Bitcoin Forum

So, from what I understand is that Bitcoin addresses can be created "on the fly" at whatever number at a time without the fear of generating a duplicate address because of the chances.

Well, Bitcoin seems to be doing pretty well, so,
what happens after 20 years?

I am pretty sure that at some point unique addresses are going to start running out....

So what happens?

 

There are this many addresses

1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976

What, currently or possible?

The sun will run out of fuel before we run out of addresses.

Possible. We wont ever reach that.

The number of possible addresses (2^160)

Currently there are only 6M addresses associated with any unspent output ("funded").

If you are worried assume there are 1 billion Bitcoin users and they each generate 1 billion new addresses per day.  How long would it take to generate 1% of the possible addresses.

lol, i don't know exactly but the figures are ridiculous. Something like if an address is created every second it would be trillions of years before we run out. Probably more to be honest :D

Everyone on the planet would have to have like 200,000,000,000,000,000,000,000,000,000,000,000,000 wallets to duplicate.

There are 2^160 unique addresses, that is around 1.4 x 10^48
The blockchain reports that only 200000 unique addresses were ever used, that is 2 x 10^5
https://blockchain.info/charts/n-unique-addresses

Estimated from the chart, used addresses triple every year.
In 20 years time, we could have used 7 x 10^14 addresses,
The address space will still be 2 x 10^33 times more than the used addresses.

Probability of address collision is still extremely low, but yes, it does made you feel less assured.

Very informative, I have often wondered about this myself.

Possibility of abiogenesis (life created on earth without God) has been calculated:

1 out of 10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000

So don't think we'll run out of wallets

I assume this factors in the fact that many people are trying to get vanity addresses?  how fast can these generators generate new addys?

We'll all be 20 years older.

It doesn't matter.  It isn't a concern.

Many people seem to have a very difficult time comprehending just how big the numbers we are dealing with are.

That is a giant scale simply put their are enough generated addresses that it would not run out for a long time
Anyways here is the FAQ should help answer most questions
https://en.bitcoin.it/wiki/FAQ

In their defense, the human brain itself is not particularly good with grokking such large numbers.

At my current calculations it would take all 7 billion people in the world to use 2,087,859,481,901,289,883,148 addresses. in other words, they would all have to generate 114,403,259,282,262,459 a day for 50 YEARS to run out of addresses. Running out of addresses is unfathomable.

Stuff like this is actually helpful.  While I realized the number of addresses was huge the thought had occurred to me that each person makes millions of financial transactions and so putting the number in terms like that really helps.

And yes, people are really poor with really big numbers, even distinguishing between millions, billions, and trillions taxes them.

Good Luck!

This topic made me chuckle :)

haha hey, these calculations literally took 45 seconds. All I did was copy and paste into the windows calculator xD Glad I could help though!

And how did you guys calculate these numbers? Is it how many possible combinations of all upper case letters, lower case letters, and numbers, with the possible 34 characters?

The bitcoin address is a base58 representation of a 160 bit hash value with a version number on the front and a 4 byte checksum on the end.

Since any given 160 bit hash will always have the same 4 bytes for the checksum, the checksum is not part of the calculation of how many distinct addresses there are.  Since we are specifically talking about 1 type of address, the version number is also not part of the calculation of how many distinct addresses there are.

The assumption everyone is making is that if you start with all possible 256 bit numbers (the ECDSA private key), and you calculate the ECDSA public keys (another set of 256 bit numbers), and you hash them with SHA256, and then hash the results of that with RIPEMD160, then you will have an even distribution across all 160 bit values.

Assuming that is true, then the total number of possible addresses is 2¹⁶⁰

Plug 2¹⁶⁰ into a calculator (or into the Google search box), and you'll find that the result is 1.4615016 X 10⁴⁸

Is that actually how many there are or did you pull that out of your behind?
If that's the number... wow.

That's the actual number (assuming that all possible 160 bit values will result from a SHA-256 hash followed by a RIPEMD-160 hash of all possible 256 bit ECDSA public keys using the Secp256k1 curve).

Long after man has fallen, future civilizations, possibly evolved from mice or cockroaches will still be generating Bitcoin addresses.

When you create an address nothing happens to the network. Only when payment is sent to that address is when the network will have a record of that address.

It would be possible, in theory (but extremely unlikely) for two people to "create" an address but neither send any BTC to it so neither would ever know that the other had created such address.

This does actually happen with brain wallet miners as they are "mining" the same kind of potential brain wallets.

The max amount of Bitcoin Addresses is more or less equal to the number of atoms that are in this world..

Save Bitcoin addresses, use mine instead  ;D

For sure.
Give us your private key and we will do just that  ;D

you will win many time at loto games before you run out of addresses.

