texts: Reading transactions from blk*.dat files

texts:
I'm reading through each blk*.dat file in order.

As I'm reading through each transaction, is it possible that I will read a transaction that is referencing an output (as an input) that I haven't encountered yet?

For example:

|--------|
| header |
|--------|
| tx1    |
| tx2    | <- This transaction is referencing inputs I haven't encountered...
| tx3    |
| tx4    | <- ...because the outputs are created in this transaction.
| tx5    |
|--------|

Furthermore, if this is true, it possible that the required inputs will be found in a transaction in a future block (and not just in a transaction further down the current block)?


texts: Good API for making shareware that accepts bitcoin?

texts: Are there any good APIs for accepting Bitcoin within Qt or similar such applications, for making paid shareware applications?


texts: I have been running a bitcoin app in an old server. I need to move everything to a new server but my question is this: is there a way I can transfer my bitcoin wallet (bitcoin core) to the new server with a clean O/S installation without losing the tx history from my old server's wallet?


texts: Does the protocol ensures that private keys are unique?

texts:
There is a very very low chance for the same private key to be generated. (source)

However, what happens when my generated private key matches a private key that is already used?

Does the protocol reject private keys if they are already used?

If not, what kind of damage will be done?


texts: is it possible to deposit bitcoin into an address without making the address public?

texts:
I thought one safe way to keep a bitcoin "cold" and safe is to not show its address ever to the public.
However, let's say if I create an address, so that means I create a pair of public and private key, and then the public key can go through some steps to become an "address".
Now, if I deposit 0.001 bitcoins from Coinbase or Coinbase Pro into my mobile wallet (or any wallet), isn't it true that the Ledger (the blockchain) has to have a record of
 Transfer of bitcoin from Address 123c6...e6.  to   987a1...39   Quantity: 0.001

So somehow, that new address has to be "public" because it is in the blockchain and anybody can see it?  So how would it be possible to have an address and be able to deposit some bitcoin into it without showing the address to the public?


texts: If I send from a segwit wallet to a non segwit wallet, does the tx not show up in the other wallet until there is a confirmation?


texts: Bitcoin wallet - why do i need it for cold storage?

texts: Why do I need a bitcoin wallet for cold storage?  Can I just write down randomly generated public address and private key pairs, and keep these on paper?  I am confused by the apparent need for a wallet stored on a thumb drive or some other data storage device that may become corrupt.  So why do I need the wallet?


texts: How to exchange small amount of bitcoin?

texts:
Hi I have a little question could you tell which is the best method to exchange 2.27mBTC (18€) in euros or USD?

I registered on coinmama but the minimum for them is 50€ is there any other exchange services that could sell USD or EUR for my small amount of mbtc?


texts: How do custodial lightning wallets work?

texts:
I just installed and tried to use a lightning wallet (bluewallet) on an Android device.

As per my understanding, when I fund my lightning wallet (This is an on-chain tx) with amount x, I open a direct channel with blue wallet of amount x. If I want to send a tx on the lightning network (say amount x) to a person B, they must have their own open channel with bluewallet of amount y where y must be greater than x for the tx to go through. If it goes through then it's routed via blue wallet to person B.

Is my understanding correct? Please correct me if I'm wrong.

What happens if the above conditions are not met, i.e. person B creates a wallet on blue wallet but doesn't fund the channel? What happens if the amount y is less than x?
Also, are my keys randomly generated on device only?


texts: Question: Can I just buy/sell/trade to BTC and hold it and still be profitable? I mean with money you'd need to invest it in stocks, bonds, and etc to make more cash and simply holding on to cash over the long term means the same as losing money. Is this also true with BTC? Will I be losing money if lets say I buy 2 BTC coins and just leave it alone without investing it?


texts: Reason behind hashing the nonce in prevBlockHash?

texts:
I understand the role that the nonce plays in the block header for calculating a hash for a valid proof of work.

But what I ask is: Do we consider the nonce in the prevBlockHash calculation of the previous block because, well, it's in the block header already (for the proof-of-work calculation), and it would be silly to write a calcPrevBlockHash function that calculates the previous block's header by ignoring the nonce?

Or is there a specific security property or assurance that we get when including the nonce in the prevBlockHash calculation of the subsequent block?

For instance, you could argue that we hash the timestamp because we want to capture the time that the block was generated. See answer here: Why the timestamp component of the block header? I guess you can argue the same for the nonce field.

But I claim that we could still have the nonce in the block header, and not hash it during the prevBlockHash calculation of the subsequent block, and things would still work. You would still be (a) able to validate this block, and (b) unable to mess around with the transactions in the block, because that would modify the hashMerkeRoot field, and thus render the block invalid.


texts: In order to reduce fees, can I 'consolidate' my wallet by sending the entire balance to a new address in the same wallet?

texts:
My balance is currently made up of lots of small amounts
I know I'm not going to be using my bitcoin wallet for a while, so I don't care if the consolidation transaction is slow.

Would creating this transaction with no(or relatively low) fee achieve the aim of making subsequent transactions smaller and therefore less likely to attract higher fees in order to go through quickly?

Assuming this sort of 'consolidation' even works..
What would happen if a wallet program had a feature that allowed people to automatically 'consolidate' overnight depending on the makeup of the wallet's balance? Might it have a negative effect on the network?


texts: How do you tell if witness data has been tampered with?

texts:
If you receive a block, how can you tell whether the witness data has been tampered with between when it was mined and when you received it?

Where in the block is the wtxid root, and how do you compute the merkle root of the witness data?


texts: Are there any cryptocurrencies with no mining beyond participation?

texts: I mean something where just participation in the decentralized network gives you coins somehow and you cannot do anything beyond (excluding more participation, of course, by having multiple PCs and IPs, for example) to increase the rate of achieving those coins. At the moment I have completely no motivation to leave my bitcoin or litecoin client on, because it doesn't gives me anything back for using me as a node in this network of hardcore miners. I'd rather find some ways to use it occasionally only when I need to do some transactions (few times a month, for example). I'm newbie in this topic, but doesn't this harm the network, when lot of people become using it this way?


texts: Why isn't the right chain chosen according to the number of nodes who are broadcasting it?

texts:
So if a new node join the game, it gets blockchain from other peers.

It may actually receive 2 different chains and it chooses the longer cos of more work done.

I wonder why isn't it simply choose the one that is being broadcast by higher number of peers instead of this mining madness??


texts: Problems Setting a Transaction Fee on a Per Transaction Basis Bitcoind

texts:
I've spent hours and hours trying to find a solution to this problem, with no success.

Using Bitcoin Core on a Linux machine, so using bitcoin-cli to process commands back to the daemon.

Here's what I want to achieve: I want to send a transaction and be able to specify a custom transaction fee in Bitcoin/KB on a "per transaction basis".

So far, I haven't found a solution. These are the areas I have been looking at:

Change the paytxfee global variable and then just send the transaction. ---> If I do this, the resultant fee once the transaction has been sent is about 40% lower than what I specified in the paytxfee variable. Why is it smaller?

So.... does anyone please have any ideas how I can just send a transaction and specify a custom fee which is the actual fee used when the transaction is broadcast to the network?

Thanks in advance for your help.

Edit

Hi. Thank you for your reply. I'm panicking a bit as I have to get this sorted by tomorrow. I've tried setting "paytxfee" with the "settxfee" command. In the last example I sent a dummy transaction using "sendtoaddress". I entered "0.00170" in the "paytxfee" global variable (170 satoshis per byte). Having looked at the resultant transaction on Blockchain.com explorer, only 114 sat/B were used instead of the requested 170. When I used "fundrawtransaction" and specified a "feeRate" option, it was calcultaing the fee on the virtual size rather than the total size, so once again I was getting about a 40% reduction in fees once the transaction was broadcast. I now have loads of transactions stuck!! Anyway, that's not a problem as they were only tests... Any ideas how I can resolve this? Happy to send screenshots or maybe we can email/use messenger? Desperate to get this sorted .... Thank you so much!


texts: How to emulate SIGHASH_NOINPUT using CHECKSIGFROMSTACKVERIFY?

texts: I read on bitcoin-dev that CHECKSIGFROMSTACKVERIFY (CHECKDATASIG in BCash) can be used to emulate new sighash flags. How would that work, concretely? As an example, please provide an example update transaction based on figure 4 of the Eltoo paper, or aj's simplified lightning (that doesn't work with watchtowers).


texts: In a multisig wallet setup what needs to be backed up and why?


texts: How was South Korean Bitcoin exchange Bithumb hacked?

texts: I've read a news article saying that a South Korean Bitcoin exchange had been hacked by someone. My question is: how does this happen? Isn't the Bitcoin network's cryptography safe enough to prevent these events?


texts: How to move only "blocks" and "chainstate" folders on an external USB hard-drive while running Bitcoin Client on connected laptop with Ubuntu?

texts: I have experience with secure-copy and secure-download but how do I move only the Bitcoin Client "blocks" and "chainstate" folders within the home directory of Ubuntu 18.04 to an external USB hard-drive while running the Bitcoin Client on the connected laptop with limited storage on board?  I'd sincerely appreciate the best-practice or recommended approach for hosting a Bitcoin full-node on a laptop with an external USB hard-drive since I am also attempting to run Blockstream and FIBRE on this environment- thank you


texts: How to make a profit doing 'spread trading'?

texts:
I understand making a profit via arbitrage trading between multiple exchanges. I understand what spread is (gap between the bid & ask). How can one make profits by leveraging this spread within a given exchange? Good examples will be helpful.
Thanks


texts: Given OP_VER was never used, is disabled and not considered useful can its meaning be stripped and it be made OP_SUCCESS?

texts:
Given OP_VER (0x62) was never used onchain, is disabled and is not considered useful can its meaning be stripped and it be made OP_SUCCESS for the purposes of introducing a new different opcode in future?
As Andrew Poelstra describes "..there was an opcode called OP_VER, OP version. I can see some grimaces. It would push the client version onto the stack. This meant that when you upgraded Bitcoin say from 0.1 to 0.2, that’s a hard fork. Now script will execute OP_VER and push 0.1 onto the stack for some people and 0.2 onto the stack for other people. You’ve forked your chain. Fortunately nobody ever used this opcode which is good. "


texts: How do websites sell cryptocurrency with fiat payments?

texts:
I'm trying to create a platform to sell cryptocurrencies in my country. the way it works is, the user enters my website, select a coin he wants to buy then the amount he/she wants to buy, he pays in our common currency (say USD) and we should send him/her the cryptocurrency he has bought. the procedure is like most of the crypto shops, but the question is how should I get cryptos to sell? say a user wants to buy 5 Bitcoins, how should I have 5 Bitcoins to give him? how do other websites do this?
Any help would be appreciated.

