How OP_EQUALVERIFY works in a standard transaction?

3 weeks ago I began learning about Bitcoins, and now I’m analyzing how it works internally. My problem is that I can’t understand what two public key hashes are compare to use de OP_EQUALVERIFY, because I understand that sender’s public key is compare with receiver’s public key, but they aren’t the same hash.

Here is an example:
A script is: the scriptSig of your tx + the scriptPubkey of the tx you spent

In the same example:
The scriptSig of your tx is: Sig + your pubkey
The scriptPubkey of the tx you spent is (according to blockexplorer):

OP_DUP OP_HASH160 fc88853163ab2a9646908a82e8a87b6f185c2047 OP_EQUALVERIFY OP_CHECKSIG

I hope

ripemd160(sha256('0x0457d7d7af586aaad529b5770bb43295051e7090e2bc884181d608dae2517c7812b25e326753cbe0b767f579bbcb5cffe492d22b93f2ff5501074eb9e8f8547c4a'))  
 = fc88853163ab2a9646908a82e8a87b6f185c2047...

I read that but I can’t understand that the stack and scripts function.
The stack is empty. On the first step the Sender’s Signature and Public Key are combined. Then these two constants are added in the stack. Then the Public Key is duplicated. After that this duplicated item is hashed. Now the Receiver´s Public Key Hash is added to the stack. The script compares the equality between the two slack items and finally the signature is checked for two slack items.

Is that correct? I think that i’m wrong with something.
If it is posible to someone answer or reply me

Thanks.

How can market-based transaction fees scale?

Can someone please explain to me what I am missing?

I don’t see how variable, market-based transaction fees can scale. I go to a merchant’s website to buy, how do I select a mining peer to pay transaction fee to? Do I attach some bounty that any peer can earn if that peer wins the Proof-of-Work block? But what if my bounty isn’t high enough to attract a peer given high transaction volume competing for priorities? Or not enough to cover any peer’s mining overhead. How do I know how much to bid to be sure my transaction completed in a timely manner?

This sounds very complex and unreliable and not at all like something that can scale to customers. Customers want to click one button and be done with the purchase and not waiting unknown hours debugging their payment processing. Amazon’s One Click.

I don’t see how with different peers charging different fees (to match their market dynamics), the sender of a transaction can know the amount to bid to get in the next block? It is impossible because the tx fees are not uniform and the random selection of the next peer is not knowable in advance.

what do red and green bars at bitcoinity.org mean?

The changebars graph at http://bitcoinity.org has red and green bars. Some of them below and some above zero.

What is their meaning?

  • If they are above zero
    • and are green
    • and are red
  • if they are below zero
    • and are green
    • and are red?

Is there a wikipedia article about that kind of graph? What would the search term be?

The rest of the graph is explained here http://i.imgur.com/516v5Nz.jpg but not the red and green bars.

Thank you.

Is it possible to create an address from a predefined private key?

I was not sure how to formulate the question title. What I want to achieve is the same as VanityGen and many other tools do to create an address starting with a predefined part, but with private keys.

So basically I want to create a Bitcoin public/private key pair of which the private key begins with a string I define.

Are there tools that already do this? If not, is it possible? How should it be done theoretically?

Is Bitcoin’s Economic Majority those who already own coins or those who will buy or keep coins?

The Economic Majority theory says that the power to control the Bitcoin protocol is held by those who [own] bitcoins.

But the article then goes on to read:

The ability for a protocol change to be successfully implemented
ultimately rests with those who accept bitcoins in exchange for value.

So that refers to investors and those who accept bitcoins for income or revenue but then aren’t immediately spending or cashing out the coins they received.

But that power doesn’t lie with those who already hold the coins but instead it lies with those who are willing to accept the newly issued coins under the revised protocol or coins with taint from coins issued under a revised protocol.

So, is the Economic Majority those that already hold bitcoins or is it instead just those who will hold the bitcoins generated following a change to the protocol? If so, how would that be best worded?

How do I get the public bitcoin address from a given private key in wallet import format offline?

I have made paper wallets. And I continually send what bitcoins I get to them. I’m paranoid that I’ve been sending bitcoins to the paper bitcoin addresses where somehow at sometime my saved private keys got corrupted. So from time to time I want to run a script, python or whatever, to check if my private keys do correspond to the public address that I’ve been sending bitcoins to. I want an offline solution so things like the satoshi client would not do. Is there a small script written by someone that can solve this?