A simple bitcoin Q/A. Learn new and interesting stuff about bitcoin.

[bitmover]

Question :How are blocks created?

A new block is created when a miner finds an acceptable nonce, that solves the proof of work puzzle.

When he finds the nonce he broadcast it and the new block to all nodes.
All miners then starting looking for a nonce at this new block, as this is now the longest chain.

[shahzadafzal]

Question :How are blocks created?

Here is the Receipt to cook (create) a bitcoin block:

Ingredients:
1- Coinbase transaction (Generation transaction)
2- Set of valid transaction (not spent, signatures verified, amounts verified)
3- Hash of previous block
4- Unixtime stmaps or Epoch

Now you have all the ingredients, try to remember and confirm this

1. You have a market root
2. You know the networks current difficulty (4 bytes)
3. Nonce, incremented when mining (4 bytes)

Lets start cooking:

- Start with nonce 0
- Hash or compute the hash with all the ingredients (the block header) using sha-256
- Check the hash, check if the hash is under a "certain range¹" (or target if in a pool) - Yes? You found the Block
- No, increments the nonce and hash again

You never found the Block, nonce reached maximum?
- Don't worry change your ingredients for exmaple change the Timestamp or extra nonce field
- and try again

1. Certain range: The hash has to start with a pre-established number of zeroes (as of today 18 zeros)

Hint: When selecting transaction select the transaction with fee to have extra BTC + block reward

[pugman]

I found both of the above posts knowledgeable,and very helpful. Thanks guys. Atleast I get to learn something. 

[r1s2g3]

Question :How are blocks created?

1. You have a market root
2. You know the networks current difficulty (4 bytes)
3. Nonce, incremented when mining (4 bytes)

I guess, you want to say Merkle root.

[shahzadafzal]

I guess, you want to say Merkle root.

You're right, sorry for the typo.

@pugman
Question: What exactly is BIP 75?
What was the correct answer to the second last question?

[pugman]

Question :  What is blockchain Endianness? I came across this from a different website, I am looking for answers so that even I can learn.

[Hazaki]

Question :  What is blockchain Endianness? I came across this from a different website, I am looking for answers so that even I can learn.

Endianess is how bytes are organized in a multi byte value , it presents the new order of bytes when every part that forms the value is put into a digital word . Bitcoin uses the little Endian to serialize almost all the data with it, and that has been always considered as an error by the community but is IMO an optimization(*) .
And since i mentionned the little Endian , people should know that there's two types , Little and Big Endian (used to serialize network adresses ) .
For a brief explanation let's take for example this hexadecimal "96385214" , if we are using the little Endian it'll be stored in the computer's memory as following : "14 52 38 96" -> we take the byte at the end (called little end) which is 14 and place it in the beginning , and keep proceeding from right to left  .
As for : Why is little Endian  used in blockchain , well it's because the dev team chose to , (*) -> and also because the majority of new generation computers use little Endian so that's why i consider it as an optimization .

[shahzadafzal]

Question :  What is blockchain Endianness?

That's like going back to uni class CS101, anyway

Endianness is ordering the bytes (or bits) in the memory, there two notations, big-endian (most significant bit) or or little-endian the (least significant bit).
So in simple words little-endian means saving the bits in reverse order.

Bitcoin use litte-endian notation.

Bitcoin is using SHA-256 algorithm for Block hashing -> it produces hash in little-endian (leading x number zeros)

For example ,this is the latest block Block #522238, below is hash and it is shown in big-endian notation:

Code:

Hash	0000000000000000001ea8f72b5af531257e061085973ff12cde30e882d57ce4

and in little-endian notation (Swap the bytes):

Code:

Hash	e47cd528e830cd12ff3f978510067e2531f55a2bf7a81e000000000000000000

Please ignore any typo as I typed in reverse manually

Now why litte-endian for blockchain its arguable, there are computational advantages in using little-endian but on the bigger picture there is no difference.

[pugman]

That's like going back to uni class CS101, anyway

Endianness is ordering the bytes (or bits) in the memory, there two notations, big-endian (most significant bit) or or little-endian the (least significant bit).
So in simple words little-endian means saving the bits in reverse order.

Bitcoin use litte-endian notation.

Bitcoin is using SHA-256 algorithm for Block hashing -> it produces hash in little-endian (leading x number zeros)

For example ,this is the latest block Block #522238, below is hash and it is shown in big-endian notation:

Code:

Hash	0000000000000000001ea8f72b5af531257e061085973ff12cde30e882d57ce4

and in little-endian notation (Swap the bytes):

Code:

Hash	e47cd528e830cd12ff3f978510067e2531f55a2bf7a81e000000000000000000

Please ignore any typo as I typed in reverse manually

Now why litte-endian for blockchain its arguable, there are computational advantages in using little-endian but on the bigger picture there is no difference.

I understood a little,but what is its purpose,especially in blockchain? I don't know a lot/anything about it.

As for : Why is little Endian  used in blockchain , well it's because the dev team chose to , (*) -> and also because the majority of new generation computers use little Endian so that's why i consider it as an optimization .

Why do they use Endian? I am worse than a noob at this,so do pardon me.

[shahzadafzal]

I understood a little,but what is its purpose,especially in blockchain? I don't know a lot/anything about it.

