texts: Opening a short position on Kraken requires BTC to begin with?

texts:
Suppose I have US Dollars on Kraken and no BTC. And suppose I expect the Bitcoin price to drop a bit (which I don't, but suppose) so I would want to speculate and take a short position.

Is this possible at all, or do I first need to have BTC in my account, in order to 'short sell' them?

It feels kind of counter-intuitive to first buy BTC to then immediately sell (short) them.

Suppose I don't want a higher leverage, i.e. I just want to short "1x" so to speak. So the price going down by 7% would mean 7% profit (minus trading fees). Am I right in thinking I should then first buy BTC, and then sell that with 2x leverage?

And similarly if I'd want to short with 3x leverage. But have no BTC yet. Should I then first buy BTC (through a normal order, not margin) and then margin sell it with 4x leverage?


texts: Could a futures market be included in the Bitcoin protocol?

texts:
One of the most common reasons I hear that Bitcoin is "not ready for prime time" is that because of its wildly oscillating valuation businesses can't accept bitcoins without becoming speculators.  In my own experience trying to use bitcoins for business, I have found this to be quite true--at the very least, it is a significant problem.

The most common solution I hear offered for this problem is that the emergence of a stable, high-volume futures market may allow for businesses to transact in bitcoins while ignoring market volatility.

If this is the case, it leads me to wonder--is there any way to incorporate some sort of futures market directly into the Bitcoin protocol?  That way bitcoins themselves, like gold, could oscillate up and down according to market demand, but through some sort of digital derivative on them, people could trade much more stable values.  Are there theoretical and practical barriers to this?  What are they?


texts: How do I monitor the performance of my P2Pool instance?

texts:
Specifically, how can I tell whether I'm finding any shares? It's not clear from the extensive log output. The relevant line seems to be...:

Pool stales: 12% Own: 50±48% Own efficiency: 57±54%

... after about an hour of mining. I'm using poclbm as the miner.

(My hashrate is a mere 30MH/s; I'm just trialling the software until I get a payout - of any size).


texts: What would happen to the world if Bitcoin were the only allowed currency?

texts:
Could a world economy be based solely on Bitcoin? I mean the only mean to pay would be bitcoin.

From the point of view of economy would this be possible or would all the economy collapse?

Could we live only on Bitcoin, to make payments to work and so on, while this currency is so volatile?


texts: On a bitcoin exchange one buys, sells, and stores bitcoins.  Having sold them, one might want to withdraw dollars, euros, pounds sterling, etc.  It is suggested that the fact that MtGox is running two months behind schedule on withdrawals in other currencies may be the result of the confiscation of $5 million from MtGox's bank accounts, so they have a cash-flow problem.  If that makes the use of MtGox as opposed to other exchanges disadvantageous, what are the pros and cons of the various others?


texts: How much computing power is required to bruteforce a Litecoin private key in reasonable time?

texts:
Say I want to break a Litecoin private key having the public key using brute force. How much computing power is required for that? Does any hardware exist which can find a matching private key in, say, a year? Is it possible that it ever becomes cheap enough to bruteforce Litecoin addresses, i.e. it costs less money than one can steal from the address once the key is found?

I'm asking about Litecoin just for the sake of being more definite. I think mostly the idea is the same for other blockchain systems.


texts: Need to configure Bitcoin RPC bitcoin.conf for production ecosystem

texts:
hello I'm building a little exchange website and need a simple solution to integrate via api, I'm looking for something that allows bitcoin payments to be sent to bitcoin addresses for users who will choose to buy bitcoin on my website. and a solution that can provide a bitcoin address to every user who chooses to sell bitcoin on my website. after much research i found bitcoin json rpc, and many tutorials on how to install and use it. now i need some help to configure my bitcoin rpc node so that it can meet my production needs. Do you advise me to run a full node or pruned node for this project and what is the best way to send transactions for this kind of project while considering the fees for each sending of payment (createrawtransaction or sendtoaddress?)
below my bitcoin configuration
rpcuser = bitcoin
rpcpassword = password
rpcallowip = 0.0.0.0 / 0
rpcport = 8332
main.rpcbind = 0.0.0.0
daemon = 1
prune = 0
minrelaytxfee = 2500
maxconnections = 20
maxuploadtarget = 250
mintxfee = 0.0001
txindex = 1
txconfirmtarget = 6
keypool = 10000


texts: Why does Bitcoin use the input/output system?

texts: Why don't we just use balances? The nodes would verify that balance > 0 before validating the transaction.


texts:
So Im having a bit of a problem with my bitcoin wallet. See, I got into bitcoin about 2 years ago, back when bitcoins were worth very little real money, if any at all, but I managed to get quite a few. I recently found out they were getting bigger, so I tried to open bitcoin with my wallet, but it crashed, so I moved it from my mac to my PC. It said it was something like 200 weeks behind, so I waited, and now when its finally done, it says I have no bitcoins, but Im sure this wallet had some. Any ideas of how to get them back?

I tried getting my wallet onto blockchain, but I always get the error-
Unexpected end of file from server

Also, in my bitcoin qt, I dont actually have any addresses


texts: Why do two miners get different hashes for the same list of transactions?

texts:
According to the Bitcoin Wiki:

  it is extremely unlikely for two people to have the same Merkle root
  because the first transaction in your block is a generation "sent" to
  one of your unique Bitcoin addresses.

What does this mean? Isn't the Merkle root the hash of all the transactions in the list? Why would we have a different set of transactions if the point is to validate the same set of transactions?

I think I'm not sure what 'generation' means here.


texts: What do these memory configurations in debug.log of BitCoin Core represent?

texts:
In the debug.log file of BitCoin Core, the cache configuration is described as follows.
Cache configuration:
  Using 2.0 MiB for block index database
  Using 8.0 MiB for chain state database
  Using 441.0 MiB for in-memory UTXO set (plus up to 286.1 MiB of unused mempool space)

What is the 8MB cache space allocated for chainstate database here used for? What is the difference and connection between it and the in-memory UTXO set?


texts: Incorporating Bitcoin into a app for person to person payments

texts: Is it possible to incorporate Bitcoin into a app my company is developing in order to process person to person payments?


texts: What alternatives are there to hardcoding checkpoints into the Bitcoin client?

texts:
Checkpoints seem like a crucial part of the security & validation apparatus in Bitcoin. Is there a written policy in place, among the developers defining the maximum interval between checkpoints?

What happens when the Bitcoin client becomes mature and releases are fewer and farther between. Has some other mechanism for checkpoint-like functionality been proposed?


texts: Difference between Byzantine Fault Tolerant Protocols and Byzantine Agreement protocol (i.e., BA*)?

texts:
What is the difference between Byzantine Fault Tolerant Protocols and Byzantine Agreement protocol (i.e., BA*)?

Is it just a naming convention or both concept differs fundamentally?

Nathan Aw


texts: How will the 2mb hard fork be implemented?

texts: With regards to SegWit2x/BIP 91. If SegWit is successfully implemented around Aug 1 what is required from the miners in November to implement the 2mb hard fork successfully? Is it also a minimum 80% signalling via blocks on predetermined dates?


texts: What is the best way to prevent replay attacks in the event of a bitcoin hard fork?

texts:
I originally thought it would be relatively simple to add replay attack protection (change something about how the tx hash is generated) in the event of a fork. But the BU folks mentioned that this would break SPV clients (including many mobile wallets). So it is not free to do that way, although still an option.

One solution we brainstormed, was using some coins that were only valid on one chain (for example newly mined coins) and adding 1 satoshi of "taint" to all generated transactions. This would work but is not perfect. For instance, newly mined coins can't be spent for 100 blocks, so at a minimum it would cause economic nodes to have a delay in the event of a hard fork. It is also non-trivial for all wallet software to implement this (fair amount of work, especially at scale). There is also an operational challenge that you would have to rush to get these newly mined coins while the hard fork was happening, so you could not prepare in advance. It would be a messy for sure.

Another option would be to try and double spend some coins across the forked chains (get a transaction with some coins going to two different addresses mined across the two chains). These coins could then also be used for "taint", but you wouldn't have to wait the full 100 blocks. This is a little bit better, but still not perfect.

I suspect there is a better solution though. What are people's thoughts?


texts: Coinbase denies transaction: Please complete verifications to send money

texts:
I use coinbase to transfer BTC for few monthes.

Everything used to be ok up to today.

I suddenly got message "Please complete verifications to send money".
I did not ever get this message before. Googling gives nothing.
My phone number is verified and nothing in the settings page explains what exactly is the problem.

Please, share your thoughts - what could this be and what should I do?

P.S.

Of course I wrote to support, but no response yet...


texts: Value of cryptocurrencies: Why does noone make Bitcoin2, 3, 4,...?

texts:
Cryptocurrency disciplee sometimes say that cryptocurrencies have just as much inherent value and potential as storage of value as fist currencies. One argument specific to the Bitcoin is that its value is guaramteed by the limited number of Bitcoins. However, I am very skeptical about this and similar arguments because of the following reasoning:

Why does noone use the exact same technology of the Bitcoin and create Bitcoin 2?  If they did, why would a Bitcoin2 be worth less than a Bitcoin? If it isn't, how can there be any worth in a Bitcoin, if there is the possibility that in five years there are a thousand different Bitcoin like system all guaranteeing the same anonymity, reliability, decentralized storage, and ease of use as the original Bitcoin? To me this is a significant difference to classical currencies which are linked to real governments and guaranteed by the fact that these governments work, pay and are paid with their respective currencies.


texts: Do all UTXO get moved to the newest change address?

texts:
There is one thing I do not understand about unspent outputs and change addresses. For example, let's say a person has 5BTC in a wallet, and they have 2 unspent outputs of 3BTC and 2BTC.

They one day need to pay 2.5BTC for something. I know about the coin selection algorithm but lets just say the Bitcoin wallet select 2.5BTC out of the 3btc unspent output. This would leave 0.5BTC to send to the change address.

Now here is my question. Let's say they make the change address to a new wallet. Will the new wallet have 0.5BTC and the old wallet have 2BTC or will the new wallet have 2.5BTC and the old wallet 0BTC

Basically the 2BTC unspent output that was never touched, does it go with the change address or does it stay in the old wallet?


texts: Is it possible to short on Bitfinex using a SELL-STOP, then BUY-STOP and BUY-LIMIT at the same time?

texts:
I would like to know if it's possible to do this short order without having to manually add the stop loss after it's opened.

Say the price is currently $300, and if it hits $280 I know it will probably drop, so I want to margin sell-stop at $280 to sell at this level.

I want to buy them back at $250, so I put in a margin buy-limit at $250 to buy them back at that level.

That all works okay and I can add those orders at the same time. But is it possible to add a stop loss to my short order, to sell if the price goes back up to $290? This would be a margin buy-stop order at $290 I believe, but if I add that to my orders list, it would be executed immediately as the price is $300 and that would ruin the trade.

