Accidentally created a wallet address that someone else already has?

[zimmah]

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.

[zimmah]

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?

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.

[Abdussamad]

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

[Light]

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

Statistically speaking, unless the protocol changes to accommodate more decimal places, only 2.1e14 addresses could contain at least one Satoshi, and that's only if everyone only had one Satoshi. If anyone has more (and pretty much everyone who has any has more than one Satoshi), then there are fewer occupied wallets.

Within the set of 2256 private keys, they only map to 2160 unique wallet addresses. So the question is how does 2160 compare to 2.1e14? One in a million? One in a trillion?
The answer is one in 6.9595 decillion. Since "decillion" isn't a commonly used word, I'll save you the bother of having to look it up: it's a one with 33 zeroes after it.

To put that 6.9595 decillion figure into perspective: The Earth has a diameter of 12,742 kilometers, giving it a surface area just shy of 50 million square kilometers. A square kilometer is 1 million square meters, and a square meter is one million square millimeters, meaning the surface area of the Earth, in millimeters, is just shy of 50 quintillion mm2.

So here's the game we'll play. I've got 140 trillion earth-sized spheres. On one of them, I have randomly selected a single square millimeter as the prize winning spot. Find it, and you'll get to spin the prize wheel to see how much you've won. The prize wheel currently has about 22 million spaces. 21 million of them contain less than a dollar. But you only get to spin the wheel if you can find the secret spot on the secret sphere.

Wanna play?

[Abdussamad]

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

In before quantum-sun pictures explaining that the chances of this happening are literally astronomical.

[Ron~Popeil]

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. 

[ranlo]

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.

[sgk]

I heard there are more Bitcoin addresses possible than there are atoms in the universe.

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.

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.

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

[UNV - ITALIA]

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

[sgk]

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

[Light]

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

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

[Rnbin]

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

[sgk]

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

[findftp]

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.

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?

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

[Meggie]

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

[E-C.Guru]

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

[miragecash]

Yup: 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.

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

[DannyHamilton]

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

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

[jc01480]

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

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

[E-C.Guru]

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

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

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