Thanks in advance.


texts: I followed this guide (https://github.com/lightningnetwork/lnd/blob/master/docs/configuring_tor.md) to setup Tor on my LND node, but this forced all my traffic through Tor, and I was no longer reachable over Clearnet. I've looked through some issues on the LND github page, and it seems there is a way to have my node listen over Tor, IPv4, and IPv6, but I'm not sure how to set it up that way. Also, they mentioned there are risks to doing this, what are those risks? I don't mind if people can correlate my IP address to my onion address (I'm just running servers in the cloud anyway). I just want to be able to connect and route payments with Tor nodes and clearnet nodes. How can I get my LND node to make connections over Tor, IPv4, and IPv6? What configuration options must I set?


texts: How do I buy Bitcoin with cash? I am Canadian, and have a lot of cash that I would like to convert to Bitcoin without using any banks. Can I do this?


texts: FPGA/ASIC with general SHA-1 and SHA-2 capabilities

texts:
With the introduction of ASICs and FPGAs, I am looking to upgrade my rig.  However, I use the rig for academic research involving brute-force SHA-1 and SHA-2 cracking (I am working on make passwords more secure for my capstone project, trying to pay for everything by mining BTC during downtime).

What are my options?  GPU's don't seem like they will matter much longer...


texts: understanding bits and difficulty in a block header

texts:
This block:
https://blockchain.info/block/00000000000000000025c089d0a7b2bf6241888c4dd90ab7a4c4baa6a2823551

Shows difficulty at 3,007,383,866,429.73, and bits at 392009692.

If I want to see how many zeros need to be in the hash, I believe I can just do:

(log2(3007383866429.73) + 32) / 4) => 18.362911541451258

Which is correct..  But how does bits come from difficulty?  How can I calculate the number of zeros from the bits instead of the difficulty?


texts: What is the most accurate Classification Of Bitcoin?

texts:
What is the most accurate classification of Bitcoin as a piece of computer "software"?

would it be considered:

An Operating system.
An Application.
A File.
A Library.
A Network.
A Server.
Framework.
Assembly Level Code.
Application Binary Interface.

These are just the examples that came to mind at the time of writing.

Please feel free to improve the efficiency and effectiveness of this question.


texts:
I would like to create a gateway on MyCelium.com. This is for my testing, so I want to test it out first. But I struggle in getting a BIP32 test pubkey.

There is no documentation on MyCelium.com, neither even Google. It is really frustrating to go through this. Could anybody please help? Thanks.


texts:
-rescan is a command line argument that is passed to the bitcoin client after restoring wallet.dat from backup.

Which files get recalculated?
Which files does the rescan command read?
Why is it a good practice to first download all the blocks, then rescan, and not the other way around? (as a comment on this answer suggests)


texts: How to avoid Bitcoin-QT's transaction fee or change size limit?

texts:
I'm trying to find an easy way to enable my website to accept bitcoin payments.  I'm trying to test out Blockchain.info's "receive payment API" (http://blockchain.info/api/api_receive).  Near the bottom of the page, there is a PHP example (https://github.com/blockchain/receive_payment_php_demo) which I like to test out.  To test it out, I need to send bitcoin to Blockchain.info's address, who will later send the bitcoin back to me.  When I try to send 0.0005 BTC in my Bitcoin-QT client (v0.8.6-beta) , I get the following message:

"This transaction is over the size limit. You can still send it for a fee of 0.0005 BTC, which goes to the nodes that process your transaction and helps to support the network. Do you want to pay the fee?"

There are only two buttons for me to click:  Cancel  or Yes.  0.0005 BTC is worth approximately 50 cents or 100% of the amount that I want to send.  This is an incredibly expensive fee and not at all what is touted as a cheap way to send money.  When developing and testing, one will likely need to send bitcoin through this PHP code many times, which means that these fees can add up, and all I'm doing is testing.

How can I send BTC to test payment processing without paying this fee?


texts: How do I export a wallet from Wasabi Wallet to Samurai?

texts:
I'm quite new to this business, and I have a question.
Here I have 12 words and a passphrase, there is a Wasabi Wallet application on the computer and created a wallet based on this data.
Can I use the same 12 words and passphrase to restore my Android wallet using Samurai Wallet?
When I try to enter the same data as in Wasabi Wallet, I have a different wallet (I compare the private keys and they do not match).
Can someone explain to me what I'm doing wrong? I want to have the same wallet on all platforms, knowing only 12 phrases and a passphrase.
Thank you in advance for your answers, I will be glad to everyone.


texts:
I have a Nvidia GTX 765 GPU, over clocked with a core KH rate of 850 (give or take a few).

When I run CGMiner, everything works fine except I have an extremely low KH rate (8 or 9 KH).

My configuration is standard, besides adding --scrypt because I'm mining LTC.

This isn't the first time I've had problems with CGMiner (gave up entirely on LTC before because of such problems) and I can't find any fix to this. The only problem I could think of is that it is using my integrated GPU, considering it claims to be using "GPU/Thread 0"

Does anyone know what the problem is? Thank you.


texts:
After adding watch only address to my bitcoin core and perform some transaction that make my watch only address balance to 0, but when i run getbalance and listaccount with watch only is true, my watch only address still have coin. Only listunspent address show that my watch only address dont have any fund to spend more.

So any idea to sync my balance for watch only address ?


texts: After receiving bitcoin, they were sent to an unknown address 16 minutes later

texts:
I received BTC payment from my friend by qr code scaning on date 31st July (1 day before 1st August HF).

https://www.blocktrail.com/BTC/tx/8710bdb6f1d34e882bab7fbbdb4b94266032672c54a042df88e25d1518ab40a8

The incoming transaction has shown on my wallet (Mycelium) as unconfirmed with another transaction says all BTC has sent out immediately to a address I never known before.

https://www.blocktrail.com/BTC/tx/176dfd5d7f28fafef60e071588bb464a6426382d8ef5315d57e5b5852c1e0e48) (as non standard transaction with version 2)

After I reload it says network error and the most of my transaction history disappeared from wallet till now.

This make all my BTC has stuck in address 1MDJk9xhPVyVH3RcXmhYBRL9bJrwgAbsN3 without move till date 4th November (nearly segwit2x) all BTC has sent to another address again.

This is huge amount of BTC for me, I tried so hard to find the answer what happen with my BTC but really has no idea. But I'm sure my wallet not compromised and my BTC still sit in that address without used.

I have 0.5 BTC and 0.5 BCH for reward if I can get it back. It's not so much but please help me...

I apologize for my poor English language skill, You can ask me for more information to understand clearly.


texts: Bitcoin paper wallet and Bitcoincash withdrawal?

texts:
Let's say I have a bitcoin paper wallet with a public and a private key, with an amount of X bitcoin on it. On the 25th of November, the hardfork of bitcoin gold will take place, so I will get the same amount of bitcoin gold.

The question is, how I will be able to withdraw only bitcoin gold from that paper wallet as I have only one public and private key as they are bound to a bitcoin wallet?


texts:
I understood that when a new transaction comes in, the miners have to start over, or at least change their merkle-tree to include the new transaction, essentially starting from scratch again.

If I look a the real-time transactions on https://blockchain.info/, how could miners ever make a block when there is never a break?

Unless you define a break as a few microseconds, and since every second you can calculate I believe billions of possible hashes, I still find it hard to grasp how a new block gets "chosen" or verified in human understandable terms.


texts: Need help I sent my bitcoin cash at the atm to the wrong bitcoin HOW can I use this address to send to the address I want it the money on !!! NEED HELP NOW


texts: What is the name of the attack where a single node spin thousands of node and take control of the cluster?

texts: When we implement Raft for a decentralised public ledger a single node can easily take over the control of a full cluster by spinning thousands of nodes and making them to elect the malicious node as a leader. What is the name of this attack in security terms?


texts: Is lightning network limited by the 'size' of channels?

texts:
Imagine we start with multiple channels which eventually link two individuals, Alice and Rob: (the BTC amounts is the total locked in their multisig address for their channels between each other)

Alice --- 100 BTC ---> David --- 50 BTC ---> Rob

Now - suppose Alice wants to send 100 BTC to Rob. Alice is connected to Rob via David but there's only 50 BTC available to be distributed between David and Rob. Therefore Rob cannot trust a payment of 100 BTC from David.

How does Alice deal with this?

Assuming Alice does not have another 100 BTC sitting around outside of lightning - she has to close out her channel with David; wait for confirmation of this; and then send Rob a traditional transaction to make payment (or open a channel with him). Is this correct? Or is there a better way of dealing with this? Some way of passing value between channels?

If not - is this a problem for lightning network? It would seem that routing across channels is only as useful as the smallest connecting channel. And users have every incentive to keep channels as small as possible to minimise 'committed' BTC. If users have to wait for confirmation to close out a channel, their ability to make fast payments over the original bitcoin network is vastly slowed down by having to wait for confirmation of a channel closure before being able to conduct a transaction on the main network.


texts:
The way I understand it,  at the very top of the block the miner adds a transaction to collect the 25 bitcoins it would earn if it solves the block.

Obviously that transaction is included in the hash/nonce when the block is solved.

But what about the fees? the only way I see it done is for the miner to also create transactions for each of the fees it finds in the block.

All these "fragments" have to be traced to some source/input address.

Q: How can the miner sign a fee transaction for itself if the miner's address is not the input of the transaction?


texts: Can I long USD/BTC instead of shorting BTC/USD?

texts:
Let's say that I think that bitcoin has hit a peak. I want to short bitcoin, but in a far less risky way. In order to do this, I want to go long on USD/BTC. Let's say (as an example) that I longed this pair when Bitcoin was $13,250 (on the dropping side, I set that as strike price), and sold it when it was $8,000 and going up. I would have made a 65% return as opposed to a USD/BTC short of just under 40%. I want to do this to be able to make a higher profit during a bear market. I feel that this is a good idea.

The question is, to clarify: can I long the USD/BTC pair? This pair is equal to one divided by the USD price for one bitcoin. I think it is good because it offers an alternative to shorting, one with a theoretically unlimited upside and a limited downside. If one bought $250 worth of bitcoin at $100 and sold the position at $6,000 in the beginning of November of 2017 or 2018, it would have brought $4.50 as opposed to a theoretical owed amount of over $14,000.