Is it possible to do this, essentially saying "only execute this order if this other order has been executed"? Or is this the kind of stuff that trading bots do?

Thanks


texts: How do I specify many utxo in a bitcoin cash transaction?

texts:
I want to create a Tx with bitcoincashjs:
create-a-transaction
But how do I specify multi inputs: from(utxo) and multi outputs: to ?


texts:
Please explain about the message hash used in P2PKH transaction ?
can we sign a transaction without message hash by only using the r and s values ?
and how does the verification work ?


texts:
The size of the Bitcoin blockchain is reaching 350 MB and adding more than 60GB per year. I feel verification node centralization a risk if the cost of storage does not drop.
My question 1:
Is using pruned nodes as good as full nodes?

I think a pruned node will have the same UTXOs as a full node (with a full blockchain) and it should be able to verify all incoming transactions and blocks.
It will not be able to provide blocks to a requesting node if it does not have them in its blockchain. But as long as newer nodes have the hash of the previous block this should not be a problem.

My question 2:
If there are a significant number of pruned nodes on the network will it impact network security?
Is there something I am missing?


texts: Is there a self contained C/C++ code snippet out there to validate a Bitcoin public address?

texts: I tried looking through the Satoshi Client to grab the necessary code. It ended up being too difficult for me as my expertise is not in C or C variants. And the fact that the code use boost made it that much more difficult. Is their a code snippet out there that does not rely on any external libraries except for maybe the SHA256 hash function?


texts: Even with dbcache=7000 and 16 core processor. Why does -reindex-chainstate take more than 24+ hours?

texts: My computer got shut off due to a power outage and when I rebooted my bitcoin core it was stuck on connecting to peers. I was told to do a -reindex-chainstate with dbcache set as high as possible. Even with these high settings of dbcache=7000 and 16 core cpu, why does reindexing take more than 24+ hours? Also I'm not using a SSD, but a regular HDD.


texts: Can I view .bit domains without having internet through my ISP provider?

texts:
I think the title says it all. But I will say this, I know I can view websites hosted on my server without having internet. I just have to be viewing the site on my network.

I wanted to know that since namecoin and .bit domain names are decentralized if their is a way of connecting and viewing .bit domain names without dealing with an ISP provider?

If so can someone refer me to some good tutorials and or how to's do something like this?


texts: Funds still showing in old Armory wallet/address after being sent+confirmed to new Electrum one?

texts:
I'm having a bit of an issue that I'm sure someone more knowledgeable will be able to clarify.   I've had an old wallet using the full node client "Armory" for a few years, with 0.2 BTC within that I'd like to send to my new Electrum wallet.

After trying to send without a fee a few times and having it rejected by the network  (Armory has a pop-up window with a link to the transaction, saying something like "if it doesn't show up on this blockchain.info transaction link in a minute, nobody picked it up so try again and this time send a fee"), I decided to have it send with a fee of 0.0001 BTC.  Armory still told me that by its calculation this wasn't enough (it suggested something like .00015555 or different amounts close to that range), but this time once I waited a moment I saw the transaction post to the blockchain.info link!    My Electrum wallet also registered the arrival of the 0.1999 BTC and started to add confirmations - as of this writing it has 68 confirmations  and the new Electrum wallet  shows that amount as a balance.   On the surface all would be well except...

My Armory wallet doesn't seem to show the money has left the wallet, still suggesting a spendable balance of 0.2 BTC!  It doesn't show in the transaction log either.  I figured this may be because it just hasn't "seen" the block as of yet, so I decided to  restart Armory even though it was currently connected to the network.  Having restarted and waited for it to go through its whole process, it still doesn't seem to notice the money is gone. I thought that Armory, because it is a full node client (and takes all that huge HDD space) would "have" to know that it happened.   The pop-up I got when I sent the funds telling me to wait and see on Blockchain if the transaction was accepted or not mentioned that Armory would "learn" about it from the network if it was..so I'm surprised it hasn't thus far.

The most likely issue I can think of is that Armory hasn't caught up yet.  According to Armory, it is "Connected" and received its last block 1.5 hours ago and has 348324 blocks currently.  However, I noticed that according to blockchain.info linked from my Electrum wallet's transaction, it takes place on block 393144 (the transaction was made probably close to 15+ hours ago) so assuming blocks are added sequentially, it would seem Armory doesn't see it yet, right?  Why would this be? After all the time it takes for Armory to connect to the network, catch up, deal with its data bases etc.. I would expect it to be up to date, not approximately 5000 blocks behind if Armory shows it is "connected"?

Is it likely the hypothesis that the transaction just hasn't been understood yet by Armory is accurate?  If so, why it so far from current?   Any other ideas  or possible issues?  Thansks


texts:
I'm new with bitcoin, and I would like create a application that have wallets and transactions, but I dont know how start, I was reading the api blockchain.info and is interested use the module that they facilitate you. But this modules is with nodejs, and I want make my application with php (laravel).
My question is, Can i use blockchain api with php?, Is mandatory install the module of blockchain?.
I have bitcoin-core installed, but nevertheless I have not used any of the 3 commands such as bitcoind, bitcoin-cli and bitcoint-qt, I would also like to know what it is for?,
if this is combined with blockchain-wallet-service?, or How I can star using bitcoin-core to start with php?.


texts: How many blocks are there in blockchain as of today?

texts: I have currently downloaded 300,000 blocks and the last one is generated 1 year and 19 weeks ago. I wonder how many blocks are more to go, before I am up to date.


texts: Can multiple different addresses in a wallet be linked easily?

texts:
Is it easy to link multiple transactions each with a different receive address to the same wallet?
What if after going to this wallet the Bitcoin was converted to Monero?


texts:
I have accidentally sent BCC from bittrex to my own BTC wallet on coinbase.
Both wallets are mine - how can I get (find out) my private keys to swap them that I get my money from wrong chain? And how can I use these private keys?
Transaction is seen here:

https://bitinfocharts.com/bitcoin%20cash/tx/64c577f636882bf8b0160aaed17da458f4f6c350463426eda11b63b003059ce0


texts: I'm looking into trading on btc-e but can't find too much info on the trading fees. All I see is a general 2%. Is there a fee for trading btc in or out? What else is there? What's the 2% calculated off of?


texts: Check if received bitcoin are in blockchain/not pending without a transaction id

texts:
I want to use the Bitstamp exchanger API to buy Bitcoin automatically. But then I see the API does not give me back a transaction-ID (txn id) if I do a withdrawal of Bitcoin to my wallet.

If the exchanger gives me no transaction-ID when I start a withdrawal, how can I check that everything is fine? Normally, I think, you wait for x confirmations of the transaction, but the exchanger won't provide it.

Is it enough to check the receipt of the Bitcoin amount in a unique account or will I be assailable for transaction malleability, double spending or similar? Is there a reason why the exchanger doesn't give back a txn-id? Because I saw other exchangers which do the same.

I am grateful for any advice.


texts: How to move paper wallet funds to another wallet

texts:
I have an old paper wallet and private key.
I want to transfer bitcoin from this wallet to another wallet? How can I accomplish this?
I tried this on coinbase for example by going to:

I click “Receive”
A QR pops up with my coinbase wallet address

The problem is there is no place to input or transact where I want to receive bitcoin from.
What is the easiest way to transfer BTC from wallet to another? (I’m also a developer so API, code, etc work for me as well).


texts: Was scammed recently of €5600 .Was approached online and encouraged to buy bitcoin through coinbase. I had no experience of it before. Was told to send my bitcoin to a company address which I now know was a scam. How can I trace my money. Have proof of all transactions


texts:
I am new to bitcoin technology, I want to build Bitcoin payment button with 2 bitcoin addresses, first is my site address where I will receive a small commission fee, second is my site seller address. When a customer pay, bitcoins will be send to both addresses, is that possible?
Thanks


texts: Correct Approach for Payments on Multiple Addresses

texts:
I have clients that would like to pay for services in BTC.
TL;DR
To generate a new payment address must I generate a new private key (essentially a new wallet)?
Is it better to generate independent private keys for each payment from each client, or to use a determinstic wallet?
Is it possible to automatically move the BTC to a central wallet address without storing the private key for either solution?
How To Generate Multiple Addresses?
Based on this bitcoin.it article:

Addresses are not intended to be used more than once, and doing so has
numerous problems associated [with it].

Therefore, the logic I have follows that each payment received from each client should be to it's own address.
However, I am confused about the generation of multiple addresses, and the best way in which to do it.
Other questions on here, such as this one and this one, indicate that each private key will result in a single address only.  Am I therefore right to conclude that each address for each payment from each client must have it's own private key?
If that is the case (as in my limited understanding it would seem to be), and I am generating the wallet addresses using software, is it better to:

Use a deterministic wallet that generates each payment address for each client from a single 'master key', or
Generate an indepedent private key for each payment address for each client?

Moving BTC To Central Wallet
I need to move the BTC from the received wallet into my wallet in order to spend it.
In either of the scenarios I mentioned, would the 'master key(s)' be securely stored on the server for programmatic use in order to facilitate moving the received funds into my wallet?
If that is the case, would it be more secure to have independent private keys for each instance of a payment from a client?


texts: How can I restore my dogecoin wallet (android client)

texts:
How can I restore my dogecoin wallet backup? It was created by the dogecoin android client and lives in my Google Drive account.

This question already exists, but no answer is given for Android (and dogecoin might be different, I guess).


texts:
Pybitcointools uses the following code for calculating a master private key (BIP32) from a seed:

def bip32_master_key(seed, vbytes=MAINNET_PRIVATE):
    I = hmac.new(from_string_to_bytes("Bitcoin seed"), seed, hashlib.sha512).digest()
    return bip32_serialize((vbytes, 0, b'\x00'*4, 0, I[32:], I[:32]+b'\x01'))

Why - specifically - is the byte string Bitcoin seed used in the HMAC algorithm? When one considers that the byte strings Mnemonic and Electrum are used in HMAC derivations (in BIP39/quasi BIP39, respectively), the labels seem overly non-specific. I'm wondering why the byte string doesn't clarify or specify a version, eg BIP32 V0.1 seed.

None of this is criticism, to be clear! I'm trying to elucidate how these decisions were chosen and implemented, which is often very difficult without being intimately knowledgeable in RFCs, Github etc.

Perhaps this could be explained in context of how HMAC works also?


texts: I was reading about how Bitcoin works from Satoshi's original paper. I had a query while going through the 7th paragraph. What is the difference between Root Hash and Block Hash? Isn't the block hash same as the hash of the root of its Merkle Tree? I have studied Merkle tree and understand how it works.


texts: How do I prune/clean wallet.dat for old unused addresses

texts: Are there any easy way to prune wallet.dat? Like, deleting keys for addresses with no current balance and generated more than a month ago?


texts: Have Blockchain.info (intentionally) removed the option to directly exchange BCH into BTC/ETH?

texts:
An article on the Blockchain Support Center documents Exchanging bitcoin cash (BCH) for bitcoin (BTC) or ethereum (ETH), with the following screenshot:

Since Monday, I've been unable to see the Exchange Bitcoin Cash option in my own wallet:

On Tuesday I reached out to @AskBlockchain on Twitter, but so far I've had no response.

