texts: Understanding how validation of a transaction works

texts:
As far as I understood, a transaction works like this:

Alice wants to send 5 BTC to Bob. Alice creates her digital signature that contains transcation info like id etc. She encrypts the signature with her private key. She creates scriptPubKey and scriptSig, she has the Bitcoin-Adress of Bob.

This transaction has to be verified by nodes. A node checks this transaction. He checks if Alice really has 5 BTC by checking her input. If it's ok, then all is fine. The node additionally checks Alice's digital signature. The node extracs Bob's Bitcoin Adress from Alice's signature. If it's ok, the Node puts the transaction to the mempool.

Nothing was mined until here. Now, due to the broadcast system and p2p network of Bitcoin, a Miner picks this transcation from the mempool.

What does he do now? Does he assume, that the transaction is valid or does he check the transaction again ?

If he does not check the transaction again, and assumes, that the transcation is valid, he creates a Merkle-Tree of several transactions, puts it in a block. Uses SHA-256(Blockhash+nonce) and tries to mine.

Is that right, what I've understood so far or did I make a mistake ?


texts: How can a bitcoin ATM charge less than the average bitcoin transaction fee?

texts:
As of this writing, the average bitcoin transaction fee is over $30, according to this chart. However, I just bought $20 worth of bitcoin from an ATM, and they charged me a fee of around $2.00.

My understanding of the fee for a transaction is that it is a function of market forces, the number of bytes in the transaction, and the time you are willing to wait for your transaction to be added to the blockchain. Overall however, I had the impression that at a given time these fees are relatively constant per transaction. So I would expect that the owners of the ATM would have to spend something around $30 in fees to give me my $18.00.

I asked a similar question about coinbase.  In that case the explanation was that coinbase wasn't actually transferring any bitcoin on the blockchain.  However, this ATM printed me a new wallet, which I assume means a new bitcoin address was created and bitcoin was transferred to it on the blockchain.

What don't I understand?


texts: Why can't coins be sent from testnet to mainnet?

texts: Why prevents bitcoins from being sent from the testnet to mainnet?


texts: How to access a blockchain.info wallet's funds from another site like greenaddress.it

texts:
I have imported a wallet to Blockchain.info but because my country now blocks the access to Blockchain.info I can't access my funds in that wallet. How can I import or somehow link my wallet to another wallet in greenaddress.it.

I have the mnemonic phrase that Blockchain.info created for me, but I don't know if it can be of any help for me to have access to my private key for that wallet without accessing Blockchain.info website. I believe if I can somehow extract the private key for that wallet I can easily import the wallet into greenaddress.it

Can anybody give me a solution

Thanks


texts: The Bitcoin scripting system is purposefully not Turing-complete - why?

texts:
Can somebody explain to me why the Bitcoin scripting system is purposefully not Turing-complete? To make malicious programs difficult to develop (I guess)? Or because it was difficult to make it Turing-complete?

  Bitcoin uses a scripting system for transactions. Forth-like, Script
  is simple, stack-based, and processed from left to right. It is
  purposefully not Turing-complete, with no loops.

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


texts: Why does using a wallet in cold storage make it less secure?

texts:
According to How to set up a secure offline savings wallet,

  Every time you retrieve bitcoins from your savings wallet, create a fresh savings wallet by repeating the above procedure, and send all your remaining savings balance there.

Why do you need to create a fresh wallet after retrieving a few bitcoins?

Is the receiving address no longer valid?

How can you create a secure offline wallet, send bitcoins to it, and then test it to make sure that it works by sending a small amount out?


texts: Comparison BTC and ETH uncomfirmed transactions queue

texts:
When I compare BTC mempool count and ETH transaction queues, ETH queues are much larger. I would appreciate explanations why it is so.

*BTC mempool count

https://blockchain.info/ja/charts/mempool-count

*ETH transaction queue

https://etherscan.io/chart/pendingtx


texts: My Bitcoin Cash is stuck unconfirmed when sending to Bittrex from Electron Cash. Please help!

texts:
I have an unconfirmed transaction with a non-trivial amount.

I had my BCH in Breadwallet, and I created a new wallet in Electron Cash and imported the private keys, which then reflected the balance of BCH in my new wallet. I was connected to the server: electrum-abc-criptolayer, but when I tried to send my coins to Bittrex, it asked for Trusted-coin's 2FA. I then changed the server to electroncash.cascharia.com, and I SOMEHOW had Trusted-Coin's 2FA code in my Google Authenticator app (not sure how I got it?), and it said the balance was sent. I accidentally sent an incredibly low fee. Now, my BCH is unconfirmed for a day, and it's not showing up in block explorer. I'm not sure what to do, no-one knows how to help me.

Txid of address that had BCH: f9425d67d6707842d45e255003a3147531767f557ab9d17912b87d76a6d69b49

Txid of address I tried sending it to:
20a0f1ab48bbf91b06ab3ca2c332c52cc11e250df82123cbe272913f3dd551f8

Please help, I am willing to PAY someone a generous amount to help me get this shit out.


texts: Why do bigger blocks make it more expensive to run a full node?

texts:
Does it cost more storage?
For the transaction verification, to which extent bigger blocks make it more computational intensive?
In terms of computational complexity, is the verification process a O(n) computation or anything else?


texts: As I know, wallet.dat saves all related data for a bitcoin wallet.  However, I don't understand what precisely is saved in the wallet.dat.  I think it must contain several private keys. Does it also contain the corresponding public key, and seed value?  Anything else?


texts: How do miners send blocks to network peers?


texts: What is the Witness and what data does it contain?

texts:
I've learned about the Segregated Witness but couldn't find info on breaking it down.

I know usually when legacy addresses are used the public keys for example will be under Scriptig.  With P2SH, I can see that the ScriptSig contains the hash of the redeemScript which must match the hash of the address in the Output ( I think). But I am not sure about the witness data.

Let's take this TX:
80975cddebaa93aa21a6477c0d050685d6820fa1068a2731db0f39b535cbd369

What info is in the witness, can someone break it down please?


texts:
I am hoping someone much smarter than i regarding bitcoin can point me in the right direction.
And im sorry if my questions sound dumb....

I am trying to work out how i can check if a transaction has been made to a specific address
(so my "ecommerce" system knows the payment was made).
I would however like to do this without relying on 3rd party sites/API's

I though the answer maybe to run bitcoind on my web-facing server, but now im not so sure; As it seems i can only get transaction details for addresses within my wallet (stored on the web server) and i did not plan on having the BTC stored in the online wallet as i only wanted to check the transaction and store the BTC's in an offline wallet.
(if i was to store BTC in a wallet hosted on a web server is this a BIG security risk of having my lovely BTC's stolen?).

I have spent all night (now 7.30 am) trying to work out a plan of action, but think i am now more confused than when i started :-(

I would be very grateful if anyone could point me in the right direction as i really want to develop a BTC related website (and think i may have a good community based idea for a site).

Best Regards
Ford


texts: What is the Elliptic Curve algorithm used in Ripple to generate public / private key pairs?

texts: The algorithm used by bitcoin to generate keys is secp256k1, is it the same for ripple?


texts:
What I mean by "completely automated" is, if all the below are taken care of by the client, no human effort is involved.

Collecting the transactions
Creating a new block

If possible can someone explain or redirect me to a resource explaining the whole mining process in detail with technical specifics.

Can a miner choose which transactions should go in which respective block?


texts: Does a soft fork result in two different blockchain versions?

texts:
I've read the following:

Both forks create a split, but a hard fork creates two blockchains
and a soft fork is meant to result in one.

Let's consider 2 situations:

block size max limit is 1mb and bitcoin introduced a new version which increased block size limit by 1, so it's 2mb now. Now, this is called hard fork, since new versions wouldn't be compatible with the old ones, because when new versions solve a block (let's say 1.5mb), old ones wouldn't accept it. (NOTE: if old ones send blocks to new ones (since old ones would only solve blocks with less than 1, new ones would always accept it)); So new ones can't communicate with old ones, but old ones can with new ones.

block size was 1mb and now, we decreased it by 0.5, so it's 0.5mb now. Now, new versions are compatible with the old ones, because, new versions would always solve blocks with 0.5mb or lower and when they send it to old ones, they would accept it. (NOTE: when old ones send blocks to new ones (since old ones might solve block with 0.8mb, new ones wouldn't accept it)); So, new ones can communicate with old ones, but old ones can't with the new ones.

Do you agree with the above? If so, why in my first sentence, does it say: that a soft work is meant to result in one ? It won't result in one, since when old ones solve blocks bigger than 0.5mb, new ones wouldn't accept it, so we still would have a different version of blockchains. Any idea?
UPDATE: @Murch, you say in the second one that since the small blocks(from new nodes) are acceptable to the old nodes, big block nodes will reorganize to the small block chain.
If 5% minority(which work on old big block chain) solves a block, only those 5% nodes will add it to their chains. 95% wont, since they have smaller limit on block size. Now, 5% minority nodes have the last block different from the last block of 95% majority.(length of both chains are the same - that could have been since after splitting the chains, 5% solved it in the same seed as 95% on their respective chain). if 95% majority now produces a new block, and share it to 5%, they still won't add it because  this newly shared block's prev hash won't match their last block's hash. So in this case, 95% majority will produce a newer block faster(at least now, the lengths are not the same), so now, majority will share 2-3 blocks to minority since they have the longest chain and that's why minority will adapt to majority's chain in the end. Is my explanation and understanding correct ?


texts: How to structure a Bitcoin charity miner?

texts:
I'm working on a project involving mining Bitcoins for charity. I'm writing my own miner, and though I may eventually set up my own pool for this purpose, for now I'm planning on using existing pools.

My question is: how can I set up the miner so that people can use it to mine toward my organization's Bitcoin address (if having a single address is even the right approach to take), without exposing this address to theft from anyone who reads the credentials from the miner's getwork requests? My understanding is that the HTTP Basic Auth used in getwork requests doesn't pass values in a safe way.

As is probably evident from this question, I'm generally pretty fuzzy on how wallets interact with payouts from mining pools and/or Bitcoins stored in accounts with said pools, so any explanation there would also be greatly appreciated.


texts: BFGMINER error while loading shared libraries

texts:
I just installed BFGMINER on my Ubuntu 12.04LTS laptop and it won't let me set it up with my pool.

administrator@T41-Server:~$ sudo bfgminer -o api.bitcoin.cz:8332 -u wizardmorax.ibm_ubuntu -px -S all
bfgminer: error while loading shared libraries: libblkmaker_jansson-0.1.so.0: cannot open shared object file: No such file or directory

I followed a tutorial for installing BFGMINER
http://www.linuxconsultantsireland.com/content/bitcoin-mining-raspberry-pi-usb-asic-miner-block-erupter

Thanks,
Jackson


texts: How is the Bitcoin node network different from the IOTA network?

texts:
I asked this question on IOTA's forum here:

Real incentives for running a full node?

