Bitcoin Forum

Hi,

Dumb question. If bitcoinaddress.org can make a bitcoin address and private key offline, theoretically, someone else might've already made an identical wallet elsewhere because you did not register on the blockchain since it was created offline. Therefore, if you receive funds, the other guy could spend it or if you spend funds, you're spending someone else's money.

Is it not a worry because the mathematical probability is so infinitesimally small due to there being so many characters in a bitcoin public address and private key? But just to be safe, you should send a small amount of money to yourself to make sure it works right and is not shared with anybody else before you tell people to pay you at your new address?

???

Thanks for the answer,
 :)

You answered your own question with the proper RNG you should be just fine.

No, it doesn't works like that.
There's no registration inside the blockchain. Only Transaction FROM A TO B where A and B are public address. And only A and B (if the have the Private Key) can spend coins.

Doesnt sound very likely. I wouldnt worry about it.

Theoretically?  You mean n the same way that, theoretically, all the air in the room could spontaneously collect in one corner leaving a vacuum in the rest of the room and causing everyone to suffocate and die?


This is not a concern.


Correct.

The probability that you will generate an address that already has bitcoins in it is significantly less than 1 in 7x10³².


More specifically, due to the bitcoin address being computed from a 160 bit hash.


This does not make you any safer.


How will sending some bitcoins to yourself help you determine if it is shared with anybody else?

I heard there are more Bitcoin addresses possible than there are atoms in the universe. If that is true, no one on earth will EVER duplicate an address.

The universe is much bigger than can be understood from an episode of Cosmos.

It could happen. But it's unlikely. Not unlikely like being in a plane crash. But unlikely like being in a plane crash 1 million times in a row.

Aren't the addresses generated randomly without regard to checking to see if it already exists anyways? Such that even if you had transfers, if someone happened to be on that address on their generation it would still go through.

The number of bitcoin addresses is big.  Very VERY big.  But, to say that there are more bitcoin addresses than atoms in the entire universe is what would be called an exaggeration.

The last I saw, the number of atoms in the entire observable universe is estimated to be within the range of 10⁷⁸ to 10⁸².

The number of possible bitcoin addresses is less than 10⁴⁹.

The last reasonable estimate I saw for atoms in the "Solar System" was on the order of 10⁵⁷.

If we exclude the Sun, and add up all the rest of the atoms in the solar system, I think the number is somewhere around 10⁵⁴

what if someone made a computer script that automatically created addresses and checks the balances? i'm guessing that if it were the case, it still wouldn't be worth it, considering that the electricity costs would likely be more than the potential $$$ you can make by stealing from others.

Maybe that person was assuming 256 bit addresses.

It's already been done.


You'd be better of solo-mining.  You'll make far more from the block reward than you'll ever get from trying to brute force addresses with bitcoins in them.

There isn't enough energy output left from the entire remaining life of our sun to power a computer that can generate enough addresses to give you anything resembling a chance.

That gets you MUCH closer to the estimated number of atoms in the universe.

2²⁵⁶ is approximately 10⁷⁷

Mere peanuts compared to Graham's number, which is so large we don't know many digits it contains.

http://en.wikipedia.org/wiki/Graham's_number

 :)

That program that creates wallets and check the Balance.. I don't buy the fact that it's not a threat to Security. At least in the future. What if Bitcoin goes to 10,000 USD and you can generate a few thousand adresses a day.. or how many adresses would it be possible to create and check? A few hundred thousands maybe With a strong computer?

What if, in the future, Bitcoin is at 100,000 USD and have 1 billion active users. Is this still not a threat?

My understanding is that if it ever became an issue, it would somehow be altered to fix it. Bitcoin is still in its infancy; if there are any risks, I'm sure someone will find a way to make them obsolete again.

Then it will take 10⁴⁵ days to check all possible addresses. That's more than 10⁴¹ centuries, or more than 10³³ times as long as the universe has existed.



Ok, a few hundred thousand per day?  That will reduce the time from 10⁴⁵ days to a bit more than 10⁴³ days.  So now we are looking at 10³⁹ centuries, or more than 10³¹ times as long as the universe has existed.


No, this still is not a threat.  Human beings have such a difficulty number with comprehension when it comes to really big numbers.  Perhaps you missed the part where I said:

People don't understand the magnitude of these numbers. If 10 billion people (more than are currently alive) had 1 million addresses each, that would still be only 10¹⁶ addresses in use, or 1/10³² of all addresses. Even if all the miners in the world (currently 75x10¹⁵ H/s) decided to brute force addresses, they would only find 1 every few million years on average.

