How many bitcoin addresses can there be?

[bigasic]

I've always wondered how many bitcoin addresses can be made. Anyone know?

[1714186079]

1714186079

[1714186079]

1714186079

[1714186079]

1714186079

[1714186079]

1714186079

[1714186079]

1714186079

[DannyHamilton]

How many different possible addresses exist mathematically?
Approximately 1.46 X 10⁴⁸

How many will actually be made?
That's impossible to predict.

It will depend variables such as:

• How popular bitcoin becomes
• How long bitcoin continues to be used
• How fast computers become
• How many new uses are discovered for bitcoin addresses

Regardless, you can be confident in assuming the number will be much MUCH less than 1.46 X 10⁴⁸

[micaman]

[bigasic]

So, I think the answer is  1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976 Is that right? Yea, thats a ton of addresses. But, if half the worlds population were to get into bitcoin and start trying to find vanity addresses, then we might get "closer" lol.. But, I think we are safe.

[jonald_fyookball]

mere peanuts.

now THIS is a big number:  http://wikipedia.org/wiki/Graham's_number

[Remember remember the 5th of November]

So, I think the answer is  1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976 Is that right? Yea, thats a ton of addresses. But, if half the worlds population were to get into bitcoin and start trying to find vanity addresses, then we might get "closer" lol.. But, I think we are safe.

Not even close. Also wasn't the number of Bitcoin private keys less than 2^256 AND also only 2^160 public keys due to RIPEMD-160?

The legend's colors for Bitcoin Addresses and Atoms in the Universe look the same to me.

[silvestar]

Nice graph.
While the bar "Bitcoin Addresses" is about twice as high as the bar "Stars on the Universe", the number 10^47 is 10^23 times larger than 10^24.

[jonald_fyookball]

So, I think the answer is  1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976 Is that right? Yea, thats a ton of addresses. But, if half the worlds population were to get into bitcoin and start trying to find vanity addresses, then we might get "closer" lol.. But, I think we are safe.

Not even close. Also wasn't the number of Bitcoin private keys less than 2^256 AND also only 2^160 public keys due to RIPEMD-160?

The legend's colors for Bitcoin Addresses and Atoms in the Universe look the same to me.

You either have a crappy monitor or some color blindness.  The Bitcoin address color is like
a forest green and the atoms in the universe is an aqua blue/green.

its 2^160 addresses (the pubkey is what gets hashed by RIPEMD-160).

[kuji kiri]

The entire solar system has only 10x07 more atoms than earth? I find that hard to believe is there a source for these numbers?

[Remember remember the 5th of November]

The entire solar system has only 10x07 more atoms than earth? I find that hard to believe is there a source for these numbers?

By increasing the exponent simply by one, the output number increases two-fold from the previous, based on 2^10 to 2^11. In the case above, I guess it would be, increased by 10 times. But I think you are wrong, it says atoms in the solar system.

[jonald_fyookball]

The entire solar system has only 10x07 more atoms than earth? I find that hard to believe is there a source for these numbers?

That actually makes sense.  We're talking the solar system, not the galaxy.
The sun is about a million times bigger than the earth, which 10^6.
So throw in all the other planets and all the stuff in between, there you go.

[micaman]

I got tricked, forget that chart. My bad.

[Zebracrypto]

there is no risk of collision ? I mean 2 person can generate the same btc address
Even if risks are low, what will happen in this case?

[DannyHamilton]

there is no risk of collision?

Correct.

I mean 2 person can generate the same btc address

And all the molecules of air can collect in the corner of the room causing everyone in the room to suffocate, but the probability is so low that we consider it impossible.

Even if risks are low, what will happen in this case?

If the users are using faulty software that does not properly generate a random number (so that multiple users end up generating the same number), then all users that generate the same number will have the ability to spend the bitcoins that are sent to the address.  Whoever spends an output and gets confirmed first gets to be the "real" transaction for that output, and any transaction created by any of the others to spend the same output are rejected.

[Zebracrypto]

there is no risk of collision?

Correct.

I mean 2 person can generate the same btc address

And all the molecules of air can collect in the corner of the room causing everyone in the room to suffocate, but the probability is so low that we consider it impossible.

Even if risks are low, what will happen in this case?

If the users are using faulty software that does not properly generate a random number (so that multiple users end up generating the same number), then all users that generate the same number will have the ability to spend the bitcoins that are sent to the address.  Whoever spends an output and gets confirmed first gets to be the "real" transaction for that output, and any transaction created by any of the others to spend the same output are rejected.

Thank you for this great explanation with the extra joke 

[DannyHamilton]

there is no risk of collision?

Correct.

I mean 2 person can generate the same btc address

And all the molecules of air can collect in the corner of the room causing everyone in the room to suffocate, but the probability is so low that we consider it impossible.

Even if risks are low, what will happen in this case?

If the users are using faulty software that does not properly generate a random number (so that multiple users end up generating the same number), then all users that generate the same number will have the ability to spend the bitcoins that are sent to the address.  Whoever spends an output and gets confirmed first gets to be the "real" transaction for that output, and any transaction created by any of the others to spend the same output are rejected.

Thank you for this great explanation with the extra joke 

Joke?

There wasn't any joke in there.

[jonald_fyookball]

Joke... He means the idea that air could randomly concentrate
in a corner of the room sounds like a ludicrous (and
thereby humorous) proposition.

[DannyHamilton]

Joke... He means the idea that air could randomly concentrate
in a corner of the room sounds like a ludicrous (and
thereby humorous) proposition.

It isn't much more ludicrous (or humorous) than the idea that two randomly generated private keys will result in a collision.

It was not intended as a joke.  It was intended as a conceptual analogy (since people seem to have a difficult time conceptualizing very large numbers).

Perhaps he was making a joke when he asked that question, and I just didn't realize that he was attempting to be humorous?

[jonald_fyookball]

Joke... He means the idea that air could randomly concentrate
in a corner of the room sounds like a ludicrous (and
thereby humorous) proposition.

It isn't much more ludicrous (or humorous) than the idea that two randomly generated private keys will result in a collision.

It was not intended as a joke.  It was intended as a conceptual analogy (since people seem to have a difficult time conceptualizing very large numbers).
 

Yes, it is a good analogy, although the air molecules would possibly
be orders of magnitude less likely.  We'd have to ask a physicist.

I guess there are funnier comparisons... like the chances
you run into Bill Murray at starbucks and he just decides
to give you 100 BTC?  Is that funny?

What about "as likely as getting attacked in your bathtub tomorrow by wild
monkeys wearing orange hats?"   

Speaking of monkeys and probability, the probability that a monkey
would randomly type Hamlet by William Shakespeare on a keyboard
is about 1 in 10^360733.