Topic: A simple bitcoin Q/A. Learn new and interesting stuff about bitcoin. - page 5. (Read 27371 times)

 I am still confused about this stealth address.

I can generate a new address for a payment, and then I will have total price on that transaction.
If for any reason I want to have privacy over the future transactions of that uotx, I could use a coinmix service.

Is there any advantage of using an stealth address over his method?
Maybe convenience, if there is an easy client to handle stealth address?

+1 merit for pugman, for the best question so far.

If a business/organization start accepting Crypto currency then business will need to put his public address. But all the transactions on this public address can be tracked.

Disadvantage for business,
1. revenue details of business are available to competitors.
2. Competitors are knowing the client wallet id too (if they able to find  client  associated with that wallet id, they can try to break that client)
3. They can track the suppliers for that business too.

What business can do.

Business can create a  series of public address  to be used individually with each client or supplier  or it can generate a stealth address .
Now when the client send the payment to business in this stealth address,  a unique address will be automatically generated and funds will go to address  and only sender and receiver determine if payment is complete and no outsider will able to trace back the transaction.

So Stealth Address provide anonymity to the sender and receiver address. 

Not answering, but this question made me look up DW again... and yeah, it's still languishing on GitHub without an update for almost two years now. Samourai, which seems to have active development, appears to implement BIP47 stealth addresses. I would be curious if anyone here has ever used a stealth address with Bitcoin. I haven't. Maybe time to check out Samourai and test this. Still in alpha, though.

Not many users will be aware of stealth address unless they have completely read everything about bitcoin or they have used Monero or other cryptonote coins. As I have used Monero once, I knew how a stealth address works. Let me try to explain this in simple terms.

A stealth address is a type of bitcoin address which is generated by the receiver to receive his funds anonymously. A stealth address generated is used to have a transaction only between the sender and the receiver where the sender cannot view the earlier transactions which were made to the address. A stealth address can be used only once and only for one transaction. The sender sends the coins to the stealth address in the sense that it can only be derived by the receiver using his private keys. Monero uses stealth address technology for its transactions. Basically a stealth address works on the mechanism of Elliptic-Curve Diffie-Hellman algorithm.

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How does a stealth address work?

For instance, let us consider Bob is the receiver of bitcoin and Alice is the sender. Bob has a private key (X) and a public key (Y) and Alice has a private key (A) and a public key (B). The public key of both sender and receiver are known to each other.

Now, Bob creates a secret channel say C, where

C= X*B (privkey of Bob * pubkey of Alice)

and Alice creates a secret channel similar to Bob, where

C= A*Y (privkey of Alice * pubkey of Bob)

When Alice pays the funds she hashes the secret channel C and then adds pubkey of Bob and creates a public key or address D where

D= Y + H(C)

This pubkey which is used by Alice to pay the bitcoin is called as Stealth Address. Bob can spend the coins by the private keys he has and also Bob's wallet need to check the OP_RETURN (B) quite often in order to discover the right address and its balances.

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Stealth address are very rarely used by Bitcoin network or people due to the disadvantages associated with it. A stealth address can be generated using Dark Wallet.

It is a way of camouflaging the destination addresses of each transaction using a unique address. You can publish a unique "stealth address" on your website. A blockchain will understand that all unique transactions for that address are different and will not allow a correlation between incoming and outgoing addresses. It does not turn the transaction into something totally anonymous. It would be the same as creating a single address for each transaction.

Receiver generates a an address and a private secret and then sends this address to someone who he wants payment from.
Sender uses the address and a "nonce" to generate the address he/she can send funds to.
Sender communicates the nonce to the receiver and by using this nonce and the secret key generated earlier he/she can unlock the address with the funds.

This concept was introduced by the user ByteCoin.
https://bitcointalksearch.org/topic/untraceable-transactions-which-can-contain-a-secure-message-are-inevitable-5965

Yeah no. Merit is not a prize, this is NOT a competition. Now tell me why do you want merit? Just to rank up and shitpost for bounties?

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The answer to your question is probably the latter. The network would rather focus on the future blocks, and the transactions in the invalid block would go to the future blocks. Although I cannot be a 100% sure.

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Its been a while since I visited this thread, here's my question:

Question:  What is a stealth address? How does it work and how does one use them? 

