The Biggest Flaw with Bitcoin that Could Crash the Entire System

[johnyj]

Currently we are still in the period of large scale of ASIC devices roll out, after more ASIC manufacturers start to deliver, private mining pool's electricity and cooling capacity will quickly reach its limit

[1715099414]

1715099414

[1715099414]

1715099414

[BitThink]

I think it's necessary to highlight here: no miner can change the blockchain history or steal anyone's bitcoin even he has more than 51% of the hash rate. What he can do is only make several blocks mined recently become orphan. It means 1) he can try double spending, but not easy after enough number of confirmations. If there're too many confirmations, it takes long time for his fork to catch up. 2) he can block some accounts to make any transactions, but at a very high price. He has to make every block including that transaction orphan.

That's almost all he could do with more than 51% of hash rate.

[btcrich]

I think it's necessary to highlight here: no miner can change the blockchain history or steal anyone's bitcoin even he has more than 51% of the hash rate. What he can do is only make several blocks mined recently become orphan. It means 1) he can try double spending, but not easy after enough number of confirmations. If there're too many confirmations, it takes long time for his fork to catch up. 2) he can block some accounts to make any transactions, but at a very high price. He has not make every block including that transaction orphan.

That's almost all he could do with more than 51% of hash rate.

True.  Double spending would probably be the most that would be accomplished, as well as orphaning a few blocks mined by others.  You can only double spend coins you own, so to even make a double spend worthwhile, you would already need to own a substantial amount if Bitcoin.  If you did own that amount of Bitcoin, you probably wouldn't want to upset its value.

[bitpop]

Seriously people stop letting them scam you.

[jubalix]

A recent post from Reddit made me aware of that Bitcoin’s biggest flaw and threat which could crash the entire system, including the Bitcoin price, is now more current than ever. The threat is becoming even more real after months with Bitfury ASIC mining pool GHash.io gaining more and more hashing power. Now let me explain what is going on.

Read the full story here:
http://www.cryptocoinsnews.com/2013/12/26/biggest-flaw-bitcoin-crash-entire-system/

What do you think of the threat that GHash.io is for the Bitcoin community?

yawn

PeerCoin solves this, and other pos

[descarte]

anyone can really destroy bitcoin if they want to... seriously. Assuming NSA has 10nm technology and build thousands of miners and dont tell the world. THen  create a new pool instantaneously with 10000000TH.

That will kill off the bitcoin mining straightway.

I believe they have the money, the brains and the capability. Why aren't they doing it?

[Puppet]

NSA doesnt have 10nm. No one does. Not that you need it, 28nm would work just fine. ~100TH per wafer, just order a few 100 wafers at less than $4000 each, thats hardly the problem.

[BitThink]

anyone can really destroy bitcoin if they want to... seriously. Assuming NSA has 10nm technology and build thousands of miners and dont tell the world. THen  create a new pool instantaneously with 10000000TH.

That will kill off the bitcoin mining straightway.

I believe they have the money, the brains and the capability. Why aren't they doing it?

First, even with 1TH per chip, thousands of chips still are only several PH. You still need to build tens of thousands of chips overnight to get 51% hash rate.
Second, not anyone can have the ability to have the technology, fund, product lines, and meanwhile keep confident for several months.
Third, only countries like USA and China have the ability to do that, but even they really want to kill bitcoin they have much simpler ways.

[BitThink]

NSA doesnt have 10nm. No one does. Not that you need it, 28nm would work just fine. ~100TH per wafer, just order a few 100 wafers at less than $4000 each, thats hardly the problem.

So you can easily get mining chips at $40/TH, or $0.04/GH. That's great, I bet you will be billionaire soon. Meanwhile, at the time you get 10 PH, the network hashing rate will definitely already 100 PH.

[Gabi]

I think it's necessary to highlight here: no miner can change the blockchain history or steal anyone's bitcoin even he has more than 51% of the hash rate. What he can do is only make several blocks mined recently become orphan. It means 1) he can try double spending, but not easy after enough number of confirmations. If there're too many confirmations, it takes long time for his fork to catch up. 2) he can block some accounts to make any transactions, but at a very high price. He has not make every block including that transaction orphan.

That's almost all he could do with more than 51% of hash rate.

True.  Double spending would probably be the most that would be accomplished, as well as orphaning a few blocks mined by others.  You can only double spend coins you own, so to even make a double spend worthwhile, you would already need to own a substantial amount if Bitcoin.  If you did own that amount of Bitcoin, you probably wouldn't want to upset its value.

False, false, false.

He can steal anyone's bitcoin and yes he can change the blockchain history.

Upset the value? Exactly what banks and governments would like!