As a commenting individual in the comments said, this move could have theoretically brought (and maybe has brought) very high returns. Even going back 1-2 years ago (roughly speaking, as of writing), such a move timed at the right time could have brought 500% or more returns depending on how good timing the trader had.


texts:
I don't really understand how binary options work and someone recommended a company called empireoptionstrading.com for me to invest in.

I tried to find more information on the company but I don't really know what to check against the company before I give them my money to trade for me.
Is it a safe, reputable, legitimate, and reliable company to invest in?

Please advise.


texts: Do transactions happen in an already mined block or a block yet to be mined?

texts:
As I understand it a miner gets a reward of 25 BTC per block he finds (as of now). I also read that some transaction fees go to the miner who found the block.

How are these two things related?

Also, how can a miner not claim all the fees? Ain't that automatic? Is there something the miner needs to do after he found the block to claim the fee?

How was the system "boostrapped" with the first block ever?


texts: bitcoind error "mempool min fee not met" preventing me from sending btc on blockchain

texts:
When I want to send btc in block chain this message is appearing:

  BitcoindException(super=com.neemre.btcdcli4j.core.BitcoindException:
  Error #-26: 66: mempool min fee not met, code=-26).

Who knows how to resolve this? Can anybody help me please?


texts:
I tried to download the pdf from the following repository but i get an error

https://github.com/merklebloom/IoMv1
Ive done the following:
$  git clone https://github.com/merklebloom/IoMv1.git
$  cd IoMv1/
$  make pdf

It fails to create the pdf.

And I get this error message:

  if [ ! -d "_build" ]; then \  mkdir _build; \     cp -R -L
  /etc/asciidoc/images _build; \    cp images/* _build; \   cp
  chapters/en/* _build; \   cp conf/* _build; \ fi; \

  export
  XML_CATALOG_FILES=/usr/share/xml/docbook/schema/dtd/catalog.xml; \ cd
  _build; \ a2x --format=pdf --conf-file=a2x.conf --fop --xsl-file=custom-docbook-styles.xsl -k --verbose master.asciidoc; \

  /bin/sh: 3: a2x: not found Makefile:65: recipe for target 'create_pdf'
  failed make: *** [create_pdf] Error 127

Same goes for creating any other file such as pdf, html, epub, kindle.


texts:
I have a simple computer: 4GB ram, Intel core 2 duo E4500 and a Geforce 315 (i also have a Geforce 9400 but I don't know which is better) and I was wondering if it would be possible (without overheating my PC) to mine bitcoin with it. I dont care much about the electricity bill because i just want to do it for a hobby but if someone could let me know that would be great.

Cheers,

Ash


texts: How many nodes would one typically check to determine the longest chain?

texts: Before posting a solved block to the longest chain, how many nodes would one need to check before making sure that the longest chain was found?


texts:
I have a bitcoin-qt wallet on computer A and some of the private keys are stored on another computer B with the ability to send transaction as well. I have to following questions :

If I generate the transaction on B and send it to bitcoin network
will it show up on the bitcoin-qt transaction history computer A ?
If 1 is true, Just by looking on computer A can I know which computer
generated the tx ?


texts:
I understand that, with BIP 100 as suggested by Jeff Garzik, in the first step the maximum block size can be increased from (then, after the hard fork) 2 MByte to at most double of that, so 4 MByte - without a hard fork. Depending on the miner's votes (counted for 12.000 blocks, 75% majority necessary) the block size may be increased further.

How can I, as a user start the voting process? What if I'm a miner? How do I determine the new maximum block size? Can two votes for 3 MByte and 4 MByte run in parallel?


texts: How i can extract all bitcoin output addresses from tx message?

texts:
I want to extract output addresses from tx messages in any bitcoin pcap.

currently, i extract tx messages which it's output script starts with "0x76" or "0xA9", but i don't know how can i extract the other types of op_codes which is introduced here:

https://en.bitcoin.it/wiki/Script


texts: I want to sell digital products (eBooks) using Bitcoin, and I want products to be instantly available after purchase. What could I do?


texts: Could you tell me how to rebuild bitcoin-core testnet node?

texts:
It seems that my local bitcoin testnet node are corrupted. Could you tell me how to rebuild blocks?

The reason why I think it is corrupted is as following.

For example, when I checked transaction "ed2ccc36c241ad00893d0596fe167a4df162989dbf8c5ff3916d4034e7f510c3" on my local testnet node, it returned the following error.

error code: -5
error message:
No information available about transaction

However, on testnet block reader it returned transaction info.


texts: Problem receiving - confirmations stuck?

texts:
I have tried to transfer some btc being a first time user from one wallet to another (both online version). It seems the btc was sent but the receiving wallet is still showing '0' 24 hours later.

Receiving wallet does require three confirmations for funds to show but from what I have been able to find on blockchain it should have passed this point! Being a newbie I'm obviously concerned if everything is as it should be!

This is the transaction for the sending wallet, it seems to show the funds transferring in and then out:

https://blockchain.info/address/1BkJ16RfYTcPbhsdWKyKkg2pNVZKjbyfTA

This is the transactions list for the receiving wallet which currently shows '0' balance:

https://blockchain.info/address/1BkKpkHVcxoQEjGxZtHaxVPX9xuVh8ru5i

It shows the transactions as 4 so am concerned all is not right! Any advice is greatly received!

Thanks


texts: What did Gavin mean when said minimum fees would be automatically suggested?

texts:
From the release notes of the Bitcoin version that introduced minimum transaction fees:

  ... note that we intend to replace the hard-coded fees with code that automatically calculates and suggests appropriate fees in the 0.9 release ...

Has Gavin expanded on the implementation of this automatic calculation?


texts: I know about the privacy and security implications of address reuse. But I was thinking about a scenario where I have one address for every person I receive transactions from. This would still have the security problems, but not the privacy problems? Did I overlook something here?


texts: Deterministic Key Generation: prove that address is in a sequence of your original seed

texts:
Lets say that someone wanted to prove they owned some metadata without revealing who they were. For instance, lets say they needed to prove they had owned a contract but that contract was in an address that had a lot of bitcoin in it, but they didn't want to show that they had that much capital (maybe a bad example) , but FOR WHATEVER REASON they didn't want to reveal their nest egg address or undermine the psuedonominity of previous linked transactions
Would it be possible to reveal the existence of the contract, by simply proving that you own an address that was generated by the same seed.

For instance, Electrum generates six addresses after you create a seed.
Lets say the contract and a lot of bitcoin was in the first address in that sequence.

Could you prove that you own this by signing the second address in that sequence (or even a change address), and it would irrevocably prove that you own/control something in the other address
without linking the two addresses together
the result being that you would know that "yes this address in within the same sequence of addresses, one of which contains the information that needs to be proven"

I think this would have perks for privacy of bitcoin and associated technologies


texts:
What is stopping me from hacking the mining software such that if I do happen to get the right hash I keep it for myself, but if not then I just submit my work done and get my share of the mined income.

The only way I can think of to check this is for the pools to monitor the block chain and look for suspicious activity, but I'm not sure what this activity would like in practice and that wouldn't just be a higher than elevated rate of whatever they're looking at.

It seems to me that this would be especially attractive on pools like Eligius that do CPPSRB and even more attractive the higher my hash rate as then I have a high chance of getting blocks all to myself.


texts: How can Bitcoin be adopted as tradeable currency pairs on Forex?

texts: There are Forex clearing-houses all over the world. How can we have a Forex clearing-house offering Bitcoin as tradeable currency pairs?


texts: How are transactions collected into new block?

texts: How are the latest transactions collected into new block to send them to miners for hashing? Which part of the network is responsible for giving miners the correct block to hash?


texts:
I find myself a victim of either my poor googling skills, or the lack of detail in the bitcoind docs.

I have a walletNotify script running on a full node that whenever a transaction to / from my wallet arrives, performs a getRawTransaction(txid, 1) on the passed transaction ID.

Now, if any of my addresses appears inside the vout array, I know that that transaction is a deposit. What I'd like to verify, is that I can indeed spend those bitcoins.

I read about non-standard transactions (specifically, unspendable transactions) and kinda panicked, so my questions are:

Does bitcoind perform any sort of verification on the "spendability" of the arriving bitcoins?
Is there any easy way of verifying this myself? is there any not-necessarily-easy way?

Thank you very much in advance!


texts: Would mining future bitcoins break the bitcoin?

texts:
assuming an bitcoin miner with very much hashrate like bitmain would decide to mine "future" bitcoin blocks and provide them within very short time to the network, would this break the bitcoin?

As i understand the bitcoin hash is generated from the version, previous block hash, the merkle root hash, current time, difficulty / target bits and the nonce. The bitcoin network does only accept blocks for timestamp with max. 2 hours in the future.

But what if an miner with that much power would start mining for a future timestamp at which he assumes it would be possible for him to mine up to 2016 blocks (every block with a little increased timestamp) before the timestamp is reached. If this would be possible, the miner would only need to mine one more block when the timestamp is finally reached to bind the chain (the missing block for the previous block header hash) and could provide all his mined blocks a nearly one timestamp to the network. The target / difficulty the miner mines at would be a little be greater than estimated by him.

Wouldn’t the network increase the difficulty after this action by such an huge factor, that mining the next 2016 blocks would be nearly impossible?


texts: Bitcoin Core Blockchain Sync Fatal Internal Error - Corrupt Block - Linux

texts:
I'm trying to perform the IBD on Bitcoin Core 0.18 and I continually receive "Fatal Internal Error" at seemingly random intervals, closing bitcoin-qt and preventing me from fully syncing.  Farthest I've gotten so far has been 5% after hours of trying and reindexing.  I might make it to 6 years back if I'm lucky, once to 5 years, but my luck has never held out any longer.  Attempts to reindex result in the sync rewinding to about 8 years back, representing <1% of the entire download.  I'm at my wits end.