How does one even say this number: 1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976  ???

I bet it would be a whole paragraph  ;D

All very interesting but here is a question how many addresses can be generated in a day one 1 fast pc?

 1 per second seems easy with a  code written for it.


 Lets say I want to possess all the address not used.  1 per second comes to 86,400 a day or  31,536,000 a year.

I also  say lets use a factor of 10   which means 315,360,000 a year    lets say everyone on the planet does that.

 10,000,000,000 is more then our real count of people but WTF   makes the math easy.


315,360,000  x 10,000,000,000 =   3,153,600,000,000,000,000   in one year    while a big number it is no where near the amount possible.  


3,153,600,000,000,000,000  is a lot smaller then 1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976



So even if people try to 'corner' the BTC address market it would take a long time to do so.

 And addresses could be increased in length  if really needed to do so.

Would it be possible for someone to write a malicious program to generate a massive amount of addresses continously?

I am thinking of a large botnet, all generating thousands of addresses a second?

Good question.

What about Quantums.
Can they not generate thousands of addresses per second?

That could also be an attack on the network (of some sort).

Avram's law: As the length of a BitcoinTalk thread increases, the probability of a quantum computer being mentioned approaches 1.

OK, your point being?

My point is that as the length of a BitcoinTalk thread increases, the probability of a quantum computer being mentioned approaches 1.

For sure it does.
Even though Quantums right now cannot crack SHA-256 it still remains a thread.
Don't you think?

How many addresses does need to be generated to have 50% change for one clash?

I assume this is same problem as birthday paradox, just with very large numbers?

There are currently around 200.000 adresses in use:

https://blockchain.info/de/charts/n-unique-addresses

with a total of 2^160 is 1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976 possbile addresses.

soooooooooooooooooo :D

The chance to hit a address in use is about:

1.34*10^-43 %

0.000,000,000,000,000,000,000,000,000,000,000,000,000,013,4 %

pretty small number, huh ;-)

So there is a chance?    ;D ;D ;D ;D ;D ;D ;D
LOL


BTW nobody answered my question:

How does one actually SAY this : 1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976

Wolfram alpha :D

well sure there is a chance..
its like winning the lottory 3-5 times a row ;-)

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

Start from there to: find the largest number and then start going down.

1 Point 46 Quindecillion

:D

Let me provide more significant figures in my wording:

One quindecillion, four hundred sixty-one quattuordecillion, five hundred one tredecillion, six hundred thirty-seven duodecillion, three hundred thirty undecillion, nine hundred two decillion, nine hundred eighteen nonillion, two hundred three octillion, six hundred eighty-four septillion, eight hundred thirty-two sextillion, seven hundred sixteen quintillion, two hundred eighty-three quadrillion, nineteen trillion, six hundred fifty-five billion, nine hundred thirty-two million, five hundred fourty-two thousand, nine hundred seventy-six.

Or, http://tts.imtranslator.net/TYni

Thanks guys, I was actually expecting to hear the full number  ::)

I am pretty curious to know how long it will be, like a paragraph or so.

^^^ We have a winner and it is a paragraph  ;D ;D ;D ;D ;D ;D

Or in other words, that will never happen.  :)
One shouldn't worry about this, these is enough room for everyone to have many addresses.

Add adresses and wallets that are intentionaly deleted after some time etc. Not only there is shitload of them, they recicyle too. Cool stuff if you ask me. It's really hard to express how large this numbers are to someone not close to mathematic and phisics. For example i tryed to explain this to my father and i just gave up after some time. Now that i have this block of text (name of number) i think it's gonna be much closer to him....just to see how freaking long does it take to pronounce it  :)

I am not worried anymore. I was working on something that uses a new address each time.
That's why I was asking ;)



It is quite long innit?  ;D

the number you give is the daily count which is more likely ~150.000 addresses used daily. The number of users on blockchain.info alone is approaching 2 millions( https://blockchain.info/charts/my-wallet-n-users), if you count all other wallets users its a figure of nearly 5 millions users or more. Nevertheless he chance of address collision is still vvvvvvvery low.

It'll take literally forever to run out of unique addresses. So don't worry about it, it won't even be used up even after hundreds of years.

Page 3 and no sphere pic.

I always enjoy the analogies of these threads.  They're different every time. I'd like to know the actual odds of creating duplicate addresses vs. 1000 people winning the lottery everyday for a year.  Give me some time and I'll do it myself...

Which lottery?  There are hundreds of them, and they each have different odds.

It's simple, really. If you somehow had vast amounts of computing power, you could mine all of the rest of the bitcoins faster than you could crack a single address.

All you need to do that is to maintain more than 50% of the total network hashing power for the next 125 years or so.

It's often called a 51% attack.

