texts: Questions about blockchains, network trust and why becoming a node?

texts:
everyone,

I'm a software developer and I'm striving to understand the concepts behind blockchain and the projects running on them. I'm not sure if this is the correct place to ask these questions, but here I go:

obs: just in advance, I'm not developing a smart contract software. I'm just using it to compare

1- How many blockchains should exist? I mean, I understand that if I create my own blockchain then a new blockchain exist. But conceptually speaking, how many of them should exist for a good global environment?

For example, smart contracts could exist in ANY blockchain? What about the actions that should occur when an event is fired and what would fire these events? The answer for these questions are a new blockchain inplementation with their own features? That would drive the answer to "as many blockchains as necessary".

Complementing this question nowadays there are more than one big blockchain out there, right? Etherium and Bitcoin, maybe?

2- What are the nodes that compose the bitcoin blockchain network? Am I one? The miners? Who are they?

If I create a blockchain for a smart contract solution, who would be the nodes in this network?

Why would someone become a node? What is the reward?

3- I read that the size of the Bitcoin blockchain is very very big. Anyone know the current size? It is entirely stored in the nodes machines? If not, how does it work?

4- I had a wallet in my computer, though I transferred my money to an exchange. What is stored in an offline wallet? Just a hash? A wallet is relevant for other kinds of implementations, like smart contracts? What would be stored in it?

5- I've been reading a lot about the motivation of the use of blockchains, because it decentralize the data. So I don't need to trust the government in the case of cryptocurrency. That, in the case of smart contracts, there aren't a third party.

But I still need to trust the organization behind the cryptocurrency, and there is a third party when it comes to smart contracts, that is the organization behind the software, right?!

When it comes to smart contracts with money exchange, I have to send my money to someone. This entity is still the man in the middle. Am I wrong?

If the organization behind Bitcoin just shut doors, turn their servers off (if there are any) what would be the impact in the environment ?

Lastly what is the blockchain.info?

please, be kind


texts: Is the secret seed number also the private number?

texts: I purchased a bitcoin in 2014 from Coinbase. I received a long alphanumeric number. No private code or seed phrase. I received a 16-digit secret seed at a later date. Is the secret seed I received a replacement for the seed phrase or private number that I can use to access my bitcoins on Coinbase?


texts: Can a malicious user recieve bitcoins by first finding the proof of work of his/her transaction then releasing it

texts:
Assume a malicious user wants to make bitcoins through mining. A user can create a transaction (let us assume it is a real transaction) and then create a block containing that single transaction. The malicious user then works on finding the correct nonce for that block before releasing the transaction to the network. Once the value is found, the malicious user releases the transaction. However, he/she already has valid proof of work and has the advantage over all other miners. Therefore, the malicious user can obtain the reward.

Is this scenario possible to happen?


texts: What is the strategy behind a sell wall?

texts:
I understand the idea behind 'bid walls', but on Kraken, prices are being kept low through the use of 'sell walls'.  The volume on this exchange is too low to have a chance of getting through these walls, even when prices on other exchanges are skyrocketing. Every so often, when the price falls a bit, up comes a new 'buy wall' keeping it there. The price on Kraken falls when other markets fall, but gets stopped at the wall on the way back up.  I am curious to know what the strategy behind this tactic could be.

Added 21 Nov for elucidation

On this small volume exchange, a 30 BTC ask equals 10% of the 24hr. volume.  It is the equivalent of a 4500 BTC ask on Bitstamp.  It alters the way bidders approach the market.  When you see such a wall sitting just above the current price, you can be sure the price will not be rising beyond it for at least the next few hours.

I watched this person re-position this block four times over the course of the day.  Each time, lowering it to sit just above the current bid price.  It was altering the dynamics of this small volume exchange.

I am not asking for you to read anyone’s mind.  I was baffled by this behavior.  I had not seen this strategy before.  I thought that there must be some method to this madness, but I could not see what I might be.  I thought that somewhere in the collective experiences of Stack Exchange there might be someone who was familiar with this strategy and might be able to provide some insight, not necessarily on this person’s behavior, but on the theory behind the strategy being employed.  Assuming, of course, that there is one.


texts: Is there any implementation of attribute-based encryption on top of Bitcoin?

texts:
I've found a few papers detailing how you could do it in theory, but haven't seen anything in practice.  Like a system for distributing bitcoin to private keys, where those keys are only distributed if the recipient possesses certain attributes that would unlock the access policy in the transaction.

EDIT: I'm thinking of something like this: ieeexplore.ieee.org/document/7846935 where there is a protocol using ABE built on top of, or aside from the Bitcoin protocol, in order to distribute coins based on certain attributes. The keys themselves are distributed by the authority who determines who possesses the attributes.


texts: How out of block chain transactions work, and is there any API for that?

texts:
i wonder how out of block chain transactions work, because till i know it happens but "is not recommended" (it is what i read on the internet), i want to manage some micro transactions but as it is well known  that the fees of each transaction would eat them up so it would be better out of block chain transactions to deal with them?, is there any API that would help me on this?

Thanks in advanced for your time.


texts: Why is my withdrawal from cryptofree.casa not completed?

texts: As a novice in bitcoin, I was told about a free bitcoin giving site which is cryptofree.casa .I have played rolls for several months and reach the required 0.3BTC. I then launched the withdrawal but I didn't receive anything since three months.


texts: Importprivkey's "label" - is it the same as an account?

texts: The "importprivkey" API call allows one to import a private key and save it with a label. Is the "label" in the API call synonymous with an account used in the wallet?


texts: Reject TXs based on fee in comparison to TX size?

texts:
Is it possible to configure a node to reject junk transactions like this
https://tradeblock.com/bitcoin/tx/6d67480fde2dd484b0ee389a6488db212ea7d0dbd2a11358efcc0b39077407ca

199 inputs, 35kb tx with a tiny 0.0003 fee.

There's minrelaytxfee, but I'm looking for something that is based on both fee and tx size.


texts: Can an invalid Omni transaction be confirmed by bitcoin miners?

texts: Is it possible that a well formed Omni transaction (with valid Omni layer data) be valid for Bitcoin miners while being invalid for the Omni token being used ?


texts: Have there been reports of botnets mining Bitcoin / crypto-currencies?

texts:
Is the threat of Botnets using massive amounts of CPUs/GPUs to mine Bitcoin, or some CPU-friendly coin, purely theoretical at this point? Or have there been reports of this actually happening?

I know of trojans stealing Bitcoin wallets, this is not related to my question.


texts: Confirmed transactions lost in my synchronised node

texts:
I tried to get a transaction information using RPC method getrawtransaction in my synchronized node, but I got no information about the transaction.

I did it in another node, and I could get the transaction information. How could this be? Maybe the database is corrupted? But I would think that when starting bitcoind, bitcoind would check the database. Maybe I am wrong. Can anyone can tell me how to figure out this case? Big thanks.


texts: Where can I read more about the fields of the transaction returned by listtransactions API

texts:
I am looking at the results returned by listtransactions API and I do not understand the difference between blocktime, time and timereceived. Help tells me the following:

"blocktime": xxx,         (numeric) The block time in seconds since epoch (1 Jan 1970 GMT).
"time": xxx,              (numeric) The transaction time in seconds since epoch (midnight Jan 1 1970 GMT).
"timereceived": xxx,      (numeric) The time received in seconds since epoch (midnight Jan 1 1970 GMT). Available for 'send' and
'receive' category of transactions.

Can anyone explain these fields in a little bit more details?


texts: Why is pycoin getting the incorrect output address?

texts:
I am using pycoin version 0.52 from pypi and it is getting the wrong output address from a transaction.