One of the founders from IOTA Come-From-Beyond (Sergey Ivancheglo) responded with this comment:

  "However, given that IOTA collects no fees and does not reward node
  operators, what actual plausible incentives exist for running one?" --
  How are Bitcoin node operator rewarded? Answer my question and you'll
  probably get the answer to your own question.

I'm curious how someone knowledgeable about Bitcoin would respond to this question and comparison? Can this question about IOTA's network incentives and viability be answered by asking the same question about Bitcoin?

What are your thoughts about this?


texts: C++ error building a fork of Bitcoin-ABC

texts:
I'm creating a Bitcoin-ABC based altcoin, everything was fine when I compiled dynamically for my Ubuntu machine, but when I try making a static release build I get:

  CXXLD    libbitcoinconsensus.la
.libs/libbitcoinconsensus_la-arith_uint256.o: In function `base_uint<256u>::GetHex() const':
/root/xeroxcoin/src/arith_uint256.cpp:135: undefined reference to `base_blob<256u>::GetHex() const'
.libs/libbitcoinconsensus_la-arith_uint256.o: In function `uint256S(char const*)':
/root/xeroxcoin/src/uint256.h:123: undefined reference to `base_blob<256u>::SetHex(char const*)'
primitives/.libs/libbitcoinconsensus_la-block.o: In function `CBlock::ToString[abi:cxx11]() const':
/root/xeroxcoin/src/primitives/block.cpp:23: undefined reference to `base_blob<256u>::ToString() const'
/root/xeroxcoin/src/primitives/block.cpp:22: undefined reference to `base_blob<256u>::ToString() const'
/root/xeroxcoin/src/primitives/block.cpp:22: undefined reference to `base_blob<256u>::ToString() const'
primitives/.libs/libbitcoinconsensus_la-transaction.o: In function `COutPoint::ToString[abi:cxx11]() const':
/root/xeroxcoin/src/primitives/transaction.cpp:13: undefined reference to `base_blob<256u>::ToString() const'
primitives/.libs/libbitcoinconsensus_la-transaction.o: In function `CTransaction::ToString[abi:cxx11]() const':
/root/xeroxcoin/src/primitives/transaction.cpp:132: undefined reference to `base_blob<256u>::ToString() const'
script/.libs/libbitcoinconsensus_la-interpreter.o: In function `uint256S(char const*)':
/root/xeroxcoin/src/./uint256.h:123: undefined reference to `base_blob<256u>::SetHex(char const*)'
collect2: error: ld returned 1 exit status
Makefile:3619: recipe for target 'libbitcoinconsensus.la' failed
make[2]: *** [libbitcoinconsensus.la] Error 1
make[2]: Leaving directory '/root/xeroxcoin/src'
Makefile:9581: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/root/xeroxcoin/src'
Makefile:690: recipe for target 'all-recursive' failed
make: *** [all-recursive] Error 1

This is with nearly vanilla Bitcoin-ABC code, and it looks to me like base_blob DOES exist and DOES have those methods.  Help?


texts:
What is the difference between a full node and a lightning (network) node?

If a lightning node, that is not a full node, opens a payment channel with another lightning node, how can the first peer check that the other peer does not send a "malicious" closing-channel transaction to the blockhain?


texts: Bitcoind writes complete wallet.dat regularly which is a problem, what can i do?

texts:
i have troubles with my system, using iotop i identified bitcoind as the source of problems.
I am running bitcoind of bitcoin-0.10.0-linux32 and am using the RPC calls of bitcoind. My wallet file is 112 MB.
My assumption is everytime an a new bitcoin address is created the whole wallet file is written to disk. In iotop i see that about ~110MB is written to disk regurarily by the bitcoind process. This is problematic for the system setup because it slows down other processings significantly. And this happens often, more than 1 time in a minute.

Can i do something about it?

Thank you
Cahoiner

*************Edit*************

This problem still exists with current bitcoind 0.11.2.

I assembled statistics with inotifywatch. I watched the bitcoin directory for 4800 seconds, the results are:
Wallet file modifications: 7585738 (ughh !!)
Modifications in subdir chainstate: 1290930 (also high, pls lower this)


texts: What is the difference between signrawtransactionwithwallet vs signrawtransactionwithkey in signing unsigned raw transaction?

texts:
I have a bitcoin address generated in bitcoin-core (offline computer)
I imported that one address into electrum as a watch-only wallet (online computer)
From electrum I created an unsigned transaction scan it back using QR code to the offline computer.
Which one should I use to sign the unsigned transaction using bitcoin-core? signrawtransactionwithwallet or signrawtransactionwithkey? If possible please tell me the different cases of which one to use?
Please also tell me if there is any better way to sign unsigned transaction using bitcoin-core.


texts:
I am interested in mining bitcoin here in the UK. I have done a quick search and cannot find anything relevant. If I were to use a cloud mining service to mine bitcoin, would it be counted as income AND/or would it have to be taxed?

Could a link also be posted so I can see more information on it please?


texts: Is it possible to send one satoshi to every bitcoin address?

texts: As a random whim, I want to see if it's possible to send one satoshi to every bitcoin address that's ever been used. How much would that be? I'm betting the transaction fee would be a lot more, though. Is this even possible? How would I do it?


texts: Ripple: a strange send I don't quite understand

texts:
A few days ago I've sent Bitstamp through Ripple 0.3168 BTC.

I had 0.4168 Bitstamp BTC before, and 0 BTC balance with everyone else.

Now strangely I noticed that instead of Bitstamp owing me 0.1 BTC as expected, it owes me 0.2022 BTC, while I owe to a friend of mine 0.1022 BTC.

While it sums up, I wonder what's the deal:

why didn't it send entirely Bitstamp BTC to Bitstamp?
how are us supposed to settle that? i.e. should I explicitly send BTC through Ripple to my friend, or simply when he tries to spend them he'll tap from my pool (hence no explicit action is needed)?


texts: Bitcoin Core full node wallet - questions about security & recovery

texts:
can you tell me pls,

1)  Which secure full node wallet implementations exist? Currently I just know of bitcoin core. Is there not any other one with a GUI?

2)  Can you use a Ledger device with those full node wallets?

3) Many wallet apps like "Ledger Live" use their own servers for transaction verification. What is the case if you use a full node wallet like Bitcoin Core? Whose servers are you pinging there during transactions?

4) Can the bitcoin core wallet censor in any way your transactions, hide them or simulate, prolong them?

5) In bitcoin core, how is the funds recovery mechanism? Is it "Hierarchical Deterministic", can you you always restore your funds with a 24word mnemonic (also by other HD wallets)?

6) If someone for example gets access to your computer where your bitcoin core  wallet is installed on, would this person be able to freely access the wallet and transact with it? What security mechanisms are in place for that scenario?

7) How can you restore funds with bitcoin core when you lost your computer where the wallet was installed on? Which different recovery options exist?
Is bitcoin core wallet compatible with this recovery mechanism listed in github:
https://github.com/iancoleman/bip39

Thanks everyone for educating me!


texts: How to find values of Prev_Hash and Tx_Root

texts:
https://bitcoin.stackexchange.com/a/13347/27951

Based upon the answer here, it seems there's values per block with each Prev_Hash and also Tx_Root

There doesn't seem to be much documentation for how to access these. How can I find the Prev_Hash and the Tx_Root of the most recent block for example?

Thanks


texts:
What is the minRelayTxFee?
What is it used for, what's the default value and how does the value change?


texts: What causes synchronous price movement within and between crypto exchanges without matching trades?

texts:
I have observed different crypto exchanges for quite some time now and analyzed the potential for different kinds of arbitrage. However, I don't quite understand what I am seeing.
Examples:

Observing Poloniex and Binance web socket streams for the same symbol, it seems like most of the time Poloniex lags behind Binance but it generally moves the same way. Interestingly, these price movements occur without any (visible) trades happening. What could cause this effect? Who makes money from this if there are no trades?
Triangular arbitrage rarely seems profitable within one exchange. I would expect that multiple symbols on a smaller exchange like Poloniex would need some time to return to balance after a major price movement. However, it seems like markets adjust faster than the real-time web socket API will let me look at the situation (1ms latency).

The attached image (sorry, didn't find a bigger one in my files) shows Binance (blue) and Poloniex (green) prices moving. There are no trades on Poloniex during this time.


texts: Is it possible to create pure lightning lockboxes (without touching the blockchain)?

texts:
I'm considering a scenario in lightning, where it would be extremely useful to be able to lock the funds in 2/3 lock

Is this possible on lightning network (even in theory)?


texts:
I have an off line laptop that will not let me sign the transaction.  I am running Armory .92.3 and Bitcoin Core .9.2.1.
I know that I need to upgrade to a new computer.  Any thoughts how and the process would be very helpful.


texts: Where to store coins while I do a factory reset on my computer?

texts:
My Macbook is having some issues and I have a desktop wallet on it for Bitcoin, Litecoin and Ripple.

I have been told to completely redo my laptop with a factory reset. How can I move or save these coins while I restore my Macbook?


texts: trying to get text of a field in json rpc 2.0 response into ar PHP variable

texts:
I use json_decode to vardump a return which yields

array(3) { ["jsonrpc"]=> string(3) "2.0" ["result"]=> array(13) { ["status"]=> string(7) "Pending" ["amount (BTC)"]=> string(10) "0.05130899" ["index_url"]=> . . . . [more fields  here] . . .  ["address"]=> string(34) "1GHHojoC4Ai1SPMN3YoNzemLNaaj2XFHKc"

I am trying to fill a variable with the text from the "address" field and I tried

$result =  json_decode($response, true);
   $address = $result->address;

but a varbump of $addrwss is NULL

any other variant like $result->"address" or $result->["address"] is improper syntax

Can someone tell me how to get at the text of the address field of a JSON PRC 2.0 response to put it in a variable in PHP


texts: In Elliptic Curve Addition, where does the second point come from?

texts:
I have a limited understanding of elliptic curve terminology, but if you can bear with me I'd like to ask this question anyway. I'll start with what I understand...

You do EC multiplication with the private key to get the public key.
EC Multiplication is just EC Addition (done over and over again).
EC Multiplication can be achieved through a combination of EC Addition and EC Double (for speed).

From the perspective of the graph:

EC Double = draw a tangent on your current point, take the intersect, invert it.
EC Addition = draw a line through your current point and a second point, take the intersect, invert it.

EC Double I understand -- you have your current point and you draw a tangent -- no need for any extra points on the curve to get the intersect.

But in EC Addition, if I have my current point, where does the second point on the curve come from when attempting to draw a line across the graph to find the next intersect?


texts: Can a system of trust be built on top of the current block chain

texts:
One way to expedite small transactions would be to have all of the miner shun all further transactions by someone who has attempted a double spend, then if someone only wants to transfer less than 50% of their wealth then it can be assumed that it is a valid transaction because their expected return with a successful double spend is exactly what they would do with a valid transaction.