Fair enough.  NY Lottery 6 numbers, chances of 1 person winning 1 time is 1 in 45,057,474

http://nylottery.ny.gov/wps/portal/!ut/p/c4/04_SB8K8xLLM9MSSzPy8xBz9CP0os_jggBC3kDBPE0MLC0dnA09vT0fLQDNvA0dfU_2CbEdFALm-TnU!/?PC_7_SPTFTVI4188AC0IKIA9Q6K0QS0_WCM_CONTEXT=/wps/wcm/connect/NYSL+Content+Library/NYSL+Internet+Site/Home/Jackpot+Games/LOTTO/Lotto+-+Chances+of+Winning

If you are trying to find a private key that will allow you to spend the bitcoins associated with a particular bitcoin address...

There are 2¹⁶⁰ possible addresses.
2¹⁶⁰ = 1.46 X 10⁴⁸

So, the odds of finding such a private key are 1 in 1.46 X 10⁴⁸

The odds of winning the NY lottery 6 numbers Y times in a row are:
1 in 45,057,474^Y

45,057,474⁶ = 8.37 X 10⁴⁵

45,057,474⁷ = 3.77 X 10⁵³

So the odds of finding such a private key are a bit better than winning the NY lottery 7 times in a row.

Math is awesome, thanks!!  I wish I was better at it. I thought the odds were actually going to be a lot more distant than that...but then when I thought about it, Those are the odds of a single person buying a single ticket on 7 different drawings and winning every time.  That person cannot ever have purchased a ticket in the past, or ever again in the future...Or as you put it, 7 times in a row.

This would be why I generally don't bother playing the lottery.  People don't realize how much the odds are stacked against them.  Winning multiple times on a single ticket each time multiplies those already astonomical odds to dizzying heights.

The best description I've heard of for government run lotteries is:

"A lottery is a government tax levied on the absence of mathematical skills."

Or as my brother puts it "The lottery is a tax on imbeciles."

And as true as what you said may be, a lot of people "gamble" on it and quite a few actually become (multi)-millionaires from it....
If your lucky then your lucky.....
That being said, I don't gamble.

Of course, and I'm happy to be an imbecile myself from time to time, but it's still worryingly true ...

But you'll never win if you don't play!

You miss 100% of the chances you don't take!

and other platitudes.

Compared to the number of people that play, I wouldn't call the number of winners "quite a few", but that's a matter of personal opinion.

Regardless, as with any tax, the government takes some of the revenue gathered and spreads it around to make people feel more comfortable with paying it.  In the case of the lottery, they just don't spread it quite a thinly.  Instead, they take a big chunk of the revenue, and give it all to one person (or small group of people) every now and then to discourage learning about math, and encourage others to keep paying the tax.

If I told you that sales tax was a tax levied on the purchase of merchandise, you wouldn't respond with "As true as what you said might be, a lot of people still make purchases, and the government spends some of that revenue on services for citizens".

Of course you will.

I know someone that's bought five $1 lottery tickets every week for the past 20 years that I've known them.  They haven't won the jackpot yet.

Relative to them, I've already "won" $5200.

I suppose they've won some smaller amounts occasionally.  If we assume they've won back about 10% of the total they've spent, then I've "won" about $4,680 more than them.

adress are generate with a random function ... random function is a variable based on the time and date.
you can't have duplicate adress "over the time".

http://3.bp.blogspot.com/-Sn7QkyYvyuA/USLSGGM3sPI/AAAAAAAACMY/O07-gMgjfb8/s1600/liam_neeson_wink+%5BGIF%5D.gif

No. It isn't.  That wouldn't be "random", that would be "deterministic", since the value could be "determined" based on the time and date.

The bitcoin random function is NOT based on time and date.

Rounded somewhat (actually, quite a lot).

The number is one point four six one five quindecillion if you use the short scale for numbers or one point four six one five Octillion if you use the long scale.

Source: http://en.wikipedia.org/wiki/Names_of_large_numbers

As the previous posts have explained, there are so many possible accounts the chances of two people creating the same account is too small to worry about.  The chances of the Sun exploding next week are much higher, for example.

However, there is a non-negligible risk that the software that one uses to generate the key/address pair is malicious, so that it will pick one among only 10 billion different address (say), rather than among the full set of 2^160.  Without inspecting the code, there is no way to tell that one's address has been generated in that fashion.  indeed, the malicious code may even erase itself after a certain time, putting the correct software in its place; so that not even code inspection would work.

After distributing that malicious software to one or more unsuspecting users, the hacker generates all those 10 billion pairs, and monitors the block chain until one of those addresses shows up with a large enough balance.  Then she issues a transfer of the whole balance to her own address.  The victim would not be able to prevent that, and would not even be able to prove that he did not issue the transaction himself.  Note that this attack works even if the victim is careful to run the address/key generation software in a separate computer that is isolated from the internet, and never takes the keys out of there.