[Voodah]

Upset the value? Exactly what banks and governments would like!

Only if you assume they cannot profit from BTC, which would in fact be easier for them to do.

[Gabi]

Easier than just printing money? Than creating money? Nah

[stompix]

I think it's necessary to highlight here: no miner can change the blockchain history or steal anyone's bitcoin even he has more than 51% of the hash rate. What he can do is only make several blocks mined recently become orphan. It means 1) he can try double spending, but not easy after enough number of confirmations. If there're too many confirmations, it takes long time for his fork to catch up. 2) he can block some accounts to make any transactions, but at a very high price. He has not make every block including that transaction orphan.

That's almost all he could do with more than 51% of hash rate.

True.  Double spending would probably be the most that would be accomplished, as well as orphaning a few blocks mined by others.  You can only double spend coins you own, so to even make a double spend worthwhile, you would already need to own a substantial amount if Bitcoin.  If you did own that amount of Bitcoin, you probably wouldn't want to upset its value.

False, false, false.

He can steal anyone's bitcoin and yes he can change the blockchain history.

Upset the value? Exactly what banks and governments would like!

Hmmm , we should correct the bitcopedia then?

The attacker can't:
Reverse other people's transactions
Prevent transactions from being sent at all (they'll show as 0/unconfirmed)
Change the number of coins generated per block
Create coins out of thin air
Send coins that never belonged to him

[Gabi]

Yes we should. Because it is wrong.

Reverse other people's transactions
Send coins that never belonged to him

The attacker CAN do these things.

[justusranvier]

Yes we should. Because it is wrong.

Reverse other people's transactions
Send coins that never belonged to him

The attacker CAN do these things.

Are you claiming that somebody broke ECDSA?

[Gabi]

Yes we should. Because it is wrong.

Reverse other people's transactions
Send coins that never belonged to him

The attacker CAN do these things.

Are you claiming that somebody broke ECDSA?

Where did i exactly claimed that? Please point me to that  Because i never said that  I just said the attacker can spend coins owned by other people 

[rarkenin]

You stated so indirectly. In order to steal coins from most transactions, ECDSA must be broken.

[btcrich]

Yes we should. Because it is wrong.

Reverse other people's transactions
Send coins that never belonged to him

The attacker CAN do these things.

Are you claiming that somebody broke ECDSA?

Where did i exactly claimed that? Please point me to that  Because i never said that  I just said the attacker can spend coins owned by other people 

Gabi, please tell me how it's possible to spend coins you don't own.  It isn't possible.  Unless you actually think that reversing a transaction is actually your victim sending coins back you you?

It's just not the way it works.

[Gabi]

You stated so indirectly. In order to steal coins from most transactions, ECDSA must be broken.

I never stated it, directly or indirectly. Nah you must not break it

Yes we should. Because it is wrong.

Reverse other people's transactions
Send coins that never belonged to him

The attacker CAN do these things.

Are you claiming that somebody broke ECDSA?

Where did i exactly claimed that? Please point me to that   Because i never said that   I just said the attacker can spend coins owned by other people  

Gabi, please tell me how it's possible to spend coins you don't own.  It isn't possible.  Unless you actually think that reversing a transaction is actually your victim sending coins back you you?

It's just not the way it works.

It is so easy and yes it is possible: just rewrite the chain from when these coins were mined. You will find the blocks, so you will have mined them, so they will be your. Thus, the other transactions never existed. That is how a 51% attack work, you can rewrite the chain as you wish.
No need to break ECDSA. You just make it so you mined these coins. So you own them. 51% attack.

[Voodah]

You stated so indirectly. In order to steal coins from most transactions, ECDSA must be broken.

I never stated it, directly or indirectly. Nah you must not break it

Yes we should. Because it is wrong.

Reverse other people's transactions
Send coins that never belonged to him

The attacker CAN do these things.

Are you claiming that somebody broke ECDSA?

Where did i exactly claimed that? Please point me to that   Because i never said that   I just said the attacker can spend coins owned by other people  

Gabi, please tell me how it's possible to spend coins you don't own.  It isn't possible.  Unless you actually think that reversing a transaction is actually your victim sending coins back you you?

It's just not the way it works.

It is so easy and yes it is possible: just rewrite the chain from when these coins were mined. You will find the blocks, so you will have mined them, so they will be your. Thus, the other transactions never existed. That is how a 51% attack work, you can rewrite the chain as you wish.
No need to break ECDSA. You just make it so you mined these coins. So you own them. 51% attack.

It is not as easy as you make it sound.

It is not the same to change the last, current or next block than to change a given block in the past. Even if you've broken the encryption there's still a LOT more work involved.