As far as I understand all that would be needed for this to be put into place would be to update the protocol, the blockchain can be preserved. Am I wrong? Is this a bad idea?


texts: Is there any blockchain-based mail services available?

texts:
According to technology behind the Bitcoin, I'd be interested in using decentralized blockchain-email. Cryptamail was only one I found but they've been told that it is in beta right now but last update seems to be in year 2014. The site isn't working.

Is Cryptamail really something, what we have to wait before start using decentralized email at tor-network or upperground?


texts:
My claim was accepted on MtGox.com - how do I get the cash out?

It lists a Yen figure but it's totally unclear what to do next.

Is it too late to transfer to Kraken and get bitcoin back?

How can I do this, can't find anything online - only options are to view, change password and transfer the amount to another person?!


texts: What has OP_RETURN been used for over Bitcoin's history? How were these use cases enabled?


texts: what happens when their is a bicoin algorithm half?

texts: I saw in an article something about a bitcoin algorithm half in 2020, what exactly is this, I have tried looking this up but I couldn't find anything that told me what it was only this.


texts: Blockchain API - Returns "Read timed out" when calling my website callback

texts:
I'm receiving payments using Blockchain API.

The receiving payment part works but after that, when it's supposed to call a link on my website to inform about the payment, it's not working.
I'm using blockchain's callback tester found on their API page at https://blockchain.info/api/api_receive

My website should return Ignoring test callback but it returns Read timed out. Also it returns the same on every link from my website I put in.

P.S: I'm using an SSL certificate and in my .htaccess I'm forcing the website to request to go to https:// from http://.


texts: I want to display information about my bitcoin node on a webpage (php or html)

texts:
I want to show information about my bitcoin node on a website.. how can I do this with windows + php + html + javascript + rpc?

I want something like that but with more information and perhaps more dynamic:

Example page:   http://199.58.210.124/


texts: Do you need to be connected to the internet to send someone bitcoin?

texts: Say I walk into a store that accepts bitcoin. I decide to buy something and go to the counter. I get my smartphone out to pay the bitcoin. Does my smartphone need to have an internet connection to send the store my bitcoin?


texts: What happens if a miner confirms their own double spend?

texts: Suppose an attacker makes a double-spend and controls the mining pool that happens to find the good which confirms the transactions.  What happens?  I suppose the network hopes that a vigilante sees the double spend on the block chain and notifies everyone. Then what happens?  Do the mining pools coordinate and remine the block?  Seems like a big disruption.  Is there a more elegant solution?


texts: How can we know our "from" address in advance?

texts:
This website ask me to enter the address FROM where I would be sending BTCs.
But every time a send some BTC it seems to be sent out from a different address...
Should I use the one I always see when I say I want to "receive" some BTC? Is it my "main" address?


texts: Why transaction shows in received but does not show in balances

texts:
I had a transaction sent while the Bitcoin Core was syncing.  Now the transaction shows up in the received transactions but there is no balance.
Is it possible to recover the coin so I can move it to a different wallet.


texts: I sent BTC to an old address, Can I get them back?

texts: I sent BTC to and old address of a friend. I`ve checked the status on blockstream.info and it is said that it has 1860 confirmations. Is is possible to get the BTC back?


texts: Is it necessary for blocks to record the nBits difficulty parameter?

texts:
The next difficulty to solve a block is determined from how fast blocks were solved before it. In addition, the difficulty only changes once every two weeks or so.

So, couldn't every node keep track of the expected difficulty and not need to have it in each block header? Or is there a reason nodes need to be communicating the current difficulty in each block? Not that it would be a major savings, or anything, it just seems strange that this is included when it's just a function of all the other pieces of a chain.

Maybe it's because calculating nBits would take a long time eventually if you had to go through all the block headers every time you wanted to calculate the next difficulty?


texts: Why can't Bitcoin transactions be stopped like SWIFT transfers?

texts: As I know, most BTC hacking happens at digital wallet (but in blocks). I believe the hacker use normal BTC transaction to transfer those stolen BTC to other block addresses. Why can't we stop the transaction like the SWIFT system does? All blocks should contain the original and source addresses. Is it because of miners doing the Merkle Tree verification to anonymously verify all executed BTC transactions mechanically and all nodes in BTC have to honor executed BTC transaction?


texts: How can a Ripple contract use random values and reach consensus?

texts:
There an interesting page about contracts on the Ripple Wiki.

My limited understanding of contracts is that like other transactions in Ripple, it is the consensus across many servers that ensures validity.  Am I right that when a contract is running in Ripple, the code runs on multiple servers and consensus ensures the contract's instructions are run correctly?

If so, I'm particularly curious about the "Lotto" example on the wiki page.  It chooses one account randomly to be paid some amount of some currency.

If that code ran simultaneously on many Ripple servers, they'd each randomly choose a different winner.  How would they ever achieve consensus?


texts: Is a gold standard commodity-backed bitcoin possible?

texts: I like bitcoin in the sense that it decentralizes currency. I would like to know though if it is a commodity-backed currency similar to the gold standard decades ago? Is it possible in the near future? As it is it seems that it is the same fiat money, except that it isn't the Fed issuing it. Is that correct to say? Thank you!


texts: I would like to sell all the forks of bitcoin especially Super Bitcoin Fork. I can see that Super Bitcoin is traded on few exchanges, but the deposit of Super Bitcoin is disabled or temporary off on all of these exchanges. Is there any way how to sell it?


texts: Can you Send Coins back from a Receive Address?

texts:
We are setting up some merchant functions

If a customer sends too many coins in a transfer for an order

Can you send the change back to address you received the coins from .

i.e
1) Order 1234 12.5 BTC Merchant Recieve Address (1234abc)

2) Customer Sends 12.6 BTC to Merchant Address (1234abc) from his Address (4567def)

3) Merchant detects overpayment And sends the 0.1 btc back to customers (4567def) Address as change

Will this work in that the customer will get his change ??


texts: In case of a grouped transaction, how to determine who sent what to whom?

texts:
Trying to understand how grouped transactions work, I came accross the following transaction on blockchain.com :

There are many senders, and even more receivers. For instance, the first sender on the picture could have sent 1 BTC to the first receiver, 10 to the fifth, and so on...
How can I determine (if it is possible) what amount sender A sent to receiver B , instead having the balance for each participant ?


texts:
I am very new to Bitcoin.  My friend and I are doing a business that will accept Bitcoin as payment.  I would like to know how easy it is to use Copay as a wallet that we can both share, and that will require both our authorizations to distribute Bitcoins into separate Bitcoin wallets for us?  If someone could please answer this for me, I would be very appreciative.

Thank you!


texts: Why does Litecoin have lower transaction fee than Bitcoin?

texts:
Is it only because LTC doesn't have as many users as BTC? Or do the faster confirmation times also help with lowering fees?

Thanks


texts: What's happening with my Bitcoin Core Wallet

texts:
I'm a total novice - sort of.

In 2013 I bought some Bitcoin through MTGox. I cannot recall how many, but not a huge amount (still would have been worth a small fortune today, but hey-ho) and some months later (2014) I sold them, but I think might have kept 2 or 3 back.

When I checked last - in 2016 I assumed/was told that if I had any they would have disappeared when MTGox went under. That was the last time I had any interest in Bitcoin.

By chance recently I found I still had my Bitcoin Core wallet on my iMac and opened it. That was two days ago and since then it has been synchronising and at present is 35pc progressed. Estimated time left fluctuates from 48 hours to - at present - 11 days. I have a couple of questions.

1/. Is there anyway of speeding this process up? (I have 60+Mps connection)
2/. Given my Bitcoin history is it possible what coins I may have, if any, are here?
3/. Given the last block time was late 2015, should i just stop the process, upgrade Bitcoin Core (if possible) and start again?

Many thanks for any help/advice


texts: Hard forking a blockchain to new codebase?

texts:
Several years ago, I forked Litecoin as a hobby project just to get some experience working with crypto code.  I generated a new genesis block and mined some for fun

I never really messed with it since then but I am still curious to learn more.  I want to change my project from Scrypt to something else like Lyra2REv2.  Monacoin for example is a litecoin fork that changed to this algo

I am not sure what all I would need to do to get a fork of Monacoin for example to sync up with my existing blockchain.  I know there are genesis block hash info in src/chainparams.cpp and block checkpoint hashes but not sure what else would need to be changed


texts: Can a Ripple Transaction Sequence have gaps?

texts:
I am wondering whether a Ripple Transaction with a Sequence number that ships over a few numbers from the previous Sequence number be accepted as a valid transaction in the Ripple Network?

For example, if I have one Payment Tx with Sequence 123, and then want to create another transaction with a Sequence 200, will it go through?

Also, I understand that the transaction Sequence numbers cannot be descending, so I couldn't submit a Tx with a Sequence of 100. Is this correct?


texts:
Unfortunately, having an issue with #btc
While synching my core node I had a power outage and now every time I try to run btc core I get this message.
“A fatal error occurred. Bitcoin Core can no longer continue safely and will quit.”
Need help...


texts: Are there any risks to giving someone your wallet address?

texts:
I set up a fundraiser for my friend and I got a message from a stranger asking for a wallet address so they can donate using BitCoin. I don’t know a whole lot about BitCoin beyond the basics, so I wanted to ask if this person does happen to be a scammer, are there are any potential risks in giving this person a BitCoin wallet address to send the donation to?
I know if he tries to send me any links or files or anything I won’t click it, I know that much, so I wouldn’t do anything more than give the address to an empty wallet. I just don’t know much about BitCoin scammers and if they have any methods other than the obvious to screw me over somehow.


texts:
There are different sets of libraries in  https://github.com/bitpay/bitcore

Node - A full node with extended capabilities using Bitcoin Core (what is the role of this node ? As i can see this code in node js . Is this means that bitpay has implemented the bitcoin core in node js ? )
Insight API - A blockchain explorer HTTP API
Insight UI - A blockchain explorer web user interface
Wallet Service - A multisig HD service for wallets
Wallet Client - A client for the wallet service

How do these different libraries interact with the Bitcoin blockchain?

Anyone explain the flow in steps will be highly appreciated.


texts:
Any way to create a multisig address from Bitcoin addresses (instead of public keys)?

If not, why not? What would the problem be?

EDITED - Thanks for the answers. This is for an application that generates multisig transactions with escrow for external users. Of course anyone who controls an address can find the public key, but that's probably beyond many casual users (or too much of an hassle).


texts:
I remember back in the day when MtGox halted its BTC withdrawals, someone put together a secondary market exchange for trading MtGoxBTC for actual BTC. You could deposit MtGox BTC to it since the exchange still allowed you to move coins between accounts even though you couldn't withdraw the coins into external addresses. I tried searching for it, but the amount of articles on MtGox collapsing and so on seems to have buried that old titbit of information.