Has Blockchain.info has removed this option completely or is this simply a bug?


texts:
I've bought bitcoin through bitcoin ATM machine several times, and this time was different that the transaction has unconfirmed for over 30 hours, usually transactions through the bitcoin ATM machine was just few minutes.

Can you guys please me and have a look at the transaction ID?Thanks!

https://blockchain.info/tx/41d3d5b80a912a566c5f842dc4e945f40c8b99291f1bf9e777616673dc7186a8


texts:
I need to specify address to send from.
I want to use option createnewaddress. And then send money from this addresse useing payto and from_addr option.
When I do like that, i got error message not enough funds.
When i do payto without argument, it use first unused address (that i create before with createnewaddress).
How can i send payment from specified address ? Or transfer amount on specified address.


texts: If I have 51% of the capacity of the entire network, can I mine absolutely all the blocks faster than the network?

texts: I'm really wondering can I mine absolutely all the blocks in the network faster than rest miners with their 49% hashing power not for the purpose of conducting double-spend attack?


texts: Warning about possible double spend at blockchain.info

texts:
What does this blockchain.info alert mean?

  Warning! this bitcoin address contains transactions which may be double spends. You should be extremely careful when trusting any transactions to or from this address.

I got my first payout today from Slush pool, and one of the the inputs of the transaction showed this message. Is that something I should worry about? As of this writing, the transaction has already 54 confirmations.


texts: How do you accept bitcoin donations on a steam group?

texts:
I am running a game giveaway group on Steam.
What is the best way to accept donations?

P.S I am completely and utterly new to Bitcoin.


texts:
At present, I have dumped my wallet and have all private key, address information. I am now wanting to understand the decryption process for the private keys within the wallet. I have completed the following so far as stated in the comments - bitcoin source code (crytper.h/.cpp)

Wallet Private Keys are then encrypted using AES-256-CBC

* with the double-sha256 of the public key as the IV, and the
 * master key's key as the encryption key

So, my data looks this way:
    E Private Key (96)
    IV Public Key (8)
    U Master Key  (16)
I am using https://www.devglan.com/online-tools/aes-encryption-decryption for the decryption. When I use this site, my answer is not the private key which I know but rather data that is 32 bits longer than the encrypted key. Has anyone tried to figure the path for the keys? If so, what am I doing wrong? Thanks for all your help.


texts: how to move my Bitcoin core wallet to electrum while syncing

texts:
How do I move my btc qt wallet to electrum while syncing?

Not address by address.

Removed some addresses already but I'm still missing some coins.

Don't understand the discrepancy.

Any help would be appreciated.


texts: i'm interested making a website allowing users to send and withdraw btc from it (every user will have private address on the site) , is there any suggestions of api i could use that will store the bitcoins on the server and not some third part service that stores the btc?


texts: Security trade-offs between centralized wallet system and a SPV wallet?

texts:
there are many wallets on the market. And I would appreciate if someone can clarify the key technical security advantages or disadvantages when using a SPV wallet vs a centralized wallet.

I am taking these two terms from the bitcoin.org page, and to give you an example by what they mean: SPV wallet would be eg the Electrum wallet. And a centralized wallet is eg the current "Ledger Live" App. SPV wallets validate transactions by connecting to multiple different  nodes/servers, while centralized wallet apps only use their own servers for transmitting transactions.

Thank you!


texts:
So I have ubuntu 16x running bitcoin core. Its a full node and fully synched. Run with bitcoind --daemon as suggested. Using a particular address from my wallet, whenever I send money to the address getblanace works fine (bitcoin-cli getbalance XXXX 1). Whenever I send money from the address, (on a completely different system using a web based wallet), it shows that the bitcoins arrive when expected, but my getbalance of my correct address never goes down. I even tried sending all the money out in 10 different transactions and saw it was failing when the the account should have been zero'd out, all the while always reporting that I had my high original balance.

I feel like I am missing something basic but I can't seem to figure it out. Thank you in advance


texts: Transaction ID not found- Status still unconfirmed after a month?

texts:
I did a transaction back to my bitstamp account on 23.02.2016 but it has not been received. Transaction ID:

1886e0c49ba43a842043fc84358a05d3faf69468c1547e1d2ef3e030b929f834

I do have the blockchain located on an external hardrive since it takes up so much space. Any help on how I can get the transaction to go through?


texts: Bitcoin explorers don't show my addresses transactions

texts:
I'm creating bitcoin addresses for a wallet we're building. To make sure the addresses are valid I went to a couple of bitcoin explorers and they reported, correctly, that the address does not have any transactions yet.

Great. But now I put in a couple of addresses from my existing wallets (Bread and Jaxx) which both have several transactions over the past year or so. Once again the explorers reported -- this time incorrectly -- that the addresses have no transactions.

The explorers I tried, with an example address that has transactions associated with it:

www.blockchain.com/btc/address/1LQs3i94JTJGimr2BiM929Zdhm1ShCatJR

insight.bitpay.com/address/1LQs3i94JTJGimr2BiM929Zdhm1ShCatJR

Why can't I see the transactions for this address?


texts:
I have seen in some videos and blogs that Blockchain can be used in our election voting system for example here:

  Another company working on creating a platform that uses Blockchain
  technology to replace and/or enhance the current voting methods used
  today is BitCongress, which released a White Paper on its approach.

  The company uses the Blockchain technology with a token based system
  to control the voting system ensuring one person, one “unchangeable”
  vote.

  This token is called a VOTE and by using the blockchain to permanently
  record each vote, it ensures that there can be no manipulation of
  those votes or voting twice

As far as I understand it, the company would assure that each person that is allowed to vote gets a unique token and can only vote once.

Then each block of the blockchain contains the information for which party one voted and the unique token. But I don't understand the following:

If there is a company who assigns each user a unique token, then how can I possibly check if the token actually belongs to a human?
How can we check that the company does'nt create some fake tokens that do not belong to a user?
How can we prevent a Brut force attack that someone just tries billions of possible tokens to make their vote?


texts: Is it possible to accurately map hashing power to network size?

texts: Let's say we have a network with n nodes in it. Is it possible, when the hashing power of the network is calculated after a proof-of-work, to accurately estimate n with an algorithm taking the calculated hashing power into account?


texts:
I need to use bitcoin testnet3 server for testing via php.

bitcoin.conf
rpcuser=bitcoinrpc
rpcpassword=random string
testnet=1
create JsonRpc object with easy bitcoin:
$bitcoin = new Bitcoin('bitcoinrpc', 'random string', 'localhost', 18332);

what is the solution for this? does rpc port is right for tesnet3 server?


texts: Qualities of "Pay to Nested Witness Key Hash"

texts:
The lightning dev tutorial mentions the np2wkh or Pay to Nested Witness Key Hash address type, and I would like to find out more about it, so far without success.

Can anybody explain how they are different from other address types, e.g. P2PKH or P2SH?


texts: Name of the country receiving the bitcoin currency

texts: Can a country be determined to whom the bitcoin is sent?


texts: Two kinds of Bitcoin addresses issued with bitaddress.org

texts: I forked the bitaddress.org repository and generated a new paper wallet. On the output page there are two addresses generated: one "regular" and one "short address". Both start with 1 and are legacy addresses. I transfered a small amount to the short address and checked the balance on blockchain.com. The problem is that there is only a transaction on the short address. I expected the addresses to be linked somehow. What am I missing here?


texts: What happens when Bitcoin's blockchain grows to 1 Terabyte in size?

texts: If bitcoin is to succeed surely the blockchain design has to be redone. Are there any other cyrptocurrencies with a different blockchain design than bitcoin?


texts: What is the new segwit network option on binance and how does it work?

texts: Recently Binance announced support for segwit deposits. I see old address and lot of other options on the right with segwit in the end. Is it a new network? What are the other options mentioned on Binance to deposit BTC and are they similar to segwit?


texts: Can a node exit the bitcoin network and return to his address and transactions?

texts:
I have read in Wikipedia that "Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will " in bitcoin network. what does it mean that a node can leave the network-what will happend to its transactions? Can he get back to the same address and claim his transactions again (its bitcoin)?

thank you


texts: How to sweep a bc1... bitcoin segwit address using a mobile app?

texts: I have a bitcoin private key with some money on the segwit bc1 address, but when I try to sweep this private key using mycellium android wallet, it shows up as a 3... address. What other mobile app lets me sweep a bc1 segwit address?


texts: binascii.Error: Odd-length string for Python Implementation of Bitcoin

texts:
https://gist.github.com/vivosmith/f0e692d9aedbc39ec8d3eb4651bc107c

I was trying to implement this video in Python 3

But the issue is that, it was implemented in Python 2

So I tried to implement this with binascii instead of encode/decode. However I keep getting a binascii.Error: Odd-length string at line 22.

How to I correct this? Or if this is completely broken, then is there any other libraries that work better for python 3?


texts:
There are two possible models, the UTXO model and the account model. Each has advantages and disadvantages. Bitcoin chose the UTXO model. XRP and Ethereum for example use an account model.

What are the advantages and disadvantages of each model?


texts: I've already fully synced the blockchain with btcd, can I point bitcoind at the same datadir and use its contents?


texts:
How do I get Bitcoin block header data with nonce?

There are tens of so called blockchain explorer websites, tens more offering on-line Bitcoin blockchain parsing.

But all I need are historic Bitcoin blockchain header data only for off-line mode study.

In theory I can set up blockchain parser on my own but I need to download full blockchain first and set up parser.

Since I live on wireless Internet 3G, it's not feasible to download 500GB data, so I would prefer an option just to buy historic Bitcoin blockchain header only data, no overheads, no transaction data.

If you know such place or can offer such download, let me know your terms.


texts: Create P2SH address is not same as address saved on rpc node

texts:
I have a private key and trying to create P2SH address on testnet like my node created but they're not same. Please help me a bit, thanks so much.