In fact, there is no way of telling whether such a hack has occurred already.  Maybe some hacker out there has a large file of address/key pairs that includes the the private keys of many unsuspecting victims, and she is only waiting for the best moment to strike.

A variant of this scam is feasible also if the key/address generation software is legitimate but has a bug in its random number generator that limits it to, say, 10 billion different addresses.  A hacker that discovers the bug could then exploit it as described above.  The chances of such a bug being introduced by accident and then discovered by a hacker are certainly small -- but still bigger than those of a collision among 2^160 addresses.  

(Actually, such a stupid "bad random generator" bug was found recently in the Brazilian electronic voting machines.  It could allow anyone to discover someone else's vote using only data files that must be public by law and the time when that person voted.  Ironically, that bug was put in by the developers in order to "strengthen" the machine's security.)

In yet another variant, the malicious code is distributed through a "trojan horse", some apparently unrelated software such as a solitaire game.  When executed, the malicious program silently scans the computer's file system for some popular key/address generation software, and modifies it by weakening its random number generator, as above.

The moral of this tale is that one cannot be careful enough when choosing, downloading, and running the key/address generation software.  It is one of the soft spots that hackers are going to aim for.

This is wrong.  The probability is 1.0.  For every earth observed life exists.  Abiogenesis occurred.

These numbers are Carl Sagan big. 

We can effectively say it is not possible to run out of addresses.

They are not.  Even the largest numbers in astronomy are MUCH MUCH smaller than 2^160.

I agree that finding private keys via brute force is not possible  ;D

But what if an agency such as the NSA simply goes ahead and reserves all 1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976 addresses for themselves? That would kill BTC wouldn't it?  ???

You're joking, right?

Sorry you lost me.
What do you mean?

Actually generating all these addresses?????

That wont happen.

Basically the reason I asked this question is that I am working on a project that uses a new (disposable) address for each transaction.

I wanted to know what are the chances of.....

The chances are well, non existant.

Your NSA will most definitely need to build a memory storage bigger than this planet to store this amount of data.

There's a difference between knowing the number of possible combinations and actually doing anything with them. We've established that even just generating them, a process that takes just a fraction of a second for each, would require more time than we have before the heat death of the universe.

with no time reference, you can't create a random formula ...

i build microprocessor for industrial use (without NTP chip) ... and random is only possible because crytal frequency is not "regulary the same in identical chip".

the adress of bitcoin must be generate in random and "row" strategy.
only based time/date strategy do this.

that why, in log of bitcoin-qt, you can see NTP mark regulary to correct the main process of mining/RPC orders.

Yeah that is still wrong no matter how many times you repeat it.   There are plenty of entropy sources which don't involve time.  


If you are referring to entries like this:


They are not references to NTP.  It is comparisons of the local machine clock against the network median time.  It isn't used to seed the PRNG but to limit how far miners can drift the timestamps of blocks.

My calc three/stats teacher stated it as:

A lottery is a tax levied on the innumerate.

:-)

one quindecillion,
four hundred sixty-one quattuordecillion,
five hundred one tredecillion,
six hundred thirty-seven duodecillion,
three hundred thirty undecillion,
nine hundred two decillion,
nine hundred eighteen nonillion,
two hundred three octillion,
six hundred eighty-four septillion,
eight hundred thirty-two sextillion,
seven hundred sixteen quintillion,
two hundred eighty-three quadrillion,
nineteen trillion,
six hundred fifty-five billion,
nine hundred thirty-two million,
five hundred forty-two thousand,
nine hundred seventy-six


;)

entropy source use a referencial system, too ...

if you talk about the random formula based on "event" of the bitcoin ... it's, at the beginning, a question of time/date ... and after this, the weight of the first block and all following blocks.

in this, random of bitcoin adress is unique ... and so, not "only based on time/date random genesis formula".
you can't create random function in mathematical environment ... because all formula answer a same result when you use it.

that's why A.I. don't exist now ... because programming tool are based on mathematic.
if you boot a hundred of machines identicals with the all choice of mathematic formula, the result will be always the same on all machines (depending of the variation of the supply for the final speed of calculation).

find me a mathematical formula that it don't always send the same result ...

---

For me, it's not a problem ... but for beginners, it's good to understand that you can't simply use a private key because of the time/date simply designed random formula "at the begin" of bitcoin network.

all beginners think that "generation of bitcoin adress" is based on a non-lineairy random strategy ... it's not true.
because time/date evolve (and you can't back to the past), all adress must and are different (+ variable with bitcoin network event).