The error I'm receiving in the debug.log is:

2019-07-22T00:14:07Z Error: Error: A fatal internal error occurred, see debug.log for details
2019-07-22T00:19:17Z ERROR: ConnectTip: ConnectBlock 0000000000000af5808c422d13a9bd6580e72a9db9a543336cb6834c9db75a40 failed, bad-txnmrklroot, hashMerkleRoot mismatch (code 16)
2019-07-22T00:19:17Z ERROR: ProcessNewBlock: ActivateBestChain failed (bad-txnmrklroot, hashMerkleRoot mismatch (code 16))
2019-07-22T00:19:17Z *** Corrupt block found indicating potential hardware failure; shutting down

I don't know what's causing the corruption.  I've tested my hardware and everything checks out fine.  I ran badblocks on the SSD, memtester on the RAM, and monitored the CPU core temps during the sync--a constant, frosty 35 degrees C.  My OS is completely up-to-date.  There's nothing obviously wrong with this system and the hardware exceeds requirements.

What could be going on here?  And is there any hope that I can actually get this node setup or am I out-of-luck?

System Specs:
Bitcoin Core 0.18

OS:  Linux Mint

CPU: i5-8500 4.1GHz

1TB SSD

8GB RAM


texts: I am building some new metrics to better understand the Bitcoin economy and one that seems to be useful is a probabilistic notion that a Bitcoin has been lost. I'm aware of the bitcoin days destroyed, but has anyone done any modeling to gain a sense if a Bitcoin has been destroyed as a result of a lost key or a transaction to a bad address?


texts: Bitcoin - Is the  in scriptPubKey already hashed?

texts:
In Bitcoin protocol, to set the output of a transaction you need a scriptPubKey which is in the following format.

scriptPubKey = OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG

Is <pubKeyHash> the address of the receiver of bitcoin or is it the hash of a address of the receiver?


texts:
I was reading the wiki article about the blockchain and I didn't understand the part in bold:

  When a block becomes an orphan block, all of its valid transactions
  are re-added to the pool of queued transactions and will be included
  in another block. The 50 BTC reward for the orphan block will be lost,
  which is why a  network-enforced 100-block maturation time for
  generations exists.

I don't know the details behind block creation and acceptance, so how does the block maturation time work? Is the block only accepted after a while?


texts: Reject transaction because of illegal data

texts:
We already know there is illegal data on the blockchain and it will be on there for ever.

That got me wondering about the potential legal implications for miners, since they are technically endorcing and worse.. distributing illegal data by including those transactions in a block.

What is the current legal situation in the US/EU ?

Is there any record of miners rejecting a transaction because of the arbitrary data after OP_RETURN?


texts: I work as a volunteer for a tax exempt organization in the US.  We are currently accepting donations in bitcoin but not issuing receipts for those donations.  I would like to start issuing receipts.  Is there any legal guidance available online about this?  I haven't been able to find anything.


texts: What's the difference between hashtx and rawtx in ZeroMQ of bitcoind?

texts:
I'm trying to use ZeroMQ integration feature from bitcoind.

According to docs it supports four topic:

hashtx
hashblock
rawblock
rawtx

Sadly, they are not very well documented.

So, what is the difference between raw/hash topics?


texts: Is there a way to delete a test wallet without stopping bitcoind?

texts:
For my unit tests, I'd like to be able to delete and recreate a wallet without having to stop bitcoind and manually deleting the wallet directory.

When I try to delete such wallet directory without stopping bitcoind, I get an error since an handle exists on "db.log" (on Windows at least).

Is there a clean way to delete a (testnet) wallet without stopping bitcoind?


texts: What is the average number of transactions that a BTC wallet contains?

texts:
If a BTC wallet has 8 addresses, and each address has 10 transactions, then that sums to 80 transactions.

Is this around the average per wallet?


texts:
Supposed that I have managed to mine a new block that meets all requirements successfully by building my own script that can collect transactions and add them to new block and hashing the new block correctly. All this can be done in 3 minutes within Linux server. However, when I tried to submit it, I didn't find anyway of doing so. Is there any specific website to submit it for broadcasting?. please, explain to me with examples?
thanks in advance


texts: Double Spend Behavior on First Network Propagation

texts: Supposing there is a double spend, call the transactions T1 and T2. If someone propagated both transactions within a short space of time to the network, of course only one of them can make it into the next mined block. Do we know anything about the probabilities of which of T1 and T2 will make it, or is it 50/50? Obviously from block 2 onward the longest chain is most likely to remain. But for the very next block, do we know anything?


texts: What is the proposed solution to solving the 2 way peg with Sidechains?

texts:
I'm trying to understand how a sidechain would work with Bitcoin using a 2 way peg. From my understanding the Bitcoin 2 way peg works like this:

A bitcoin is sent to an address that the sidechain can monitor for received funds.
After say 144 blocks (1 day) is confirmed, the sidechain will release the the virtual bitcoins on the sidechain to their sidechain account.
When the user wants to convert this virtual btc back to on-chain btc, those coins get sent to another address on the sidechain. Once those are confirmed, the sidechain releases the real bitcoins onto the main chain back to their account.

What I don't understand is:

Wouldn't the sidechain require having the bitcoin blockchain downloaded along with the sidechain blockchain in order for it to monitor the btc blockchain?
Since the sidechain has the ability to release the locked BTC, what stops someone from forking the sidechain and then tricking the system to release the locked btc on their own fork?
It seems that sidechains isn't possible as of right now as it requires a centralized entity to verify the pegs. What are some solutions to solve this centralization?


texts: As you can see my client is stuck on 99,7% with unknown. Syncing Headers(577895), It has been in this state since last day synced(which you can see). How can I get it to work since I have plenty of disk space and I run a computer maintenance program quite often.


texts: I had around 20 BTC on my blockchain.info when bitcoin-cash forked and so after the fork I exported my seed and pasted it into electro-cash in order to receive my BCH (done it before and it worked) but when i synced it I was greeted by zero balance with a ton of transactions from 2016/09 to 2017/07 so there is no history after the fork nor the BCH


texts:
My bitcoind wallet does not update the balance, I tried with two different wallet. It shows the correct balance on BlockChain.info.

I have tried the bitcoind -rescan solution given  in :Transaction confirmed by network but never showed up in bitcoin-qt

However, the balance still shows as 0.

Machine : Ubuntu Linux
Bitcoin Version : 80600

Any Suggestions?


texts: How is a transaction verified in a micropayment channel?

texts:
Let's say Alice opens a micropayment channel with Bob and sends $10 into the multi sig transaction.

How do we know that Alice has those $10? Or are we taking the risk of her double spending it?


texts: Imported Multibit HD wallet into electrum - Bitcoins are gone!

texts: I got locked out of my multibit HD wallet and couldn't restore it with the seed phrase (even though it said they're valid) so I installed electrum and used the seed words to import the wallet. It worked but the bitcoins have disappeared. Is there a way I can recover them?


texts: What is the best way to send money to a friend overseas using a Bitcoin ATM?

texts: I have a close friend living overseas who I wanted to send money to. They suggested using a Bitcoin ATM instead of other methods. What is the suggested best way or method for me to use this method?


texts: what is preventing me from changing difficulty every submit when pool mining?

texts:
If I do pool mining at difficulty=1000 and I find a share with difficulty=2000, I can tell the pool that I was mining at difficulty=2000 and then submit the share. I can earn more in this way.

Does the pool allow me to change difficulty whenever I want? If not, assume that it let me change difficulty every 30 minutes, then I can use a high difficulty which makes every share more than 30 minutes.

Even if this cannot be done, when I find a share with difficulty=2000, I can connect to the pool as a new worker with a static difficulty=2000 and submit the share.

What is preventing me from doing this?


texts: How to dump peers.dat file to a plain text file?

texts:
Is there a simple solution to dump [whole] peers.dat file to a text file?

There are similar questions for example How do I read peers.dat file to get a list of all peers seen or that bitcoind has connected to? but I want to insert this code in Bitcoin Core Client (in fact: forked client) and dump the contents of this database on client start.

bitnodes.earn.com is not an answer for me.


texts: What are the risks of keeping USD in an exchange account?

texts:
Bitfloor, mtgox and others allow me to keep a balance of both btc and usd that is not being traded. So the usd is apparently in the hands of the exchange company rather than at my bank. This is an advantage because it allows me to quickly buy in and out of btc without waiting for a wire transfer or paying for something like bitinstant.

Is my usd held by the exchange protected in anyway from hacking or other losses, the way it is at my bank?


texts: How can you restore a password in MultiBit if you are given the wallet words BEFORE you even enter a password?

texts:
How is it possible to recover a wallet password when the wallet words are provided before you even enter the password?

https://multibit.org/en/help/hd0.1/restore-password.html

  Restore password

  If you forget your wallet password, then you can restore your password from your wallet words.


texts:
Are there any examples of cryptoequities or cryptoliabilities?

I've seen the cryptostocks site, but it doesn't look to be what I'm envisioning.

For simplicity's stake, please imagine a corporation that wants to issue stock that will never pay a dividend.

Could a fully integrated trading system be built off of the cryptocurrency concept?

Here are some of the criteria:

A corporation is the only issuer in a blockchain, so no mining rewards, only fees
The blockchain would probably need to be denominated in a single cryptocurrency
There would need to be some sort of automatically resolving escrow system where a buyer first deposits cash through into the blockchain before a trade can go through with automatic refunds if the trade fails
Buyer and seller would both have to sign the transaction, buyer pledging an amount of cryptocurrency, seller pledging an amount of cryptoequity
Orders would have to be able to be left in an "open" state to provide a limit book; in other words, buyers would need to be able to post how much cryptocurrency they would want to sell so to buy some amount of cryptoequity while whether the transaction will complete is uncertain, and sellers would need to be able to do the reverse while of course pre-depositing in the escrow
Open orders would need some mechanism to be canceled
Orders would need to be able to be partially filled, so an open bid could be partially filled by a seller leaving behind the remaining order and vice versa

How could this be accomplished?

(I will post any other necessary details)


texts: How does bitcoind choose its data directory?

texts:
Sorry, noob question I am new to anything linux related. I managed to set up bitcoin core just fine on my raspberry pi 4 and I have an external HDD that I want to use as my data directory for the 250 GB or so of blocks (this is not my main storage that I boot from).