PrivateKey: c5964e19634e473e9c8fed3b149c4d44b6d62d62724035aad3eb911a1495ae27

P2SH address from 1 threshold and 1 pubkey:
2N4GriyLchUgwwCBonzYHgsCHNhYRHW45w7

P2WPKH address: 2NGA8uGdnaQ21phNpVyV5uye5cbUtudxBWh || tb1qld2fzw9gj30wxjamsz73fug62das7cyq0em4mn

Address from node: 2N8qKVKuR3QAy2cA5fF2QbuCpBGfGCmbUHx

Here is more detail from getaddressinfo:

{
    "result": {
        "address": "2N8qKVKuR3QAy2cA5fF2QbuCpBGfGCmbUHx",
        "scriptPubKey": "a914aafc9f09b99cbb1ba46001ec4868ba4fb32543ca87",
        "ismine": true,
        "solvable": true,
        "desc": "sh(wpkh([a1696bdc/0'/0'/375509']02a7065a210c28d27a591e55ac6be092111349fc4b23927bb4d13c46a683bcfff7))#hrgzj3gs",
        "iswatchonly": false,
        "isscript": true,
        "iswitness": false,
        "script": "witness_v0_keyhash",
        "hex": "00146da71bc5de0c0b59bbf73520df7e7d4048d02594",
        "pubkey": "02a7065a210c28d27a591e55ac6be092111349fc4b23927bb4d13c46a683bcfff7",
        "embedded": {
            "isscript": false,
            "iswitness": true,
            "witness_version": 0,
            "witness_program": "6da71bc5de0c0b59bbf73520df7e7d4048d02594",
            "pubkey": "02a7065a210c28d27a591e55ac6be092111349fc4b23927bb4d13c46a683bcfff7",
            "address": "tb1qdkn3h3w7ps94nwlhx5sd7lnagpydqfv5pyqurf",
            "scriptPubKey": "00146da71bc5de0c0b59bbf73520df7e7d4048d02594"
        },
        "label": "test",
        "ischange": false,
        "timestamp": 1561438016,
        "hdkeypath": "m/0'/0'/375509'",
        "hdseedid": "e2e9dd17501f967b789c28c4be1dbf64897ad8d2",
        "hdmasterfingerprint": "a1696bdc",
        "labels": [
            {
                "name": "test",
                "purpose": "receive"
            }
        ]
    },
    "error": null,
    "id": 1
}


texts: How can one be truly anonymous without mining?

texts:
Assume that person wanting to be anonymous has reason to do so. Powerful enemies will see what is bought with bitcoins, perhaps web blog on server and domain name. Even in nations with rule of law, United States applies strong pressure and registrars and server hosts give up bitcoin address used to pay for things.

They trace address to address until find person who sold bitcoins for cash or credit card or wire fee.

If cash, famous exchanges know which city and bank address cash was deposited. Modern law enforcement technique is excellent for figuring identity once given such a clue. If not famous and idiot from Craigslit or similar, roll over in hurry when threatened with prison. Will try very hard to remember. And credit card or wire more even more trivial to figure.

I run tests, bitcoin mining take 22 million million years to give pocket change. Computer not so fancy after all.

Forgive poverty english please, translated to many languages and back before posting.


texts: How do i recover a past bitcoin account?

texts: I invested in bitcoin the 90's, but don't remember where the account is. How can I recover and see if I still have coins?


texts: What has the nonaggression principle to do with bitcoin trading?

texts:
In the Introductory page of the book 'Attack of the 50 foot Blockchain', the author says (in reference to Ross Ulbricht) :

  A young physics student starts a revolutionary new marketplace based on
  the nonaggression principle, immune to State coercion.

What does the author actually mean by that please?


texts:
In the bitcoin source code, I am looking at chainparams.cpp. I can see on line 81 something called consensus.BIP34Height? What is that? I can't figure out what this is.

I'm not sure what else to ask other than what is this? I can't see any mention of it in the developer reference.


texts: Extract the tag list from blockchain.info

texts:
Is there any way to download the address-tags list as a file?
This would be very useful for a bitcoin data analysis project.


texts:
Can anyone tell me how to set up a watch-only address using bcoin?

while using the command:

bcoin wallet create myNewWallet

this will always be a  "watchOnly": false wallet by default. Is there any documentation for these commands?


texts: Bitcoind functionality w/o running a full node

texts:
I'd like to do some of the example in "Mastering Bitcoin, Programming the Open Blockchain" using bitoind on my Ubuntu system. Is there a program (possibly bitcoind itself) that allows me to do this w/o setting up a full not which I can currently not do for Hardware reasons?

I would mainly like to be able to explore transaction with comments such as bitcoin-cli decoderawtransaction for instance.

Many thanks and sorry if this is a stupid question.


texts:
Does anyone know if bitcoin-wallet on Andriod (https://github.com/bitcoin-wallet/bitcoin-wallet) supports BIP148?

I've been Googling and checked their GitHub page but I can't find BIP148 mentioned anywhere.


texts: Are sockets kept open when connections are made?

texts: The bitcoin protocol says that any given node is connected to at least 8 other nodes. Does that mean that when a client connects to a node and learns about new peers... will the client keep the socket open and wait on recv? Or does it just record the new peers and closes the sockets and opens a new connection when there is new data to be received or sent?


texts: I just sent bitcoin to my bitcoin cash wallet.  I’m using blockchain and Coinbase and all the reading I’ve been doing it doesn’t appear there is anything I can do about this. I’ve tried getting ahold of Coinbase to see if they can help and I’m just put on hold forever. Can someone please help   Thanks


texts: how EC Public key is generated from the private key effectively

texts:
if my private key is 123456789123456789, doesn't that mean I have to dot G point that many times to generate my pubkey? there must be a shortcut to generate pubkey, otherwise the time complicity of generating the pubkey is the same compare to brutal force from trying from 1 to k? Am I missing anything here?

according to the article here: https://arstechnica.com/information-technology/2013/10/a-relatively-easy-to-understand-primer-on-elliptic-curve-cryptography/

it looks like generating pubkey from a random generated private key(which could be a 32 bytes BigInteger) requires to dot many times = integer value of the private key. which is impossible considering the key size for the private key is 2^256(32 bytes key space).


texts: How does Market cap and daily movement affect a Crypto stock , do these numbers mean much?

texts:
Really want to understand how the daily volume and overall cap works. I read that don't buy when a market cap is over 75 million and the best time to buy is between 25 and 75 million.
I understand that certain coins have mineable limits. Do some coins have unlimited caps ? How would they be valuable and not subject to inflation ?


texts:
What is the benefit of forced signaling in a soft fork activation mechanism? e.g. the MUST_SIGNAL phase in revised BIP 8.
I understand the benefits of setting lockinontimeout (LOT) to true (some of those benefits are described here) but why have a period of say two weeks when miners have to signal before the soft fork moves into the LOCKED_IN phase. Why not just define when that LOCKED_IN phase will begin (assuming miners fail to activate the soft fork before then) and ditch the MUST_SIGNAL phase?
Matt Corallo states "Forced signaling isn’t required for many flag day designs, and is the biggest single risk of any proposed feature for an uncontroversial activation."


texts: How/where is the informatioin regarding the mapping of a transaction to a particular block stored?

texts:
According to the bitcoin white paper a block contains Previous Hash, Nonce and Root Hash. The root hash is a merkle tree root node of all the transactions that have been confirmed to that particular block.
I read here in the fifth paragraph of the top answer that "a transaction that claims to have been from block #234133 we can get the transactions for that block, verify the Merkle tree, and know that the transaction is valid."
So say a block m somewhere in the blockchain holds n transactions. Where and how is the mapping of a particular set of transaction to a particular block stored? Because the blockchain itself only contains the root hash of all transactions to save space. So are there other hidden components that haven't been published in the white paper and are there resources to get a comprehensive idea about them?
Thanks.


texts: 0/unconfirmed and cannot find my bitcoin folder (Mac)

texts:
I'm running OSX 10.7 and the newest version of Bitcoin-Qt. I put Bitcoin-Qt on my desktop, and found an old wallet.dat that was saved on a USB. I 'opened with' Bitcoin-qt, saw my balance, and tried a transaction before the most recent block was downloaded.

Now, after the entire blockchain has been downloaded, I see that my transaction is 0/unconfirmed. It's been a couple of days now.

In an attempt to get to the bottom of this, I read that it's best to find the bitoin folder in Application Data/Bitcoin, however there is no Bitcoin folder in application data. I've tried deleting the bitcoin client and downloading a new one, but the freshly downloaded bitcoin client is still using the wallet.dat from the USB stick. (the USB is not connected).

My question is, how do I find the bitcoin folder on Lion, so I can start over. I know not to delete the wallet.dat file when I do find it...

Oh, I've enabled my mac to see all hidden folders, just in case.


texts: A crypto-currency for supporting informal education?

texts:
I am involved with Funoon (funoonfoundation.org), a non-profit working to organise informal learning spaces. These informal spaces are basically physical spaces where learning happens on a peer-to-peer basis, guided by a mentor/ tutor.

We are brainstorming on how to incentivise talented people to come in and spend an hour or so weekly with a learning group. We can't pay them (at least not to start with), and without a solid incentive, its hard to get things going.

So I am wondering, if its a possibility to create a crypto-currency that solely exists to pay out a small chunk to anyone who comes along to mentor/ tutor at a learning space. My knowledge on how a crypto-currency works is quite limited, so I am looking to get enlightened  on this.


texts: wireshark packet analysis missing checksum in version msg

texts:
I'm trying to send a raw bitcoin transaction through a raw socket connection in python. To debug I'm using wireshark to sniff the packets.

Wireshark figures out that the packet is for Bitcoin and that it's a 'version' message, and gets the first couple fields right, but then neglects the checksum field and instead assigns what should be the checksum to the protocol version, throwing everything else off.  I can't seem to get to the bottom of it.

Other message types, like 'tx', include the checksum but have other issues (I'll get to later).  Any ideas why wireshark isn't picking up on the checksum for the version message?


texts: Effect of price increase on usage of Bitcoin

texts:
I was just about to pay for something with Bitcoins today and I hesitated for an instant thinking that the price might be $10 more next week.

Is it possible that Bitcoin holders will be less likely to spend their Bitcoins on actual goods or services given the wild increase in prices? Or if the prices suddenly start to drop, will people be more likely to spend their Bitcoins?


texts: Is Mt.Gox currently accepting Dwolla deposits or withdrawals?

texts:
I know that Dwolla stopped depositing/withdrawing funds in Mt.Gox due to a court order, but does anyone know if this is still in place?
Related
Why can't Dwolla send to Mt Gox?


texts: Why the shell return the balance normal but php not?

texts:
I am using the easybitcoin.php library and in my application. I use the getreceivedbyaddress method in php. It returns 0, but in my shell when I use bitcoin-cli it returns 0.000000000.
My question is, how can I return in php the same as the shell?
Tried this, $ data2 = shell_exec ('bitcoin-cli getreceivedbyaddress address'); and it returns 0.00000000, but is there another way?


texts:
I've seen a number of sites advertise they support "hot", "warm" and "cold" wallet storage solutions (the only thing I haven't seen so far are "frozen" wallets).
What's the difference between the three? I think the difference between "hot" and "cold" wallets are pretty clear. But what makes a wallet "warm" instead of "hot" or "cold"?
P.S
I understand that at some level "warm" wallets are obviously more accessible than cold wallets (hence the name "warm") but how would they differ from a tech perspective - at what point is something hot and at what point is something warm?


texts: What would stop some major company from blacklisting specific Bitcoins based on the "inputs" used and their "origins"?

texts:
I remember news about some exchange actually banning users based on some kind of "reputation score" on the inputs/coin parts they controlled/used, or got Bitcoin sent to them from. So even years and years back, they had this mapped out somehow.
Why can't they do the same today? Aren't they? If not, why? Why do they not take this obvious path to harassing and restricting people to only use Bitcoin in "approved" ways with "approved" people/entities?
Did they stop doing it for some reason? What stops them from doing this and thus locking out tons of people who have "dealt with undesirables"?


texts: Verifying a digital signature that a transaction is going to an output with value X inside a script

texts:
Edit; after writing this post i have found that OP_CHECKDATASIG is basically this in a nutshell. It is implemented on Bitcoin Cash and may soon be on Bitcoin Core as well.