Code

# testnet txid and corresponding rawtx
# see https://test-insight.bitpay.com/tx/e20af2349c48774eddda161b74659e3e64ad0f62794df9a2271e6baa313796f2
txid = "e20af2349c48774eddda161b74659e3e64ad0f62794df9a2271e6baa313796f2"
rawtx = "010000000120addc4fc706417fad4158b4b9e30f9289e7dac4918277dc189e03f9a0155064000000006b483045022100b49bae1352d24d9673396bb01a23da583e01c5226347be6cf0f75477cce7f628022062eeb7a5a9b87a97f834660ce417278d4889d525e7e0f947020efdda045d54530121028895b78ad435814caecbeeb43453e4881a96d32c23d61b909dee06ad44c07ad5ffffffff0273a139c3000000001976a914a6d608497ad283ca93c1bdc3abb0a610b8edb18988ac80a81201000000001976a914f4131906b10615a61af347c56f1223ddc214f95c88ac00000000"

from pycoin.tx.Tx import Tx

tx = Tx.tx_from_hex(rawtx)
out = tx.txs_out[1]

print "expected", "n3mW3o8XNMyH6xHWBkN98rm7zxxxswzpGM"
print "actually", out.bitcoin_address()

Output

$ python test.py
expected n3mW3o8XNMyH6xHWBkN98rm7zxxxswzpGM
actually 1PFYkk3YZLY2KqotUBPmJwYo8yNFz3Nxyy


texts: How to monitor the blockchain for new blocks

texts:
I want to scan new transactions as they are added to the block chain.

Does anyone have a suggestion on how to do this. Are there any APIs that allow for this? Or is there a way to directly tap into the bitcoin network with ruby?


texts:
I want to create an original network by forking bitcoind.
I changed chainparams.cpp and other programs for loading it.
Then, I set DNS for my seed node.

When I boot my seed node, my seed node tries to download blocks from others.
However, there is only a single seed node(itself). So, I expected that my seed node loads blocks which are pre-located in the local data directory. But, my seed node executes the initial block download process.

In this situation, other nodes cannot sync with my seed node because bitcoind ignores getheaders message while initial block download.

To operate a seed node, is there any command options for disabling initial block download?

As an additional question, is there any discussions and best practice for operating seed nodes?


texts: What happens if while mining, you lose internet connection?  Do you lose all the work your computer has done, or is something like bitcoin-plus smart enough to post the data across when the internet connection has been re-established again?


texts: Import bitaddress.org wallet into Bitcoin-Qt client?

texts:
I've received some bitcoins in a wallet created by bitaddress.org, and I've saved a screenshot of the webpage that has the public/private keys and the QR codes:

I've now downloaded the Bitcoin-Qt client, how do I import what I have into it as a wallet?


texts: What is the request limit number in the blockchain.info API?

texts:
I'm planning to use https://www.blockchain.com/api, precisely single block https://www.blockchain.com/api/blockchain_api for testing purposes on my script.
I noticed there this line on the the API site 'Request Limits: To bypass the request limiter, please request an API key', the registration for an API key required me to have a website or app but I don't have any.
I'm planning to use their API to run a script for a few days to test.
So I'm wondering: does anyone know what is the current request limit for their API? I see no mention about the request number on the website or document.


texts: What's the easiest/fastest way to experiment with bitcoin-cli?

texts:
I want to experiment with the bitcoin-cli in the easiest way.
I just installed bitcoin core and waiting for it to download the blockchain.
Is there a way meanwhile I can run bitcoind and/or bitcoin-cli, that doesn't require downloading the whole blockchain?
I guess running the test-net is a natural approach.
My main problem is: I don't see the bitcoind and bitcoin-cli executables anywhere on my system.
I'm running Ubuntu 16.04.1 LTS
and installed bitcoin core through the command line as described here:
http://bitzuma.com/posts/getting-started-with-bitcoin-core-on-ubuntu/

ultimately running bitcoin-qt from the command line.


texts: How can I get address wise UTXO balance for Zcash t-address

texts:
I tried to create user specific account wise zcash t-address, got the following error

zcash-cli getnewaddress "testaccount"
error code: -11
error message:
Accounts are unsupported

Is it possible to create account wise t-address?

But I have created zcash t-address successfully without account. Once I sent some amount to another t-address, remaining balance shifted to newly created t-address. Please assist me how can I get user specific address wise t-address balance?


texts: do the trezor wallets support all crypto currencies for strorage?

texts: I am considering buying a trezor wallet. I am wondering if this type of wallet can support all types of crypto currencies?


texts: Can I transfer bitcoins generated in regtest mode to a friend?

texts: I am running Bitcoin in regtest mode. Is it possible to send bitcoins generated in regtest mode to a friend ? (I only want to test it). Is it possible ?


texts:
This morning I opened my brand new Trezor and plugged it into my laptop. The message I received was that the device was not installed correctly or something like that. I tried three times. Then I installed the Trezor plugin for Chrome and now the laptop doesn't recognize the device at all - no message, nothing. The device screen still lights up with its welcome message.
What should I do?


texts: Leading zeros and numbers of hashes before arriving to solution

texts:
Had been reading a post written by Adam Back a couple years back (no pun intended) with regards to calculating bitcoin difficulty in bits (so we could arrive to the number of hashes roughly needed before a solution to a block is found).

The equation being log2(difficulty)+32.

Link: https://bitcointalk.org/index.php?topic=192886.0

From his post I also understood we could also find the difficulty in bits via the block hash in hex, i.e. each leading zero * 4, then check the next hex char with the following rule: >7=+0bits, >3=+1bit, >1=+2bits, 1=+3bits.

Question being:

What is the intuition to Adam's elaboration of >7=+0bits, >3=+1bit, >1=+2bits, 1=+3bits? Maybe there is something with regards to hex conversion that I need to catch up on?
With log2(difficulty)+32, we could arrive to a fractional bit (e.g. 54.8713). Would it be possible to derive the same fractional bit given the leading block hash values, or are we at best left with an approximation?

Thanks in advance!


texts: Armory takes 8 Hours to sync. Is it going to get worse as Bitcoin becomes more popular?

texts:
I have been experimenting with Bitcoin and I installed Armory wallet. It told me that it would take approximately 8 hours to sync the worldwide ledger.

My question is, as Bitcoin gets more popular, will it take longer to download the ledger?

If so, doesn't this pose a problem - could it get to big to be feasible?


texts: From a legel perspective, are Bitcoins "created" by a miner or the Bitcoin Protocol?

texts:
The recent FinCEN announcement said explicitly that virtual currency isn't a "currency" by the standard sense of the word, and shouldn't be regarded as such.

Should Bitcoin ever be considered a "currency" I think it would be helpful to know if the coins were created by the miner or created by the protocol.

Miners

Miners claim and distribute brand new coins that have never been used before.
The ability to claim a coin is distributed worldwide and is equally random

Protocol

The protocol existed before any miner was configured.
The protocol demands that no more than 21 million coins ever exist
The protocol controls the inflation/deflation of the coins through "difficulty"

To me it seems that the "creator" of a Bitcoin is the protocol, and not a miner, and that the term "miner" may not be appropriate.

For most legal purposes, is it ever likely that a "miner" will be considered illegal in any country as if they are "creating" a currency"


texts: How safe it is that a single San Francisco company controls the canonical location of Bitcoin code?

texts:
The single most-trusted canonical source of Bitcoin client is https://github.com/bitcoin/bitcoin

This URL is controlled by a single US company GitHub Inc., headquartered in San Francisco, United States. The US government (nor any other government) is probably not a friend of Bitcoin, and they could theoretically threat the CEOs of GitHub Inc. with an arrest, unless they implement some kind of backdoor into the Bitcoin code, which could be downloaded by a large number of people before it would get noticed.

If and how is the Bitcoin network protected from being poisoned and destroyed this way?


texts: use addwitnessaddress outside bitcoin core's wallet. Are there any libraries?

texts:
I want to create P2SH of witness script. I know bitcoin core has addwitnessaddress rpc method but I want to use it for addresses which are outside bitcoin core's wallet. I tried to find the tools on github but I couldn't find it. I think I can create it. Before that I want to ask you whether the libraries already exist or not.

Update 1

Seems NBitcoin has the feature.