Problem is, I have absolutely no idea how the bitcoind program decides on its data directory. I have run 3 or 4 times and I have 3 or 4 different data directories, none of which are on the HDD. How do I tell it where to store the data? Also, where do I put the bitcoin.conf file because it can never seem to find it. I have most of the blockchain pre-installed on my HDD from my windows pc and so I would ideally use that same directory but if thats not possible thats fine, I at least want it on my HDD though. I have followed several guides and nothing has worked for me so far. I appreciate your time for any respones!


texts:
I am trying to get my foot in the door wrt to bitcoind. I pulled the github version here. As suggested here, I am starting the daemon like so

bitcoind -daemon

and I am monitoring it like so

bitcoind getinfo

And I get the following output

{
    "version" : 89900,
    "protocolversion" : 70002,
    "walletversion" : 60000,
    "balance" : 0.00000000,
    "blocks" : 269516,
    "timeoffset" : -2,
    "connections" : 8,
    "proxy" : "",
    "difficulty" : 510929738.01615179,
    "testnet" : false,
    "keypoololdest" : 1386220819,
    "keypoolsize" : 101,
    "paytxfee" : 0.00000000,
    "errors" : "This is a pre-release test build - use at your own risk - do not use for mining or merchant applications"
}

Obviously some are self explanatory, but could someone go through and explain what all of this output means?


texts: Generated a transaction id but not seen on blockchain

texts:
Transaction id:

  a667e6d1a80c17bd0b55afec7c6ec618ca64a2a6c1b4f9badaf1c883bf5cb5dd

I sent bitcoin from electrum wallet with a 0.002 miner fee but it is showing unconfirmed. I tried to manually broadcast the transaction on blockchain.info but I am getting a transaction rejected because of High S value error.

If I don't see my transaction on the blockchain does that mean that my transaction was not broadcasted on the network? I am hoping that the transaction drops from the network as I do not want to resend.


texts: bitcoin block size and etherenum gas limit

texts:
I understand that bitcoin has a fixed block size (1MB).

On the other hand, Etherenum does not seem to have a fixed gas limit.

(https://ethereum.stackexchange.com/questions/1106/is-there-a-limit-for-transaction-size/1110#1110)

What is the rationale that bitcoin block size is fixed unlike Etherenum?


texts: Is it possible to use "Bitcoin days destroyed" as unit of currency? If yes, how to price anything using this? If no, why not?


texts: Add bitcoin payments to java app using BitcoinJ

texts:
I need to add Bitcoin payment to my application using the BitcoinJ library, but I'm new to using Bitcoin. I have one thought To create a new address for each new user, but I don't know if this is the right approach or not. Please tell me how to implement it correctly.
(I need to determine from which user the payment was received and in what amount)


texts: How will other coins like LiteCoin influence market price of BTC?

texts:
More generally, in economic aspect, when new currency are issued, and be accepted by groups of people, how will the new currency affect existing currency, ignoring other factors.

Ex. How will BTC affect existing USD?

Ex2. How will LTC affect existing BTC?

Ex3. If a country used to use USD as there currency, but they decide to use a new currency to replace USD, when this currency is becoming more and more important, how will USD be influenced?

It seems that it is more easier to develop new currency for people, not only country, how will BTC find a way out to win the competition with other currency like LTC. What will be the key point in the process?


texts: Mining operations: what's allowed and what's not?

texts:
I understand that miner's compete to create blocks that meet certain (very specific) cryptographic criteria. However, I'm still having trouble seeing the "forest through the trees" here, and have a few very-similarly-related questions that I think will tie everything together for me:

What are these competitions/races called? Block bids? Block challenges?
What software announces to all the miners that a new "block bid" is ready? In other words, how do miners know to start competing with each other?
What software do miners use to compete with? bitcoind? Something else?
Can miners write custom software the interfaces with #3 above (bitcoind or other), or is that "not allowed"?
Can miners divide a "block bid" problem over multiple computers, or again, is that "not allowed"?

I usually don't like to ask "multi-questions" like this one, but these questions are so small/micro in and of themselves, and so closely-related, I think their answer will make for a nice "mining overview"-type question for future readers and newcomers.

Thanks in advance!


texts: Where Can i Buy Bitcoins without using exchange?

texts: I'm Planning to work on a exchange where i dont want to connect to other exchanges. so where is the exact source or marketplace to buy/sell bitcoins without accessing any other exchanges . Any help plz reply ASAP


texts: How can I pay with Bitcoin on overstock.com o.co?

texts:
I just registered at overstock.com to buy something, because I heard that they accept bitcoins as of today. But when I checked out, there was no option to pay with bitcoins. Only PayPal and credit cards.

Do I have to do something specific to activate bitcoin payment?

Can someone post a screenshot of a working Bitcoin checkout?


texts: How can I get the block number of given transaction?

texts:
For a given transaction, I have its incoming transactions and I am trying to get the number of the block of those transactions. This seems like something that cannot achieve directly.

I am working on python with Json RPC and I want to work directly on the block-chain on my computer and not to use online API such as blockchain.info.

How can I get efficiently the block number of a given transaction?


texts:
This question seems to me to be such an obvious question, that it must be answered somewhere.
As I understand it is necessary to buy bitcoins using dollars or some other currency. Where do those dollars etc. go?


texts: Please anyone explain as IQOPTION is telling me that I have to purchase a $700 private key to get access to my BTC Blockchian wallet once they wired my Finds in to this wallet?? anyone please have an answer?


texts: How is hash rate of mining hardware calculated

texts:
The mining hardware does a double sha-256 hash of the header while mining.  Is each sha-256 operation counted when determining the hash rate or is the whole sha256(sha256(header)) counted as one hash?

Just to throw out some example numbers, if the hardware can do 300 Mhash/s is the hash rate 300 Mhash/s or is it 150 Mhash/s because two sha-256 operations are required for each attempt?


texts: How to calculate bitcoins in fees spent dailly? (Avg)

texts:
From https://bitcoinfees.earn.com/ I can see a list of bitcoin satoshi fees/byte

From https://thenextweb.com/hardfork/2018/07/12/bitcoin-block-size/ I can see that we can have block sizes of up to 2mb with segwit.

If I assume that segwit adoption increases in the next year, then I will base all calculations on the block size being ~2mb.

How do I back-of-envelope calculate total fees in bitcoin spent daily?

Assuming 6 blocks / hour, & with 24 hours in a day, is it:

~satoshiFee * 2m * 6 * 24

Which, assuming an average satoshi fee of 10 (using https://bitcoinfees.info/)

Gives:

10 * 2m * 6 * 24

And in BTC that's divided by 10^8, so we'd get:

20m * 144 / 10^8 = 28.8

Is that correct?


texts: Using the bitcoind, can I query if funds have been sent to a multisig address?

texts:
I would like to query whether funds have been sent to a multi-sig address.

Using the daemon: the address is valid, but listunspent and getreceivedbyaddress don't show the multisig address. I can see a txn, which reports the target address is my multisig address.

I suppose I am asking how do the apis from blockr.io work (e.g. btc.blockr.io/api/v1/address/info/...... ) ?

TIA


texts:
I understand that P2SH addresses are used to allow "segwit unaware" wallets to create outputs spendable by segwit wallets (please correct me if I got something wrong). For new clients I think I got it: they will check that the script cointaned in the witness matches the script hash and execute it.

What I do not understand is how this  output is spendable by a segwit aware client to the eyes of an old client. Because it clearly doesn't look like an anyone can spend. How does it work?

Thanks.


texts: What are some potential scenarios that a state actor can harm bitcoin if they control more than 51% of the hashing power?

texts:
As reported recently, China controls more than 51% of the hashing power and just in one province in China controls 54%. Assuming China has bad intentions and forces all these mining operators to collude to harm the Bitcoin network. What are some of the potential scenarios to dethrone bitcoin from the #1 spot?

From my understanding a 51% attack would just cause a loss of confidence, but wouldn't kill Bitcoin as the real chain will just fork off onto its own.


texts: How many paths are tried on average before a payment succeeds in Lightning?

texts:
In Lightning, the sender can never be sure that a multi-hop payment will go through, as intermediary nodes don't announce the distribution of funds in their channels (only the total capacity). Is there any publicly available data on how many attempts it takes on average in practice to route payments of different sizes? Something like this (the numbers are my wild guess):

Amount - Average paths tried

100 sat - 1.8

1000 sat - 3.3

10000 sat - 5.9

1000000 sat - 13.2

There is a similar question Lightning network routing failure rate and a 2018 article linked from there, but it addresses the success probabilities based on capacities only (this can be calculated from a network snapshot). I'm interested on the data from real-world transactions.


texts: How does SPV prevent double spending of UTXO?

texts:
I am new to Bitcoins. I have read about how double spending is prevented in Bitcoins.

Suppose  A, a peer, receives 'B' BTCs from various transactions: B1,B2,B3, etc. Also, A had spent 'S' BTCs in various transactions S1,S2,S3, etc.  Now, whenever a new transaction is initiated from A to B (eg: A wants to transfer X bitcoins to B), the transaction has to be verified as follows.

Fullnodes have the Unspent Transactions Output (UTXO) database. A's address is scanned in this database and checked if A has any unspent bitcoins. If there are at least X unspent bitcoins against A's address, then the transaction is legitimate.

Q 1) Where does SPV and Merkel trees come into picture during the above-mentioned verification process? I have read elsewhere on the internet that SPV nodes will query for the previous transactions B1,B2,B3, .. and S1,S2,S3 & check if whether A's claim is valid or not.

Q 2) How many previous transactions do usually SPVs look into? My understanding is that SPVs have to look at all the transactions associated with A's address. What if A does not input all its previous transactions? (Eg: A hides its some of its spending transactions, say, S1)


texts: Requirements to accept and send SegWit transactions?

texts:
I roughly understand how SegWit works, but not the details, got a few practical questions.

If I understood correctly there are separate 'SegWit addresses'. How does that work, do they look like normal addresses? Will older non-SegWit clients also be able to send txs to such addresses? Or is it a new address format, that will not be recognized by older clients?

If I want people to be able to send SegWit transactions to me, do I have to give them a SegWit address, or can they also send SegWit txs to regular addresses?

Similarly, if I send a SegWit tx to someone else, will they receive it even if they are using an older non-SegWit client? Or perhaps will they not recognize or accept the tx as long as it's unconfirmed, but once it's confirmed they have the bitcoins?


texts: Is it the case that the blockchain has information on the balance associated with each public key-address, such that the client on my PC, say, will look at every public/private keys pair in wallet.dat, find all public keys in the blockchain for each of my private keys, sum up the balances for each, and show me the overall balance?


texts: What will happen if transactions are being generated by multiple person with same one private key?

texts:
Let's assume people got the same private key of 1 BTC amount(Unspent state) for somehow lucky. Let's call that wallet address is WALLET_A.