Someone has even written this post into a Bitcoin Cash smart contract: https://honest.cash/pein_sama/spending-constraints-with-op_checkdatasig-172


texts: What will happen when the last bitcoin will be find

texts:
I have read there is a mathematical limitation of bitcoin count.
What will happen when a miner will find the last bitcoin ? I have read nobody will do mining anymore.
But, we will need miners in order to compute proof of work of transactions ?
They will earn bitcoin with transaction fees ? So mining won't stop ?

Thanks


texts: GUIMiner not detecting my GPU (AMD Radeon HD 7600M Series)?

texts:
GUIMiner does not appear to be detecting my GPU. Under available devices, I am only able to see my CPU. I have an AMD Radeon 7670M GPU, that I have the most updated driver for and can confirm that it is enabled and working.

In my Device Manager, the GPU shows up under Display Adapters and there are no errors.

Screenshot of my GUIMiner GUI, as well as the summary of my GPU from GPU-Z:

Why is this GPU not being recognized? For the record, I have been able to use GUIMiner previously using the same graphics card, but have not used it for months and since that time I have upgraded to Windows 8.1 (x64).


texts: How to identify the sender from crypto payments

texts:
I want my users to deposit crypto into the website for credits, but the biggest issue is getting the input address (the user's address). How can I identify the sender from the transaction (since there can be multiple inputs) as well as the amount they sent (since there can be multiple outputs)?
A lot of services offer payment forwarding but they all seem the same but have different fees, some requiring a subscription of over 80$ a month (cryptoapis, blockcypher) or some having service fees (apirone, bitapis, etc). However they all seem to be the same so I don't understand the price differences, in fact some of them are downright identical (cryptoapis & blockcypher). How would I make my own, and would it be worth it for a start up?


texts: Can I have multiple OP_RETURN outputs in one transaction?

texts: I am wondering if I can inject multiple OP_RETURN outputs in one transaction?


texts: POW based blockchains systems Majority Attack

texts:
TL;DR: With only 30% of network power a Majority Attack is possible and profitable. Am I missing anything?

Generally speaking, blockchains based on Proof-of-Work authentications are using amount of work as the weight of one's vote.

I will be talking specifically about bitcoin to simplify the discussion (Although I hate reading people who talks about cryptocurrency here).

A transaction is consider confirmed usually after 6 blocks have been mined above it. Mostly even 2 blocks are considered enough, but let's examine the secure decision of 6 block. Now assume I have 30% of the network power.

Me and the network have the same prefix of blockchain. At this point I'm beging to work and append to it my own blocks, ignoring the rest of the network. The chances I will manage to build a blockchain that is at least as long as longest chain in the network, by the time the transaction is "confirmed" - is roughly 15% (reference below).

That means I can revert my confirmed transactions 15% of the times. Now all I need is to earn more money on a reverted block than I'm paying for the total computing power. This is not impossible. If a "confirmed" block is even half-fulled with my transactions, the total amount of money can easily be 2 million usd (reference below).
Reverting at 15% success rate means at least one block every two hours (one block every ten minutes).

But 2 hours of work only cost me about 140,000 usd.

Or more importantly: playing fair doesn't seem necessarily more profitable.

Playing by the rules for two hours equals today about 1.2 million usd income (If you own 30% of the network power).

It seems profitable to attack the system every now and then, even with 30% of network power.

(Obviously I rather revert a lot of "small" transactions than a huge one, so no one will get susplicious and wait for more confirmations.)

What am I missing?

A few points:
- I rather not address issues such as "an attacker can be easily found". This may, or may not, be true. But it's not relevant for the question: Is it possible and profitable to attack the network with 30% network power.
- If you are stating I'm not mistaken and this is true (which I doubt), please do specify your amount of familirity with the protocol and the security of the system.

Refernces:

Success rate with 30% network power (math here is simple but clumbsy to write down rigorously)
https://pastebin.com/RhnGi04W
A single block carry a few thousand bitcoins (namely, a few million usd)
https://blockchain.info/
Bitcoin value in usd
https://coinmarketcap.com/currencies/bitcoin
Profits and costs of the entire bitcoin network:
https://digiconomist.net/bitcoin-energy-consumption

(I assumed one hour of my working profits roughly: total_bitcoin_mining_income/365/24*0.3
as I own 0.3 of the network power)


texts: How to connect the Blockchain to the Network without IP Address?

texts:
I would like to know how do we connect the blockchain to the network when there is no IP?
Indeed we all use bitcoin core (for bitcoin) to connect and retrieve information and update.
However the source code of bitcoin core (I have never read it) does not redirect us to an IP address, but people still manage to find themselves, without ever saving the IP.
How can people know or find the information, when the source code of the software does not have IP, they do not know address (IP) which has the information?
Knowing that the IP is the basis of the connection ...


texts: How can I fix an unconfirmed low-fee transaction sent from Multibit HD?

texts:
I have tried researching this issue for hours. I do not think the majority of usual solutions are possible with Multibit HD. The only solution I believe I do not fully understand (and therefore it may be possible) is

1) Repair/Restart the wallet multiple times, hoping to get lucky and have it connect to a node that will handle a low fee transaction.

2) Something to do with Bitcoin Core. This looks promising, but I don't believe there even are "wallet.dat" files with Multibit HD, so I'm not sure how to execute these directions:

Why is my transaction not getting confirmed and what can I do about it?

https://www.reddit.com/r/Bitcoin/comments/4ggg0m/how_do_i_run_command_line_on_the_bitcoin_core/

Information on my situation:

I accidentally sent some transactions with an extremely low fee. Judging by the mempool, it could take 48~ hours for these transactions to process. I would like to "cancel" these transactions, and resend them for a higher fee. With a wallet balance of 0 and no way to implement any of the common methods to orphan blocks... is there any way I can recall my coins?

If not, how long does it take before the transactions are dropped? I read that if every node in the network looks at my transaction and denies it, then it will be recalled even with Multibit HD, is that true?

TX ID:  7f078efec60078aa4575cc6fb3f4064886fb3a88b0a5078069d86bb29ebe55bc

"before txs" is certainly not following a downward trend...oftentimes when I check, the number has increased up into the 15,000 but never lower than 8,000.

What are my options?

Any help at all would be greatly appreciated!


texts: How are transaction fees collected in Bitcoin?

texts:
I'm looking into the structure of blocks in the Bitcoin blockchain, and I can't figure out when\how the fees collected by miner of the blocks are transferred to the miner.
According to what I can tell they are not a part of the coinbase transaction (which as I understand has to be constant since changing it after discovering a block would change the hash of the block).
Are the fees paid as separate a transaction? Are they written directly to the UTXO without appearing on the blockchain? Something else?

Thanks!


texts: Less circuitous way to get network fee in raw transaction

texts:
I have my code working correctly now to create and send a transaction with the correct network fee. Here is my pseudo-code using the json rpc:

Estimate network fee using estimatesmartfee "ECONOMICAL" based on a typical transaction size
Adjust payout amount based on fee estimate
createrawtransaction using estimated payout amount
signrawtransaction
read size of decoded raw transaction from step 2
Recalculate network fee using estimatesmartfee "ECONOMICAL" based on a actual transaction size from last step
Adjust payout amount based on actual network fee
createrawtransaction using actual payout amount
signrawtransaction
sendrawtransaction

Steps 6-9 repeats Steps 1-4.

Is there a way to do this without having to call everything twice?


texts: Im new to Bitcoin and want to know if storing wallet on my hard drive could corupt it?

texts: Will storing a wallet on my hard drive increase the risk of corruption to the drive?


texts: How can importprivkey compromise wallet security when importing a publicly known private key?

texts:
A question was asked on reddit over here which I gave a reply: https://www.reddit.com/r/Bitcoin/comments/3khrvm/how_do_i_use_private_keys_to_receive_bitcoin/

However, luke-jr replies with:

  Don't do this. You compromise your wallet's security to import a private key that others know.

without further elaboration. Can someone explain what he's talking about?


texts: What is the most lightweight proof-of-work algorithm?

texts: I know litecoin was created back in the day using Scrypt as to make it more lightweight but also harder to build ASIC hardware from - so everyday computers could mine. Are there other algorithms one should be aware of nowadays? Possibly ones that require little resources and make it impractical to build ASICs.


texts:
I'm reading this article by Vitalik Buterin on Problems in Cryptocurrency and don't quite understand what this means:

  Ideally, after some number of blocks (perhaps logarithmic in the total size of the network) every transaction should require 51% of network hashpower to reverse. However, solutions where transactions can pay very small fees for a lower "level" of security are acceptable, though one should take care to avoid situations where an attacker can profit by performing one attack to reverse very many small transactions at the same time

I understand that Sybil attack can happen if more than 51% of the network is under one person's control, but I don't understand what it means to reverse network hashpower, and why 51% of it should be reversed.


texts: Who operates WeExchange, the first Ripple Gateway?

texts:
Is it operated by OpenCoin, the company behind Ripple?

https://weexchange.co/

https://ripple.com/wiki/Gateway_List


texts: How to implement a green address in Bitcoind?

texts: There are a few websites that use green addresses, but how can one go about implementing it using the standard Bitcoin API?


texts: When and where to add extra information when signing P2SH raw transaction?

texts:
This post is quite long so in summary: I'm wondering where I can add extra information when signing a raw transaction (in this case a cleartext of a digest). I'm also wondering if Missing inputs (code -25) which I'm getting without having provided the digest and trying to sign anyway is because of that or because of something else.

I am trying to sign a hashed time-lock contract with bitcoind that looks like this:

OP_IF
    [HASHOP] <digest> OP_EQUALVERIFY OP_DUP OP_HASH160 <seller pubkey hash>
OP_ELSE
    <num> [TIMEOUTOP] OP_DROP OP_DUP OP_HASH160 <buyer pubkey hash>
OP_ENDIF
OP_EQUALVERIFY
OP_CHECKSIG

and like all P2SH this is how you are supposed to add it to the network and sign it:

Pubkey script: OP_HASH160 <Hash160(redeemScript)> OP_EQUAL
Signature script: <sig> [sig] [sig...] <redeemScript>.