English

https://programmingblockchain.gitbooks.io/programmingblockchain/content/other_types_of_ownership/p2w_over_p2sh.html

Japanese

https://programmingblockchain.gitbooks.io/programmingblockchain-japanese/content/other_types_of_ownership/p2w_over_p2sh.html


texts: Is there any academic research on the influences of Bitcoin's long term valuation?

texts: Is there any academic research or theories about what future events and metrics will most influence BTC's long term valuation relative to fiat currency?


texts: Why doesn't Bitcoin use a DHT for choosing peers?

texts: Why does Bitcoin use a gossip protocol rather than a DHT for peer discovery? I believe that kademlia XOR distance helps shape the network topology so that peers are more evenly disturbed.


texts: Doesn't bitcoin have the same inflationary problems as fractional reserve banking?

texts: I keep hearing that Bitcoin is immune to inflation because You can't make more bit coins than some fixed constant of bitcoins through a process of mining.  However, assuming enough people take it seriously, doesn't bitcoin have the same inflationary problems as fractional reserve banking?  As soon as you put it in a bank because people hate storing their bitcoins in a "vaults" like gold, you introduce the same old fractional reserve banking system that the US federal reserve watches over...  and because its an international currency that's not regulated, who sets the fractional reserve rate for bitcoin?  isn't that a bubble waiting to happen?  What happens if there's a run on a bitcoin bank?


texts:
instead of maintaining digital wallet and syncing the blockchain, is it okay if I just use paper wallet now and later import the addresses in digital wallet?
Will I get all my transactions to show up in digital wallet?


texts: Bitcoin recovery possible from some kind of private key?

texts:
back in 2012 I've acquired a small amount of bitcoins, which as far as I remember I saved in a wallet on instantwallet. I wasn't following what was happening with the bitcoin until I listened lately about its value. I also found out that instawallet does not exist anymore since it was hacked in 2014.
Apart from a URL on instawallet, I have a Bitcoin address and some kind of a private key. Could somenone please tell me for sure if there is any chance to recover my bitcoins or should I just forget it?


texts: How to get addresses from scriptPubKey in segwit transactions?

texts:
I'm running through raw transaction data, and I'd like to be able to gather addresses (where possible).

So far, I've made this diagram to help me understand when it's possible to figure out addresses from the scriptPubKey of each output:

However, as you can see, I'm not sure how I can work out an address from a P2WSH.

Is it possible to get addresses from the scriptPubKey alone, or can I only get them when the witness is revealed when the output has been spent?  (as shown here):

witness:      0 <signature1> <1 <pubkey1> <pubkey2> 2 CHECKMULTISIG>
scriptSig:    (empty)
scriptPubKey: 0 <32-byte-hash>
              (0x0020{32-byte-hash})

EDIT: Also, please let me know if you notice that any of my pattern matching in this diagram is incorrect (or if I'm missing any patterns that allow me to find out more addresses).


texts: What are ways a BTC Exchange could steal from its customers, and how can they protect themselves?

texts:
Mt Gox is the dominant Exchange that handles BTC to USD conversions.  Given the recent spike in price, and that Mt Gox is the primary exchange that publishes this price, it's conceivable that a second set of books could be used to manipulate the public -vs- non-published value of the coins.

What are the methods in which an Exchange can steal from its customers? (dual set of books, etc)
How can consumers and businesses protect themselves from exchange based fraud?


texts:
So basically I have a BLF non-Jalapeno variety 50Gh/s miner. I run cgminer and have recently been mining from ozcoin after eclipsemc was hit with a recent DDoS.
Normally, I have been clocking at around 46.xxG-50.xxG/50.xx-51.xxGh/s. Last night I noticed a bunch of incoherent errors pop up on my terminal window. About 5-8 lines long. The miner would stall out, it dropped to around 18.xxG/19.xxGh/s stuttered around that level for a few minutes then slowly climbed back up to the rather disappointing 36.xxG-39.xxG/37.xx-39.xxGh/s I have been seeing ever since.
I've poked around looking for reason for this, and maybe haven't poked hard enough, but I am at a loss. Any ideas on what is happening?


texts: When or how does one becomes a part of Bitcoin P2P network

texts: I am new to bitcoins and got a question raised in my mind recently. I learnt that every person doing a transaction is a node in btc p2p network and that when he/she joins the network he/she gets a full blockchain starting from the genesis block. But can anyone tell me that in reality am I becoming a node while I am registering myself on a trading site like Zebpay, Koinex or IQ Option. If so then how can I see the blockchain I have received.


texts: Why my bitcoin node does not show the same mempool size than a web blockexplorer?

texts: It's supposed to match after a while. When several bitcoin nodes are running for days they should have the same mempool, but my bitcoind node shows arround 2k transactions less than blockchain.info webpage. My mempool size limit is 300Mb and at the moment of writing is arround 16Mb. Why is this happening?


texts: Which miners support generating their own midstate?

texts: Currently I was testing RPCMiner on my Mac running a custom pool, and it appears to crash because I can't generate a proper midstate value. Which miners support generating their own midstate (as per an extension of the protocol)?


texts: how long can it take me to get 1 BTC on mining speed 30.9945H/s and 72.99451H/s respectively

texts:
im new to this biticoin mining, i justed to know is it going to earn me anything soon where my mining speed is at 30.9945165416H/s and 72.9945165416H/s really? how long can it take me to get 1 BTC

like for;
30.9945165416H/s how many days

72.9945165416H/s how many days


texts:
Sent .10 from my Electrum to my trezor. Now more than 30 comfirmations, but not showing on my Trezor Balance. Put in a ticket with support have not heard back. Here is my trezor receiving address and the block explorer validates confirmations. 1PZz1GAhtVx4nWg4Me85jFe3Xg3anoGPLR
Sept-7/17
Any ideas. Would like to have the funds recorded so I can spend them.


texts: BTC taxation: difference between EU and US

texts:
How is it possible in US if someone reveiced salary in Bitcoin, right on that day income become taxable? In Europe, in Hungary only when BTC is sold and sent to a bank account it become taxable. So in my country my assumption is, it is possible to postpone when income become taxable received in BTC.

My tax consultant said the reason is because BTC is not an acknowledged currency at our central bank, this is the difference between EU and US BTC taxation. Do you agree?


texts: Is it possible to have a cryptocurrency based on email address?

texts:
I would like to know if there is any existing cryptocurrency that lets you control the public and private keys generated.

I just don't like the fact that cryptocurrency keys are randomly generated. Even though I know generating such a pair again is almost impossible. I don't like it because it's "almost" impossible.

I have a few ideas that I would like to be used for the generation of these pairs but because I don't have an understanding of how the blockchain works, these ideas might not be practical.

I am still willing to share here if someone is willing to get back on the feasibility.

PS: Please excuse my poor grammar. English isn't my first language. I can only get the spellings right :)

PSS: I am now editing this to include my idea of a blockchain which I think I could trust:

Like I said, I just don't like the randomness that is involved. I would love to see a cryptocurrency where you have control over both the keys or at least one of the keys, preferabbly the public key.

Is it possible to have a currency with the following features?

Public key is an email address
Every transaction made on the blockchain sends a confirmation to the email address with a secret key. Once this is processed by the user, the blockchain verifies the transaction and either adds it to the blockchain or rejects it.

With such a set up, my coins would be as safe as my email address. To steal my coins, you would have to gain access to the associated email address.


texts: When computing the hash, do you need anything after the number of difficulty bits?

texts:
I'm going to screw up a lot of the terminology here.  I'm trying to understand the Bitcoin algortihm and wanted to use this JS miner -- https://github.com/howardchung/jsminer .  Specifically, I'm trying to understand how to build the data that someone attempts to hash.  They attempt to do this in the JS miner by the following

    var header = version + prevhash + merkle_root + ntime + nbits + '00000000' + '000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000';
    curr_block.data = header;

I'm following most of this, using the Bitcoin wiki as a reference, but what I can't figure out at all is what are these last two numerical constants -- '00000000' and the bigger one beginning with "0000008".  I have seen these come up in other examples but I can't figure out why these are needed or if these are hard-coded values in the JS miner that shouldn't be there in real life.  Any help is appreciated.


texts: using my own public and private key for managing wallet

texts:
I managed to create wallets for bitcoin with public and private key. I can get the balance of these wallets.
But when I want to send someone tokens from this wallet, I can't because there is no website nor application that will accept my wallet (rather they create wallets on registration or installing the app).
I used Node.js for programming the application and I don't have a full node.
Please do not answer about security or other stuff just want to know
how I can use this token or transform them to other wallets without programming.