I try to reply because i saw inaccurate answers. We are talking about the same transaction still not confirmed. In this case is possible that miner A and B include this transaction in 2 different blocks (one made by A and the other made by B). Then miner A proposes his block to node i and miner B does the same with node j. In this case there will be other miners which will consider the "previous block hash" that of i and other that of j. So other miners like C,D will mine after A-block and miners F,G will mine after B-block. This story will end as soon as most miners (and therefore the greater quantity of hashing power) will continue the story from i (or j) and the other story will be rejected by nodes, so this is reduced by the common sentence "the longest chain wins". If we are talking about the same transaction but in 2 different period it has no sense because the inputs used in the second transaction (which would be the same of the first) are "empty" because they have already spent so it is necessary changing inputs, changing hash, changing transaction.

where can I find similar kintes? I want to have a better contribution in this forum and get merit prizes. thanks

I think it's possible for two miner include the same transaction in one block. If both miners include it in the same time then only one will be choosen and the other will be an orphan block. If transactions will come in different time then the second one will be invalid or it will allow a double spending.

Just did a quick bit of research and this is my 'non-technical' interpretation. The only way a transaction can be included in more than one block is if two miners reach it at the same time. Both would be broadcast and create a brief fork, with nodes building on whichever one they deem as correct (the first one they found) and rejecting the other one. It falls back into line once the next block is mined, confirming a winner and leaving the other initially legitimate block stranded. All subsequent blocks would then continue on the longest chain, with any nodes that found the stranded block first joining back in with the pack.

Only one of the transactions would be valid in the BTC blockchain.

For the transaction to be valid in 2 different blocks it would have to be during a fork of the original chain.

After typing this I looked for validation on my theory
and came across this
https://bitcoin.stackexchange.com/questions/18656/can-a-transaction-be-in-two-blocks

After reading the response and given when it was written, it looks like other than a fork this would only occur if someone was trying to 51% attack the chain and create a double spend opportunity for themselves.

What I did learn and did not know before, or really think about is that, if you include an already confirmed transaction in a found block it will be rejected and you would lose out on the block reward.

This brings me to another question if someone feels like learning me some knowledge... If someone did lose a block by including an already confirmed transaction, does the network keep working on that particular block, or do all valid transactions that were included in the block go back to the mempool, and the block reward is lost?

If the two miners were able to find block linearly on the network, that mean the two blocks have what is called intersection included transactions whereby the two block in their right are valid but only one of this transaction will be included in the longest chain while the other become invalid on the network.

When transaction is included in more than one block then first block is validated by the miners and the other blocks are put on hold.
 
(Non Google researched answer)

A transaction can only be valid in one block and the other transaction would cause the whole 2nd block to become invalid in such a case.
Pieter Wuille explains this nicely in this topic - https://bitcointalksearch.org/topic/can-a-transaction-be-included-in-multiple-blocks-216938

When transaction is present in more than one block then the first block that is broadcasted on the network will be considered valid, other blocks will be considered invalid and it will be ignored by other nodes.

We should note that the block as a whole is either accepted or rejected, not the individual transactions. So all other blocks having that transaction will become invalid.

This is what double spending problem is, the second transaction will be considered a double spend.

Assuming that the block would be valid then it couldn't happen. Transaction can be included in the block only once since it's not possible to spend your bitcoins again.


There is no such issue in the Lightning Network since all transactions are settled immediately between two parties as a sort of agreement.

Actually, there is no first mover advantage when it comes to transactions, or more precisely said, not anymore. Double spending with a higher fee will make sure the later transaction confirms before the first one.

It's all economics based, where miners only confirm transactions with the highest fees, especially in times where unconfirmed transactions are piled up and impossible to confirm by the next block.

Only one transaction will be considered valid (the one which gets included in the block that is broadcasted first on the network). The other transaction (and/or block) will be considered invalid and will be rejected by the nodes.

Source:
https://bitcointalksearch.org/topic/can-a-transaction-be-included-in-multiple-blocks-216938

Question: What happens when a transaction is included in more than one block?

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Don't break the forum rules,and no PLAGIARIZING!

A coinbase transaction is a unique type of bitcoin transaction that can only be created by a miner. This type of transaction has no inputs, and there is one created with each new block that is mined on the network. In other words, this is the transaction that rewards a miner with the block reward for their work...