So people trying to send all the balance to their each own wallet address, like:

tx1:WALLET_A(input) -> Person_A_WALLET(output)
tx2:WALLET_A(input) -> Person_B_WALLET(output)
tx3:WALLET_A(input) -> Person_C_WALLET(output)
...

But we all knows only one transaction can be mined which is unspent state of WALLET_A for all 1 BTC balance.

How's gonna the mempool handle when people generates transactions simultaneously?
Will miners mine the first registered transaction in mempool? If any person pay a much higher fee, can it be mined instead of the old one?
What happens if people compete by repeating infinitely resending their transaction through the -zapwallettxes option in Bitcoin Core?


texts: Central banks create money supply. Who creates bitcoin supply? Is it the miners? The dollars go into someone's pocket when bitcoins are first purchased for dollars. Is it like tulip bulbs?


texts: Would it be possible for a cryptocurrency to have a price before its first block?

texts:
For example, the cryptocurrency Kin had a price in 2017 according to coinmarketcap.com, but according to its block explorer, its first block launched in 2019 (I got this by typing in "2" in the search bar. Since typing in "1" gave a timestamp in 1970, which is from the start of the Unix timestamp.).
Is the timestamp from the block explorer wrong? If that is not the case, how could such phenomena happen? (The price on coinmarketcap.com must be calculated from trading data (reference), which should be included in the blocks.)


texts: How to use the lightning network with Electrum multisig wallet?

texts:
I want to experience the lightning network transactions with my Electrum wallet. But the lightning network is not available, and it shows the following information:
"Lightning is currently restricted to HD wallets with p2wpkh addresses."
What are p2wpkh addresses? I generated my multisig wallet with all the addresses starting with "bc1". Why cannot I use the lightning network with these addresses?


texts:
Due to a copying error the last word of my 12 word mnemonic recovery phrase for blockchain is missing.

Just wondering if anyone knows of any software that could generate words and automatically test them out to see if they work?

Cheers!


texts: can cryptocurrencies be energy efficient?

texts: Is there an intrinsic reason why cryptocurrencies currently take a lot of energy to keep working? Is there a way to make a cryptocurrency still widely used but make it energy efficient?


texts: What is the current Status of major proposed BTC upgrades like Taproot, MAST, Submarine Swaps?

texts:
I have read during the last year about some very interesting BIPs or initiatives. I am not asking for their explanations, just would be great if anyone would know about their simple status as of now, whether they are still considered to be implemented at some point (do you know when?), or whether they have been removed from consideration...

1)  MAST

2)  TAPROOT

3)  SCHNORR

4)  Submarine Swaps

5)  Consumer Lightning-based applications (desktop+mobile by Jack Mallers)

6)  Drivechain Sidechain, by Paul Sztorc

7)  Lightning over NFC, by Igor Cota

I just dont know where to track those initiatives .

Thanks!!


texts: Recovery Words from ~2013 Wallet Contains 4 Invalid Words

texts:
I came across my wallet from 2013 on an old external hard drive along with info like the 12 recovery words, address, etc.
I've tried recovering/importing it to a bunch of different wallets, but all of them are marking 4 of the 12 words as invalid and I'm confused as to how they would've become invalid between then and now, and how I can recover the funds in that situation.
I'm unsure what wallet/service I used to create it at the time.
Does anyone have any idea what might have happened here or how I might be able to recover this?


texts: Is there logically any way to "live off of Bitcoin interest" without giving up control of your coins?

texts:
All my life, I've been told that rich people don't need to spend any of that wealth. Instead, they just have a bank account where they receive a percentage of the total sum on the account every year or month or whatever time period, simply for allowing the money to be there rather than at home in the mattress or as gold bars in a safe. And then they live off of that amount, meaning they never spend any of their "actual" money.
But if you own 10 BTC, that's 10 BTC... and then it's 9.999998... and then 9.999997, and so on. Its absolute number slowly decreases until 0, unless you keep buying new coins for fiat money (or otherwise obtain them) to add to your wallet.
I frankly don't understand why any bank would give you money (rather than charge money from me, as my bank does) for simply keeping your money there, but since it's apparently a thing, I thought that I should at least ask if this is logically possible with Bitcoin.
And I do not mean sending my BTC away to some website or any kind of third party. I'm talking about retaining control of them in my Bitcoin Core fullnode wallet on my encrypted PC.
Is there some way, or planned future feature of Bitcoin, to get "interest" on your coins simply by holding on to them? So that they always grow a little, not just in terms of their "value" in the real world, but as in increasing ever so slightly?
Maybe they would never do this at this point, now that Bitcoin's rules are somewhat "established", and maybe it's not logically possible without sending your coins somewhere and trusting that party (which I would never do), but I need to at least ask.


texts: Help me resolve few queries about bitcoin network ( regarding validation, mining and state of transactions...)

texts:
Q1. Suppose I make a transaction from node A to node B, it is gets validated by the nodes in the network, A new block hasn’t been mined yet, in the meantime miner is stashing up the transactions Miner doesn’t include my transaction in the newly minted block, what happens to my bitcoin in the time between the next miner decides to put my transaction in the next block?

Q2. Bitcoin has a public ledger, by public ledger do we mean that each node in the network has a chain of blocks, each block having a set of transactions…and all these node have the same chain of blocks associated with them?

Q3. Whilst my transaction is internally being validated by the nodes in the network (not yet accepted by the miners), is this transaction being added to the ledger of various nodes in the network?

Q4. Also, let say, some node in the network validated a transaction, will the same node propagate this result to its neighbours, and the neighbours to their neighbours?


texts: How to connect my mining pool to another mining pool

texts: What are some ways to connect my mining pool to another mining pool without altering any settings on the miners?


texts: How does Bitcoin verifies signature if addresses are one way hashed

texts: I'm stuck at understanding Bitcoin's transactions. So, the owner must sign the transaction with his private key, then miners can verify whether this signature matches his public key. However the public key is hashed with three functions (RIPEMD160, SHA256 and Base58) and it's impossible to get the original ECDSA public key from the address. So how does the transaction verification actually work?


texts: When a user generates an address using Bitcoin Core, is that address by default stored on the blockchain or will it only be stored after it is used in a transactions


texts: Problem with receiving bitcoins on my VPS

texts:
I installed bitcoind v.0.8 on my VPS (with Debian 6 (Squeeze)). Then I generated a wallet for it: 12VWVmNEM1q6N9zMjX9aH3wSfRUbjVkZ21.

Here is my transaction to this wallet, but when I'm looking for this wallet balance with getreceivedbyaddress or getbalance I get 0.00000000. What can cause it? How can I receive my funds?


texts: How do transaction volume and block reward relate?

texts:
As an example, assume a block has 10 transactions with a total value of 1BTC.
Does a miner get 25 BTC for validating and committing that 1BTC? What's the economics of this model?


texts:
It was super cool to discover so many alt coins have cloned the Bitcoin Wallet Android app, however I noticed that the phone started running unusally hot after installing all the coin apps, even when I hadn't opened any since device boot.

After booting my phone (it had been off for a few hours and was cool to the touch) I found that it was running hot after a few minutes.

I  opened the app manager and found that the following coins were running:

Vertcoin (Beta)

Execoin (Beta)

Einsteinium

I remember reading an article about apps that use your phone to steal hashes. http://www.dailymail.co.uk/sciencetech/article-2613612/Has-battery-life-Android-phone-got-worse-Researchers-warn-rogue-apps-secretly-bitcoin-background.html

Does anyone know if these apps (or any other wallet apps) have any malicious/devious code?


texts: Difficulty in obtaining vanity Bitcoin addresses

texts: What is the formula I can use to estimate the difficulty in generating vanity Bitcoin addresses?


texts: Bitcoin to ether lost on transaction via Bity.com

texts: Today I (tried to) use bity.com to change BTC to ETH from an Electrum to a MyEtherWallet account I was. I sent the funds using the bity.com provided specific address, but the transfer from Electrum was not complete before the transaction at bity.com was registered. bity.com cancelled the transaction, however Electrum completed it! Transaction: 9fb533c74e634e1b1756663cb0e0d5e6865268f4d7ed7250b7694b230dd927b9 and now I have transferred the funds, but not received the ETH. I have written bity.com, but no response yet. Any suggestions?


texts:
Which BIPs are already implemented by bitcoin-core and which are scheduled to be supported by the client in the scheduled releases?

I found these questions to be relevant:

Where can I find out which BIP (bitcoin improvement proposal) are going to be implemented or not?
What BIPs are supported by the standard client Bitcoin Core?

but still didn't manage to get an answer to that question.


texts: Can I download only a coinbase transaction at a specified block height?

texts:
I want to implement a client similar to SPV client.
The client will download block headers and coinbase transactions.
There is an api of downloading block headers such as getheaders.
However, it seemed that there is no api of downloading only a coinbase transaction.

Can I download only a coinbase transaction at a specified height without downloading all transactions at the same block height?


texts: How much Bitcoin is needed to start a Lightning node?

texts:
I've never used Lightning but can someone recommend how much Bitcoin I need to fund a Lightning node? I will be using the Eclair client.

Thanks


texts:
As far as I understand it, the target T is a floating point number that is adjusted based on the moving average of the difficulty of some previous transactions. Mining a block happens when somebody is able to find a block x so that H(x) < T (by varying the nonce and/or block contents by brute force). Please correct me if I'm wrong.

Now, due to the structure of a hash function, there is basicaly no way to know if for a given y, there exists a x so that H(X) = y, meaning that there are some "unreachable" hashes. These unreachable hashes are supposed to be distributed randomly (as are all hash outputs), which would mean that there can also be continuous ranges of unreachable hash outputs.

Is there anything that prevents the target from becoming so small that no valid blocks can be found that match the target requirement, because all of the hashes close enough to the target are unreachable?

I realize that the difficulty would have to rise more than we can currently imagine, but I wonder if there is any way to deterministically rule out that possibility, in addition to it being very, very, very unlikely?


texts: Lightning Network: hashlocks vs private keys exchange

texts:
I am reading the Lightning Network paper and noticed that when describing bidirectional payment channels, the authors used "Breach Remedy transactions" and the exchange of the two parties' private keys to discourage any of the parties to broadcast an old commitment transaction. This is indeed an effective solution, however I read in more than one place (e.g. here, here) that this is actually achieved through hashlocks (i.e. the two parties create hashlocked transactions from their commitment transactions and share the hashlock secret instead of exchanging their private keys to discourage the broadcasting of previous commitment transactions when they update the channel). In the paper, hashlocks are used when the bidirectional payment channels are used to relay payments among more than two nodes, however they are not used for payment channels between two nodes.