texts: Can someone explain me ECDSA (creating public from private key) with 8-bit numbers?

texts: Trying to understand Elliptic Curve maths with 256-bit numbers seems like hard to explain/understand. I wonder if by lowering down the possible numbers get's a little bit easier.


texts: I am thinking if secure encryption like one time pad (OTP) is achievable using bitcoin blockchain? The reason is bitcoin blockchain size is over 70 GB, which could potentially encrypt/decrypt 70 GB worth of data. All that is needed by the sender and receiver is blockchain and an application that encrypts and decrypts the data on the sender and receiver end respectively. Please share your thoughts if it is a bad or wild idea and why? How about using other public blockchains like Ethereum or private ones like Eris or Hyperledger. What would make it work?


texts: txout script criteria (scriptpubkey critieria)

texts:
what is the criteria for a txout script to be accepted into a mined block? is there any criteria at all? the reason i ask is that OP_RETURN is regularly used in txout scripts yet it is not spendable:

case OP_RETURN:
{
    return set_error(serror, SCRIPT_ERR_OP_RETURN);
}

and i have also seen transactions which push elements to the stack which are more than MAX_SCRIPT_ELEMENT_SIZE bytes.

i'm guessing that a syntactically incorrect script such as:

05aa
(ie OP_PUSHDATA(5) <aa>)

would not be permitted?

could someone point me to the code which miners use to validate whether a tx will be included or discarded as invalid (due to its txout scripts). i'm guessing it lies in main.cpp, but i would like to know where exactly, thanks.

obviously anybody can mine a block that is set up any way they like, but presumably there are fixed rules for whether it is considered valid or not - so other miners will know whether to use its hash as their prev-header-hash when mining the next block?


texts: Lost bitcoin because of deleted receiving wallet id

texts: Is it possible to recover the bitcoin that was sent to a wallet that generated using payeer which I deleted on accident? The transaction also shows completed from the other wallet.


texts: Differences between MemoryBlockStore and SPVBlockStore

texts:
What are differences between MemoryBlockStore and SPVBlockStore in bitcoinj?

Which should be used for downloading the blockchain and why?

Can I use same SPVChain format file for all wallets?


texts:
BitCoin is (arguably) the world's best chance thus far at a virtual currency (although it's very unstable).  Even though it's a high risk, it is able to be converted to regular dollars, and some shops and online sites accept payment in Bitcoins.

Is there a way to convert BitCoins to regular currency online, or is there a world-wide travel website that you can use BitCoins to purchase flights, tickets, etc with?


texts: I sent bitcoin from my BitcoinQt wallet while it was unsynced to another wallet, do I have to wait for it to sync?

texts: The wallet shows that the transaction has not been broadcasted yet with 0 of 6 confirmations. My wallet is stuck on a block right now.


texts: Is the potential number of blocks in the Bitcoin blockchain limited?

texts:
i.e. Is there a finite number of transactions that will ever take place using Bitcoin?

I have Googled this somewhat and found discussions about Bitcoin's limited, finite supply, but it's unclear to me whether the blockchain itself is a finite resource.


texts: What is the format of the databases that are used in the core bitcoin client?

texts:
This question tells what each of the files in the bitcoin directory are, but it doesn't explain the structure of the databases used. What is the table structure (columns, data type, etc) for each of the tables that the bitcoin client maintains?

Thanks!


texts:
Is there something like Mt.Gox Live but for Intersango?

I don't expect the same quality, but at least to be better than this horrible bugged mess which is BitcoinCharts/BitcoinWatch.


texts: How many bytes of entropy are recommended for seeding a mnemonic phrase?

texts: If I wanted to generate a 12 word mnemonic, how many additional bytes of entropy is recommended I use?


texts: Are Closed Prices just the last trade or are they averaged?

texts: Since these exchanges run 24/7, are the posted close prices (say if the chart shows 1 hour increments like on bitcoinwisdom.com) based on the last trade for that time frame?  Or are they averaged over that time frame?


texts: Transaction overriding in lightning network

texts:
I'm reading the lightning network whitepaper, and at some point it states this:

  Therefore, it is possible in bitcoin to devise a bitcoin script
  whereby all old transactions are invalidated, and only the new
  transaction is valid.

I would like to know the specifics of how this can be done. Seems to me that what they are describing here is some kind of transaction overriding? It is somewhat different from the mechanism I understood a micro payment channel works.


texts:
I am running a btc node and it is taking too long to sync. Is there any way to transfer the wallet to an electrum wallet? If so how?

1)Upgraded my btc node

2)Syncing

3)Transfer receiving addresses from btc to electrum

4)Whole amount from btc wallet does not match electrum wallet

5)About 15% difference

I am ready to shut down my btc node and save electricity.  Will I still be able to retrieve the lost bitcoins some time in the future.

I imagine a day where I could bring it to a place like Walmart or Best Buy to fix it.  Or Are there places you can bring it now?


texts: Lightning Network LND - Retrieve payment by hash

texts: How do I get an outgoing Payment by paymentHash using LND REST API? I know that GET /v1/payments returns all payments, but I would like to get one in particular, not all as there may be thousands. Thanks.


texts:
I am creating a dashboard, and I want to add Market Depth as an indicator from different exchanges.

I have understood market depth from the following thread -

https://bitcointalk.org/index.php?topic=147716.0

The issue is I am a little confused as to the API's provided by Mt.Gox - They provide an API for depth which is linked closely to the volume.
The other exchanges provide API's for Bids and Asks - from which as per the link we can plot two curves and show the depth.

So what is the right way to go about building this plot for the different exchanges? Is there an algorithm that has to used. Is there a site that already provides the market Depth Info for different Exchanges.

Thanks for pointing me in the right direction.


texts:
I'm new to Bitcoin and am considering allowing people to pay for my software with them. Before I continue I would like to clarify some things. My googling did not get me the answers I was after.

I understand that you can create new addresses for each transaction. Say I have 1BTC paid to A and 1BTC paid to B.

On the overview tab of the default Bitcoin client, the balance would be displayed as 2BTC. I can only assume it has simply added up all the amounts in A and B address?

But when I send 2BTC to address C, does it create a new 'sending address' X and move to amounts from A and B to X and then send to C or send two transactions, one from each account A and B?


texts: Are change addresses visible from the GUI in the Bitcoin-QT client?

texts:
I've seen this question pop up on reddit multiple times, and I don't know the answer.

However, I do know that in my own wallet, several unlabelled addresses have appeared over time without me requesting for them to be created. Are these be the change addresses used when I spend bitcoins, or are the change addresses invisible from the GUI?


texts:
I'd like to start mining Bitcoins on a CPU for testing purposes. I've downloaded CGMiner, compiled it and created a config file without any problems, however starting it results in an error message:

  All devices disabled, cannot mine!

What do I need to do in order for CGMiner to consider my CPU a device?


texts: How long would it take to solo-mine with these crypto-currencies

texts: I have a Windows 10 machine with an AMD Ryzen 5 3600. How long would it take to solo-mine a Bitcoin with my GPU. What mining software should I use?


texts: farmers quest to exchange goods and services

texts:
I would like to know whether it is possible for farmers to use Bitcoin to exchange good and services without ever using other money. We are trying to build a network between local farmers and would like to use Bitcoin in exchange for our services.
Looking forward to hearing from you.


texts: Any plans for Bitcoin Core app to integrate Hardware Wallet support?

texts:
So I could use the full node and wallet easily integrated with a HW wallet and avoid security exploits?
Recently had a case of someone that had all his wallet stolen probably because of a keylogger - not a good experience for a noob that was just starting and was trusting the "best" full(complete) node Bitcoin (don't trust, verify) experience.

We know the key creation is flawed from the user perspective and this is something that already has a solution but still not implemented into the full node wallet client. Any plans for adding this extra layer of security for non-technical end-users?


texts:
I am confused about how getdata() is actually implemented at full nodes.

Suppose a full node receives a getdata() request with MSG_BLOCK flag and a hash H of some block B. Then would it simply look up H into its levelDB database to fetch B from its disk and return it to the caller (in constt time) or something more expensive is done?

