Bitcoin Forum

Other => Beginners & Help => Topic started by: open_sauce on May 23, 2013, 06:41:59 PM



Title: New here but not too new to bitcoin, couple of questions
Post by: open_sauce on May 23, 2013, 06:41:59 PM
I first got into bitcoins at the end of 2011, bought a few when they were under £10, wish I'd bought more!

They have, for a significant amount of this time, taken over my brain.

I believe I have a fairly well developed understanding of the bitcoin network but stop short of understanding some of the cryptographic details.

A couple of questions:

When generating public / private key pairs, can any number (satisfying the requisite size constraints) be a private key that has a corresponding public key,  or is there some property of private keys that rule out some values?  Hope that makes sense.

Also, given the size of the blockchain, are there any ideas about keeping the size manageable as bitcoin becomes more mainstream? From my understanding, if a transaction history is to remain traceable (if this is a desired property), then you can't get rid of that data in the blockchain. Also I suppose another difficulty as I understand it is unspent transaction outputs that existing in old blocks, meaning these also cannot be got rid of.

I would appreciate any thoughts.


Title: Re: New here but not too new to bitcoin, couple of questions
Post by: DonDe on May 23, 2013, 06:46:25 PM
I don't think there is a way to prevent the size of blockchain growing/manageable. Bitcoin is one thing, think about those new alt-coin with block time of 15 secs, those blockchains are going to be huuuuge.


Title: Re: New here but not too new to bitcoin, couple of questions
Post by: DannyHamilton on May 24, 2013, 02:45:09 PM
A couple of questions:

When generating public / private key pairs, can any number (satisfying the requisite size constraints) be a private key that has a corresponding public key,  or is there some property of private keys that rule out some values?  Hope that makes sense.

Assuming that I've converted from Hex to decimal properly, a private key can be any value at all between 1 and 115,792,089,237,316,195,423,570,985,008,687,907,852,837,564,279,074,904,382,605,163,141,518,161,494,337

(Expressed as a Hexadecimal value, that would be: 0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4141)


Also, given the size of the blockchain, are there any ideas about keeping the size manageable as bitcoin becomes more mainstream?

Yes, there are pruning processes that are being investigated and tested.

Also I suppose another difficulty as I understand it is unspent transaction outputs that existing in old blocks, meaning these also cannot be got rid of.

Correct.  To verify transactions, the UTXO will have to be stored.


Title: Re: New here but not too new to bitcoin, couple of questions
Post by: yamer on May 24, 2013, 02:56:18 PM
I first got into bitcoins at the end of 2011, bought a few when they were under £10, wish I'd bought more!

+1