So the question is: are commitment transactions between two nodes revoked through hashlocks or through private keys exchange?


texts: How to find wallet details with bitcoin address?

texts: I have send my bitcoins thinking that it's the address of which I am currently using the wallet after the transaction was confirmed and I didn't receive the credit then I realized that I've sent my credits to a wallets I don't remember anything about. I forgot the name of the wallet  and I don't remember any others details about it.Now I only have is address.If there any way to find the details or another piece of information about my problem that u know about please let me know


texts: Why the difference in send/receive fees on localbitcoins.com?

texts:
At least in https://localbitcoins.com/, the fees for sending and receiving Bitcoins (from/to outside localbitcoins, of course) differ by a factor of three, approximately. Currently:
0.08715 mBTC for sending, 0.26144 mBTC for receiving.

Is there some rationale for this?


texts: what are BTR points in Bter exchange? Can we convert BTR into an alt-coin? If so, is there any fees they charge. How many times can I exercise this option for a particular month?


texts: Is the checksum used in BIP39 mnemonic sentences too short?

texts:
In the BIP39 specification, you add 1 bit of checksum for every 32 bits of entropy you generate.

Therefore, with a common entropy size of 128 bits, you are only adding 4 bits of checksum. This means that if you were to write down the words in the mnemonic sentence in the wrong order (or write down an incorrect word from the wordlist), there is a 1 in 16 (0b1111) chance that a tool for validating your mnemonic will tell you that you have written down a valid mnemonic.

Is this too short to make checksums for mnemonic sentences reliable?

Alternatively, you could instead add 4 bits of checksum for every 32 bits, which would mean a mnemonic from 128 bits of entropy will have a 1 in 65535 (1 in 0b1111111111111111) chance of being valid if written down incorrectly. This would require a wordlist of 4096 words (12 bits per word) to accommodate the checksum and keep the mnemonic sentence the same length, but it seems that it would be much more reliable.

Is there a reason why BIP39 chose to use such small checksums?


texts: Percentage of BTC belong to early adopters

texts:
Are there any statistics that break down the total amount of circulated BTC that is owned by “early adopters”? I know it’s theoretically possible by manually examining the blockchain for unspent transactions that occurred prior to a certain point in time, I’m just wondering if there are any good sources already out there for quick reference

(I know the term “early adopter” is subjective but anything relevant to the theme would be much appreciated.)


texts: How can Trezor update firmware but never receive malware?

texts: I understood from What is it about a Trezor that means it can't be infected by malware? that a Trezor would only interpret data as transaction details, but the Trezor also updates firmware.  How is it that an attacker can't hack the firmware update to somehow install malware?


texts: any exchange to sell naked puts on bitcoin?

texts:
I would like to sell puts on bitcoin to collect premiums if bitcoin goes up in value to usd, and to be long bitcoins at a lower price if I get exercised. This is much more predictable for me than just buying bitcoins at the top of a rally, given the volatile pricing in this market.

Does any active exchange have options on bitcoins? www.icbit.se has futures and options but doesn't seem to have any relevant products listed


texts: View backed up wallet.dat using sqlite browser

texts:
I backed up my wallet.dat using the command as mentioned in the api ref:
bitcoin-cli -rpcport=18332 -rpcuser=user -rpcpassword=password backupwallet "/bitcoin/backup.dat"
I would like to view the backed-up db file using 'DB browser for sqlite' (or any other sqlite browser). However when opening the db file it prompts for the password / key to decrypt the wallet file.
Which password / key is it referring to? When creating the backup I didnt specify any password or key..


texts: Bitcoin Core initialization taking forever

texts: Today is the third day, when I'm waiting for Bitcoin Core win-x64 application will sync/initialize. How long should I wait more?


texts: Can somebody show me a working gettxoutproof / verifytxoutproof pair?

texts:
Can somebody please show me a working gettxoutproof / verifytxoutproof pair, I am looking for the input used on bitcoin-cli or console window in Bitcoin Core to make this happen, and the outputs.

For example, TXID: D97A21CF46FD5AFB0BF9EA4237BC4BF5C84E8B47D38D1EEE2BBEB5C0F8A1C625 is included in block 0000000000000a3290f20e75860d505ce0e948a1d1d846bec7e39015d242884b

The input to gettxoutproof should include the txid and the blockhash.


texts: How to get passphrase from a private key?

texts: I have private key. How can I get passphrase for my bitcoin address.


texts: Intrinsically useful proof-of-work using Mersenne or Fermat numbers factorization. Could it be possible?

texts:
I was reading this question and got myself thinking - why can't a crypto-currency use as proof-of-work a difficult problem that has value outside of the network? I understand the effort to produce all those hashes is not completely "useless", but still it seems like too much electricity consumption just to secure a crypto-currency - a proof-of-work that could produce a valuable by-product would be much appreciated, I think.

So I was thinking, what problems could there be if proof-of-work were, say, the factorization of Mersenne or Fermat numbers? Validating a number's factorization is relatively easy, compared to looking for the factors. And a crypto-currency based on it could give an big bonus to finding a Mersenne prime, and a mega-enormous bonus should a miner find a new Fermat prime (assuming there are some more), for these are intrinsically valuable even though validating the discovery would also be incredibly heavy, computationally speaking...

Appart from the obvious problem of difficulty being uncontrollable and going always up, (might be solved by allowing less profitable blocks be mined using another proof-of-work), I thought of the case where a country gets disconnected from the rest of the Internet: In current bitcoin this means coins mined there during the disconnection are lost after the country's reconnected, and any merchant accepting those locally-mined coins will lose their money.

In a system aiming to have a useful by-product as proof of work, all discovered factorizations should get eventually accepted, even if they were mined in such isolated conditions or were initially included in a blockchain that happened not to be the longest - unless some other miner discovered them independently and included them in a longer blockchain.

But then I realized this system could mean miners could attempt using this proof in more than one blockchain - I guess this would open the door for some types of fraud.

Could it also lower difficulty for double spending attacks? What other problems could arise in a system of this type? Are they intrinsically unsolvable?

The same could be said of using protein-folding, or analyzing SETI@home packages as proof of work...


texts: Can government agencies trace if I mine bitcoin?

texts: I live in a country where the government has strict rules against using bitcoin. in fact, they are trying to find out the citizens who are related to bitcoin. I was just wondering if they can catch me if I just mine bitcoin without doing any transaction? if yes then I wanted to know if there are any alternatives which can make me untraceable.


texts: What is the timeline for Lightning Network's availability?

texts:
I have been reading a lot about this Lightning Network and what it does.
But what I still don't know is if this Lightning Network is already being used for Bitcoin or when Bitcoin will start to use it ?


texts: Hawala is an old indian/middle east , money transaction system , based on mutual trust, and uses an encryption system based on spoken keycodes.How is it similar to bitcoin transaction system?


texts: What are Fidelity bonds and how do they work in Joinmarket?

texts: I am interested to know the basic concept of Fidelity bonds in finance and how will it be used in Joinmarket.


texts: If I delete any of my digital desktop wallet and of course without any digital coins stored in them, Will my hard disk become spaced out of all those GB taken by the blockchain stored in my computer?


texts: Pseudo-Node and putative attack vectors on the network

texts:
Pseudo-Node is discussed here on Reddit's /r/Bitcoin
Essentially it functions to relay calls from connected nodes in a random fashion.

This was an experiment into how easily can full nodes be "faked".  In conclusion: very easily.
A proof-of-concept implementation (& documentation) is available here:
https://github.com/basil00/PseudoNode
To the network, PseudoNode appears to be a normal full node.  It relays invs, txs, blocks, etc. just like a full node.  In reality, PseudoNode is a type of p2p proxy server.  It merely forwards any request it cannot handle (getdata, getheaders, etc.) to neighboring nodes.  For more information see the above links.
PseudoNode uses no disk (no blockchain download required), uses little CPU/RAM, and uses less network resources (bandwidth) than a normal full node.  A PseudoNode can "sync" with the network within seconds.
PseudoNode demonstrates some of the problems with incentivized full nodes (including the "Bitnodes Incentive Program").  It is difficult to prove that a full node is really a full node.
The implementation mostly has novelty/proof-of-concept value.  It is not intended to be "production" software.

And the FAQ:

Does PseudoNode harm the network?
Short answer: No.
Long answer: Not unless the number of PseudoNodes significantly overwhelms the number of normal full nodes. Otherwise, if PseudoNode can connect to at least some good nodes (default 2), then will PseudoNode will acts just like a normal node and contributes network bandwidth.
Can PseudoNode cause the network to fork?
No, PseudoNode just follows what other nodes are doing.
Can PseudoNode steal coins?
No.
Can PseudoNodes be banned from the network?
Not easily. Requests that PseudoNode cannot handle directly can always be forwarded to other (cooperative) full nodes.

This seems incredibly reckless in terms of attack vectors to me. Obviously a balance between the pros and cons needs assessing, and since its value is "novelty" (self-described by the developer), several cons seem immediately evident:

Latency will effectively increase blockchain download times such that new latency = original latency * performance decrease %
Nefarious pseudonode could throttle latency to just above the threshold of the nodes enforcing blacklisting (ie throttled latency ~> cutoff latency)
An increased percentage of nefarious nodes could possibly execute a Sybil Attack (?)

2 related questions:

What other attack vectors (in high-level terms) and their
repercussions could be expected from Pseudo-Nodes?
Is there any feasible contingencies in the protocol to delineate between a PN and a node? For example, would different Bitcoincore versions identify PNs (or a simple modification to the protocol)?


texts:
I'm trying to download the block chain and synchronize with the network (using Bitcoin-qt 0.8.6). I have a 2 year old wallet.dat file with a fractions worth of unconfirmed bitcoins.

After over a day downloading the blocks folder has stopped increasing in size and is at 13.4GB.

In the debug.log file the following messages are repeatedly shown.

stored orphan tx 8d724a...ad48cfb140 (mapsz 10001)
mapOrphan overflow, removed 1 tx

It will then add another orphan transaction and then remove another one from the pool. The pool stays at 1001.

Should this be happening?

The message in the client says it has processed 0 of 280295 (estimated) blocks of history and that I am 162 weeks behind.


texts: Is it possible to definitely lose bitcoins?

texts:
The maximum number of Bitcoin is 21 000 000.
However this number of Bitcoin may never exist.