Can I also get some references to read about it?


texts: Is it safe to import my private key into another wallet?

texts: I sent some bitcoin to my bitcoin core wallet before it synced, not knowing this sync would take days, and was wondering if i was to import my private key into a different wallet if that would work?


texts: I'm reading about the Stratum protocol where miners contribute to pools.  Specifically there is a "mining.submit" method -- https://en.bitcoin.it/wiki/Stratum_mining_protocol, in which I miner will submit a share for consideration.  The details on this doc are a little sparse.  Specifically, what is the "ExtraNonce2" value they describe as being submitted back to the pool?


texts: Version prefix used for Bech32 addresses

texts:
I was compiling a table for Version prefix (hex)  and Base-58 result's prefix for different types of Bitcoin addresses.
I came across the content here: https://en.bitcoin.it/wiki/List_of_address_prefixes, which does not contain information about Decimal, prefix Hex for Bech32 addresses (I guess they also called SegWit address, right?)
So, I checked this chart here:
https://en.bitcoin.it/w/images/en/4/48/Address_map.jpg but, I don't understand the meaning of "x03x03x00x02x03".

If x00 equal 0x00 in hex and x80 equal 0x80 in hex, how should I interpret x03x03x00x02x03?
What is the version prefix for Bech32 addresses (bc1 addresses)?


texts: Can I log-in to my wallet on new PC using just my wallet number and passphrase?

texts: I was into bitcoin years back. I just stumbled upon my wallet number and passphrase. Can I use these info and sort of log-in using any client I can download online?


texts: How does Transaction Remote Release work?

texts:
How exactly does TRR (Transaction Remote Release) work?

What are the similarities (and differences) with the way TOR works?


texts:
User1 bet the hash of Block 999,000 that hash(block(999,000) = even
user2 bet the hash of Block 999,000 that hash(block(999,000) = odd
Both users pay/sign 1 BTC in a CoinJoin for that bet to a P2SH. The winner will win 1.99BTC and 0.01 BTC is the tx fee.
How to make the scripts that can perform such action?

Script1 that perform the betting section.(that specify the criteria for redemption).

Script2. Redeem script (based on the output of block 999,000) that transfers the fund to the winner new PubKey Hash.


texts: So I closed my wallet in MultiBit and there isn't a trace of my wallet

texts: I've looked through every file imaginable and I can't find the Wallet I had all my bitcoin in. I'm about to faint, you have no idea how much money I just lost. I'm trying my best not to curse up a storm in here, but I don't see the wallet anywhere, i'm beyond angry right now. Can anyone help? Please?


texts: Why Ripple is able to process transaction faster than ethereum and bitcoin?

texts:
I was wondering what makes Ripple very fast(Transaction per seconds) rather than Ethereum and Bitcoin? Currently, I'm doing a research on how to reduce transaction confirmation time in blockchain.
Is it because Ethereum and Bitcoin has mining activity and that's why the transaction time becomes very long compared to Ripple? I tried to find technical answer about it, maybe because of the algorithm used(?), maybe because the process to verify transaction in Bitcoin is longer than Ethereum(?) and so on but I couldn't find about it. From what I had already searched, the process from transaction to verification of Ethereum and Bitcoin is the same so where's the technical difference that makes Ethereum able to process transaction more in second than Bitcoin?


texts: OP_ADD operation in bitcoin script for integers greater than 128 in java

texts:
I want to execute a simple series of instructions to implement a bitcoin script in java using bitcoinj API. All I am looking for is performing arithmetic operations for negative integers or integers greater than 128. An example bitcoin script for the task would look like this:

150 120 OP_ADD 270 OP_CHECKNUMEQUAL

This script should return True eventually. To implement this in java, to push integer values like 150, 270 etc i have to first convert them to byte arrays. I have followed answers given in https://stackoverflow.com/questions/1936857/convert-integer-into-byte-array-java but none of them works in here probably because of differently defined arithmetic operations in bitcoinj API script. Can anyone please help me in this.


texts: What are the differences between the transaction and block versions? (v1, v2, v3, etc..)

texts:
If I run command to fetch a block, I see version 2 is returned:

getblock 0000000000000000ae22455f90306f43e8c806585fe2dfc3b0e92ac7b7620bff

Output

{
"hash" : "0000000000000000ae22455f90306f43e8c806585fe2dfc3b0e92ac7b7620bff",
"confirmations" : 5885,
"size" : 249065,
"height" : 280557,
"version" : 2,
"merkleroot" : "5b4c401a2ad5a82ef26efb1d7ad82a0b6abea18118b50a12b555ea9e8663042b",
"tx" : [    .... snip ...

and when I run the command to fetch a transaction, I see that version 1 is returned

 getrawtransaction 260ef6a9bbb401ecbfdace19c84ae3245f0ab5b229ea716209a38e9ec0fd14c1 1

output

{
"hex" : "01000000027f4e827503d7d52617.. snip ..9763caaf4b6216343fa460b88ac00000000",
"txid" : "260ef6a9bbb401ecbfdace19c84ae3245f0ab5b229ea716209a38e9ec0fd14c1",
"version" : 1,
"locktime" : 0,
"vin" : [

Question

I read somewhere that BIP32 will cause both of them to be version 3.  Can anyone explain:

Where I can find a concise list of rules of what is expected from each version (it's not on the wiki)
When that version changed (year and/or block number)
Are old version banned, or are they still supported?


texts: How does Whopper Coin released in the summer of 2017 on the Waves platform solve the native fee problem inherit with many colored coin approaches?

texts: Whopper Coin was recently released in Russia using the Waves platform, but what is the native fee a user has to pay when sending the Whopper coin back to the establishment? If a customer receives Whopper coin from Burger King, now the customer would have to redeem these coins by sending it back to Burger King. How are the fees paid? Are the fees in Whopper Coin or the main Waves coin? How did they solve this inherit problem when issuing coins like this on top of an existing blockchain platform.


texts: What happens when you send a transaction that ends up in an orphaned block. Is it recoverable?

texts:
I've found a lot of information regarding orphan blocks, but I can't find an answer to this simple question.

If I send a payment to a user and my transaction happens to end up in an orphaned block, how will I recover my bitcoins?  When the block-chain reorganizes itself and orphans the original block, will the client automatically add back my funds?

I've never encountered an orphan block so I have no clue how the transactions are resolved.  Could someone please clarify what happens to the funds within these blocks?


texts: Non-bidirection payment channels for lightning network

texts:
I am trying to understand the technology behind LN and similar concepts.

As I understand it, LN is a network of bidirectional channels, which are created with some limited capacity, within which the channel can operate. So, we can have Alice putting 3 coins to the channel and Bob putting 20 coins to the channel and this 3:20 ratio can then change in time with each off-chain payment, until it eventually reach the point where Alice and Bob want to close the channel at some final balance ratio - say 13:10.

This bidirectional concept has some features (or disadvantages) of e.g. requirement to balance the channel (or create a new one) if payments in one direction are more common. Also each such channel connecting two parties needs two on-chain transactions.

Questions:
Why do we use channels only between 2 parties? Would it not be possible to have a channel that is formed e.g. by 4 parties, e.g. Alice with 3 coins, Bob with 4 coins, Cecil with 5 coins and Daniel with 6 coins? It should allow Alice to send e.g. 2 coins to Bob, thus modifying the state of the channel from "A3:B4:C5:D6" to "A1:B6:C5:D6" etc.

If this was possible, we could have 2 on-chain transactions to interconnect 4 (or more) entities, so it seems it would be more effective than bidirectional approach. It also seems to me that keeping the channel balanced would be little bit easier than in case of bidirectional case.

Obviously there would be more communication needed for each off-chain transaction within the channel (all parties would probably have to be involved).

So, is there any fundamental problem with having more than 2 entities in one channel? Or is it just that the benefits of having them would not outweigh the additional complexity?


texts: Can a coinbase transaction have a segwit output?

texts: And more generally speaking, are there any restrictions on the output of a coinbase transaction?


texts:
Why can't there be a p2p software that works like bitcoin but you load it with dollars?

Can't something be made that's just p2p dollar transfers and not deal with a speculative new currency and its volatility?


texts: What does OP_CHECKSEQUENCEVERIFY (OP_CSV) do?

texts:
Some people have suggested repurposing OP_NOP3 as a new opcode, OP_CHECKSEQUENCEVERIFY.