Does anyone have any information about MtGox's secondary market, what it was, how long did it operate, what were the prices and so on?


texts: What does "Trailing Stop buy Order" on Bitstamp mean?

texts:
a Trailing Stop limit Order is clear in my mind.
You want to sell your stock when the price starts to fall after reaching a max;
or you want to buy a stock after the price starts to rise after a minimum.
So far so good.

Bitstamp however only has the trailing options for stop loss orders
(see pic).

This does not make sense in my mind: "I would want to wait for a minimum price and than sell when it starts to grow again?" Non sense. The same non sense applies for stop buy trailing orders.

In the picture bellow i plot 4 graphs with MY UNDERSTANDING of these options.

Please help me understand what Bitstamp means with that.

Thx a lot!


texts: Generating zero-amount transactions in regtest mode?

texts:
I'm setting up a larger test network of regtest nodes in which all of them should be easily capable of creating blocks and sending transactions.
To this end, I'm looking for a simple way for the nodes to be able to submit new transactions into the system, without requiring them to either previously mine blocks, or to introduce a convoluted setup process, e.g, where every node first loads a pre-filled chain state and wallet.
So far I had the hope that it would be possible to create new wallets and addresses and then simply send zero-amount and zero-fee transactions. So far, my efforts are met with a "Transaction amount too small" error.
One 'solution' I found is to write a script that creates new wallets, mines (at least) 101 new blocks to a new address, unloads the wallet and repeats. However, I then would need to distribute the wallets and the blockchain data to all nodes. This seems like a really tedious and error prone setup step to enable a reliable a regtest environment.
Is this possible, can bitcoind in regtest mode be reconfigured to accept transactions of value 0? Or is there any other easy way to initiate new addresses or generate new mock transactions, similar to the generatetoaddress call for blocks?


texts: How to get Bitcoin input transaction hash string from bitcoinjslib Transaction object?

texts:
I'm using bitcoinjs-lib and its Transaction object. Transaction.ins is an array of objects, each which has a hash and script property. Both of these properties are Uint8Arrays.

I am trying to get the hex string version of the input.hash but Transaction.ins[i].hash.toString('hex') produces an incorrect result. Is there a way to get this value properly?


texts:
How much memory (RAM) does a Bitcoin node use?

I am planning on running a Bitcoin full-node on a RasPi Model A+. It only has 256MB of RAM, so I'm not sure if this will work. Most of the threads on here and bitcointalk are very old, and I'm not sure if the memory requirements are greater now.


texts: C# parse bitcoin blockchain to get balance of an address

texts:
Is there a way to scan the Bitcoin blockchain in C# without using an external API? I am looking for the amount of spendable money of a Bitcoin address.

I am using NBitcoin.

// create new key pair based on private key
NBitcoin.Key key = new NBitcoin.Key(privateKey, privateKey.Length, false);

// parse blk*.dat
// get balance for address key.PubKey.Hash
// How to do that?


texts: What would happen if I publish a modified version of an earlier block? Would it be rejected immediately by peer nodes?

texts:
I am reading the book "Mastering Bitcoin" and have finished reading Chapter 2 and 10, but I still don't find the answer.

Suppose the current main chain has 5 blocks:

B0 <- B1 <- B2 <- B3 <- B4

As new transactions flowing in, the honest miners are mining B5, the 6th block.

If I publish a modified B2, say B2', to the Bitcoin network, what happens to this modified block when it is received by the other peers? Suppose B2' contains all the transactions that B2 has except that the amount of transferred bitcoin of one transaction is slightly modified but still a valid amount.

Would B2' be rejected immediately? It doesn't look like so because the modified transaction seems to be still valid. As far as I have learned, the recipient node uses the earlier blocks, B0 and B1, to validate B2', and I think the validation would succeed. Am I right?
If B2' is not rejected immediately, would the peer nodes link it to B1 as a secondary chain? I actually think B2' should be rejected but after reading Chapter 10 of Mastering Bitcoin I don't seem to find a reason to justify why it should be rejected.
Furthermore, if B2' is linked to B1 anyway, what would happen when the 6th block, B5, is now mined and published? According to the Chapter 10, "the transactions ... are re-inserted in the mempool for inclusion in the next block, because the block they were in is no longer in the main chain." so I think now B2' would be removed and its transactions would be re-inserted into the mempool. Then all the unmodified transactions in B2' will be removed again because they have been included in B2 in the main chain, and the modified transaction in B2' would be rejected because it conflicts with the counterpart in B2.

Thanks for any help!


texts: History of transactions in Lighting Network

texts:
I'm just a beginner in lighting network. Have some questions about transactions in LN when im doing the research

Transactions in LN are off-chain, so transactions couldn't be stored in main-chain, so how could you look-up the transactions history?
Payment channel is private for someone outside, and if there is no transaction history, how do i give the information to others to proof that I've just made a payment in LN.

Any helps, tks


texts: Do the various Ripple clients leak any data about account names?

texts:
If I use the official client at Ripple.com, and add someone to my contact list ... does the information "I believe that X's Ripple address is Y" get stored anywhere in unencrypted form? Is it broadcast to any central server?

I assume the answer is No, but I want to get an official confirmation. (These days many websites log a lot of user actions, my expectations from the Ripple client is that it does not).


texts: What is the rationale behind Bitcoin mining?

texts: I don't understand the logic of "mining", if bitcoins are a digital currency, why do we need a GPU to "make 'em"?


texts: How big can the block chain become? It's already 7 GB after a couple years!


texts: Does a full Bitcoin API reference exist with examples?

texts:
I know that all Bitcoin API methods are listed on the wiki: https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list. However, some of the methods are very poorly documented.

F.e. the lockunspent method is only documented as taking the parameters <unlock?> [array-of-objects]. No clue about what type of objects. And there are more examples like this.

Is there a good API reference that specifies what parameters are expected and what result they give back?

This would so much lower the bar for new developers!


texts:
I'm thinking, is it dangerous to buy bitcoin, in case if government want to block it?
How bitcoin wallets connected between?
If I'm right - there are support servers, who providing connection between wallets?
At least, when you downloading cold wallet to your computer, it starts the download and syncs blockchain from the servers?
What if some government wants to block the servers?


texts: Why same output address is invalid in a transaction on Bitcoin Core?

texts:
I'm studying Bitcoin Core currently. I found incomprehensible code, that shows making a transaction is rejected if there are same output addresses in a transaction.

See Fig1, Fig2

Origin source code : https://github.com/bitcoin/bitcoin/blob/8aac85d71e218783bc7ce06e5bf8bc660e24079d/src/rpc/rawtransaction_util.cpp#L95

So, the transaction illustrated in Fig1 will be rejected as shown Fig3.

Can you give reason about the policy of described in this post ?


texts:
Hello I run bitcoind and i get this 8333 failed after select(): Connection refused (111).
Can you help me with this? because it was working suddenly this happened.


texts: How can I pick the data directory of Bitcoin Core on Windows 10?

texts: I'm using Bitcoin Core on Windows 10.  Despite setting it up in a folder on my larger drive, it's eating all the space on my SSD. How do I direct the blockchain to the drive I want?


texts:
Hello bitcoin community.

I'm running startup and we think how to accept payments. Our customers are far not geeks and they don't know what BTC is. However, I'd prefer to collect BTC on may wallet, not fiat. I've solved all tax issues in my country and I can deliver invoices to my customer where we will use fiat currency they paid in. But I'm looking for some merchant service that automatically turns fiat they pay through Visa/SWIFT or probably even PayPal into BTC using actual exchange rate. Could anyone suggest something?


texts: Why one miner can dig out many blocks continually in one moment?

texts:
I am new to bitcoin and blockchain, I browed the website just now. There is  a question confusing me,  I find that one miner dig out blocks many times even in one hour. For example, this miner dig out four block in 6:00 - 7:00 AM. Is it possible that this miner control 51% CPU? And may this would break the whole bitcoin blockchain?

I hope someone can answer me, thanks！


texts: What is a brief summary of the ECB's report on virtual currency?

texts:
On 29th Oct 2012, the European Central Bank released this report on virtual currency.

What is a summary of its comments on Bitcoin?


texts: How many bitcoins will there eventually be?

texts: Since bitcoins are being regularly rewarded to miners, will the number of bitcoins continue to grow indefinitely, or will there be a maximum total number of bitcoins in existence?  And if there is some kind of limit, what is it and how is it enforced?


texts: Can you delay transactions so that you pay no fees?

texts: Online wallets, such as inputs.io, require you to pay a fee, but transactions occur instantly. Is there any way to not pay fees (probably by delaying payments)?


texts: If anyone with your seed phrase can generate your wallet private keys, what is the advantage of a hardware wallet?

texts:
When you start using a cryptocurrency hardware wallet, you get to write down a seed phrase in some physical medium (paper, metal, etc.) so you can regain access to your funds if you lose the hardware wallet.

If anyone who gains access to this seed phrase can regenerate your private keys in another wallet and get access to your funds, why use a hardware wallet in the first place? Why not just keep the seed phrase well hidden, remove your data from any wallet app and use the seed phrase to regenerate your keys anytime you need to transfer funds? Is it only a matter of convenience and security when actually transferring the funds?


texts: produce a public key from private key with ecc, with clear description about k=k*g

texts:
According to this answer: https://bitcoin.stackexchange.com/a/63996/100526
When he wants to generate a public key from the private key, he has used K=k*G. but I can't understand it's result.
If we assume our private key is (according to the answer) :

0F479245FB19A38A1954C5C7C0EBAB2F9BDFD96A17563EF28A6A4B1A2A764EF4

and according to Secp256k1 G point is:

- Compressed form (prefix 02)
02 79BE667E F9DCBBAC 55A06295 CE870B07 029BFCDB 2DCE28D9 59F2815B 16F81798

 - Uncompressed form (prefix 04)
04 79BE667E F9DCBBAC 55A06295 CE870B07 029BFCDB 2DCE28D9 59F2815B 16F81798
483ADA77 26A3C465 5DA4FBFC 0E1108A8 FD17B448 A6855419 9C47D08F FB10D4B8

So to calculate the public key I used this site: https://www.boxentriq.com/code-breaking/big-number-calculator

I used compressed form and private key:
0279BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798  *  0F479245FB19A38A1954C5C7C0EBAB2F9BDFD96A17563EF28A6A4B1A2A764EF4

and result is :

25d355ebb23e6ce0fd5463bf40e6da2ccc4e2e8ce654db6a8a8e5a275f0d2266005569112cfda60d14f9b6d0c0218cc072047a3b2fcf97aee95a437b4bb6cce0

but in that answer the result is :

02E8445082A72F29B75CA48748A914DF60622A609CACFCE8ED0E35804560741D29

what's wrong?


texts: MultiBit Password Protection - How Secure is it?

texts:
I'm new to BitCoin but a friend of mine was recently stung when a bunch of his coins were stolen. Naturally, I'm now very cautious. I've password protected my MultiBit wallet and, to test the security of this, I have copied the .wallet file to another computer and opened in a new installation of MultiBit. However, I was not asked for my password and I can see my transactions in there. Can someone explain what the password does if it doesn't stop you accessing the wallet?

