Bitcoin Forum

Can someone find a way to hack Bitcoins or find a way to hack and get the private keys. If it might happen what will happen to Bitcoin? , Is it the worst nightmare a Bitcoin holder can have to wake up one day to see that someone hacked and found a way to extract all the private keys? All opinions and constructive answers are welcome  :D

The Private keys can be brute forced. But I don't think you're going to find the correct combination if you do so very easily or soon. It will take some of the world's super computers years to do that, millions.
However, if you're keeping your bitcoin on a Online wallet just consider your bitcoins lost/hacked already ;)

The Bitcoin network it self can be hacked with a 51% attack, which is highely unlikely.

If you ever see on the news "Bitcoin hacked" it likely means an exchange or online wallet was hacked, not Bitcoin it self.

As described by CrackedLogic, brute forcing private keys is theoretically possible.

But I guess hackers or other tech geeks will need hundreds of years worth of patience. And then still, chances are high that there is not any progress made  :D

Perhaps that a huge botnet can get you a quicker brute force result, but again, it's not very likely. At this point our private keys are safe.

It is good to hear that Bitcoin will be safe and will take many supercomputers so many years to hack it, it is a good thing to not keep good quantity of bitcoin on online wallets, but rather store it offline in cold storage wallets  :D

What if someone reverse engineers the Bitcoin source code and finds a loophole in the system itself? Is it possible?

brute forcing a private key is only theorically possible, practically will never happen, even using all the supercomputer of the world it would require so much time, that the universe might collapse first, before you finish brute forcing your key

For now you are right. But look at computers and technology we had not so long ago. Do you know that computer on space shuttle NASA had in 70. was less powerful than today's smartphone? Brute forcing a private key may be closer than we think. But then again we should have upgraded code of bitcoin or bitcoin 2.0 by that time too.

It happened properly once in 2010. 184 billion coins were created out of nowhere. They forked the blockchain and patched the issue. I can imagine if that happened today it would cause a teensy bit more alarm in the wider world.  

https://en.bitcoin.it/wiki/CVE-2010-5139

It seems to be semi forgotten these days but it was a tiny space back then.

If someone were to dump them and withdraw the money fast enough, they could make out with tons.

Also for the private key, you could generate trillions of random codes (2048 bit I think?) and maybe make a password list to try and brute force it.

Yeah, it is buried in history, people are ready to find any small loophole the system might have  :D

The wallet of each particular user can be hacked, it theory. BTC, as a system. no way.

So Bitcoin system can be called as the triumph of maths and cryptography?

Not far off. I'm sure thousands of hackers have been trying to bust it wide open for years on end. They've failed miserably apart from that one hiccup. I assume those who've chucked their time and big bucks in researched it ruthlessly before taking the plunge. 

It was happened also this thing :



It "was not related" with the bitcoin code itselft but with a bad generation of the private key (and address).

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This is an interesting article (about that situation) :

Upon running the script last Monday morning, he said he recognized immediately that it had found something. The script, which had discovered only about 500 such 'broken' keys in the bitcoin blockchain's five-year history, had suddenly unveiled 500 more in a single day. A second script he wrote scanned the public ledger to see if any funds had been sent to those addresses, and was startled to see the amount. "I had prepared some scripts to assist finding and spending the money from the broken addresses, but I hadn't prepared it for this scale." He sorted the transactions, starting with the most valuable ones and sweeping the funds from the broken addresses into one he controlled. The scripts prepared and signed the transactions, double-checking for correctness and transaction fees, about one every two or three minutes. Some, such as freshly mined bitcoins that can only be spent after 100 confirmations, took longer.


http://www.coindesk.com/good-samaritan-blockchain-hacker-returned-255-btc-speaks/

Apparently, Bitcoin can be hacked theoretically, and brute-forcing, that is. There is no easy way to achieve brute-forcing. It requires a massive amount of computing power before being able to achieve such a feat. And by that, it means that even the supercomputers in existence wouldn't be able to solve it in a short span of time.

Going back to the question, yes it can, theoretically, but in the current times, it is highly improbable.

It would be more effective for you to do more research before asking questions like this.

First of all, there is no "the Bitcoin source code". Originally, people used the original Bitcoin client written by Satoshi, and then they wrote their own software derived from Satoshi's source code. These days there are several completely independent sets of what you call "Bitcoin source code".

