Bitcoin Forum

Bitcoin => Development & Technical Discussion => Topic started by: Gewinnermorte on March 15, 2019, 01:49:19 PM



Title: [ASK] Bitcoin Address
Post by: Gewinnermorte on March 15, 2019, 01:49:19 PM
AFAIK a bitcoin wallet private key was generated from 64 Hexadecimal Number(2256 Combination).
And There Is Only About 2160 Bitcoin Wallet.
Did that mean every bitcoin wallet has a corresponding 296 Hexadecimal Private Key?




Title: Re: [ASK] Bitcoin Address
Post by: achow101 on March 15, 2019, 02:26:28 PM
In theory, yes.

However it may actually be higher than 2^96 because the hash functions used for Bitcoin may not actually distribute across all possible values so some 160 bit values may not have anything hash to them, while others have even more that do.

Also, while this may seem like a terrible thing that 2^96 keys have public keys that hash to the same thing, both 2^160 and 2^256 are still incredibly huge numbers and 2^96 is incredibly tiny compared to them. The probability of finding such a collision is so incredibly small that it is basically zero.


Title: Re: [ASK] Bitcoin Address
Post by: Farul on March 16, 2019, 11:20:45 AM
In theory, yes.

However it may actually be higher than 2^96 because the hash functions used for Bitcoin may not actually distribute across all possible values so some 160 bit values may not have anything hash to them, while others have even more that do.

Also, while this may seem like a terrible thing that 2^96 keys have public keys that hash to the same thing, both 2^160 and 2^256 are still incredibly huge numbers and 2^96 is incredibly tiny compared to them. The probability of finding such a collision is so incredibly small that it is basically zero.
Did The Collision Spread Regularly (Predictable) Or Randomly?

I Planned To Make A Private Key Out Of String (So You Can Remember It Easily)(This Maybe A Dumb Idea)
32 String Character ---> Hexadecimal ----> WIF
But Since Not All String Character Was Used,
So, I Want To Calculate How Vulnerable This Method.


Title: Re: [ASK] Bitcoin Address
Post by: amaclin1 on March 16, 2019, 01:20:02 PM
32 String Character ---> Hexadecimal ----> WIF

Why not to 32 String Character ---> SHA256 ----> WIF
I think using hash function instead of converting to hex is much better.
We can call this technology... Hmmm... Brainwallet!


Title: Re: [ASK] Bitcoin Address
Post by: achow101 on March 16, 2019, 03:33:19 PM
Did The Collision Spread Regularly (Predictable) Or Randomly?
If the collisions were predictable, the hash function would be broken. So they are spread randomly. So far, in the hash functions used by Bitcoin, no collisions have been found.


Title: Re: [ASK] Bitcoin Address
Post by: bob123 on March 16, 2019, 04:42:58 PM
I Planned To Make A Private Key Out Of String (So You Can Remember It Easily)(This Maybe A Dumb Idea)b

Actually, this is a (very) bad idea.

Wallets (containing private keys) created this way are called 'brain wallets'.

The reason this idea is bad, is because the human brain can only 'create' a very small amount of entropy.
Even if you believe your text phrase is completely random, it will in fact be WAY less random than a computer could produce it.
A human brain is said to be able to produce about 20 - 30 bits of entropy. Thats extremely low in comparison to 256 bits of entropy.

Using sentences or phrases from a book is an even worse idea. Cracking brainwallets is doable and can be quite profitable.
Cracking randomly generated private keys on the other hand, is not possible.


Title: Re: [ASK] Bitcoin Address
Post by: Farul on March 16, 2019, 11:38:55 PM
Actually, this is a (very) bad idea.

Wallets (containing private keys) created this way are called 'brain wallets'.

The reason this idea is bad, is because the human brain can only 'create' a very small amount of entropy.
Even if you believe your text phrase is completely random, it will in fact be WAY less random than a computer could produce it.
A human brain is said to be able to produce about 20 - 30 bits of entropy. Thats extremely low in comparison to 256 bits of entropy.
What If We Multisig The Wallet?
A Hex Can Generate 2 Pair Of Private key (Compressed & Uncompressed)
And Then We Create A Multisig Wallet Out Of That 2 Private key

BTW
What If We Generated Private Key From Our "Personal Number(ID Number,Special Date,etc)"?
Bunch Of Your Special Number(64 Digit)(2213 possibility) -----> WIF
Is It Safe?



Title: Re: [ASK] Bitcoin Address
Post by: pooya87 on March 17, 2019, 03:04:03 AM
~
Is It Safe?

the reality about brainwalles (or any alternate method similar to them) is that they can technically be safe but there is always a very high possibility that what you created is not at all safe.
in your case, all it takes for you to lose your money is someone who is familiar with you (so that they can guess what kind of passwords you use) and try them all in a loop.
so it is best to leave the randomness to your wallet instead of trying to come up with a complicated thing yourself which may not be as random.