Thanks in advance.

PG9


texts: How transaction becomes confirmed by miners if InputScript has only the Sig

texts:
Please help me to understand how bitcoind client verifying TX with Input Script which consist only from the Sig.

For example TX 6D5DF6C0D66CFFC25CC1ABA3655952D7B081ED4E9EA3B70FCD964FDBBA01E91E has one input from D9A9C88110775B196CDAF6FC8113B33547C8E33E68519F60D9C9FF306E096473 transaction (8 output) with Input Script 4730440220797681C6711BB3D97AE373FC5CFF47F06EEC928DD46B8A9892D92C30953C9DF3022079C36E9A4C32D4E36B9E3ACCED0D40D70D8F90890C0E9F8F4F9AC083AFFD21B301.

This script has only the Sig (r,s) and has no any representation of Public Key or Address.

As I understand the Sig creates with UnsignedTX doubleSHA256 hash, Random Number and Private Key.

Sig checking by using UnsignedTX doubleSHA256 hash and a Public Key, but here is no any of it.

Also the question is about "Where is stored UnsignedTX doubleSHA256 hash?". Because it is not the transaction hash, because TX hash is for the signed transaction.


texts: Creating transaction with using blockcypher

texts:
https://api.blockcypher.com/v1/btc/main/txs/new?token={{TOKEN}}
To use BlockCypher's two-endpoint transaction creation tool, first you
need to provide the input address(es), output address, and value to
transfer (in satoshis). Provide this in a partially-filled out TX
request object.

From where can I get input addresses to create transaction?


texts: If every block generated all 10 Minutes to validate a transaction, and the last bitcoin will generated in 2140. And there is no limitation of blocks.. Whats after 2140, because all miner have no intention to validate any transaction. How will Bitcoin generate the other blocks?


texts:
Presume that I have 1 BTC (the total of my UTXO) and I have to pay Bob With 1 BTC.
I set 0 for fees.

My Input is 1 and my Output is 1 versus Bob or there are always 2 outputs?

one versus Bob

and

one versus my change address with 0 btc?


texts: Where can I find how much one XRP (Ripple unit) is worth?

texts:
XRP are the units of the new Ripple.com system.

Where can I find how much they're worth right now? Historic charts?


texts: How is the Blockchain.info Bitcoin Market Price Exactly Calculated?

texts:
I am about to apply traditional univariate GARCH tools to analyze the volatility of the Bitcoin - US Dollar exchange rate.

The index that I would like to investigate is the Bitcoin Market Price (hereafter simply "BMP") that is compiled and reported by the Blockchain.info information provider at this link: https://blockchain.info/en/charts/market-price.

Blockchain.info provides open, high, low, close and 24h-average exchange rates series. In my analysis, I will use the 24h-average series.

The above page's headline states that the BMP is an "average USD market price across major bitcoin exchanges" which, I guess, are those tracked at the "Markets" section of the website.

PS: I do not have at least 10 points of reputation right now. Therefore, I cannot post here the link for the Markets page which is one of the top-screen ribbons on the main page of the website.

So, my question is:

Is there any available detailed information on how the BMP is technically calculated?

It would be of particular interest to me to know the following:

a) Is the BMP calculated as an average of the exchange rates that are tracked at the Markets section that I already mentioned? If so, what kind of average? (e.g. simple, weighed, etc.)

b) Is the BMP weighed by the four exchanges' respective transaction volumes?

c) Are Bitcoin trades other than those with US Dollar included in the BMP? If so, which (official/unofficial) fiat exchange rates are used to state the BMP in US Dollar terms?

d) How often is the BMP updated during any calendar day? Does update take place every 15 minutes (i.e. time for the Blockchain.info Price API to update) ?

Basically, what I am looking for is a schedule of the criteria for the calculation of the BMP like the one that e.g. Coindesk provides for its own ticker.

I hope the question is clear enough.

Any help is deeply appreciated.


texts: How does mining work on the moving target (variables change every second)?

texts:
In bitcoin, miners hash the header twice with the SHA256 function. This header consists of the fields listed below:

version (v)
previousHashBlock (p)
merkleRoot (m)
time (t)
difficulty (d)
nonce (n)

Let's simplify and say that I am a pool miner with nonce range from 1-100. So if I do my share and find that on 9th minute the Nonce value of 91, solves the puzzle (proof of work). But by the time I send to network, merkleRoot and time has changed, so the nonce that I've found is not true anymore. We know that hash changes dramatically with slightest change of input, but in this formula, not one but TWO variable change constantly throughout my mining period (in this case 9 minute). Transaction occured and time changed.
So how does this formula hold true thoughout the mining time?

SHA256(v + p + m + t + d + n(91)) => 0000000asd8f686asd6das

Where m and t changes constantly? Wouldn't 91 be irrelevant at the time of finding?


texts: Is there a way to tell that our bitcoin is safe after we put it in a hardware wallet for cold storage after 3 or 5 years?

texts:
If I consolidated 1 bitcoin into an address using a hardware wallet, and put it in cold storage. Can I know after 3 to 5 years that the bitcoin is safe?
So far the research I have is: can I go to https://www.blockchain.com/btc/blocks and search for that address, and see that it was still used once (for the time I put the bitcoin in), and therefore know that the bitcoin is safe?


texts: i have good pc can i mine on it, if i don't have to pay for electricity?

texts:
i have gtx 970 g1 gpu and intel i7 4790k cpu. i dont have to pay for my electricity costs. i used to play games but now i don't play them any-more. i was hopping someone will tell me if i can make a profit and how much i can make in a week by bitcion mining.
i dont have a clue how to mine if i will profit from mining can someone list in steps the things i need to start mining.

Main reason i got idea for mining is because i don't have to pay for electric costs. any advice will be helpfull


texts: what is the longest period for a bitcoin transection to be confirm?

texts: It's been three months but the bitcoin transaction has not been completed. Can anyone inform me?


texts:
I've been reading about Litecoin, yet I haven't found any mention to a person or group responsible for the fork. Who created litecoin and did he write a whitepaper explaining why?

Edit:

After some searching it appears to be Charles Lee. Yet no whitepaper yet :(


texts: What contributes more to bitcoin network? Using Bitcoin-Qt or running a miner?

texts:
What would make a better support for bitcoin?
Does it really makes any difference to store blockchain locally instead on a remote server?


texts: Does PPS reward depend on specific block difficulty?

texts:
How is reward per share calculated on PPS payments system? Does it depend on specific block difficulty or average difficulty per day/week/month used? If I have mined two successive blocks with difficulty 10,000,000 and 11,000,000 and there was the same number of shares for each block, will I obtain 10% higher reward on first block than second block? Or rewards will be the same?

If it depends on particular pool, I need answers on questions:

What is the most common practice?
How common are the pools that use difficulty of a specific block, rather than average?


texts: AltCoins based on Scrypt - How to do transactions with PHP?

texts:
Im interested in other scrypt based coins other than Litecoin.

I have noticed that most of these coins have no documentation. So is it safe to assume that I can follow the Litecoin documentation if I have a question about a function or feature of said other scrypt based coin?

Second, I cant find anything about using PHP and doing transactions with Litecoins or any other coins (just javascript). Can anybody point me to some examples of how to do things like create wallets, send and receive transactions, etc..

Thanks.


texts:
Payment was processed to me. Fees were requested to pay to sender.
Transaction was unconfirmed and due to delay I was requested to pay the following fees to unblock transaction. Is this correct?


texts: Double Spending - Does each node maintain a list of unspent transaction references?

texts:
My Understanding Of How Bitcoin Prevents Double Spending

Each transaction contains references to the input transactions and ever node has to verify all transactions from time immemorial to ensure that the inputs are in fact unspent. Once this is confirmed, and subject to other conditions, the transaction can be added to the block chain.

I can not fathom the practicality of  what this means, lets say there have already been 50 million transactions on bit coin, for the transaction after the 50 millionth, each input transaction reference will have been looked against 50 million rows to see if it appears anywhere as an input transactions (it shouldn't) and it was in fact an output transaction then benefiting the now spender. This is done for all transactions being broadcast in an interval of time before miners can start working for that good looking cipher.

However to make this simple, each nodes maintains a list of unspent transaction references of all nodes (say U list), when is used as a starting point and updated every time a transaction is added and these updates are committed across the network  after a transaction block is confirmed giving the starting point of the next block.

My Questions

Sounds too much hard work for this to be practical.

Does it mean that every miner will have a database of those 50 million records? Isn't that a massive and expensive requirement?
Every miner will compare each input transaction references  to each of those 50 million before including the new transaction in a  block to ensure that it has not been spent already and was in fact valid?
Quoting myself,

  however to make this simple, each nodes maintains a list of unspent transaction references of all nodes (say U list), when is used as a starting point and updated every time a transaction is added and these updates are committed across the network  after a transaction block is confirmed giving the starting point of the next block

Doesn't this go against the principle of not having a book showing each node's balance? In case a node has only 2, 3, 5, or 5000 unspent input transaction references. This more or less boils down to a book of balances  that needs to be referred to for each transaction before block inclusion and the new block is committed over it on confirmation (i.e. when a proof of work is found). Does it not?
Given the above post, how close am I to understanding controls over double spending? I am a CPA trying to get my head around this.

Preliminary Doubt

Only miners need bother about assembling transactions in blocks. Shoppers and Payers may execute transactions and simply await block confirmation. All transactions shall be broadcast to them and they need not bother recording those unless they are involved or a block confirmation is broadcast.


texts: I'm looking for for historical data on crypto currencies that tracks down to at least the hour if not 5 minutes for each day for at least the past year. I need OHLV price, and volume at a minimum for each interval, but further trade data would be a great plus. I would prefer to get this from an API if one is available, but at least some csv's would help to start with, all the historical sources i see only track on a once per day basis.


texts: Trojans detected in ldb bitcoin database?

texts:
I started regular scan and clamscan found lots of trojans in bitcon.lfb blocks.

