Bitcoin Forum

Could a super hacker make a counterfeit Bitcoin?

We've all be assured by all bitcoins sources that bitcoins are unfraudable.

I'm curious after reading so many times its impossible what the general belief is at this point

what do you think? Could a super hacker make a counterfeit Bitcoin?

Please share your comments...

~Wavey

Since there is no such thing as an actual bitcoin, there isn't anything for a hacker to counterfeit.  When we talk about "a bitcoin" we are using an abstraction to make communication easier.

The best a hacker could hope to do would be to replace your bitcoin wallet with a fake wallet that shows the balance that the hacker wants you to see.  Anybody who is running a real wallet will still see the correct balance, and anyone who looks through the real blockchain will see the real balance, but they could fool anyone who they could get to run their fake wallet program.

As soon as you replace the fake wallet with a real wallet  you would see the correct balance again.

I suppose perhaps you could consider that "counterfeiting", since the person being attacked would see a balance that is greater then the rest of the system believes they have.

The Bitcoin.org client is open source.   That means the source code in the Bitcoin-Qt client that you run is visible to anyone and everyone.  There are "super hackers" looking at this code as well.  And at other clients as well, BitcoinJ, etc.  There's $300+ million worth of bitcoin funds there for the taking to the first person to figure out some exploit (actually, that's not true ... if there were an exploit the value would plummet, or else a fix is made and losses were only incurred by those who exchanged value for certain bitcoins that ultimately were made worthless due to the fix of the exploit.)


There's a saying that "no one of us is smarter than all of us".  There may be a super hacker smarter out there smarter than the most skilled person working on Bitcoin.  But there isn't a super hacker that is smarter than all the people working on bitcoin collectively.
 - http://en.wikipedia.org/wiki/Distributed_knowledge

A super hacker (cracker) would probably be better of stealing "real" bitcoins rather than making "counterfeit" bitcoins. That's what they do when they hack the exchanges.

I'm sure that sometime in the near future, there will be a TV show or movie in which a "super hacker" counterfeits bitcoins. We will all die a little inside, but it would certainly not be the worst departure from reality for the entertainment industry.

theoretically: Yes, someone COULD do that.
practically: Hahahahah!!! No, the chances are 1 to 50.000.000.000.

You're mising several dozen 0 there.

Are you saying that permanent double-spends are theoretically possible? That's how counterfeiting bitcoins would work. How did you arrive at those odds?

Are you sure you know what you are talking about?  Perhaps you are using a different definition for the phrase "counterfeit bitcoin" than I am?

no

There are two main cryptographic primitives used for bitcoin. Hashing (on which mining is based) and signatures (which ensure that only the owner of a coin can send money).

Someone who breaks the hash function used by bitcoin could cause a lot of damage (probably manipulate arbitrary places in the block chain, which means he could fake arbitrary transactions, including mining transactions). This would probably be detected sooner or later, widely pulicized, and most probably, bitcoin would need to be restarted with a different hash function.

Someone who breaks the signature algorithm could steal bitcoins by making transactions on bitcoins that are not his own. Again, little could be done except restarting bitcoin with a different signature method.

Luckily, both primitives used in Bitcoin (AFAIK these are SHA256 and ECDSA) are considered secure and were reviewed by thousands of professional cryptographers. If anyone broke them in a meaningful, practical attack, it would break a lot more things than Bitcoin.

Most probably, a break will come slowly: Someone will discover some weaknesses, then someone else will discover some more, and before there is a practical attack that could actually be abused, the Bitcoin system will be migrated to another algorithm. This will pose challenges, and if this is not done in time (e.g. because the community fails to agree on how to do it or because an attack comes suddenly), Bitcoin will probably disappear as soon as the first practical attack is executed.

It usually takes many, many years (decades) before "secure" algorithms are broken.

There is also the threat from quantum computers. If someone (e.g. the NSA) manages to build one, they have broken ECDSA. Revealing (and proving) a working, sufficiently powerful quantum computer would mean ECDSA is broken and Bitcoin needs to migrate before the first attack becomes known or it will die.