Now to answer your question: There is no need to reverse engineer anything. Nothing about Bitcoin is secret. It is 100% transparent. Notice that I used the word "derived" above. That's right. Anyone that wants to look at or use Satoshi's (et al.) "Bitcoin source code" can. It is right here: https://github.com/bitcoin/bitcoin

It is theoretically possible to find a loophole in any system.

But so far in 6 years no one has hacked the Bitcoin system as such.
The most viable attack vector is the 51% attack.

Ok thanks for letting me know, I am relatively new to Bitcoins and I am very much interested in the inner workings of the Bitcoins, so it is a group effort to over write the original source code from Satoshi, does someone verifies the integrity of new codes added or someone can manipulate as it was done earlier by creating false Bitcoins? Thanks and I'm just curious about all this as i think it will be the future of money  :D

I think there needs to be tighter constraints over how the bitcoin core is updated. At the moment, the power is concentrated in a tiny group of developers that can pretty much take liberties as they choose. Most likely, the solution will be to spread the world's wealth across multiple blockchains.

I think bitcoin can be hacked in the future when computing power escalates. When the devs see SHA256 is starting to be weak, they will change to SHA512 and so on. The bitcoin protocol is not fixed, it can be changed when the community agree on it.

Sure anything is possible. Someone could, in theory figure out a way to reverse calculate the epileptic curve, however I doubt that this is actually possible.

If someone wanted to steal bitcoin from people, a more efficient way would probably be to do so via either social engineering, malware or some other weakness in someone's security.

Bitcoin has grown past the point of being hacked by any person or group of people...

This video will explain it all>>>> http://landofbitcoin.science/understand-bitcoin-better/   ;)

On a protocol level, private keys appear safe from people attacking or analyzing the block chain; of the private key fur any address can be extracted, that will be it for Bitcoin. But if that happens, lots of other things far more valuable will fall apart as well.

But ln the individual level, the threat of Any one persons key getting stolen can be substantial if they aren't taking adequate steps to protect themselves.

Can bitcoin be hacked: Yes
The Result: At least 1 fork and a whole lot of fixes/improvements.

Answer solved. No need for thread to continue.

wow I actually agree with microguy on something, especially when Andresen openly admits he only has to convince 5 people in order to change anything on bitcoin.

oddly enough at the same time many of the powers to be within bitcoin what sidechains to replace and eliminate alternatives..............................................................dange rous path.

Watch this video https://www.youtube.com/watch?v=ZloHVKk7DHk and tell me if you still think it's possible to brute force a private key?

If that happens, everything will collapse around Bitcoin until SHA512 is implemented and they will have to start over again.

This is not a real issue in my opinion... be more worried about 3rd party software being hacked that is built on top of the protocol.

No, it is impossible to find (bruteforce) a number = 10^48 .... Have you seen how it is big that number or not? You need 100 years of time and maybe you can find only one bitcoin private key (converted in binary code). It is not so simple as you think, come one mate... this is math!

There are no 100% secure system. However hacking bitcoin needs munch more effort then the value you can get in return.

Lots of service depends on SHA256 algorithm, if it was hacked, the effect is not only for bitcoin.

There is no way for you to find out the private key just by knowing the public key but you can certainly brute force. However the probability using this method to find a private key that actually holds bitcoin is low. To hack the network you will need considerable hash rate to do so, thus overall in general very much unlikely.

This is a serious understatement. Are you trying to do this on purpose or is it the lack knowledge?
https://i.imgur.com/fYFBsqp.jpg

Exactly. Everything can be hacked. If we stood united during/after the hack we would easily recover. The development would definitely speed up.

Yes of course, if someone will break the sha256 algorithm I am sure the first target will be the bank system and not the bitcoin. Most people will think that the actual banks are safe but they are wrong.

The bitcoin code is hacked every day and the result is some new shitcoin. Yes, it can be hacked and is hacked all the time but there is no successful exploit.

If the actual developers take the wrong path that nobody accepts, we can fork Bitcoin.
Remember that its the people that chooses or not to upgrade their clients and daemons to the new release.

You shouldnt care so much about bitcoin hacked but about your smartphone or notebook hacked. It contains your wallet most probably and if a hacker could get into your computer then he might be able to steal from you. Thats why solutions like armory exist where you can hold your wallet away from internet.