So I have sent some bitcoins to the base58-encoded P2SH address and created a raw transaction to the same address as seller pubkey hash. But when I am about to sign it I just can't find where I can put the digest.

According to the signrawtransaction RPC call: http://chainquery.com/bitcoin-api/signrawtransaction I need to add

2. "prevtxs"       (string, optional) An json array of previous dependent transaction outputs
     [               (json array of json objects, or 'null' if none provided)
       {
         "txid":"id",             (string, required) The transaction id
         "vout":n,                  (numeric, required) The output number
         "scriptPubKey": "hex",   (string, required) script key
         "redeemScript": "hex",   (string, required for P2SH or P2WSH) redeem script
         "amount": value            (numeric, required) The amount spent
       }
       ,...
    ]

which is where I'm guessing I can add the digest. Should it maybe be added to the redeemScript?

Then there is also:

3. "privkeys"     (string, optional) A json array of base58-encoded private keys for signing
    [                  (json array of strings, or 'null' if none provided)
      "privatekey"   (string) private key in base58-encoding
      ,...
    ]

but it seems weird to me that I should have to base58-encode the digest when it should probably be a hex string?

Just in case I don't miss anything important I will also list some of the steps in detail I've done up to this point (all done on regtest).

So I started by creating  a raw transaction to the P2SH address (since sendtoaddress gave me errors about the fee being too high or low):

createrawtransaction "[{\"txid\":\"5f3671ca7d5dea44dd3dd40fad076e76c57189702a4bb92bacb1747017136982\",\"vout\":0}]" "{\"2N5ZRwT42rHFjAtizZPa3Rp7Tn88PcoSzEB\":5, \"n1uGNwJ5nrrhTh4wQX5XKYpxDoZsp3w2fB\":40}"

After signing the raw transaction and decoding it to get the txid I then created another transaction to my own account:

createrawtransaction "[{\"txid\":\"f345938d21bc3fc0966a4f11a0e6b98831640b2cc6cf49bd143758cd95762a1c\",\"vout\":0}]" "{ \"n1uGNwJ5nrrhTh4wQX5XKYpxDoZsp3w2fB\":5}".

Finally I tried signing the transaction with nothing but the fields I knew from prevtxs:

signrawtransaction "02000000011c2a7695cd583714bd49cfc62c0b643188b9e6a0114f6a96c03fbc218d9345f30000000000ffffffff010065cd1d000000001976a914df9ac343e79ae35a727ff757b02e93ac5a4748dd88ac00000000" "[{\"txid\":\"f345938d21bc3fc0966a4f11a0e6b98831640b2cc6cf49bd143758cd95762a1c\",\"vout\":0, \"scriptPubKey\": \"76a9149a57624114b8c67ea007616a210ffe79e711bbd988ac\", \"redeemScript\":\"63a61486b8e067c700620260ad44f108e4add2ebf3c1d28876a91422a29435b1386d8fbc779a72612ccda7401d4aa2675cb27576a9147074ce8ff2f417d6b232d73a789ca09e7c0e8ef36888ac\", \"amount\":5}]".

When trying to sendrawtransaction on this I get error code Missing inputs (code -25). So my final question is: is Missing inputs related with not having provided digest in signrawtransaction or is it because I have missed to add something else?


texts: difference between pre-mining and mining

texts:
I am new in blockchain and not an IT person.

is there a difference between pre-mining a cryptocurrency and mining a block?
I do understand the rewarding action when a miner solves a hash puzzle to add a block to the chain.  However, I do not get the pre-mining activity.  Maybe I am mixing up 2 different functionalities.


texts:
I have been following the Bitcoin Core tutorial on creating a simple raw transaction from an offline computer using the CLI.

The part on createrawtransaction indicates that the raw transaction should have a vout value:

  The output index number (vout) of the outpoint; the first output in a
  transaction is index 0

Therefore, if there is only one outpoint, its vout value should be 0.

However, createrawtransaction only works with vout=1, even though I have only one txid in the command - what am I missing here?


texts: how use destination tag in remote in ripple when we make a payment?I tried with destination_tag and dtag in remote block.


texts: How do different implementations of the Bitcoin Cash client know which type of coin they're processing?

texts:
TL;DR: Where in this code does the SV client figure out that it's not processing an ABC blockchain?

This image prompted my question.

There are a couple different mutually incompatible (I am assuming anyway) implementations of the Bitcoin Cash cryptocurrency client software...

Bitcoin Cash ABC
Bitcon Cash SV

My question assumes that each implementation processes their respective transactions using similar but mutually-incompatible blockchain processing rules.

Is it normal to run a Bitcoin Cash SV client implementation in a Bitcoin Cash ABC network? And vise versa? How, then, does one implementation know that the network it is running in, is (in)compatible with its particular processing rules?


texts: How do I configure Bitcoin Core to connect always to a particular node?

texts:
By reading https://bitcoin.org/en/full-node I've decided that I want to run a FULL node (let's call it 'X'), to contribute to the P2P network.

So, I'll leave its ports open, or have a DMZ zone with a public IP address in it.

But this comes with security risks, so I will not have any funds in this instance of the Bitcoin Core QT client.

Then, I will keep my BTC funds in a different computer (let's call it 'Y') that will not be a full node (but still use bitcoin-core QT main client).

However, how can I configure 'Y' to always connect (in order to broadcast my transactions) to my server 'X' and not a different one?

Thanks


texts: How does a client decide which is the longest block chain if there is a fork?

texts: Is it only the block height or is it the effort that went into the forks? In other words: does this decision account for different difficulties?


texts:
I am using bitcoind json rpc api to send bitcoin to multiple bitcoin addresses. I am using sendrawtransaction. When i have 24 unconfirmed payments sent from my account, i can't send anymore because i get this error :

  64: too-long-mempool-chain

I have increased the maxmempool to 1500 but it still doesn't fix it.

root@B2:~# bitcoin-cli getmempoolinfo

    {
      "size": 3946,
      "bytes": 1789073,
      "usage": 6043088,
      "maxmempool": 1500000000,
      "mempoolminfee": 0.00000000
    }

I use Ubuntu on a 32GB RAM , 4TB HDD server.

Any ideas on how to fix it ? I want to be able to create for example 300 unconfirmed transactions and not to receive that error.


texts: Setting up a coinbase like service in India , need suggestions

texts: I have read and researched extensively on bitcoin, but I haven't found any service like coinbase that allows a user to buy or sell bitcoins online without having a US bank account. So how can one start an exchange like coinbase for India ? What are the legal obligations and initial startup cost ? Any advise would be welcome.


texts:
Can someone explain fees in layman’s terms
I thought I would throw a few dollars into bitcoins more for a laugh than anything - but the fees are confusing me.
I googled best wallet for newbies & most people suggested Exodus as simple and easy for beginners.
Using Apple Pay I bought $100 at around 44k - I got $99 worth of coins and paid $1 fee (seems fair)
They are now at 48k and my $99 is up to about $109
I have no interest in cashing out, but still leaning my way around so thought I would check how much the fee would be to cash out.
From what I can tell, I have to use a company like coin base to convert to hard cash and so I’m looking at paying a transaction fee to send the money to coin base plus a fee to coin base for converting my Bitcoin to hard cash / depositing in my bank account.
The transaction fee exodus shows me to send my coins anywhere is $15 which seems a bit steep.
Would I be better off having a coin base wallet so I’m not having to pay that $15 when I want to cash out on top of cashing out fees?
Looking online people say coin base fees are a few % and exodus is 5% plus - but they are quoting me 15% (or is that just because I only have small amounts & it would be cheaper if I had $1,000)
I may throw $50 or $100 a month into BC moving forwards, nothing big, an amount I can afford to forget about for years or even lose large amounts of, but don’t want to lose 20% when I cash out between transfer & cash out fees!
Any help would be much appreciated


texts: I got this pretty good question the other day - why does bitcoin have a value at all?  After all it's nothing - who is willing to pay for nothing?


texts: Can you verify partial blockchain information from a third party, without yourself having an entire blockchain?

texts:
I'm considering consuming, or if unavailable, I'm considering providing, a bitcoin blockchain querying service along the lines of json rpc.
Would it be possible for me as a consumer of such as service, to verify the integrity of returned data from such queries, without myself running a full node? (If not there wouldn't be much point using such a service!)
Would it be possible for me as a provider of such a service, to provide enough data for a consumer to verify the validity of the data I send them, when the consumer is not running a full node? (If not there wouldn't be much point providing such a service!)
My end goal is to run something like a bitcoin blockchain explorer website on the cloud, but the cost of running a full node (particularly storage) on the cloud is more than I can afford. Obviously I have some feature ideas I've not yet seen on other explorers


texts: What is impact of the possible nitwit fork on August 1? Will it double the coins I have?

texts:
If the Nitwit proposal is activated at the end of July then as I understand a hard fork will occur because miners and nodes that continue using the old software will generate blocks in the old format, but those blocks will be ignored by nitwit clients, and vice versa. So, basically there will be two chains.

If that happens and I transfer some coins, how is it decided which chain the transaction occurs on? Can I double spend my coins, once on each chain?


texts: Is it true that only one message can be sent at a time in Bitcoin Core?

texts: I looked into Bitcoin Core client code, and it seems that there is a lock that allows only one thread to send data (Block, TX, etc.) at a given time point. If this is true, it means that transactions and blocks have to wait in a queue until the previous once are done sending. Am I right?


texts: Which server(s) determine the difficulty and issue coins

texts: I understand that the blockchain is a decentralized database, however what I don't understand is who runs the bitcoin software. Is this also decentralized? There has to be some form of "backend" to run the checks and balances?


texts: BitcoinCore 0.13 HD wallet chain structure

texts:
What are the "paths" of keys from BitcoinCore 0.13 HDWallet?
As is described in BIP32
, I consider a path to be the route from the root node to the key node. For example, m/0'/0'/1' stands for the second hardened child of the first hardened child of the first hardened child of the master root node.

I want to know that to be able to regenerate this chain myself using some bitcoin library in case gaps in my chain will exceed 20 keys (current default gap value of BitcoinCore 0.13).


texts: I'm trying to compile bitcoind on Windows but build_unix for db-4.8.30.NC is empty. What do I need to do?

texts:
I've been working on setting up the proper environment to compile litecoin, and have been following the instructions from this:

https://bitcointalk.org/index.php?PHPSESSID=1dl8pkva2oqpjsd3h455k7hrj7&topic=149479.0;all

  2.2 Berkeley DB: http://download.oracle.com/berkeley-db/db-4.8.30.NC.tar.gz

  We'll use version 4.8 to preserve binary wallet compatibility.