If you can break  ECDSA  there's way more juicy targets out there than some dude's wallets.

*Asks himself, aka a super hacker*

Errgh, yes and no..No, not a counterfeit thats just silly.

However they can take over the system by having control over more bad bitcoin nodes then good ones.

Once that happens they can do some pretty crafty (&shady) shit. Easiest way to put it is duping..they'd send coins to someone (most likely large amounts such as cashing out their hundreds or probably thousands of bitcoins..get the cash, then automatically the coins will be reversed and go back to the original sender...why? cause he who controls the nodes, he hath control of zee system!

If that were the case...watch out!...

Spending 500000 $ to cheat on a 2,50 $ transaction makes perfect economic sense.

Can you make transactions that low? Never tried...Figured there was a base limit.

People transact with dust all the time on SatoshiDice, I know one guy who won a jackpot the other day was only betting with like $0.60 worth of coins. Lucky guy won 30 grand.

The simple answer is, of course, no.  You can't copy something that doesn't really exist.  But, I assume, what you mean to ask is, "could a hacker trick the network into believing that he has more bitcoins to spend than he actually does"?  The answer to that questions a "yes, sort-of".  However, the two known ways of doing so are; 1)already known and well considered and 2) extremely difficult to pull off.  Those two attack vectors are the Double Spend attack and a 51% hashrate attack.  Considering that Bitcoin now rings in at 300 Petaflops continuously dedicated to securing against a 51% attack, the only realistic vector is the Double Spend.  And that is effectively negated simply by waiting for multiple confirmations.

My coins are associated with a brand new, never-sent-from address. To "forge" bitcoins would mean to get an unauthorized (by me) transaction from that address. First, the hacker would need to break hash function so badly as to be able to quickly reverse my address into the public key. Then, the hacker would need to break the digital signature algo so badly as to be able to reverse public into private key. All this is essentially impossible to happen without years of warning signs of weakened security of the two algorithms.

One thing to worry about is forging (replacing) public addresses with fake ones. Just think about all the donations and trades happening where person sending coins cannot easily be sure the website or email was not tampered with, and that he is sending coins to the correct address. This is not Bitcoin problem, this is the Web/email security problem. There are solutions, but for some reason general public generally doesn't care.  

But there may be bugs in the dominate client sofeware, like last time's overflow error.

As far as brute-forcing keys:

https://i.imgur.com/VjtG3.jpg (https://i.imgur.com/VjtG3.jpg)

 - https://i.imgur.com/VjtG3.jpg

Interesting.... 
Any counter-argument, my fellow bitcointers?

I'd call that "theft", not "counterfeit".


Another form of "theft", still not "counterfeit".


Which again would not permit counterfeiting, only theft.


That's the best suggestion I've heard so far.

You're right, certainly there could.  And if one such bug were to appear and be leveraged, it would be repaired, just like it was last time. So I suppose if there is such a bug, and someone can figure out how to exploit it, the coins that would be temporarily created could be considered "counterfeit". Especially if the "counterfeiter" can get anyone to accept them.  Then after the repair, the coins would cease to exist, and the result would be "theft".

This is very calming to read, future seems good for the BTC.

FTFY  ;)

to anyone asking how  i got my magic numbers: pulled it out of my ass, but EVERYTHING is hackable. and therefor ts a good estimate(not saying stuff gets cracked, but maybe a software flaw).

As stated above there would be no way to do this so question has already been answered I guess.

Thanks guys

This was all very insightful!

 :)

~Wavey

I think no one can crack or hack Bitcoin. But what hackers will do is social engineer your wallet or private key, or the passwords that protect them. People are stupid. No, not all 7 billion of us. But there's a sucker born every minute.

Someone will shoulder surf, bug your house, use rubber-hose cryptography (threaten you with force), kidnap your family, ... before any super hacker can derive a single private key from a public key, or before any super hacker group can do a successful 51% attack and fork the blockchain forcefully.