Read this: http://codinginmysleep.com/stealing-bitcoins-the-hardest-way/

Lets say you build a super ASIC on 12nm (4 generations ahead of current tech) process that could create, validate, and steal one trillion key pairs per second (1 TK/s). That would be about 50,000x more powerful than faster GPU’s today. Lets also say you built a thousand of them and ran them continually with no downtime 24/7/365. In 1 year you could brute force 3*10^28 possible addresses.
If there are 1 quadrillion funded addresses you would still have a ~1% chance of colliding with a random funded address in the next 1,000 years.
Comparatively speaking, your odds of being struck by lightning are about 1 in 280,000, so you’re about 500,000,000,000,000,000,000 times more likely to be struck by lightning than to find an address within the first year. Since that’s also a big number, the odds are equivalent to being struck by lightning about 4.6 times in your lifetime

1) the chances of that happening are really really small, so it's safe to assume it will never happen

2) no matter online or offline, an address is never registered. When you create an address you create a private key, and from the private key your computer finds the public key (this is an easy thing to do, however it's impossible to calculate the private key from the public key). When you computer finds a private key it would be meaningless to register it because it would be unsafe if there was a large online database storing all known active private keys. And the fact that there is basically an unlimited amount of private keys in the first place.

Most people have a hard time understanding how big a large number actually is. But trust me even if a billion users generate a million addresses each we wouldn't even have used a percentage if all available addresses, not even close.

10^44 is a billion times a billion times a billion times a billion times a million times hundred.

That's a pretty large number indeed.

So considering a population of 10 billion (current population of the world is just over 7 billion including poor people and children) and everyone has a million adress we would only need to use 1*10^-26% of the avialable addresses or in other words 0,0000000000000000000000001% (I may have missed a zero or two, but you hopefully get the idea)

Also note that if we break bitcoin into the smallest units possible with the current protocol (satoshies) and we generate 1 adress for each satoshi we would need 21000000 times 10000000 addresses (all the other addresses would be empty because there would simply not be any more satoshies left). That's 2.1 *10^15 addresses or just 2.1*10^-27%

If in this case you wanted to steal a satoshi (and note you'd only win a single satoshi!) you would have a chance of approximately 1 in 47619047619047621434313142608 of finding the right adress. Even if somehow you have an insanely fast computer that can make 1000 trillion calculations a second (I don't believe such computers even exists yet) you'd still need 1.5 million years to find an address with a satoshi on it.

If you have such a computer you're much much better off mining.

In other words the number of addresses possible might as well be infinite.

People keep asking this question over and over again and people here keep answering it. Most of the time it's a wasted effort when they could just link to past answers. But sometimes questions like these lead to interesting threads. This thread is not one one of those but here is an example of one:

https://bitcointalk.org/index.php?topic=604002.20

I've always found that an example is the best way to convey the sheer size of numbers. I'll just leave this here:

I don't pretend to understand the intricacies of the numbers we are discussing, but like with almost any threat the currency can evolve to protect itself. I do find these threads to be educational though. 

What makes these more interesting, though, is that we're using computers to generate random numbers. They are actually pseudo-random, as there's no way for a computer to do a truly random number. And then we look at things like the RNG that was in (what was it, Android?) that was exploited... it makes me think that things are still possible and just haven't been discovered yet.

That scenario is addressed in this infographic, quoted from gweedo's post:
https://bitcointalk.org/index.php?topic=587371.msg6434251#msg6434251

https://i.imgur.com/R7W9oiC.jpg

The chances are equal to a kid that invents a nuclear bomb

Even less than that. I can imagine a super intelligent kid, but I can't imagine duplicate public / private keys

Some kid got pretty close a while back. Only difference between a thermonuclear bomb and a nuclear reactor is the control rods. See here:

http://en.wikipedia.org/wiki/David_Hahn

is it possible to manipulate a new wallet address (read: generate one by yourself and not a random one) by experts ? or is it 100% safe

You can't manipulate it; it's completely safe

Wow dude, I'm going to use this quote very often! Very powerful and very funny.

oh,don't worry about it, just be more attentive with creation wallet address

Can someone please calculate the odds of life spontaneously creating itself from dead materia? Thank you :)

Yup: http://en.wikipedia.org/wiki/David_Hahn (http://en.wikipedia.org/wiki/David_Hahn)
This child actually built a nuclear breeder reactor in his back yard at home. It produced a small amount of uranium and plutonium, but he was stopped by the "authorities" and discouraged from further experimentation. This caused him to become severely depressed and drop out of going to college/university. This often happens to genius children growing up in an unsupportive household. Geniuses are often not understood. I mean, if the intelligence difference is as great as the gulf between a human and a dolphin or chimp between an average human and a genius, how can a genius ever be understood? I mean how can a chimp understand you when you talk about bitcoin? Likewise, anything the genius child gets excited about and tries to communicate with his friends and family about is likely only to get discouragement and quizzical looks. This is more likely to be true in blue collar families and poor families than in white collar or affluent families. Guess what the occupation of the world's highest IQ man is? Bouncer. This kid who built the nuclear reactor ended up joining the military. These poor kids often never reach their full potential. God knows how many Teslas (invented A/c electricity, radio, flourescent lights, radar, x-rays, & electric motor) and Enrico Fermis (nuclear reactor) ended up in jobs like grunt soldier and bouncer. Sad.