  From a MinGW shell unpack the source archive, configure, edit line 113 of db.h then make:

  Code:

cd /c/deps/

tar xvfz db-4.8.30.NC.tar.gz

cd db-4.8.30.NC/build_unix

../dist/configure --disable-replication --enable-mingw --enable-cxx

  after configuring make sure to edit your build_unix/db.h by replacing line 113:

  Code:

typedef pthread_t db_threadid_t;

  with

  Code:

typedef u_int32_t db_threadid_t;

I was all set to do it, but this happened:

I've tried getting db-4.8.30.NC from multiple sources, but no luck—the build_unix folder is always empty.

So what's the deal?


texts: Generate address of 'private key' from user input

texts:
I want to take a private key as input from the user and convert it to a wallet address using C#.
I have seen this in a tutorial to generate a random key:
Key privateKey = new Key();
PubKey publicKey = privateKey.PubKey;
Console.WriteLine(publicKey.GetAddress(ScriptPubKeyType.Legacy, Network.Main));

How do I convert a private key string from the user to a wallet address for main net?


texts: How to deal with bitcoin/crypto volatility as an online casino?

texts:
Let's say an online casino has btc as a deposit and withdrawal method.
Assuming A player deposits 1 btc, plays and does neither win nor lose much and then cashes out the balance, which happens to be exactly 1 btc. I am using simple values to focus on the main issue.
However, the btc price was 15% volatile since the deposit was made.
Technically, the player has neither won nor lost based on game play, but he would get a free 15% in value just due to the btc price increase.
The opposite applies if btc loses 15% of value.
Of course it is a nice thing for the casino if the btc price plummets, but potentially disastrous if the price goes up, assuming an average 4% house edge for the casino.
What would be a fair solution for both parties?
Edit: The main game play would be slots, but the same problem arises for Black Jack, Roulette and sports book events. Poker could be affected to a degree as well.
There is no crypto to fiat conversion. An option would be to convert the bitcoin to a Casino token, but fiat is off the table .


texts: I am working with an older version of Bitcoin and want to upgrade to version .4.  Is there a specific way to do this?  I want to try to upgrade, but am paranoid that I could lose my wallet if I do something wrong.


texts: Deleting Electrum wallet and setting up new one

texts:
I set up an Electrum wallet before I learnt that you should verify the signature. While I went straight to the electrum.org website to download it, I would still like to be secure, just in case. So I want to start again (I had no crypto yet in this wallet).
What should I do to be sure that I have eliminated all the files for the old wallet from my PC (Windows 10), so there is no chance of confusion when I download a second time? I downloaded the Windows Installer version.


texts: Is it possible to detect if flag -txindex is enabled using RPC?

texts: Using JSONRPC, how do I detect if a node has -txindex enabled?


texts: How can I sell bitcoins and transfer the funds to my bank account?

texts: A friend of mine gave me two bitcoins which I now want to sell. I don't understand the process which would enable me send the funds generated to my bank account.


texts: Spending BTC from an Electrum watch-only paper wallet?

texts:
I've an old BIP-38 paper wallet, and I imported that address into an Electrum (version 3.3.6) watch-only wallet.

I now want to transfer that BTC to an Exchange. I have the relevant password for the Electrum wallet and private key for the paper wallet and I've checked on a block explorer that the balance at that address is correct and it is.

Question: How do I spend from that Electrum watch-only wallet?

If I open Electum I'm only given an Export option (and from there select amount, select fee, preview, copy display where I end up with a type of report on amount sent, size of transaction, fee, locktime, inputs and outputs

I followed this option, but nothing is happening. Btc is still at my address and not at the Exchange's address and its been a while and the fee was set to max.

Where to from here? Any advice?

(PS: I see advice here to sweep the paper wallet address into the Electum wallet but I understand that would incur a transaction fee, and seeings that I'm going to send that BTC to an Exchange and that transaction would also cost fees - so I don't want to go that route :) )

ty


texts: I provided my XPUB and YPUB to Trezor support - should I continue to use my Trezor?

texts: I have a Trezor.  In attempting to find out why I have have not received Bitcoin Gold coins Trezor Support asked for my XPUB - I gave it to them along with the YPUB too.  Is this safe?  Should I move my coins?  Your help is greatly appreciated.


texts:
I see several coins advertising 1 day PoW.
An example is this coin. https://github.com/concealcoin/concealcoin

I have been studying the code but must be missing a critical part as none of the math adds to 1 day.

Can anyone shed light on this? What part of the code am I missing?

Main.cpp

CBigNum bnProofOfWorkLimit(~uint256(0) >> 20); // "standard" scrypt target limit for proof of work, results with 0,000244140625 proof-of-work difficulty
CBigNum bnProofOfStakeLimit(~uint256(0) >> 20);
CBigNum bnProofOfWorkLimitTestNet(~uint256(0) >> 16);

unsigned int nTargetSpacing = 1 * 30; // 30 seconds
unsigned int nStakeMinAge = 24 * 60 * 60; // 24 hours
unsigned int nStakeMaxAge = 30 * 24 * 60 * 60;           // 30 days
unsigned int nModifierInterval = 10 * 60; // time to elapse before new modifier is computed

int nCoinbaseMaturity = 80;
CBlockIndex* pindexGenesisBlock = NULL;
int nBestHeight = -1;

and the rewards from main.cpp
// miner's coin base reward
int64_t GetProofOfWorkReward(int64_t nFees)
{
    int64_t nSubsidy = 3500 * COIN;

    if (fDebug && GetBoolArg("-printcreation"))
        printf("GetProofOfWorkReward() : create=%s nSubsidy=%"PRId64"\n", FormatMoney(nSubsidy).c_str(), nSubsidy);

    return nSubsidy + nFees;
}

Main.h

static const int LAST_POW_BLOCK = 2880;

static const unsigned int MAX_BLOCK_SIZE = 1000000;
static const unsigned int MAX_BLOCK_SIZE_GEN = MAX_BLOCK_SIZE/2;
static const unsigned int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50;
static const unsigned int MAX_ORPHAN_TRANSACTIONS = MAX_BLOCK_SIZE/100;
static const unsigned int MAX_INV_SZ = 50000;
static const int64_t MIN_TX_FEE = 1000;
static const int64_t MIN_RELAY_TX_FEE = MIN_TX_FEE;
static const int64_t MAX_MONEY = 17000000 * COIN;
static const int64_t COIN_YEAR_REWARD = 3 * CENT; // 3% per year
static const int64_t MAX_MINT_PROOF_OF_STAKE = 0.03 * COIN; // 3% annual interest
static const int MODIFIER_INTERVAL_SWITCH = 2000;


texts: Sent BTC to public key instead of my address

texts: Friend of mine was trying to buy BTC from ATM, instead of BTC address he scanned the public key from coinomi wallet (I dont know why the ATM accepted it, but it did). Is it possible to somehow access the BTC? Thanks!


texts: How can I verify the BTC supply with my own node?

texts: With all the supply talk going on I wanted to verify the active supply on my new node I got. What is the best way to "run the numbers" I am running a raspiblitz node.


texts: I just compiled bitcoind and run for the first time. Do I already have a private key?

texts:
Since I have a wallet.dat I suspect I already have a private key and so I could extract it for backup purpose (on paper).

How do I do it via terminal with bitcoin-cli?


texts: How can the blockchain be used to verify "rarity"?

texts:
The question was inspired by this article, about an art collector, who said that he knew that the piece of art he was collecting was "rare," with only 391 copies, because of the blockchain.

First, would this have been recorded on the original blockchain itself, or just a blockchain "knockoff?" Second, how would the blockchain "tag" all 391 copies and then trace them? Suppose someone made a counterfeit of the picture, would the system "know" about this, and fail to tag the fake copy? How would the blockchain mechanism operate in this, or similar contexts?


texts: I'm trying to confirm my BCH is being held on my trezor

texts: When I go to https://trezor.io/claim-bch/ I'm being told my trezor needs a firmware update. However, I have updated my firmware on wallet.trezor.io. Is there an issue with claiming BCH? If not, why am I being told I need new firmware? My firmware version is 1.5.0.


texts:
Assume I am running a mini-blockchain that is I only have blocks' headers but no transactions. I wish to verify a transaction of a third party. For that I need the transaction's path to the Merkle root. Given that no one stores Merkle tree and it is computed on the fly. My question is that who will compute Merkle tree. That is:

Option # 1) I will receive all transactions hashes of the block and I will be computing the Merkle tree myself. Pitfall: That implies, I will be receiving lots of data and sender has to send lots of data.

Option # 2) A node running full-block chain will compute Merkle tree and will send me only the transaction path. Pitfall: the sender will be computing Merkle trees of lots of people. What reward he is getting for his services?

I feel both options are not ideal. May be there is a third option which I do not know. I will appreciate your reply.

PS: Please also point me towards a publication which has all the information.


texts: Stateless bitcoin daemon for server, capable of signing transactions

texts:
I am trying to do the following:

Have a daemon running on a server
That daemon exposes an API (Json, etc...)
I can call that API from localhost with:
1: Address From
2: Address To
3: Key for Address From
The daemon creates a valid transaction using the unspent outputs, signs the transaction using the key, and broadcasts it to the network, then forgets about the key.

I don't want the daemon to store the private key (stateless) and sign transactions on-demand. The daemon should be as light as possible (if possible, use less than 256 MB of RAM).

I looked at Bitcoind but it doesn't seem to provide that kind of API, since I either need to setup the wallet with the private key beforehand (not stateless) or build the raw transaction from scratch, and I don't want to have to figure out the outputs to use, format of the raw transaction, etc...

What's the easiest way to achieve this?


texts: Any method to check balance of particular address in bitcoin core (0.18) using json rpc?

texts:
Setup bitcoin core (0.18) in my local node.In new version maximum methods are deprecated.I create new address using json rpc method and send some coin s on it.Now I am unable to check the balance of particular address.In this link its shows I received some amount. https://www.blockchain.com/btc/address/37pwsrhT3gkWpDgTxskWf4m4eUiZ9CXJzJ

I am getting issue in many method.I try to use sendtoaddress method using jsonrpc but how they will recognize from which account I will transfer amount.

I also try to dumpprivate key of some address but this method returns me blank array.

Please help me out from all of this issues.

Thanks in Advance!


texts:
The following commentator writes:

  When transactions are announced to the Bitcoin networks, they appear as part of a ‘block’. Bitcoin blocks are produced on average every 10 minutes. Bitcoin blocks have a maximum size, so if there is no room then your transaction will be delayed. If you are desperate to have your transaction included in a Bitcoin block promptly, you will have to increase the transaction fees that you pay to the Bitcoin network.

Now it seems if you had a flexible block size - this transaction confirmation time issue would be addressed.