What would the new opcode do? Why is it useful? Can't the signer choose the sequence field when they sign?


texts: Will ripple automagically use the ordebook when finding a path?

texts:
I have a question regarding this scenario.

A (test-gateway)

28000 XRP in balance

B (user1)

trust line with A for 1000 USD
400 XRP in balance

C (user2)

trust line with bitstamp for 100 BTC
400 XRP in balance

A issues 100 USD/A to B

B now holds 100 USD/A in the balance

A open a trade giving 10 XRP for 1 USD/A
B wants to send 0.1 BTC/bitstamp to C using his USD/A IOUs as source.

Will ripple do this?
  USD/A => XRP => BTC/bitstamp

Because i can't make it work.

C has a trust line to bitstamp.
B has no trust line with bitstamp, should it have one?

(there's a lot liquidity XRP<=>BTC/bitstamp in the order book)


texts: Why does bitcoind not recognize the uncompressed version of my address?

texts:
I have an address representing a compressed public address, which bitcoind is recognizing as "ismine":

compressed_address = n2HCyN8GWPuc8CrwbiiBASCS7iWku3Ke8S
compressed_key     = 03c6debc01d8cf1c7eae826b8acb0ba6ff5d37b8d840b2bfc5244cdebab83a6781
> bitcoind  -testnet validateaddress n2HCyN8GWPuc8CrwbiiBASCS7iWku3Ke8S
{
    "isvalid" : true,
    "address" : "n2HCyN8GWPuc8CrwbiiBASCS7iWku3Ke8S",
    "ismine" : true,
    "isscript" : false,
    "pubkey" : "03c6debc01d8cf1c7eae826b8acb0ba6ff5d37b8d840b2bfc5244cdebab83a6781",
    "iscompressed" : true,
    "account" : ""
}

I extract the y value from the compressed public keys, and create an address from that (with the same function I wrote for compressed keys):

decompressed_key     = 04c6debc01d8cf1c7eae826b8acb0ba6ff5d37b8d840b2bfc5244cdebab83a6781a8b69757635c64ce32eed71115b68174d7241c716b1f76d317c6440635d8bc01
decompressed_address = mfjsW5m8CL5EazGBvjutZ4dgJwd6AjHM11

The address is valid since if satisfies the curve equation... x, y values are as follows:

x = 89951481645973345162937095289811840492311042685266238084455665220379660150657
y = 76311169247456070080081989221882104208438035444189442719121845261776897752065
y * y         = 107822876231389859288843816887520488062823501023166616425651229464214081607136
x * x * x - 7 = 107822876231389859288843816887520488062823501023166616425651229464214081607136

However, bitcoind does not recognize the decompressed address as "ismine".

> bitcoind  -testnet validateaddress mfjsW5m8CL5EazGBvjutZ4dgJwd6AjHM11
{
    "isvalid" : true,
    "address" : "mfjsW5m8CL5EazGBvjutZ4dgJwd6AjHM11",
    "ismine" : false
}

I don't understand... the only difference between the two is that one key is compressed to save 32 bytes... the private key should be the same!  Shouldn't they be interchangeable? Does this mean I won't be able to spend to spend coins send to the de/uncompressed address?


texts: What's wrong with this getrawtransaction JSON-RPC call?

texts:
This is a very simple question. I'm trying implement a client for Bitcoind JSON API and I'm stuck on this getrawtransaction call:

{"id":"getrawtransaction",
"param":["91eb6cb34b9253cce0ab5da171a0f5aae9d3d36208e23062ba61cd9e21c09a3d",1],
"method":"getrawtransaction","jsonrpc":"2.0"}

As the result I get:

{"result":null,"error":{"code":-1,"message":"getrawtransaction <txid>
[verbose=0]\nIf verbose=0, returns a string that is\nserialized, hex-encoded data for
 <txid>.\nIf verbose is non-zero, returns an Object\nwith information about
 <txid>."},"id":"getrawtransaction"}

Could someone point me at what can be wrong? I'm sure it's something simple but I cannot get it. Bitcoind v. 0.8.


texts: Restore Block.io multisig wallet in Electrum

texts:
I've exported my private keys from Block.io. They're compressed WIF keys (starting with L...).

Additionally I've got the following data from Block.io:

Address type: P2SH (obviously)
Redeem script
Redeem script hex
Two public keys

I've tried to restore that wallet in Electrum with the information I have. But as far as I understand, Electrum needs extended private keys to restore the wallet, right?

So, is there a way to restore that wallet? Maybe in a different wallet client? I've researched a whole evening but couldn't find the answer.


texts: Why does getblocktemplate use priority for transaction selection?

texts:
I don't know how getblocktemplate works exactly, but it seems to include transactions based on priority.

Selecting transactions based on priority isn't the most profitable method for building a block (as opposed to fee/byte), so is getblocktemplate only going to be used by miners who haven't figured out how to construct their own blocks?

Why would anyone use getblocktemplate otherwise?

Bitcoin transaction priority calculation
https://github.com/bitcoin/bitcoin/blob/86b800c6a299455580fe76e5fb43218f0222e179/src/miner.cpp


texts: Blockchain - How can I cancel my blockchain transaction, unconfirmed after +1 day

texts:
I am using blockchain.info.

I have made a bitcoin transaction of 4.79 BTC to the address 1DWaEfPbcKQvjMi9D9eNMrVRQzWiSLVvaS. (exchanger)

You can see the transaction at https://blockchain.info/tx/92f565e23499437ed4d54bc946a044c56353c4d1f512cf514b40a31e49292732

I have paid a 0.0001 BTC fee but it has been almost +24 hours and it still shows "Unconfirmed".

Network Propagation 1% - 18 Nodes - (Very Poor) - Why is so poor the network propagation, what;s to do?

What could be the error? Also, more importantly, how do I cancel the unconfirmed transaction and get back my coins?


texts: how to fix mining software make error? bfgminer bitcoin

texts:
so i have bfgminer up on a linux machine running fine purring away at 67Mh/s solo mining (geforce gtx460)
im attempting to build on a windows 10 machine
i have tried msys2 mgwin32 and 64 bit
nothing seems to work i get errors in all stages: autogen, configure and make
im using mgwin64bit now and got to the make stage succesfully...
i am able to autogen, configure but when it comes to make i get an error:
make[3]: Leaving directory '/home/virtu/bfgminer/libblkmaker'
  CCLD     bfgminer.exe
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bfgminer-miner.o:miner.c:(.rdata$.refptr.cpus[.refptr.cpus]+0x0): undefined reference to `cpus'
collect2.exe: error: ld returned 1 exit status
make[2]: *** [Makefile:1340: bfgminer.exe] Error 1
make[2]: Leaving directory '/home/virtu/bfgminer'
make[1]: *** [Makefile:2844: all-recursive] Error 1
make[1]: Leaving directory '/home/virtu/bfgminer'
make: *** [Makefile:1209: all] Error 2

Could someone help me come up with a solution?
in the meantime i will return to mingw32 and attempt to fix the no gcc or c compatible compiler issue on autogen/configure


texts: Should fractional reserve banking be prohibited through the bitcoin protocol or otherwise, and how could such a change be implemented?

texts:
There's a massive macroeconomic debate between Keynesians, who want central banks to control the money supply, and Austrians who want no central banks doing any such thing--or at least competing currencies which provide an alternative to central banks which do.  Bitcoin, with its set mining schedule, takes a clear stand against the former and opts for what will in 2033 become a stable/deflationary currency.

A debate which has not been settled, even among hardcore Austrians, is whether fractional reserve banking is good or bad for economies.  Similar to central banks, fractional reserve banking expands the money supply, but not at the fundamental level.  The effect is often the same, however, and the result is booms and inevitable busts as growing loans and investment cycle with contractions and bank runs.

For bitcoin enthusiasts who are skeptical about inflation, fractional reserve banking poses a similar threat.  As long as anyone except you are holding your bitcoins, there's no way to prove that your coins aren't being lent out at any possible reserve ratio.  Gresham's law suggests that 'bad money drives out good', meaning people will first use unsecure, inflationary currencies and hoard better ones.  Since bitcoin aims to be an optimal currency, it should explore avoiding the fate where it is bested by a regime which prevents fractional reserve banking.