What is it? A mistake?

sudo clamscan --infected --recursive --exclude-dir="^/sys" /

/root/.bitcoin/data/blocks/index/592744.ldb: Win.Trojan.Jerusalem-47 FOUND
/root/.bitcoin/data/blocks/index/589268.ldb: Win.Trojan.Nomenclatura-1 FOUND
/root/.bitcoin/data/blocks/index/644616.ldb: Win.Trojan.Redx-1 FOUND
/root/.bitcoin/data/blocks/index/638596.ldb: Win.Trojan.Phantom-5 FOUND
/root/.bitcoin/data/blocks/index/649206.ldb: Win.Trojan.Trojan-251 FOUND
/root/.bitcoin/data/blocks/index/335390.ldb: Win.Trojan.Zherkov-8 FOUND
/root/.bitcoin/data/blocks/index/589273.ldb: Win.Trojan.B-67 FOUND
/root/.bitcoin/data/blocks/index/647056.ldb: Win.Trojan.EDV-3 FOUND
/root/.bitcoin/data/blocks/index/333900.ldb: Win.Trojan.AIDS-1 FOUND
/root/.bitcoin/data/blocks/index/590327.ldb: Win.Trojan.Syslock-2 FOUND
/root/.bitcoin/data/blocks/index/641108.ldb: Win.Trojan.Jerusalem-15 FOUND
/root/.bitcoin/data/blocks/index/336793.ldb: Win.Trojan.CIA-1 FOUND
/root/.bitcoin/data/blocks/index/590264.ldb: Win.Trojan.Yankee-16 FOUND
/root/.bitcoin/data/blocks/index/647796.ldb: Win.Trojan.Vienna-43 FOUND
/root/.bitcoin/data/blocks/index/638638.ldb: Win.Trojan.Tori-1 FOUND
/root/.bitcoin/data/blocks/index/642244.ldb: Win.Trojan.Ping-2 FOUND
/root/.bitcoin/data/blocks/index/649309.ldb: Win.Trojan.Copyright-2 FOUND


texts: Where can I trade BTC/USD with a small transaction fee?

texts:
I don't need a leveraged account. I just want to trade with real money.

The Mt. Gox transaction fee is 0.60%. Is there a place with a lower transaction fee?


texts:
I'm planning to buy myself a Bitmain Antminer S7 Batch 9.

Unfortunately, the Bitmain PSU (APW3-12-1600-B2) is not available to me, and I need to replace it with a regular PSU from another shop.

I think S7 needs a 9 6pin PCI-E connector. I haven't seen a 9 6pin PSU ever.

Which PSU could power my S7?


texts: I'm currently using the JSON Rest API to get lots of transaction data from bitcoin. Unfortunately thats quite slow. I know there is also a binary format (see Unauthenticated REST Interface), but I couldn't find any description of the bin format. Is there any description of that format available?


texts: How can i get balance of bitcoin address not exist in my wallet?

texts:
How can i get balance of bitcoin address not exist in my wallet ?

I try to use bitcoin-Abe but it is complicated and take seral days to full database with blockchain.

Is there exists other tools like bitcoin-Abe but easy and fast to parse blockchain, i want from parse blcokchain to get balance and transactions of bitcoin address ?

Does armory contain any facility to parse blockchain or get balance of any address and it's transactions ?


texts: How does vanitygen calculate difficulty?

texts:
It seems really random. 1d is 1353, 1L is 22, 11 is 256, 11L is 78508, 11x is 78508, 111 is 65536, 112 is is 1335, 113 is 1330, 114 is 1330, 1L1 is 1330.
I thought it was 58 to the power of the number of digits. Why isn't it?


texts: Is the transaction database ever shortened?

texts:
I just downloaded the bitcoin client and the full transaction database and did not fail to notice that it took me more than a day to download and check the transaction database and that it occupies more than 2 GB of diskspace.

What will happen when the number of transaction will grow to several millions a day?

Will the Database grow over a TB?
Is that even viable ?


texts: Bitcoin RPC getbalance of address I sent coins to on regtest

texts:
Here is my terminal session:

$ echo $address
mvt7M16caMH1xoJyfWU5orjArfq97jhZ7k
$ bitcoin-cli -regtest getbalance
5899.99990000
$ bitcoin-cli -regtest sendtoaddress $address 10.0
6ed7452f8f11fe25904867b57e127a6b65cb180c2013e667e3d399c4179ff1f0
$ bitcoin-cli -regtest setgenerate true 1
$ bitcoin-cli -regtest getbalance $address
0.00000000

Shouldn't the balance of this address be 10 now? I thought that by generating a block, I will have that transaction included, which will show up on the addresses balance?


texts: What are bitcoin miners actually solving?

texts: I've read all other answer, but nobody really gives an answer. Whom for are they solving, and what entity outside BTC community has benefits from all the electric energy wasted in the process of doing math?


texts: Would it really be this easy to steal peoples bitcoins?

texts:
I was just looking for an Ethereum wallet app for Android, and something hit me.

Could someone create a wallet app for Android/iOS that simply pretends to create a wallet address but really just displays the address of the one who created the app, causing the victim to transfer his/her funds straight to the app creator instead of their (supposedly) newly created wallet?

This seems too easy...


texts: Why does all cold/offline storage setup require three steps?

texts: I was reading about cold/offline storage and from what I have seen all clients seem to work the same. Requiring you to create the transaction on the online computer, getting it to the offline computer and signing it, then getting it back to the online computer to broadcast, but I don't get why? It seems to me you should be able to make this in two steps and it would also make it more secure as data only ever have to flow in one direction. You create and sign the transaction on the offline computer then you get it to the online computer to broadcast. So why is it not implemented like this in clients?


texts: Send cash: bitcoins vs western union: which is cheap?

texts: Bitcoin has been advertised as a very low cost and fast method of sending people money around the world, So if I need to send someone $1000 USD, the cost/fee of using WU is less than $20 USD (Using credit card - UNFORTUNATELY, WU doesn't work. They deny me sending $1000 and give me no reason. I will never use WU again.) but if I use bitcoin, what will be the minimal cost? Since I need to buy the bitcoin in the first place, and that other person need to sell it to get the cash, the conversation fees and the transaction fee would be more than $100 in the end? and if send someone $1000 in bitcoin, there is a chance that when she/he gets the cash next day, my $1000 will be less than $1000? If that is true, how can I trust bitcoin?


texts: Is there a way to get stats about fees paid (highest, lowest, average) in a specific block?

texts: I'd prefer to get the stats from my full node via bitcoin-cli, but if that's not possible some API would do the job too...


texts: Butterfly Labs Little Single No Devices Found

texts: When I am trying to mine with my new butterfly labs little single BFGminer says that it cannot detect any devices. I try and add devices, and it doesn't work. I know that it is getting power, because my OS will recognize that the miner has been plugged into the computer. I have tried now on both linux and windows with no luck getting it to recognize it. Any ideas?


texts: Bitcoin-qt and lost local blockchain files

texts: For some reason I've lost all data in my .bitcoin directory except the wallet.dat file. Now bitcoin-qt shows 0 balance, and it's 5 years behind sync. Is this possible to restore coins in this case?


texts:
I am experiencing some major issues which I honestly can't understand.
When I am generating a wallet from Electrum the public key looks like this: xpub661MyMwAqRbcG8Zah6TcX3QpP5yJApaXcyLK8CJcZkuYjczivsHxVL5qm9cw8BYLYehgFeddK5WrxhntpcvqJKTVg96dUVL9P7hZ7Kcvqvd

When I am generating a wallet address from bitcoin core rpc, the public key looks like this: 037acd3408dfb612a69204c5f5bafe2a326646398cdd16c85fedd65a4e96a28278

When I am trying to create a multisig address in the core using this type of public keys, I get errror: xpub661MyMwAqRbcG8Zah6TcX3QpP5yJApaXcyLK8CJcZkuYjczivsHxVL5qm9cw8BYLYehgFeddK5WrxhntpcvqJKTVg96dUVL9P7hZ7Kcvqvd

When I am trying to create a multisig address in the core ( via PHP ) using this type of public keys, it works: 037acd3408dfb612a69204c5f5bafe2a326646398cdd16c85fedd65a4e96a28278

I am super confused.

I am developing a multisig system for bitcoin, but it seems that I can't do it, since the clients will almost always use this type of public key generated from Electrum: xpub661MyMwAqRbcG8Zah6TcX3QpP5yJApaXcyLK8CJcZkuYjczivsHxVL5qm9cw8BYLYehgFeddK5WrxhntpcvqJKTVg96dUVL9P7hZ7Kcvqvd

Is there any type of conversion way in PHP from this type of public key:  xpub661MyMwAqRbcG8Zah6TcX3QpP5yJApaXcyLK8CJcZkuYjczivsHxVL5qm9cw8BYLYehgFeddK5WrxhntpcvqJKTVg96dUVL9P7hZ7Kcvqvd to this type: 037acd3408dfb612a69204c5f5bafe2a326646398cdd16c85fedd65a4e96a28278 ?
I am trying to understand what I am doing wrong

Thank you for your time, and hope to get an answer!


texts:
How do I unlock a bitcoin-qt wallet? I know my passphrase and all.
It says that my wallet is encrypted and locked for now so how do i unlock it?


texts: LedgerJS - How to P2SH sign multiple transactions from multiple wallets in 1 function call?

texts:
First some explanation

I have made 2 raw transactions via Electrum using my Nano S Ledger as seed and exported them to .txn files.

let rawTx1 = "02000000000101bf00f7aca2e0d393ad0a762224ad4cd5a10d9950804fbc5a22fe970918301179000000001716001400ce8131595e014b45ec6ca49495d547ab8bd872fdffffff02a08601000000000017a91457fd0d41e459a4227b8932327786cf512d99399987bc72ca...";
let rawTx2 = "02000000000101bf00f7aca2e0d393ad0a762224ad4cd5a10d9950804fbc5a22fe970918301179000000001716001400ce8131595e014b45ec6ca49495d547ab8bd872fdffffff02a08601000000000017a914a66dff1bf27dd1a5944b5bc9ff2b0f410efb64cd87bc72ca...";

Then I turned them into UTXO objects using the splitTransaction() function:

const UTXO1 = await btc.splitTransaction(rawTx1, true);
const UTXO2 = await btc.splitTransaction(rawTx2, true);

Next, I get the Wallet public keys I used for these transactions:

const wallet_1 = await btc.getWalletPublicKey("m/49'/1'/1'", false, true);
const wallet_2 = await btc.getWalletPublicKey("m/49'/1'/2'", false, true);

So transaction 1 was made with wallet 1 and transaction 2 with wallet 2. According to LedgerJS, I have to respect that order when calling the signP2SH() function:

btc.signP2SHTransaction([[UTXO1, 1, wallet_1.publicKey], [UTXO2, 1, wallet_2.publicKey]],
    ["m/49'/1'/1'", "m/49'/1'/2'"],
    btc.serializeTransactionOutputs(???).toString('hex')
);

Here,

[UTXO1, 1, wallet_1.publicKey]

are the Transaction object, output index, and redeem script in that order. And

["m/49'/1'/1'", "m/49'/1'/2'"]

are the derivation paths of both of my wallets.

My question is about the third line:

btc.serializeTransactionOutputs(???).toString('hex')

I know for a single transaction from a single wallet, I just toss in the UTXO1 in there:

btc.serializeTransactionOutputs(UTXO1).toString('hex')

But now that I have multiple UTXO's, I don't know what to fill in there anymore. Any ideas?