If you have your coins in an online wallet website then you have risks of they stealing it or hackers stealing from the website.

While im at it... make backups of your wallet. You dont want to wake up, finding that your harddisc is broken and that you lost your coins on the way.

So it is safe with sha256 algorithm, good, but I'm sure many people are working towards trying to hack it, many things what people thought impossible when later people achieved by finding simple solutions, I think it is just a matter of when and I think it will rarely ever happen during our life times  :D

For attacking any given key, you needs far far far more time than 100 years. If it was just 100 years, with moores law doubling power every 2, Youd probably only be looking at 10 or 12 years tops (I know the math isn't difficult, I'm just on my phone not bothering to look it up).

I've been curious about the effort to attack a private key that was generated in a controlled environment that you can recreate; say if a key was generated in a VM, if one recreated that VM in its entirety, platform, OS, any serial numbers, MAC address, system time, etc, would that shorten the time taken to attack a private key? Like, what sources does a VM have or use for generating random numbers, since everything, even hardware RNGs is then virtualized.

Can anyone give insight on that?

Is the 51% attack where someone gains control over most of the network? How would that work

The generation of a private key is not related with the "machine" itself, so also if you can recrete that exact instance you will not be able to get that "key" a second time. I hope you have seen this video :

- https://www.youtube.com/watch?v=ZloHVKk7DHk

I think you will understand a lot of things.

the protocol itself is pretty safe

all the third parties running on it, not so much

Thats why I always say to trust only your self with your Bitcoin, its only a matter of time till Coinbase or Circle gets hacked.

Nope. Cryptocurrencies can. Bitcoin — just first and so far most popular and "big" product of technology with its own strengths and weaknesses

I understand a lot of things. Like that public key encryption depends on random number generators. And that random number generators can either be hardware or in software. A VM, without a paravirtualized driver to access a hardware RNG, needs to depend on a software RNG. And entropy can be a real issue for virtual machines.

Your video explains how secure bitcoin can be by virtue of the large keyspace, where a random number generator helps you generate a key from anywhere within that keyspace. But it doesn't address my question, where keys are generated on a platform that might not have access to true random numbers.

From: http://log.amitshah.net/2013/01/about-random-numbers-and-virtual-machines/


Weak random numbers were the cause of the thefts from Android generated wallets a couple of years ago. And it sounds like there are still issue with generating random numbers in virtual machines.

My question is still open.

Bitcoin within itself cannot be hacked, theoretically yes, practically no. What can be hacked tho, is people's computer if they don't take care of it. That's how Bitcoins get stolen. The system itself is bulletproof.

Cryptographically secure random numbers are used in a wide variety of computer security systems.  It really isn't rocket science to do it correctly.  The developers in question simply didn't do their job correctly.  If you'd like to be even more stringent, there are several deterministic wallet solutions that use real-world (physical) entropy for the random seed.  

I think this is a pretty good summary.  Sites like directory.io, which creep me out even though it has been discredited, suggests there's some potential issues that we haven't seen yet.  But overall Bitcoin is pretty solid.

Yea. Wee still passing the buck, though. "Developed weren't strungent". YaDa yada yada. Point being that random numbers are only as random as the computer has random inputs; virtual machines are terrible entropy wise.

Yes, implemented correctly, Bitcoin is very strong. But an attaxker wnt attack the strongest point, they'll attack the weakest; I'd wager that any implementation running on a VM is going to have a lot more potential vulnerabilities, whether it's memory dumps or recreating the pool of entropy sources in order to "back into" the private keys.

That goes for services running in VM's, VMs that people create as pseudo cold storage devices or even (and ill have to read up more) keys generated on Tails live Cd's now that electrum is included.

It's easy to look at the reference white papers and say "implemented correctly, Bitcoin is as close to 100% secure as is possible", but know that no attacker will attack the strongest point. We need to review examine and discuss all of the weakest links and see how vulnerable those point are, and bring those to peoples attention so they know to avoid those.

The android RNG flaw for example; everyone assumed that Googke wouldn't release shoddy code like that, so android was trusted, people only looked above that later, it was inly after a lot of coins went missing that people realized that the platform itself was the problem.