My question is:  Can fractional reserve banking be prohibited, technically, a) through a change the bitcoin client itself; b) in a customer-bank protocol; or c) in another cryptocurrency scheme.

I don't know enough about public key cryptography, but I have an inkling that it would involve limiting return addresses, so for example, I send 10 bitcoins to address A, but those bitcoins can ONLY be sent back to an address I provide, and nowhere else.  Could that kind of scheme be implemented at any level, even just as an option?


texts:
I really like the weusecoins.com introduction video. Who made the video?

It explains very clearly what bitcoins are, how it is different from other money, and how you can buy and sell bitcoins. They did a great job.


texts: How to verify if it's Segwit Transaction or not?

texts:
Segwit Usage chart example : https://p2sh.info/dashboard/db/segwit-usage?orgId=1

I Would like to verify by checking tx if it's Segwit Transaction or not.

Is there any simple method to do this?

legacy -> P2SH tx (Is this Segwit Transaction?)
P2SH -> legacy tx (Is this Segwit Transaction?)
bech32 -> legacy tx (Is this Segwit Transaction?)

What about when many types of addresses are set as inputs and outputs?


texts:
What, either technically or not, is preventing bitcoin core miners from expanding the number of transactions included in each block?

Wouldn't the corresponding increase in maximum number of transactions per second, and higher compensation per block, be a welcome benefit?


texts: Bitcoin security/vulnerability on computer backed up by cloud?

texts:
I understand that BTC are stored as file in wallet.dat on hard/external drives.

Is there an added layer of security to Bitcoin storage when the computer is backed up by a trusted cloud storage company, or does this make BTC more vulnerable to raids/theft?
Does this redundancy allow remote access to BTC wallet without increasing security risks?
Can the third party (cloud storage company) access/steal BTC value of wallet.dat?


texts: Would it be a dilemma to wanting to earn interest if our bitcoin is in some exchange, but we also want the security in our own wallet?

texts:
I think one general thinking is that, for the bitcoin to be secure, it has to be in our own wallet, and preferably, a hardware cold wallet.
But at the same time, we would also see that 3% interest we can earn on our bitcoin gone every year, if the bitcoin is kept in some exchange.
Is there a way to solve this problem currently? But except maybe if there is a insurance system like FDIC insured, so that we can deposit our bitcoin somewhere, have it guarded against theft, and at the same time earning interest?


texts: Can I easily use Bitcoin as a inexpensive way to transfer my money into another currency?

texts: I have a home business in the US and I am spending a significant amount of time in Europe.I have both a US and a EU bank account as well as a coinbase account. I am wondering if I can by bitcoins in USD and then sell them back to my EU bank account in Euro? My normal bank charges $35 plus they give me an exchange rate 4.5% more than the market. So, for each $1,000 I send, I pay almost $45 in exchange fees plus the $35 transfer fee...I am wondering if using bitcoin can help me significantly reduce my costs for this type of international money movement? has anyone done this and can you tell me of any problems or pitfalls? Thank you!


texts: What is the real size of the non-pruned Bitcoin blockchain?

texts:
My node (via Bitcoin Explorer) tells me as of now: 340.98 GB

Most website online: 280-300 GB
Why is there such a large delta?


texts: Is it true that only UTXOs can be used as Transaction Inputs?

texts:
I was reading this GitHub book on Bitcoin

They state that "True or False: Only UTXOs can be used as inputs to transactions."

Is the answer, True because you can only spend what you have.

Or False, you can out a spent output in the transaction as input, but the network or the miner will reject it.


texts: Where can I find code that allows me to calculate Z1 and Z2 from an ECDSA signature?

texts:
By following Recovering Bitcoin private keys using weak signatures from the blockchain, I am able to do other calculations, but I have no idea how to calculate Z1 or Z2. There was a public code available by Sean Bradley:

http://2coin.org/tx.asmx?op=GetTXExtended

But it does not seems to work now. Is there some other public code to calculate Z1 and Z2 in any language. I can convert it to the language of my preference. Any help is appreciated.


texts: Where is the location of the private keys of my wallet on my PC?

texts:
I have searched this forum and the internet for information on the location of the private keys of my wallet on my PC and found no answers.

I am using Microsoft Windows 7 and installed the Bitcoin software from http://bitcoin.org/en/download (At the moment it is version 0.8.2)

The default installation path is C:\Users\username\AppData\Roaming\Bitcoin

In the default installation Bitcoin folder/directory, I can only see the following:

blocks sub-directory
chainstate sub-directory
.lock
db.log
debug.log
peers.dat
wallet.dat

Where are the private keys?


texts: How can one know which way mining pools will vote for P2SH?

texts:
Is there a list somewhere showing how each mining pool will vote on the P2SH question?

and

If a pool says that it is voting one way, is it possible to independently verify that they are indeed voting that way with their mining power?


texts: What if duplicate wallet addresses are created?

texts:
I'm a newbie to Bitcoin, so I apologize if this seems like a "noob" question.

So, from what I've read: anyone can create a new Bitcoin wallet. Upon creation, a wallet address is automatically generated. The wallet address can be used by others to make transactions to that particular wallet.

Now, my question is, what guarantees that two automatically generated wallet addresses will be unique? If my friend and I created separate wallets on our own computers offline, then what is the guarantee that the two wallet addresses will be unique? What if the two randomly generated wallet addresses turned out to be the same?


texts: Which block explorer indexes the keys used in mutisig scripts?

texts:
Consider transaction 0846e91bc3afdf2275db14bcbb10e19f141069d77f17dae6bcbd907fd28f4747, which takes money out of the script address 3PJQGGnBQr8DJBdPYowd6Mp2kSWvFFo7Gk. As we can see in the input scripts, this script address references script 51210261afd7a2796e9bb83896089293f11edd2987ebbd67ed2075f5e45b7c4bb7edcb51ae, which, according to the decodescript command, is

    "asm": "1 0261afd7a2796e9bb83896089293f11edd2987ebbd67ed2075f5e45b7c4bb7edcb 1 OP_CHECKMULTISIG",
    "reqSigs": 1,
    "type": "multisig",
    "addresses": [
        "1xW3APNVG6Ro1HY8hysmnKq8mvgVk6oPU"
    ],
    "p2sh": "3PJQGGnBQr8DJBdPYowd6Mp2kSWvFFo7Gk"

So this payment was made to anyone who has access to the key with the address 1xW3APNVG6Ro1HY8hysmnKq8mvgVk6oPU.

But none of the common block explorer websites seem to index this; when I ask them about the address 1xW3APNVG6Ro1HY8hysmnKq8mvgVk6oPU, they list no transactions.

Is there a block explorer that maintains a mapping from key address to the script addresses the key is mentioned in?


texts: Can I use my Bitcoins to buy household commodities just like ordinary money?  You see, I'm a newbie and have yet to learn the basics including all the facts about Bitcoins.  However,  I want to be ascertained as to whether my time and efforts in learning the trade will be rewarding in such a way that,  I'll be able to use whatever amount of Bitcoins I may earn someday to actually purchase things from the nearby store.


texts:
For study and fun I try to create my own altcoin.
I forked Litecoin, removed checkpoints, changed nTime, *pszTimestamp, noNce and hashed new hashes for genesis block in main net, testnet and regressiontest net.
The hardcoded assertions goes OK but when I start the deamon

./src/cryptoind

I get alwais the same result:

ERROR: ReadBlockFromDisk: Errors in block header at CBlockDiskPos(nFile=0, nPos=8) ... ActivateBestChainStep --> Failed!

Going deeper in the code the following statement always fails (main.cpp):

if (UintToArith256(hash) > bnTarget)

Seems like the genesis block does not respect the difficulty (PoW)

Someone faced the same issue? Thank you all


texts: How do mining-pools prevent work duplication?

texts: Do mining pools take any precautions to make sure that their members are not doing the exact same work (i.e. they've been given the exact same block to mine, and thus they're doing the same hash calculations as a fellow member)?


texts: can someone give me an example on how collaboration is difficult without the Blockchain?

texts: i understand the technology and i understand how it helps in two domains which are voting and currency but i don't understand how the Blockchain helps in other domains such as health care or supplychain, i mean what is wrong with today's health care and supplychain !


texts: 2 mBTC that was outputted as change in a transaction I just sent didn't come back to my wallet

texts:
Hi I'm new to this so may be asking a stupid question.