EDIT

Thanks to @Pierre Pollastri's answer I figured out the hashed script form.

So this code

const outputScript1 = btc.serializeTransactionOutputs(UTXO1).toString('hex')
const outputScript2 = btc.serializeTransactionOutputs(UTXO2).toString('hex')

produces the Output script for both UTXO's. Since we are processing two transactions we need to merge these output scripts. These scripts look as follows:

outputScript1 = 02404b4c000000000017a914c436f95c2ab5062dbc884a7c76ac805b58c00fe5879eaa7f000000000017a914429b7a8975c97dad6f90604faf732d9c7045279a87
outputScript2 = 02404b4c000000000017a914c436f95c2ab5062dbc884a7c76ac805b58c00fe587ee337e000000000017a914284c4c58d659cd485a283b48b4dc79da7571043587

They both start with 02, which indicates that each script handles 2 transactions. So what I did was simply change 02 into 04, remove the 02 from the 2nd script and then concatenate the 2nd script after the 1st script:

finalScript = 04404b4c000000000017a914c436f95c2ab5062dbc884a7c76ac805b58c00fe5879eaa7f000000000017a914429b7a8975c97dad6f90604faf732d9c7045279a87404b4c000000000017a914c436f95c2ab5062dbc884a7c76ac805b58c00fe587ee337e000000000017a914284c4c58d659cd485a283b48b4dc79da7571043587

Then call the function as stated above:

btc.signP2SHTransaction([[UTXO1, 1, wallet_1.publicKey], [UTXO2, 1, wallet_2.publicKey]],
    ["m/49'/1'/1'", "m/49'/1'/2'"],
    finalScript
);

It worked and I was able to sign the transaction :)


texts: Let's say I found a tarball with blockchain data files which I load to my datadir and start my Bitcoin Core client, what sort of attacks am I vulnerable to? Could the files contain fake balances? If yes, what will happen if another peer requests a block which has altered data in it, how will that other peer handle this situation?


texts: Blockchain.info - generated addresses & the blockchain

texts:
I am generating new addresses with the blockchain api and sending funds to them from a primary blockchain.info address. Just wanted to know if those transactions will appear in the blockchain or are they internal to blockchain.info?

Thanks


texts: Why doesn't Core know where the transaction is coming from

texts:
Someone I know sent me a transaction. I know where it came from, and blockchain.info knows it too. But why does BTC Core say it's unknown?

Can't it find the address by looking at the blockchain?


texts: 51% attack + ignore blocks not mined by yourself

texts:
If you own 51% of the mining power and decide to ignore all blocks not mined by yourself.
You would eventually end up having the longest chain, and would eat up the 49% of block-reward you werent getting prior.
And now control 100% of the blocks, and could censor transactions etc, since any blocks not mined by you would eventually be a stale fork.

Is there some measure that would stop this?
It seems if you control 51%, it would be in your economical interest to ignore blocks not mined by yourself.
(other than it being bad publicity for btc, and maybe crash the price)


texts: So, Im the only tech savvy guy in my house unfortunately, and I live in the middle of nowhere, so my modem/ethernet data limit is limited to 10 gigs. My only way of feeding the internet to my computer is through my phones USB, cause thats all I can use to get unlimited data. Is there a possible way to set my antminer S3 to feed off of my computer while connected to my phone, and now to the modem?


texts: How was a pay to ip transaction created?

texts:
How can you create a pay to ip transaction or is this not possible with the current client?

If so why was it disabled?


texts: How can i print out my bitcoin address that resides on my android phone?

texts: I run a repair shop and im thinking of taking bitcoins, but I want to get the QR image of my wallet address onto my site. The wallet address is on my phone, but I'm not sure how or where I can go to print out the QR image of my address. I did a google search, but everyone has a wallet generator. I just want to print out an existing address i have.


texts: Won't DNS records reveal who Satoshi is?

texts: Fine, we don't know who he is. I get that. But he did register bitcoin.org, and as a result had to use a credit card. So the original domain registrar must know who he is, no?


texts: Need to use two bitcoin core but issue with syncing

texts:
Need to know how we can use two bitcoin node for example. I do have two bitcoin full nodes A and B. Created wallet address at A and has all transaction details at wallet.db in node A. But I need to keep PK in DB and take those and send request to B node, but it fails as it dont have all transaction details, I dont want to re scan B node every time, is there any way we can achieve this. So that i dont need to worry on which node my request is going.

Thanks,
Prad


texts:
Originally I installed my Trezor wallet onto my wife's computer (since my computer doesn't have a USB 2.0 port). Later, I bought an adapter and decided to transition the Trezor wallet to my computer. I went through the process and added a passphrase (which I had not previously done on my wife's computer). I am aware that the passphrase has to be exact, because entering a different passphrase will just bring me to a new wallet. I am sure that the passphrase is correct.
Confusingly, it looks like all of my Bitcoin was transferred out of my wallet when I view it on Bitcoin Explorer. I did not make this transaction and frankly I can't really tell what this transaction means. I am at a loss for where it went and how to get it back.
Any thoughts on what could have happened? Is this a bug?


texts:
I'm working my way through "Mastering Bitcoin".

The author made a transaction:

0627052b6f28912f2703066a912ea577f2ce4da4caa5a5fbd8a57286c345c2f2

https://www.blockchain.com/btc/tx/0627052b6f28912f2703066a912ea577f2ce4da4caa5a5fbd8a57286c345c2f2

I tried to execute the transaction script (with the Unlock script in vout) in a Bitcoin Script online simulator:
https://siminchen.github.io/bitcoinIDE/build/editor.html
putting the current ScriptSig:

ScriptSig: PUSHDATA(72)[3045022100884d142d86652a3f47ba4746ec719bbfbd040a570b1deccbb6498c75c4ae24cb02204b9f039ff08df09cbe9f6addac960298cad530a863ea8f53982c09db8f6e381301] PUSHDATA(65)[0484ecc0d46f1918b30928fa0e4ed99f16a0fb4fde0735e7ade8416ab9fe423cc5412336376789d172787ec3457eee41c04f4938de5cc17b4a10fa336a8d752adf]

with the output script:

DUP HASH160 PUSHDATA(20)[7f9b1a7fb68d60c536c2fd8aeaa53a8f3cc025a8] EQUALVERIFY CHECKSIG

according the blockchain explorer.

I got "execution unsuccessful" even though i didn't figure out what's the problem.
Apparently the op_EQUALVERIFY got failed.


texts: Is it possible to / should one use a Lightning Network client?

texts:
When looking at all of the examples with the Lightning Network, they involve "Alice" and "Bob". Alice is usually sending some kind of payment to Bob (or vice-versa). The thing is, "Alice" and "Bob" are Lightning Network daemons. From my understanding, these LN daemons require "BTCD" in order to work properly (or work at all).

Payment Channels also seem to require the use of the "Public ID" of a Lightning Network node in order to be created.

FROM: https://themerkle.com/what-is-the-lightning-network-daemon/

  LND requires BTCD as its direct connection to the Bitcoin blockchain.
  The daemon has to receive on-chain event information in some way, and
  using BTCD is the most viable solution right now.

I have also seen that BTCD needs to be synched(?) properly (which could take > 12 hours to do).

So, with that, how excactly is one to run a LN Node on their Smartphone (especially since a BTCD node - which is not pruned - is needed for the LN Node to function in the first place)?

Is some other kind of client software supposed to be used? If so, what is it?

TIA


texts:
The following statement appears on the "Script" page in the wiki:

  Note that there is a small number of standard script forms that are relayed from node to node; non-standard scripts are accepted if they are in a block, but nodes will not relay them.

This begs a lot of questions:

What use is a transaction that is never relayed?
How did the transaction make it into a block in the first place if it cannot be relayed? Did this transaction come directly from a client? Was it created at an origin node and put in a block somehow by that node?
What does it mean that the script is "accepted" if it's "in a block"? (I'm aware of the script evaluation process, but the sense of the word "accepted" here doesn't seem to be the same as the standard "evaluate to true" verification process.)
Perhaps most importantly: What good is all this wonderful scripting capability if interesting transactions are not relayed? Won't this cripple the scripting capability for more complex transaction types?


texts: Is there a reason to why Bitcoin Core does not implement BIP39?

texts: Is there a specific reason to why BIP39 isn't added to Bitcoin Core? Seems very trivial to add and am confused to why it isn't there.


texts: Bitcoin open source web wallet with Bitcoin wallet service

texts:
Where the user email and password are stored when user registered on the web wallet websites like blockchain.com ?

Is the blockchain.com directly interact with the bitcoin blockchain and store the email and password on blockchain ??

How the web wallet works ? How they are interact with the blockchain ?

Sorry for lots of questions in one , The main thing that i want to understand how the more secured web wallet interact with blockchain ?


texts: What is the current state of the Hashcash protocol that is cited in the Bitcoin whitepaper?

texts: I have been reading the Hashcash paper which is referenced in the Bitcoin whitepaper. I would like to know what is the current state of the Hashcash protocol and what are the services that are actively using it?


texts: bitcoind getrawtransaction has no value for vin, what am I doing wrong?

texts: I’m able to get the value for vout but my node is not returning the value for vin, how do I get the value for vin?


texts: How can I retrieve the mnemonic words from my bitcoin core wallet?

texts:
I studied with Aaron Jaramillo's Libbitcoin tutorial.
And I have a question regarding mnenonic word.
In that tutorial, I should use testnet for making raw transaction.
And I should make wallet from mnemonic words from my testnet wallet.
But I cannot find my mnemonic word from bitcoin-qt.
Please let me know, how can I get my mnemonic words from bitcoin-qt.

BRs.


texts: Are there any services/freelancer websites where I can get paid in dogecoin?


texts: Cheapest way to move money from MultiBit to Coinbase

texts: After the launch of MultiBit HD, I decided to move from MultiBit to Coinbase. What is the cheapest way to transfer all my money from one wallet to another? Can I somehow export/import my key/wallet (if yes, how) or the only way would be to send money and pay transaction fees (if yes, should I transfer them all at once or in smaller chunks)?


texts: Automatically forward bitcoins from address A to Address C At 0 confirmations?

texts:
I run a bitcoin full node,at that node i have an Address A.
Assuming that Address A receive an Amount from Address B.(i can get UTXO information from blockchain.info API)
How can I automaticlly resend the received amount To an Address C (on 0 confirmations) before its display in my wallet.
In fact i want to create a raw transaction with that UTXO information (txid,vout and amount) and send it to Address C.
That UTXO belong to my private key so i can sign it and send it to the network.
Transaction must be created and send to the network before block is confirmed, so that in most cases the receiving transaction and sending transaction are confirmed in the same block that is mined.
This is technically possible, because I have seen this many times (https://explorer.bitcoin.com/btc/address/1Nc4oHe7TeDNjnvGfm7ZB6Pi2YtkST9znn).
But the question is how ?


texts: Transaction shows up in blockchain.info but not in Electrum wallet

texts:
I sent a test transaction earlier today. It shows up in Blockchain.info but not in the Electrum wallet.