When I have the money someday, I'd like to build a free school equipped with the latest scientific lab equipment and best professors to teach gifted children of blue collar / poor families for free. It is a boarding school so they can come from any corner of this planet. They'll get frequent plane tickets home for visits and unlimited internet access to videoconference with their family back home. Kinda like that X-men school. This would be a great way to accelerate scientific development on this planet and improve the lives of everyone on our world.

Sure, but first you have to settle the debate over whether there was an intelligence outside the universe that was involved in the process.

Come, now.  This isn't a political discussion.  Lol

No I don't. We were discussin probability weren't we? So, what are the odds of life spontaneously creating itself from dead materia? It's far less probable than that of creating an already existing bitcoin wallet. Yet, here we are :)

The part I highlighted in red appears to imply that you may have made some false assumptions about the part I highlighted in blue.

http://www.parentcompany.com/creation_essays/essay44.htm




Isn't that less of a chance than:


Scientists tells me a forum-scientist is wrong. I make the assumption he is right.

You seem to be assuming that Robert E. Kofahl is a scientist, or that his math is based on reasonable assumptions.


It looks to me as if he is trying to manipulate the mathematics to push an particular non-scientific viewpoint.

More specifically, you say "Yet, here we are" as if the fact that we exist proves that things far less likely than the brute-forcing of a bitcoin private key can happen by chance.  Then, to demonstrate this, you use something published by someone saying that the fact that we are here did not happen by chance.

Now we see why I asked you to "settle the debate over whether there was an intelligence outside the universe that was involved in the process" before we tried to discuss probabilities, and occurrences.

Either it's a non-sequitor, or its gambler's fallacy.

Either way, its freakin irrelevant! lol. :)

Robert E. Whatever is also talking about a professor. Did you read that long into the article?

I say "Yet, here we are" as a testiment to the fact that "it" did happen. The spontaneous creation of life.

And now we know that it was far less probable than someone creating an already existing wallet. Yet, here we are.

Irrelevant is a huge understatement, this is absolutely meaningless  EDIT: Meaningless, yet here we are. :D

Man struck by lightning 7 times.

http://www.washingtonpost.com/lifestyle/magazine/inside-the-life-of-the-man-known-as-the-spark-ranger/2013/08/15/947cf2d8-ea40-11e2-8f22-de4bd2a2bd39_story.html

The odds of becoming a lightning victim in the U.S. in any one year is 1 in 700,000
The odds of being struck in your lifetime is 1 in 3,000

http://news.nationalgeographic.co.in/news/2004/06/0623_040623_lightningfacts.html

 ;D

Lightning strikes are a bad example of probability.  It assumes that everyone has an equal chance of being struck by lightning, and that the distribution is random across the globe.

In actuality, there are some areas that have significantly more electrical storms, and some people spend much more time exposed to the opportunity to be struck.

If you really want to use a lightning based example, I prefer this one:


You'll notice that even with the addition of the requirement of actually being in the process of "taking a crap" at the very moment of being struck by lightning, it is still significantly less likely than being strucm 4.6 (or 7) times in a lifetime.

Source?

FUD

https://bitcointalk.org/index.php?topic=107172.0

Nope.  Not FUD.  The script was written and made public in 2012.  It doesn't matter.  2¹⁶⁰ is a very big number.  Bigger than many people seem to be able to comprehend.

OK, I apologize for my comment.

This is somewhat similar to that site directory.io

Anyone could create N number of public address / private keys but the total number is so huge there's almost zero chance of someone finding an actual public-private combination that is in use by someone else.

The chances are extremely small.

If this were to happen it would likely be due to some kind of attack at your RNG.

There are many more less advanced ways to attack you to attempt to steal your coins. I would personally not worry about this.

Never thought there might be such a problem

It is not a problem. The chances of this happening are smaller then you could likely imagine, smaller then I can imagine.

EDIT: you have a greater chance of having the same DNA of someone not related to you

The download link is broken. Is there any Github rep where this project is hosted ?

I can tell you with a good amount of certainty that you did not create a BTC address that belongs to someone else.

Where is this at?  Would be interesting to look at.

Has there ever been a documented address collision?

Only when using a faulty random number generator.

File not available.

What are you saying?  Sorry... can't tell if you're being sarcastic or serious.  :S

I'm being serious.

Private keys are supposed to be generated randomly.

As long as a properly working random number generator is used, there are no proven cases of address collision.

On the other hand, many people like to choose their private keys (they call them "brainwallets").  In this case, there have been MANY collisions since the human mind isn't very good at being random.

Try taking a few minutes to actually read the thread.  You'll find it.