Supposing someone have 5 BTC in their wallet. In order to protect them, they encrypted it and then forgot the passphrase, or die (sorry, this example is sad).
In this case, the real maximum number of usable Bitcoin would be 20 999 995...

Is that understanding correct? What do you think about this?


texts: Is it impossible to GPU mine without OpenCL?

texts:
I have an Nvidia 7300 GX and want to start mining with it. This card doesn't support OpenCL. Can I still use it for mining? With BitMinter I can only use CPU mining; it doesn't see the Nvidia card.

I am using Linux Ubuntu 11.10 (Oneiric Ocelot) with all extras...


texts: bitcoin-cli createwallet electrumpersonal server true

texts:
I'm a noob following instructions to setup Electrum Personal Server on Linux.

I came to this instruction and I'm stuck.

Got an warning. What is this?

{
  "name": "electrumpersonalserver",
  "warning": ""
}

Thanks


texts: How to receive transaction in bitcoinj wallet

texts:
I am a real noob with bitcoin and bitcoin. I have a lot of questions and I don't know where to start. Let me try.

I have a bitcoin-qt client and I downloaded the chain (took me one day) and now I am playing with bitcoinj.

Can I use the block chain downloaded with bitcoin-qt with bitcoinj ? If yes how ?

I created a wallet with bitcoinj client and I get the adress inside it and send money from my bitcoin-qt client to this address.

Do I need to download the block chain to receive this btc ?

There is this code:

// We want to know when the balance changes.
wallet.addEventListener(new AbstractWalletEventListener() {
    public void onCoinsReceived(Wallet w, Transaction tx, BigInteger prevBalance, BigInteger newBalance) {
        // Running on a peer thread.
    }
}

Do this code need the block chain ?

Thanks for your answers and the help.


texts: Blockchain, smart-contracts and migration

texts:
I'm investigating what blockchain technology to use for basically intercompany asset management assets like laptops, shares, intellectual property and other, more complex contracts where party X agrees with Y on Z.

Now, ethereum looks very suitable but I have a few things that I can't seem to find a clear answer to.

What if I create a new private blockchain with a genesis file, am I stuck forever with this chain and all its contracts? (i.e. is migrating existing data to another blockchain even possible in any way?)
Is the usecase of where X agrees on Y doable? Since contracts cannot read eachothers data. How would you translate existing legal documents to a functional or automated entity? I think that third party, centralized servers would be needed in almost any case where the complexity is slightly more that transfer X value to Y. Because otherwise contracts are meaningless, other than being registered.

example #1:

When time X expires, then invalidate contract Y.

At the very least I would need to externally trigger a new transaction in the blockchain, whenever that time is past?

And in what degree would it be possible to digitalize human-readable contract, albeit simplified versions of it, would one human-contract equate to one solidity contract (or LLL or serpent), or would these have to be cut up, and how would they then communicate with eachother?


texts: How to find ripple faucet coin for development

texts: I'm developing an app with ripple. I need some faucet coin for ripple. How can I find it?


texts: How does Electrum make a keypair out of a seed?

texts:
Electrum uses a seed of 12 words to generate a keypair and then hierarchically generates addresses out of that keypair.

I know how to generate hierarchic addresses from a keypair, but what I don't understand is how Electrum generates a keypair from the seed. I understand the seed consists of words coming from a 2048 length wordlist, but after that it is unclear to me how it starts to generate the sequence of addresses.

I'd like to do the HD generation in either Java / C++ / Python or C#.
If I can understand the process, I might be able to reproduce it myself and generate hierarchical addresses from a seed.

EDIT:

A day later I find this Java implementation... Thanks for the answers!

https://github.com/harningt/atomun-mnemonic


texts: Consolidating BTC across multiple address but same account

texts:
Say a user generates three "linked" addresses (e.g. m/44'/0'/0'/0/0, m/44'/0'/0'/0/1, m/44'/0'/0'/0/2) using an HDWallet and receives 1 BTC to each unique address.  For each of the addresses we have the private/public key.  Now the user needs to pay another user 2.5 BTC to address D.
I'm googling around for how to do this but I can't seem to find any example code.  Is there a way to do it using bitcore-lib or bitcoinjs?


texts: What is the difference between PPS+ and PPS?

texts:
Some pools do offer such a payment method as PPS+. This method is claimed as better than the PPS method, it should insure against losses on orphans and blocks with bad luck. But this explanation is too fuzzy and obscure for me so I do not understand how to calculate exact payments.
Is it true that the PPS+ is not only insure against the losses on the bad-luck blocks but also prevent to earn a surplus on the block with high luck? And I need a formula to calculate rewards on per-block basis.


texts:
I am using bitcoin daemon in my system to get and pass btc to users. So now I want to pass some btc to another users but I can not understand what is the difference between sendfrom and sendtoaddress. I have read about sendtoaddress command in
http://chainquery.com/bitcoin-api/sendtoaddress but could not understand where this btc is going from


texts: How does a Bitcoin client know its transaction has been accepted by the whole network?

texts:
Say Belly, Alice and Teddy are Bitcoin clients.

Belly makes a transaction to send 1 btc to Alice.
He broadcasts this transaction to the P2P network.
Teddy calculates a valid hashcode and add Belly's transaction into his block chain.

Then here is the question. How does Belly know his transaction has been accepted? Even he knows Teddy has added it into his block chain, this block chain can be rejected later if there is a longer block chain on the network, right? And what if Teddy is malicious and lying?

I heard you need to wait until 6 clients accept your transaction. I'm not sure what this exactly means. And why 6, not 5 or 7?


texts:
I am looking for on-line or off-line run Bitcoin Blockchain Parser to get all block headers only

All I need is

########## Block Header ##########
Version:         1
Previous Hash    00000000000000000000000000000000
Merkle Root    4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b
Time             1231006505
Difficulty       1d00ffff
Nonce            2083236893

No transactions data.


texts:
In the last few hours I am getting 100% connection rejections from Eligius. I am using a Mac and the Asteroid miner GUI. I also have MacMiner setup. both are not failing after about a month of successfully working.  But that is not the point of the question.

My question is trying to understand the pool URL, here is what Eligius provides:
Stratum Host: stratum.mining.eligius.st Port: 3334 | Getwork Host: getwork.mining.eligius.st Port: 8337 GBT Host: gbt.mining.eligius.st Port: 9337

I have been using "http://gbt.mining.eligius.st:9337"

Question 1: Why is the scheme missing, that is "http://", etc. It needs to be entered as part of the pool URL, what if any scheme should be entered?

Also is there some reason the scheme is not provided? Or it just a lazy web developer?

Question 2:
Please direct me to some information about the host types: Stratum, Getwork and GBT.


texts: What new transactions are possible with 15 operations?

texts:
Today Gavin tweeted that he's relaxing the IsStandard rules for pay-to-script-hash transactions to allow any transaction with 15 or less operations. (Full git commit here)

When this is merged and widely used, what new types of transactions become possible?


texts: What is the biggest bitcoin transaction ever performed so far?

texts: What is the biggest bitcoin transaction ever performed so far (by value at the time of transaction)? And what was its transaction fee?


texts: What attacks are possible with a malicious bootstrap.dat?

texts:
The standard Bitcoin client normally needs to download the entire blockchain from the p2p network when first installed, but a shortcut is to provide it with a snapshot of the blockchain (at some point in time) in a file called bootstrap.dat.  One can get this file from various sites and file sharing mechanisms such as BitTorrent.

My understanding is that the blocks taken from bootstrap.dat are not subjected to all the same checks as those downloaded from the p2p network (see this question).  Therefore, an attacker might be able to get you to accept some invalid blocks by giving you a malicious bootstrap.dat.  What, if anything, could they accomplish in this way?

For instance, if signatures are not verified for transactions coming from bootstrap.dat, the attacker might include a bogus transaction appearing to send a bunch of coins to one of their addresses.  They could then convince you that they hold more coins than they actually do.  But it's not clear how useful that would be; if they actually try to send you those nonexistent coins in payment for something, your client might believe the transaction is valid, but miners won't be fooled and the transaction will never confirm.

Are there other attacks I have not thought of?


texts: Help please recovering a wallet from a 17 word mnemonic phrase and other info

texts:
4 years ago I bought bitcoin and I have
a 17 word mnemonic phrase
an identifier
a bitcoin address
and what I believe is a password

Does anyone know how I can access this bitcoin?


texts: Can we design the protocol, so that an address can only be used once as an output in a transaction?

texts:
Most users reuse their addresses for deposits (ie. they receive money more than once on a given address).
Can the protocol be designed in such a way that an address can be used only once as an output in a transaction?
I guess there would need to be a way of quickly looking up if an address was already "used-up".
Also there would need to be a way to somehow to get "next address". For eg if an address is used for dividends and it can be used only once, the dividend payer should be able to automatically get a new address without the owner's (payee's) repeated input. (a one time set up of this, would be ok)
The point of this is to enhance privacy.

These are just thoughts, comments welcome.


texts: When are private Keys created on Wallets?

texts:
I have just started mining and in another question of mine it came up, that there can be multiple private keys in a wallet because of defining a backup strategy.

I would like to understand when private keys are created in the wallet?
If it is specific of the coin / wallet, I am refering to dogecoin wallet application with currently 1 address created in it.


texts: Possible to build a coin that will never change it's code?

texts: I want to know if it's possible to create a coin that will never go through any kind of forks. Where there would be some kind of consequence for the majority of miners trying to change what it is. Is the only way to do this to make it not open source, or is there a simpler way?


texts: Do I need to register my shiny new Crypto with some agency if I want to pay someone with it?

texts: While I am guessing that, as most anyone can create a crypto and sell it or accept it as a form of payment, that it would be legal to give crypto as a form of payment (as bitcoin originally did with the Pizzas). However with SEC (or possibly some other government body) wanting to regulate and/or tax cryptos I wonder, am I allowed to give crypto as a form of payment without some sort of registering it with a government agency? I have not found any laws prohibiting it and can only find info about registering ICOs with SEC (in the US). Any thoughts?


texts:
I've just started reading about bitcoin, and I had this question, what if :

I created two bitcoin addresses.
added for example 1 btc to one of them.
then I start sending that 1 btc back and forth between the two
addresses till I complete one block but somehow I don't broadcast
those transactions.
I calculate the magic number.
broadcast the block and I claim the mining fee without any
competition.

I know there is something preventing this from being possible I just don't know what it is ?
thank you for time.