Well actually there is nothing specific related to blockchian it came into discussion because of bitcoin's block hashing algorithm SHA-256, however conventional microprocessors used little-endian notation like Intel-836 and other followed. Big-endian is become most common in internet-protocols IPv4 and IPv6 that's why it's also called network byte order.

[pugman]

Are there competitions for Arabs?

This is not a competition,atleast not exactly. Anyone can answer questions here. And you did not even read the OP.

[azguard2]

Question :  What is blockchain Endianness?

When a new transaction is signed, it is broadcasted on the Bitcoin network. It will then be collected and recorded in a block. Each block, once constituted, will in turn be broadcasted.
All these messages are public and verifiable.
They make it possible to notify and therefore take to witness all the participants of the Bitcoin network on any new information that enriches the blockchain.
Messages are transferred over the network in a binary format, encoding numbers on 32 bits or 256 bits using the Little-Endian convention.
The Little-Endian convention sets the bytes from the lowest weight to the strongest weight, the Big-Endian convention sets the bytes from the strongest weight to the lowest weight.


For example the number 1 is represented in hexadecimal on 32 bits by 00000001 with the Big-Endian convention and 01000000 with the Little-Endian convention.

The number 1 on 32 bits with the Big-Endian convention:
 Byte 3 |  Byte 2 |  Byte 1 |  Byte 0
--------+---------+---------+--------
     00 |     00  |     00  |      01

The number 1 on 32 bits with the Little-Endian convention:
 Byte 0 |  Byte 1 |  Byte 2 |  Byte 3
--------+---------+---------+--------
     01 |      00 |      00 |      00

[marktanlao]

Question :  What is blockchain Endianness? I came across this from a different website, I am looking for answers so that even I can learn.

i found some info about it

Understanding, Extracting, and Analyzing Blockchain Evidence Nick Furneaux ... of hexadecimal, you need understand a computing concept called Endianness.

[Nanoverso]

Why do they use Endian? I am worse than a noob at this,so do pardon me.

Well, they had to choose the use of one of the endian representation schemes because numerical data needs to be stored and manipulated in its binary form in the blockchain one way or another.

This comes from the fact that digital cryptography used in chain usually operates on the data in the bit level (binary form), so programmers needs to be aware of what kind of representation/storage scheme is being used so they can write algorithms that correctly manipulate the data.

Hope it helped!

[pugman]

Well, they had to choose the use of one of the endian representation schemes because numerical data needs to be stored and manipulated in its binary form in the blockchain one way or another.

This comes from the fact that digital cryptography used in chain usually operates on the data in the bit level (binary form), so programmers needs to be aware of what kind of representation/storage scheme is being used so they can write algorithms that correctly manipulate the data.

Hope it helped!

Understood something, more than what I expected. Thank you.

i found some info about it

Understanding, Extracting, and Analyzing Blockchain Evidence Nick Furneaux ... of hexadecimal, you need understand a computing concept called Endianness.

Its not clear enough and it's very vague. But I do know that I need to understand and even learn what Endianness means.

[pugman]

Question :  What is the difference between a regular transaction and a coinbase transaction? Do explain the both type of transactions with or without any examples.

[PHPSELLER]

Question :  What is the difference between a regular transaction and a coinbase transaction? Do explain the both type of transactions with or without any examples.

I think the difference between a regular transaction and a coinbase transaction is on the Input. A coinbase transaction is a type of transaction that created by miners, It has not no inputs, In other hand, a regular transaction has a transaction input, output, and an amount of money.

[bitmover]

Question :  What is the difference between a regular transaction and a coinbase transaction? Do explain the both type of transactions with or without any examples.

A coinbase transaction is a special transaction that transfer new generated coins to a miner's wallet. It's the first transaction of a block.

Whoever solves the PoW puzzle faster creates a new block and receives it reward. This reward is a newly generated bitcoin, called coinbase.
Example:
https://blockchain.info/tx/451329336cfaa7896fb4aba504bb3acd9964fc27b3fe6bbbf05615d19df313a1


A regular transaction is any other transaction, which does not involve newly generated coins.
Example:
https://blockchain.info/tx/e038d1191d09eed13ef8e4d87f95b0e3499c63aaf7bc14001e099a4e5bf50172

[just_Alice]

Question :  What is the difference between a regular transaction and a coinbase transaction? Do explain the both type of transactions with or without any examples.

A regular transaction has inputs (where the coins came from) and outputs (where the coins are going). A coinbase transaction has no inputs, because it is newly generated coins and has one or more outputs (where the miner wants the reward to go).

[pugman]

A coinbase transaction is a special transaction that transfer new generated coins to a miner's wallet. It's the first transaction of a block.

Whoever solves the PoW puzzle faster creates a new block and receives it reward. This reward is a newly generated bitcoin, called coinbase.
Example:
https://blockchain.info/tx/451329336cfaa7896fb4aba504bb3acd9964fc27b3fe6bbbf05615d19df313a1


A regular transaction is any other transaction, which does not involve newly generated coins.
Example:
https://blockchain.info/tx/e038d1191d09eed13ef8e4d87f95b0e3499c63aaf7bc14001e099a4e5bf50172

You just got your 200th merit and good explanation.

Question :  What is a cryptography nonce?