Understanding Public and Private Keys - page 3.

cp1

hero member

Activity: 616

Merit: 500

Stop using branwallets

Quote from: BigOrangeBee on May 31, 2014, 11:22:21 AM

Ok, but that doesn't really satisfy. Because as more people used bitcoin, and more an more addresses are generated, and the longer its been around, there would be more and more of a chance of duplicate addresses.

Question: after an addresses is loaded with funds and added to the blockchain, then, does that information get sent to these automatic addresses generators in all the web, desk, and mobile wallets, and the bitaddress.org generator too? I don't think so. So how do they know they are not creating an address which was already created?

The chances are extremely slim, but technically speaking, it IS POSSIBLE.

Send me your private key and I'll promise not to use that address. Pinky swear.

odolvlobo

legendary

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Quote from: BigOrangeBee on May 31, 2014, 11:22:21 AM

Quote from: odolvlobo on May 31, 2014, 10:54:06 AM

In short, the chances of two people generating the same private keys are so low that it is not worth worrying about. Do you worry about being hit by a meteor?

Ok, but that doesn't really satisfy. Because as more people used bitcoin, and more an more addresses are generated, and the longer its been around, there would be more and more of a chance of duplicate addresses.

Question: after an addresses is loaded with funds and added to the blockchain, then, does that information get sent to these automatic addresses generators in all the web, desk, and mobile wallets, and the bitaddress.org generator too? I don't think so. So how do they know they are not creating an address which was already created?

The numbers are so huge that none of the things you mention, even multiplied by a billion, make the slightest difference.

The number of possible addresses is 2¹⁶⁰. If 10 billion people have generated 1 billion addresses each, then the chances of a new address colliding with any of those is 1 in 2¹⁴¹. That's a 1 in 2,787,593,149,816,327,892,691,964,784,081,045,188,247,552 chance.

Let's pretend that Bitcoin is as big as Visa, which can process 24,000 transactions per second. In a million years, bitcoin will have processed up to 800,000,000,000,000,000 transactions. If a new key were generated for each of those, then there is still only a 1 in 2,000,000,000,000,000,000,000,000,000,000 chance that it will be a duplicate.

BigOrangeBee

newbie

Activity: 56

Merit: 0

Quote from: odolvlobo on May 31, 2014, 10:54:06 AM

In short, the chances of two people generating the same private keys are so low that it is not worth worrying about. Do you worry about being hit by a meteor?

Ok, but that doesn't really satisfy. Because as more people used bitcoin, and more an more addresses are generated, and the longer its been around, there would be more and more of a chance of duplicate addresses.

Question: after an addresses is loaded with funds and added to the blockchain, then, does that information get sent to these automatic addresses generators in all the web, desk, and mobile wallets, and the bitaddress.org generator too? I don't think so. So how do they know they are not creating an address which was already created?

The chances are extremely slim, but technically speaking, it IS POSSIBLE.

cp1

hero member

Activity: 616

Merit: 500

Stop using branwallets

Quote from: BigOrangeBee on May 31, 2014, 07:12:24 AM

And none of them are telling the other what keys have been used already.

If you had to ask other people not to use your private key then your coins would be stolen in seconds.

shorena

copper member

Activity: 1498

Merit: 1528

No I dont escrow anymore.

Quote from: BigOrangeBee on May 31, 2014, 07:12:24 AM

-snip-
So why is it not possible that duplicate addresses can be created? Why is it not possible that a private key can be discovered by luck or brute force?

Because for one

Quote from: odolvlobo on May 31, 2014, 10:54:06 AM

-snip-the chances of two people generating the same private keys are so low that it is not worth worrying about. -snip-

but most people dont grasp how slim the chance for this actually is.

Lets play a game with private/public keys, shall we?

I have a public key (e.g. the one in my signature) the chance for you finding the private key for it is the same chance to find a bucky ball within planet earth (this includes the core and the air). If you want to see the calculation go here: https://bitcointalksearch.org/topic/m.6473942

If this is to abstract you can think off it as finding a single water molecule in every water source (this would ofc include animals and humans) on earth. Yet this is way off, you have a very good chance to find this water molecule compared to your chance to find the private key to my public one.

These chances are so minimal that even if everyone would make a new address for every transaction for the next 1000 years, the chance of collision (2 same private keys) is still minimal. I probably will do a calculation on how slim exactly sometime in the future.

odolvlobo

legendary

Activity: 4466

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In short, the chances of two people generating the same private keys are so low that it is not worth worrying about. Do you worry about being hit by a meteor?

BigOrangeBee

newbie

Activity: 56

Merit: 0

Quote from: gagalady on May 31, 2014, 07:19:07 AM

Hey, If you want consistent explanation reads It on wiki.

Private key: https://en.bitcoin.it/wiki/Private_key

Public key: https://en.bitcoin.it/wiki/Address

I read both of those wikis completely but I did not find the answers to my questions.

gagalady

legendary

Activity: 938

Merit: 1000

Hey, If you want consistent explanation reads It on wiki.

Private key: https://en.bitcoin.it/wiki/Private_key

Public key: https://en.bitcoin.it/wiki/Address

BigOrangeBee

newbie

Activity: 56

Merit: 0

Can anybody explain in simple form why keys are safe?

There are several exchanges with wallets, desktop wallets, web wallets, mobile wallets, etc, and all of them are generating new addresses and private keys all the time for every user. And none of them are telling the other what keys have been used already. So why is it not possible that duplicate addresses can be created? Why is it not possible that a private key can be discovered by luck or brute force?

Topic: Understanding Public and Private Keys - page 3. (Read 2242 times)