My question is: Are bitcoin transaction confirmation times limited by block size?


texts: Why can the race between the honest chain and an attacker chain be characterized as a Binomial Random Walk?

texts:
I am not familiar with Bitcoin, hope someone can tell me why. Thank you!
Let's consider the following scenario.
The probability of the attacker finds the next block is q and the probability of the honest node finds the next block is p.
Suppose the attacker and the honest node began to find the next block in the meantime (so they spend the same time on finding the PoW solution). If now the attacker finds the next block, since the attacker will not broadcast the block, it won't affect the honest node. The honest node will continue to work on its own PoW. So maybe the probability of the honest node finds the next block is larger than p now (Because the honest node now will spend more time than the attacker on finding the solution of the next block's PoW).
Why can Satoshi consider this catch-up process as the gambler game? Is this just a simplified math model? Or is there any procedure I don't know such that once one node finds the next block, all miners will restart their mining work?


texts: Why the bitcoin address is not valid in any of the testNet faucet

texts:
I develop a simple Java/Maven/JSP app for bitcoin and generated the address
    167Bqf3Mi3gnfhw5DhCfoYNTMxqANt3Zky
I would like to send some money to this address from a bitcoin testnet faucet. I feel it weird that none of the testNet faucet out there seems to recognize the address and indicate it as invalid. Funny thing is I used the same code for generating the address that is provided in the BitcoinJ github page.

How should I approach from here?


texts: Building an blockchain address monitoring service. Best way to monitor an address for bitcoin and other altcoins?

texts:
I'm looking to build a blockchain address monitoring service for bitcoin and other altcoins. What is the best way to monitor a bunch of addresses for incoming/outgoing transactions?

Currently I wrote a php script that checks the address every 5 minutes for any new activity and then store this data to a file and then another 5 minutes I fetch the data again and diff the file to see any differences and if so do something.

Another method I was thinking was to fetch each block as its mined then see if any of the addresses match what I have listed then do something.


texts: How is BIP 158 wallet rescanning supposed to work with xpub keys?

texts:
A light client implementing BIP158 downloads filters and checks its addresses against that filter. If one matches, it downloads the block.
Now, let's say we have an HD wallet (BIP32), and/or an xpub key. How would we decide whether to download the block, based on the filter? Do we have to iterate over all possible derivations/addresses (potentially thousands) for each filter? Is there a more efficient solution?


texts: Is Bech32 transaction on blockchain.info size accurate?

texts:
I have made a transaction and paid like 120 sat/B, on blockchain it says that I've paid 78.995 sat/B and noticed that transaction size is 191 (bytes)

Transaction size supposed to be: 102 (input) + 32 (output) + 10 (headers) = 144 Byte

Is this a problem of blockchain.info and transaction fee is right or the wallet didn't send the correct fees and Do miners take my transaction as I paid 120 sat/b or 78 sat/b?

87e4a93012116020d7c385d92a0d307363e8040bfb89800c709f66c47ca58316


texts: Error parsing JSON in bitcoin-cli signrawtransactionwithkey

texts:
I have issues trying to sign a 2/3 multisig tx with the first private key.

What am I doing something wrong or am I missing something for the arg?

Command format:

/usr/bin/bitcoin-cli -testnet signrawtransactionwithkey "multisig_tx_hexstring" \"privatekey1\"  {\"txid\":\"id\",\"vout\":n,\"scriptPubKey\":\"hex\",\"redeemScript\":\"hex\"}

Filled in:

/usr/bin/bitcoin-cli -testnet signrawtransactionwithkey "02000000017b0cd6ab6beebace32e00f27aea8092879e178a77d2d0e74d001e10b39f560d10100000000ffffffff0100093d000000000017a9145e235c002eb66a1c33abccfb805043a036baf7798700000000" \"cNoe7mVGEVFwUwQXuCJadosEVPYU5rcCVxzTr46gYWbWMD8gXR7b\"  {\"txid\":\"d160f5390be101d0740e2d7da778e1792809a8ae270fe032cebaee6babd60c7b\",\"vout\":1,\"scriptPubKey\":\"a9145c975f4c6d18fa1abd25018e1fa3c18e58c9e93b87\",\"redeemScript\":\"5221029558bd8bc6e0cac883cac93a420bf8e68e76e8e07944f6034e3c5eadd3f1a4db21038d217a8fa3960a3b3212bc545566c5c48add11003551cb23c0d744a13f9ab8272102fcd0e6ff324c7a3bc9a8e224d61cd9ccd244c54186848ca3035a54736a9780d653ae\"}

And the error:

error: Error parsing JSON:"txid":"d160f5390be101d0740e2d7da778e1792809a8ae270fe032cebaee6babd60c7b"


texts:
Deterministically signing a Tx with RFC6979 returns v, r, s, where r and s are the 2 values used in standard ECDSA signatures. v = 27 + (y % 2), so 27 + the parity of r, as pybitcointools indicates.

So for even r, we get v = 27, odd r we get v = 28.

How is the value of v (27 or 28) important? Why is it necessary to have a v value? Also, why is it 27?


texts: Bitcoin recovery - forgot my 12th recovery word for recovering my crypto account

texts:
I have managed to forget the last (12th) mnemonic word to my crypto-account.
Could you please show me how I can find software with which I can enter recovery words from a file so that I can attempt recovering by changing the last word, which I do not know, from the dictionary.
I have read some answers but did not understood how to do it.


texts: How is a miner prevented from adding transactions without signatures to their block?

texts:
Consider I'm a miner. I mine on my own, I don't mine in pools. I have power enough to find the hash, lets say, once per 2 years.

When I find the hash within those 2 years I send the block back to the network and since the hash is low enough the block would be accepted and added to the block-chain.

It's up to miners (so me) to check the transaction signatures but the block AFAIK doesn't contain the signatures. How can others within the network can be sure that all the transactions in my block which I calculated were signed?

If I was an evil miner, I could have added a transaction without a signature. How is this prevented? Am I the only one who checks the signatures within my block?

Thanks for explanation.


texts: Two identical R value finding z value from two transaction


texts: I see quite a few answers from Joel Katz, and a friend of mine referred to him as "a Ripple founder". Is this true? His name is not mentioned on this question.


texts: Why does the wallet keep a pointer to the best chain

texts:
When I run Bitcoin core to synchronize the blockchain without getting innvolved in any transaction, the wallet.dat gets written to nevertheless.

I believe this is the case because the wallet keeps track of the best chain. (However, I am not sure if this is the only change that is written to the wallet.)

Now, I am wondering why the wallet needs to keep track of the best chain. My possibly faulty understaning is that there is a consensus about the best chain which can be deduced from the blockchain. Hence, no seperate storing of it should be necessary.


texts: C secp256k1 : ec_pubkey_parse successful on NULL context despite attribute

texts:
Looking at the main API file secp256k1.h of the C library, we have:

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_parse(
    const secp256k1_context* ctx,
    secp256k1_pubkey* pubkey,
    const unsigned char *input,
    size_t inputlen
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);

Hence I am expecting the function secp256k1_ec_pubkey_parse to fail if any of the three pointer arguments are NULL. This is indeed the case when pubkey or input are NULL (and in fact if we set up a callback function with secp256k1_context_set_illegal_callback, it will be duly called with the appropriate return value). However this function succeeds on NULL context. Does anyone know why this is happening? Is this the expected behaviour? I am guessing this isn't very important, but I am trying to learn and I don't like it when I don't understand. I attach a C snippet:

#include "secp256k1.h"
#include <assert.h>

int main()
{
  int return_value;

  secp256k1_context *ctx;
  secp256k1_pubkey pub;

  ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);

  // This is a valid public key
  const unsigned char *pub1 = "\x03"
    "\xf0\x28\x89\x2b\xad\x7e\xd5\x7d\x2f\xb5\x7b\xf3\x30\x81\xd5\xcf"
    "\xcf\x6f\x9e\xd3\xd3\xd7\xf1\x59\xc2\xe2\xff\xf5\x79\xdc\x34\x1a";

  // secp256k1_ec_pubkey_parse
  return_value = secp256k1_ec_pubkey_parse(ctx, &pub, pub1, 33);
  assert(return_value == 1);  // public key is indeed valid

  // same call with NULL context
  return_value = secp256k1_ec_pubkey_parse(NULL, &pub, pub1, 33);
  assert(return_value == 1);  // call is successfull

  // secp2561k1_context_destroy
 secp256k1_context_destroy(ctx);
}


texts: Electrum personal server rescan-script.py

texts:
when i run the rescan script i get the following output:

Traceback (most recent call last):
  File "/home/bitcoin/electrumserver/eps/rescan-script.py", line 71, in <module>
    main()
  File "/home/bitcoin/electrumserver/eps/rescan-script.py", line 67, in main
    rpc.call("rescanblockchain", [height])
  File "/home/bitcoin/electrumserver/eps/electrumpersonalserver/jsonrpc.py", line 58, in call
    raise JsonRpcError(response["error"])
electrumpersonalserver.jsonrpc.JsonRpcError: {'code': -32601, 'message': 'Method not found'}

I am very new to this, so please explain for beginners :).


texts:
I am wondering if it is possible to give someone a bitcoin transaction ID and with that he can read some hidden data, like the blockchain.info notes on transactions, but for real, stored in the blockchain forever.

I had this idea but I don't think if it would be a good practice:

Send the minimum amount of BTC possible, wich is 0.00000001 BTC, or 1 satoshi, to an address, and in that address would be the data.

1 ArFAXhvMbwJuub4ujnVbLFszqX3McuzsX

As far as I know, the address is formed by 30 letters in base58, but since the first char must be 1 and the last four have to be the checksum, then you have 25 letters in base58, and that's like 17 bytes.

So, you have to pay like 0.0001 BTC for the transaction fee, and after that you can add data to that transaction at a price of 17bytes per 1 satoshi, by sending satoshis to many addresses that contains the whole data. Imagine if we could store data there forever,.. and communicate with the future...

Is there any other technique of doing this? Is this technique a good practice?


texts: It seems to me that to keep Bitcoin both decentralized and secure, the whole of the Bitcoin process should ultimately depend on each user, or rather, that the involvement of each user should incorporate all aspects i.e. mining, full nodes, wallets, and exchanging.  Perhaps this is too much to think about at this stage, or maybe I simply have not found this, but is there any product or community that is focused on empowering individuals with simple systems that incorporate ALL of these aspects, and may I dare say, while being itself decentralized?


texts: Difference (if any) between proof-of-work in mining bitcoin vs verifying transaction

texts:
I'm trying to understand the proof-of-work idea for verifying a transaction. I think I understand why proof of work is needed to verify transactions (essentially to prevent spoofing/double spending etc).

But my understanding is this:

the proof of work for verifying a transaction is the same as for mining a new bitcoin
if this is the case, then it becomes harder and harder to verify transactions.

I'm pretty certain the first statement is false, in which case I'd like to know what exactly is the proof-of-work for verifying a transaction.


texts: Why is my P2SH sigScript field prepended with 0x00?