There are more than 20 confirmations already.

Electrum version: 2.6.4

Why is the transaction not showing up and how can I fix this?


texts: Is it possible to interact with the blockchain through bitcoin-core without a wallet?

texts:
Im running a full node and am developing an application that interacts with it. One of its features is users should be able to create a pair of Bitcoin PrivKey and PubKey. But for security reasons, I dont want to save them. Not on my wallet.dat, not on database. I want to create the keys programmatically and serve them for the user to manage them.

I don't see a way of doing this through bitcoin-core. How could I accomplish this? Is there a library I could use? Should I create my own methods? Can you think of a workaround?


texts:
I am considering holding Bitcoin for the long term. I have learned a few basics about the blockchain and BTC mechanisms, but still unable to find a complete guide on how to safely store bitcoin.

How to generate a private key safely? Online tools are obviously undesirable as they might keep a back door on all keys generated. Similar reason for any library or packages even they operate offline (I cannot check if these keys generated are in fact following some predetermined sequence).
I can use a random number generator on a offline PC. But I am not a real 'hacker' and have concerns on whether any programming language can produce truly random numbers that cannot be reproduced (or say predicted) on another PC.
Currently, I can only think of throwing dice in my room for key generating but that cannot scale.

I do not want to use any 3rd party software as wallet. Suppose I just store my private key on a piece of paper and later transfer coins into it using exchanges. Would that be a valid transaction and allows me later to spend these coins?  Is there anything else I need to store together with the private key (like the hashed transaction number in transaction_input in the blockchain?)  I really want to avoid 3rd party software because it might be obsolete in the future, get wiped out, and cannot be backed up on a single paper.

Any advice?


texts: Can I use an earlier version of testnet?

texts: I am looking to mine bitcoins with ease. But, first, I want to know how can I access an earlier testnet (testnet2). I have future plans to do this. I need to know how to open it up on the command line and I will take it from there.


texts: What is the best suitable transaction fee to avoid high fees but still get confirmed?

texts:
Which is the best suitable transaction or also called as the network fee that can be set in order to avoid high fees and yet get the confirmation of the transaction.

Can we say that 0.00000100 BTC is appropriate ?


texts: Given a Bitcoin transaction as JSON data, how can I determine the number of confirmations?

texts:
According to blockchain.info, 4,198 confirmations have been received on the following Bitcoin transaction at the time of this writing. Give then following Bitcoin transaction as JSON (ref: transaction on blockhain.info as JSON) how can I determine the number of confirmations?

Transaction as JSON

{
   "ver":1,
   "inputs":[
      {
         "sequence":4294967295,
         "witness":"",
         "prev_out":{
            "spent":true,
            "spending_outpoints":[
               {
                  "tx_index":0,
                  "n":0
               }
            ],
            "tx_index":0,
            "type":0,
            "addr":"1BiYTVfoAWpEf5vTCVyWgWzsbdTbi3X4Lb",
            "value":4371338,
            "n":1,
            "script":"76a914758c92328cb8f0d5a9e2bc6a1b27b6fdf83fa86588ac"
         },
         "script":"483045022100f6d8e0e386079721dc286d25c88c5cddd8733ee3d93247f3ff0127e8aa7dcb9a02206ce2b7e524e4796e93688442dcc95bb7c8e2bcf3a46ac660633fac3e0becfd5e012102a9dba5ef4653f48190bf6b12130f001fe14cda8b8e2e06bf2e96b9cf3c442503"
      }
   ],
   "weight":760,
   "block_height":615893,
   "relayed_by":"0.0.0.0",
   "out":[
      {
         "spent":true,
         "spending_outpoints":[
            {
               "tx_index":0,
               "n":0
            }
         ],
         "tx_index":0,
         "type":0,
         "addr":"3BMEXDcDGPjGGR6MHiFiHRPfz6LeGeYYM3",
         "value":4366812,
         "n":0,
         "script":"a91469f3746a2b4246695de6ae4fd0d2c27221b1cd9d87"
      }
   ],
   "lock_time":0,
   "size":190,
   "block_index":0,
   "time":1580790109,
   "tx_index":0,
   "vin_sz":1,
   "hash":"406fe52a8cb99cfdc3ed6cc3e2ef461608e369943a9c1f4132421d3de425e66c",
   "vout_sz":1
}


texts:
I am trying to understand how bitcoin works internally in solo minning, and i am a little confused with the submitblock method:

version:     The current version
prev block:  The previous block
merkle root: The merkle root (Double SHA of the coinbase transaction)
timestamp:   The middle time
bits:        The difficulty
nonce        The valid nonce
num txs:     Number of the transaction (01 if it contains only coinbase transaction)
tx1:         The coinbase transaction (Built from the createrawtransaction method)

Is that correct?
Thank you for your help


texts: Is it possible to build mining reward pooling directly into Bitcoin?

texts:
Mining pools were formed quite early in Bitcoin's history. Since then, they have not been considered ideal because of more and more centralization creeping in. But it seemed the community has learned to accept and live with this necessary evil.

So in this context, has it ever been discussed to build mining reward pooling into the actual Bitcoin protocol, making centrally administrated mining pools obsolete?

A technical implementation could look like this:

A miner that finds a hash with difficulty n still solves a block around every 10 minutes, but also miners who find a hash with difficulty n-1, n-2, or even n-3 can submit their solution[1], however without triggering a solution for the current block.

The mining reward could then be distributed in one transaction proportionally to all miners who have found hashes.

Are there any altcoins that implement this or a similar concept already?

I'm aware there's P2Pool, but it uses a separate blockchain, which causes latency issues that make it unable to compete with centralized mining pools.

[1] Submit their solution how and to where? This would be a technical detail to discuss later. They could be opening a transaction channel or the like.


texts:
When I try use electrum or other wallets I have error: the transaction was rejected by network rules.\n\n66: min relay fee not met
How to send bitcon with zero fee?


texts: Does Amit Sahai's indistinguishability obfuscator enable Autonomous Virtual Corporations or "Agents"?

texts:
Given that an "Agent" is described as

  Agents are autonomous programs that maintain their own wallet, which they use to buy server time. Money is obtained by the agent selling services. If demand exceeds supply the agents can spawn children that either survive or die depending on whether they can get enough business.

When combined with this cryptographic breakthrough, it seems that Virtual Corporations and "Agents", which were purely theoretical, might now have the ability to exist and can encrypt a wallet's private key from a person who is running it.  The agent could then spend from it when pre-determined conditions are met (as verified from an oracle of some type).

Question

Is it possible to use this technology, based in fully homomorphic encryption, or a variant thereof, to create an autonomous agent with it's own wallet?

What other bitcoin solutions can be made with this?


texts: Why is not Bech32 address selected as default in Bitcoin Core 0.16.0?

texts:
So, thankfully Bitcoin Core 0.16.0 came to us, general people.

But however, native segwit address Bech32 wasn't selected as default.

Is not it better to use a Bech32 address right away rather than P2SH segwit-wrapped address?


texts: Why is SegWit disabled and old address gone when recovering an Armory paper wallet?

texts:
I wanted to make absolutely sure I could recover my Armory wallet with M of N recovery keys. So instead of doing just a test, I deleted the wallet and restored it. But now Segwit for getting receiving address is disabled

And my old receive address isn't showing.
I'm using the Goatpig fork of Armory, version 0.96.3.99-beta since it's the only one which properly created M-of-N keys in the GUI rather than command line.
Will I still be able to receive BTC in this wallet with my old Segwit receive address even though I can't make any new ones?


texts:
I got an issue with cgminer constantly rejecting shares. How can I fix it?

Here's example rejection (note that Diff jumps - sometimes it's 6/1 sometimes it's 1/1) :

[2013-04-09 14:24:05] Rejected fe26cac1 Diff 4/1 GPU 0 (lowdifficulty)

Here's the .bat file I use:

cgminer --scrypt -o eu-stratum.btcguild.com:3333 -u MyUser -p 123

My OS is Win 7 32 bit.


texts: What's more important GPU cores or GPU memory?

texts:
I have been on the sidelines, watching on and off, looking to attempt mining a few coins. I have also looked at just buying coins, but found that's not so easy to do with anonnimity with all the verifications, ID requests and concern of identity theft from scams. Plus FIAT to Bitcoin can run as high as 20% in transaction fees at a bitcoin ATM....sheesh!

So... I'm looking at mining and attempting to decipher the current GPU hardware requirements by COIN TYPE in terms of hash rate, on card memory and other items like CPU cache and main system memory and even M.2 onboard storage/cache on the newer motherboards and if these have any effect at all on a GPU miner setup.

TOTALLY BRAIN FRIED TRYING TO SORT APPLES, ORANGES and LEMONS OF MIXED DATA.

How do you determine how much GPU core or MEMORY is the minimum needed to mine a specific coin. I'm sure there might be some instances where a lower hash rate card at a lower watt rating might do fine mining, just not as fast as the best of the breed. gpuboss,com has been great for card info, but not all the cards are listed, and some do not give details on power consumption, which when compared at today's crazy prices doesn't give the cost/profit/overhead details.

At this stage it's clear that only a few will continue to mine BITCOIN and ETHERIUM directly given the custom miner farms. Call me a bottom feeder or whatever, but I'm looking at using maybe some less popular cards, lower power cards and less frequented coins to mine and get into the game and migrate into more stable crypto coins to HOLD long term.

Suggestions on plotting the details or sites to follow?

Also some pooled mining does not appear to use all the GPU hash benchmarked from some cards, or at least it doesn't pay the total hash credits offered at that rate.


texts:
If testnet coins are this difficult to get, what's the chance people start throwing in some real money to speed along the process?
If only to just have to not wait to test, say if you have an important time sensitive simulation you want to run?


texts: Difference between downloading bitcoire core from bitcoin.org and compiling from Github

texts:
I'm following instructions to install Bitcoin Client in Andreas Antonopoulous' Mastering Bitcoin.  In Chapter 3, the author details options of installing the bitcoin core from bitcoin.org or compiling it from the source code.  From a practical perspective, what is the difference?

What do I lose by just installing it from bitcoin.org?  (Since that seems easier than making sure that I have all required dependencies in Linux)


texts: During transaction getting 'Insufficient funds' message from Bitcoin core

texts:
I am trying to make sendbtc transaction using bitcoin rpc call but getting failed message "Insufficient Funds" from bitcoin core.

In addition, once I am trying to make transaction for small amount like below .5 BTC, that transaction successfully done. But for higher value, bitcoin is sending a message "Insufficient funds".

Please suggest me what can I do to make higher value transaction.