Topic: A simple bitcoin Q/A. Learn new and interesting stuff about bitcoin. - page 7. (Read 27371 times)

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:

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

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 .

Question :  What is blockchain Endianness?

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I came across this from a different website, I am looking for answers so that even I can learn.

You're right, sorry for the typo.

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

I guess, you want to say Merkle root.

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

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

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.

Question :How are blocks created?

I am really sorry guys that I am not in the situation to reply to every single one of your posts,but please give me some time,I'll come around really soon and correct. It may be even tomorrow,I just need some time. Please ,I am sorry again.

The way I understand it is that BIP 75 allows both parties in the transaction option to know the identity of the person they are making the transaction with. But the information is still secure so no 3rd party will have access to the information. If I understand correctly this is used when for example I buy something from a merchant that accepts Bitcoin, they can also record shipping addresses etc and I the buyer knows who I am doing business with.

Hopefully I understand this correctly  If not, feel free to help me understand. Please also pardon me if the English is not 100%

BIP stands for Bitcoin Improvement Proposal and BIP-XX are the payment protocols. BIP 75 proposed some major enhancements to the Bitcoin Payments Protocol.
 
- Support for 2-way identity exchange (the bitcoin payment information can be exchanged between both parties of the transaction, at the same time information is secured by strong end-to-end encryption)
- With BIP 75 users can generate a payment request like an invoice with verified identity and receiver can directly make the payment minimizing the chances of sending payment to a wrong address.

BIP0075 is basically an upgrade of the BIP0070 suggested by Gavin and Mike. Before explaining BIP 75, we need to understand what is a Payment Protocol?

A payment protocol is basically a communication method between a sender and receiver of coins. The communication method is a human understandable payment destinations where the receiver will authorize the payment. This proposal most probably prevents the man in the middle attack and the sender receives a "Payment received" message to conform the transaction. Additionally refund addresses are also generated.

These protocol options has a disadvantage that it cannot be used for peer to peer payments. But BIP0075 solves this by encrypting the communication end to end. This protocol also allows the sender to validate the identity of the receiver and a user friendly transaction is thus created.

Question: What exactly is BIP 75?

It is tough to give very brief summary on lightinig Network but I will try to be very brief and put as much information in less words.

Why we need Lighting network?
The current bitcoin network will not be able to handle if we have to do transactions on large scale as current network will able to handle only 7 (tps) transactions per seconds (which is nowhere when compared to 56000 tps capablity of VISA and handling 4000 tps during peaktime.) So Lightinig Network is a proposed solution that will able to help in doing billion of transactions per day without affecting the blockchain.

How Lightining Network will work?
When two parties are interacting with each other on regular basis then they can commit to signing the transaction  without broadcasting to global bitcoin blockchain. This will remove dependency from blockchain. They can create fund into a 2 of-2 multisignature address (where it requires consent from both parties to create spend).

Micro payment channel created above will create relationship between two parties only. To make bitcoin scalable we will need  a large network of channels on the Bitcoin blockchain. That network will be lighting network.

Lightinig Network will use Hashed TimeLock Contract for security of transactions.

Benefit of lightining network
Rapid payments: payments within an established channel can be made almost as fast as data can travel over the Internet between the two peers.
No third-party trust: the two peers in a channel pay each other directly using regular Bitcoin transactions (of which only one is broadcast) so at no point does any third party control their funds.
Reduced blockchain load
Channels can stay open indefinitely
Rapid cooperative closes
Outsourcable enforcement
Onion-style routing
Multisignature capable
Securely cross blockchains
Sub-satoshi payments
Single-funded channels

Current vulnerability in Lighting network.
Improper Timelocks: Participants must choose timelocks with sufficient amounts of time. If insufficient time is given, it is possible that timelocked transactions believed to be invalid will become valid, enabling coin theft by the counterparty.
Forced Expiration Spam:If a malicious participant creates many  channels and forces them all to expire at once, these may overwhelm block  data capacity, forcing expiration and broadcast to the blockchain. The resultwould be mass spam on the bitcoin network.
Coin Theft via Cracking: As parties must be online and using private keys to sign, there is a possibility  that, if the computer where the private keys are stored is compromised, coins will be stolen by the attacker.
Data Loss : When one party loses data, it is possible for the counterparty to steal funds.
Forgetting to Broadcast the Transaction in Time

All these vulnerablity can be mitigated and Lighting Network will give Bitcoin Network to do billion transactions in a day using the desktop/Home pcs.

In short, Lightning Network will be bidirectional micro payment channel that will help to solve the problem of scalablity in bitcoin Network.

References:
https://www.weusecoins.com/assets/pdf/library/Lightning%20Network%20Whitepaper.pdf
https://en.bitcoin.it/wiki/Lightning_Network
https://en.bitcoin.it/wiki/Hashed_Timelock_Contracts
https://en.bitcoin.it/wiki/Payment_channels

Glad to help, bill gator. I will assist pugman while you are busy; this thread inspired me to start a topic about merit service in Philippine section, it is assign of my gratitude(helping here). Looking forward to hear positive feedback about your mining operation project, bill gator. Congrats in advance.

I've given you a little bit of merit for your findings, because I have been too busy to help pugman out with this thread very much. I hope to be back to business as usual very soon, but I've been working on putting together a mining operation and it has been very time consuming. Regardless, good catch on the plagiarism; it's unfortunate that we didn't catch it prior to awarding it merit.

Don't beat yourself up over it pugman, it's only a single merit and it is insignificant in the grand scheme of things. Let's try to be more diligent moving forward, with maybe a quick google search on different portions of their answer, or something like that. There are free plagiarism checkers all around the internet that would make this a very easy part of the job.

Hmmm...Yeah. My bad that I didn't do any background check,can't help it,I am a lazy ass. But don't worry,I'll keep an eye,especially in my thread.

But hey,in my defense,it looked like he was actually explaining it by himself but apparently not. Still,I apologize for that laziness of mine.

What's done is done,he's banned now:

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Doesn't matter now that I merited him,I still have a few left,and I'll probably be a little more stricter in handing out merits from now on.. I wasn't looking for that answer but I liked the way he had explained it only to find out that it was a copy/paste.

Sure,let me first go through the answers,and get one for y'all.

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Do not worry anymore,he's perma-banned.

He/she is a serial copy paster, didn't even have to go too deep in to the posts to come to that inevitable conclusion. I reported a couple of the ones they got merit for to hopefully avoid anyone else giving merit to them undeservedly.

He joined my topic Get Merit Service, which is why I got the chance to check his profile and his post. Upon reviewing, I have notice some words that I have already read from another article, so I did my research to check if I am correct. Yes, correct, all from www.quora.com. See summary.