Bitcoin Forum

Hi!

 First of all, I'm sorry for another thread about ASIC... Please, lock this thread if it is useless...

 A lots of people seems to be terrified with the idea of some bad guys (i.e. bank cartels and/or governments (FED)), develop and build a ASIC to take over the Bitcoin network... But, I don't think they will do something like that, never...

 Simple, because there is the Litecoin! And the ASIC build for Bitcoin is useless for Litecoin... So, will they build a ASIC for each cryptocurrency out there?! I don't think so... So, they will build none!

 Bu, if the Bitcoin Network becomes unsafe, we can move quickly to another CryptoCurrency... Because if that happens, the ASIC guys with 51% of power will not allow a protocol change within Bitcoin itself... So, we can move to Litecoin...

 Sounds logical?!

Cheers!
Thiago

No, move along

http://www.youtube.com/watch?v=5hfYJsQAhl0

 :P

This.

explain why OP is idiotic. hash-function lock-in is a valid danger for ASIC investors.

I wouldn't go as far as saying for that reason noone will ever try to attack bitcoin in that way, but it does make it more unlikely.

If you don't think so, please explain the reasoning.

Do people even know what a 51% attack is, what it takes to do, and that it is much less profitable than mining with that sort of power ?
Some people heard that a 51% attack is possible, so they assume it's a bad thing and anyone with the resources would want to do it.

With 51% attack you can only invalidate a transaction that you made so it returns to your wallet, you cannot make money out of thin air with it.

This would mean you have to have a huge amount of money in your wallet to begin with, $1mil for example, then send it to someone, have them dispatch the goods worth that amount withing an hour, then reverse the transaction using your 51% hashing power and hope they don't contact the courier to stop the goods being shipped on.

So you see it's not very practical.

Also 99.9999% of people who mine wouldn't have a clue how to modify a block and launch a 51% attack as most miners are business investors and not hackers.

No, perhaps you're thinking of a finny attack. A 51% attack can rewrite the blockchain.


It only takes 1 person to do a 51% attack. It can be done with ~$200,000 worth of BFL's new ASIC's (3.5Ghash for $150). At this moment in time, BFL probably has the money and access to the ASIC's, there's nothing stopping them from doing a 51%.


You forgot that everyone who has BTC will loose it all when we switch to another alt-currency/hashing function.

Also, it wouldn't be hard to use FPGA's to 51% most of the alt-currencies due to their low hashpower.

Also, if everyone switches to an existing chain like Litecoin then anyone who's already holding that currency will make money. That might be a good way to profit from attacking Bitcoin actually.

It is you do not know what a 51% attack is. 51% attack can kill a coin. Search "Coiledcoin"

What's the incentive to "kill a coin" compared to "making loads of coin" by simply mining?

to earlier poster: you can "rewrite" the blockchain to a certain extent, but you cannot put invalid transactions into it.

What's the cost to vandalize a car?


How exactly would the destruction work? Do you have a link to a good description or can describe it yourself?

I too would like to hear this from those that claim to know, as far as I understand a 51% attack can rewrite the block to invalidate recent transaction, this means reversing the money that you sent to someone, but as the Bitcoin documentation clearly states (those who ever bothered to read it will know) you cannot create coins out of thin air and put them in your wallet.

As a side-effect of creating a longer chain in order to reverse transactions, you also can control the payout of the block reward in the blocks in that chain. Therefore, you get as many bitcoins as are in the longer fork until you stop mining on it.

You can invalidate (at your discretion) all transactions contained within all the blocks in the longer fork.

A person with 51% hashing power can refuse any new transaction or charge ridiculous transaction fee, so basically no one can spend or receive coins.

That's an interesting thread but the likelihood that such an attack would kill interest in all cryptocurrencies is quite high; So holders of litecoin would still make a very risky investment by attacking bitcoin.
In fact we are back to the Nash equilibrium: it's more profitable to mine bitcoin than to attack it unless you are sitting on an oligopoly like Visa or Mastercard.

However it's not easy for them to attack bitcoin that way because they are public companies and must disclose the attack one way or another (their management is at high risk if they engage in an attack without disclosing it).
If they disclose the attack, then the network can apply countermeasures (even after the attack) and bitcoin comes out on top because an attack by Visa would be a tremendous vindication for bitcoin.

Ive pondered on such things, I dont think litecoin is a solution for... well anything.

I can see the blockchain being forked should we ever end up with an ASIC Supervillain dominating our chain we create a forked client + miner that uses bcrypt.
People swap to new clients and start mining the new chain and viola.

I cannot see this happening in the next 5-10 years.

Exactly. The LTC chain was developed by ArtForz and used a deliberately crappy version of scrypt ( weak parameters ) so that it could be mined with GPU from the start while the rest of us idiots mined with CPU and all this was kept secret from the SHEEP by coblee, ArtForz and other knowledgeable people.

LTC is a joke and not a real alternative to BTC. Note : BTC will be named BFLCoin sooner than later ...

Problem is, it was more profitable to GPU mine BTC than GPU mine LTC. Sounds like a nice scam they had going doesn't it?


Yep, LTC's main function was to be GPU hostile, now that it isn't it has no point. There is nothing that LTC can do that BTC can't.


Don't worry, people will probe BFL's ASIC's and make their own copies.

Wrong. Just goes to show you who has been here since May 10 2011 and who hasn't.

At first the LTC price ( when it was only GPU mined by ArtForz and his buddies in secret and they had like 60% of the chain - lookup bigcpuminer guy and his GPU "botnet" ) was high and GPU mining then would make much more than BTC.

When SC folks released GPU miner they reached a balance and slowly it became more profitable to GPU mine BTC than LTC.

Price slowly reached 0.0005 due to GPU miners dumping publicly. Before Reaper release price was 0.0012.

Now somebody is pumping LTC like mad and price is back up.

I doubt that. The price of making an ASIC is so high you probably have the expertise to design an ASIC from scratch. In which case you probably think you can do a better job of it then BFL and thus you go about making your own.

Current network hash rate is 12.733 TH/s. In order to possess 51% of the network power you would need to add more hashing power than is already in the network (because your power adds to the existing network rate). About 13.3 TH/s. So that's $570,000 worth of BFL gear.

Or you can get a 30%-50% free discount by ddosing 2-3 big pools at once, while powering up your 1 TH/s BFL gear at the same time.

Ultimately I0coin was killed by a 51% attack. (The incentive was there to sell them multiple times on an exchange for BTC)