by smtddr | Hacker News Reader

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Think of it this way, you create a bunch of purple 20 dollar bills and convince most(51%) of the population that your purple bills are the only legit ones. So people begin transactions with only the purple bills and green bills are worthless outside their little town(subnet)... but then someone else splits up these people again and convinces 51% that red bills are the only legit one.

So now we have this mess where transactions and various business deals were made with green, purple and red bills and everyone is arguing about which color to accept.

There's no sensible way to resolve this without nearly two-thirds of people being screwed... so you need to wipe everything out and start from the beginning. Which is lost resources for almost everyone.

So there's no good ending. Any solution to this will cause over 50% of Auroracoin-holders to lose everything.... this is absolute worse-case doomsday scenario, assuming someone did a 51% attack with their own blockchain that may or may not be based on the original. If it's a fork of original, those who didn't trade and have their coins in offline wallets will be on all forks.

That's an exaggeration. People who haven't traded since the fork haven't lost anything. If it's caught quickly and resolved, only some of the people who did trade since the fork lost something.

An obvious workaround would be for the major exchanges to make sure they're on the same fork and stop all trades if anything goes wrong, until it can be fixed.

Of course, the secondary effects from loss of reputation are a big problem.

So, there are some caveats here.

>>People who haven't traded since the fork haven't lost anything. If it's caught quickly and resolved, only some of the people who did trade since the fork lost something.

T̶h̶e̶ ̶p̶e̶o̶p̶l̶e̶ ̶w̶h̶o̶ ̶h̶a̶v̶e̶n̶'̶t̶ ̶t̶r̶a̶d̶e̶d̶ ̶s̶i̶n̶c̶e̶ ̶t̶h̶e̶ ̶f̶o̶r̶k̶ ̶w̶o̶n̶'̶t̶ ̶l̶o̶s̶e̶ ̶a̶n̶y̶t̶h̶i̶n̶g̶ ̶_̶I̶F̶_̶ ̶t̶h̶e̶ ̶f̶o̶r̶k̶ ̶t̶h̶e̶i̶r̶ ̶c̶o̶i̶n̶s̶ ̶a̶r̶e̶ ̶o̶n̶ ̶i̶s̶ ̶t̶h̶e̶ ̶o̶n̶e̶ ̶c̶h̶o̶s̶e̶n̶ ̶a̶s̶ ̶l̶e̶g̶i̶t̶. Also, the people who keep coins in exchanges(against advise to do otherwise), if the exchange is operating on a losing fork... all costumers are kinda screwed.

But you're right that if action is swift enough and some authorative-group of people can say "use this fork and ignore the other two", then minimal damage will be done.

If this is not dealt with early enough.... ever second that goes by all kinds of transactions are taking place and if all major exchanges are not on the same fork, the exchanges running on a losing fork(and all its costumers) are in for some bad times. My guess is they'll probably have to pick the fork that has the most exchanges running on it. Or, if what I've read is correct and Auroracoin is premined... then those premined coins must be rescued.

We'll see in the days to come what ends up happening...

EDIT: To those who replied below me, you're right. If you haven't traded your coins are on all forks.

If someone hasn't traded since the fork, their coins are on both forks and it doesn't matter which fork is chosen.

If they haven't traded, won't their coins be on the common ancestor of either fork?

If you haven't traded since the fork, then all your transactions are on the, um, "handle" part. Both sides of the fork will have all of your transactions, so they aren't lost.

yeah, roughly. but also you have the effect that if you know precisely why some red bills pop up you can start a new fork for the green bills. so a 51% attack is by no means terminal. if an attack is terminal all coins on all chains are worthless, because the remaining network can be attacked again.

I really like this explanation; thank you.

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