I just sent a payment for 198.52 mBTC. There were two outputs. One for 196.39 mBTC that arrived. There was another output of 2 mBTC that didn't arrive and wasn't refunded to the first wallet. I looked on google and I read that the 2 mBTC was change for the transaction. Can somebody tell me how I retrieve this 2 mBTC as it's not in my wallet?

Many thanks


texts: Proof for "Is an immutable, decentralized blockchain possible without economical incentives?"

texts:
Bitcoin is immutable because of economical incentives. Those who are able to 51% the network can't do it, because it'll result in the value of the currency to drop tremendously, which causes waste of a lot of money as there's a 100-block limit to spend coinbase transactions. Those who aren't miners having large capital to attack the network can't turn on a considerable amount of miners at once as it's not a PoS coin.

What I'm asking is "Is there any proof that a decentralized consensual blockchain can't be immutable without economical incentives?"


texts:
I know this was probably brought up before but I cannot find any good resources on some potential, at least theoretical way of achieving this.

So basically I have a lot of UTXOs whose value is between lets say 1k sats and 5k sats and I want to transfer them all into a single UTXO.

With current fee rates of 15sats/byte I would barely break even in the best case scenario.

Is there any strategy or algorithm that could help with this kind of issue?


texts: Can I quickly check the cofactor of secp256k1 is 1

texts:
I was wondering if there was a quick way to check that the group underlying the elliptic curve secp256k1 was indeed cyclic with the usual point G a generator. I am given the prime number underlying the field Fp, I am given the point G, I am given the integer orderwhich is presented as the order of the curve. I can check that the scalar multiplication order.G yields the infinity point. So I know that the order of G (i.e. the cardinal of its generated subgroup) divides order. I can check that order is a probable prime. So I reach the conclusion that the order of G is indeed order. But how do I know its generated subgroup is the whole elliptic curve?

import java.math.BigInteger;
import org.bitcoinj.core.ECKey;
import org.spongycastle.math.ec.ECCurve;
import org.spongycastle.math.ec.ECPoint;

public class Test {
  public static void main(String[] args){

  // secp256k1 elliptic curve
  ECCurve curve = ECKey.CURVE.getCurve();

  // the order of the curve
  BigInteger order = curve.getOrder();

  // fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141
  System.out.println(order.toString(16));

  // The generator of the curve
  ECPoint G = ECKey.CURVE.getG();
  BigInteger X = G.getAffineXCoord().toBigInteger();
  BigInteger Y = G.getAffineYCoord().toBigInteger();

  // 79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
  System.out.println(X.toString(16));

  // 483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
  System.out.println(Y.toString(16));

  // Computing scalar multiplication order.G
  ECPoint test = G.multiply(order);

  System.out.println(test.isInfinity());  // true

  // so we know the order of G (i.e. the cardinal of its
  // generated subgroup) divides 'order'. However:

  System.out.println(order.isProbablePrime(128)); // true

  // and G is not infinity. So the order of G is precisely order.
  // How do I check that the subgroup generated by G is actually
  // the whole elliptic curve group, i.e. that the cofactor is 1?
  }
}


texts:
I read here that:

  If you could process one trillion private keys per second, it would
  take more than one million times the age of the universe to count them
  all. Even worse, just enumerating these keys would consume more than
  the total energy output of the sun for 32 years.

However this website http://directory.io says that they generated all private keys. Who is right? or what is it that I misunderstand ?

And why this (from here)

  A private key is a 256-bit value, meaning there are approximately
  1.1579e77 possible keys (There are about 1.2288e66 invalid values...


texts: Bitcoin has only 8 active connections, and I read somewhere that it helps to forward ports. I know how to forward a port, but which port should I forward, and how should I tell Bitcoin-qt to use the forwarded port?


texts: How do I cancel my BTC transaction (Unconfirmed for 5 hours)?

texts:
am using blockchain.info.

You can see the transaction at https://blockchain.info/tx-index/7122f25e4d2e79d5a93cf3797de44b00625cb8407d49c9fce0434f9d3cf32a82?show_adv=true

HERE IS MY OTHER TRANSACTION THAT IS UNCONFIRMED:
https://l.facebook.com/l.php?u=https%3A%2F%2Fblockchain.info%2Ftx-index%2F8290eebdbd663b27b428979b9d2b55f4171d62fbb6e81e09100f6f7788e02a14&h=8AQHbDyU2

I added a small fee, but my transactions are usually sent alot quicker than this.
What could be the error? Also, more importantly, how do I cancel the unconfirmed transaction and get back my coins?


texts:
How to share new block and get reward without pools?
For example i find next block what do with it?
Where i can send solutions to get reward?
I can find new block in solo mining but don't know where it share.


texts: Using bitcoind JSON-RPC, how to get transaction from input address?

texts: I have an address from which all unspent txouts were used in a single transaction. How can I find out what transaction was that? In my node instance, listtransactions will not list addresses that spent the coins, only those that received them.


texts: Send Bitcoin payments to any bank via API

texts:
I am looking into paying our overseas suppliers via bitcoin to speed up the process of settling invoices. The issue is that I don't want them to have to deal with bitcoin themselves.

My question is - is there an API available that I can use to build my app that will allow me to deposit BTC to any bank account number that I choose?

Thanks!


texts:
I have installed bitcoind on Ubuntu Server. It didn't download a single block

bitcoind getblockcount

This returns 0 everytime I run.
Here is bitcoind getinfo

{
    "version" : 80500,
    "protocolversion" : 70001,
    "walletversion" : 60000,
    "balance" : 0.00000000,
    "blocks" : 0,
    "timeoffset" : 0,
    "connections" : 0,
    "proxy" : "127.0.0.1:9050",
    "difficulty" : 1.00000000,
    "testnet" : false,
    "keypoololdest" : 1385148166,
    "keypoolsize" : 101,
    "paytxfee" : 0.00000000,
    "errors" : ""
}


texts: My bitcoin core is delaying in sync saying two years remaining. And av sent bitcoin from my block chain wallet it's been deducted but am not seeing it. How can I go about it seeing that I can't wait for two years. The synching is not fast


texts: Can an unconfirmed transaction fall under the radar?

texts:
Something very peculiar has happened with a transaction and I would like to understand what network conditions can possibly be the cause of this.

I transferred about 150mBTC from my Android wallet to my bitcoin core HD wallet (v0.13.0) I have done quite a few of these transfers, and typically within at most a few seconds, the transaction is relayed by the network and appears in my bitcoin core mempool. In this case, the transaction still has not been seen by bitcoin-qt for almost an hour. It is a very ordinary transaction with quite a high fee of 0.1 mBTC (for only 225 bytes).

I initially thought that my Android had failed to broadcast the transaction. However, this assumption can be dismissed as blockchain.info has successfully received it, providing me with a transaction id.

I then thought that bitcoin-qt possibly did not recognize the transaction was in relation to my HD wallet. However, it seems that the transaction was in fact never received by my node:

$ cat ~/.bitcoin/debug.log | grep <transaction id>    # nothing appears

So I am now under the impression that the transaction was successfully broadcast but for some reason was never relayed to my node. In fact, something like 5 new blocks have appeared since the initial broadcast and the transaction still isn't confirmed (which given the level of fees and no apparent network bottleneck seems very unusual). So I am now under the impression that some miners may not have seen the transaction either (after all if this can happen to my node, why not others?)

Incidentally I have tried to re-broadcast the transaction with https://blockchain.info/pushtx and the raw transaction id, but it tells me the transaction already exists.

Does anyone have a plausible explanation of what may trigger this sort of rare event, where a transaction is seemingly successfully broadcast, but not all nodes seem to hear about it (assuming this interpretation is valid)?

EDIT:
Actually looking at https://blockchain.info/unconfirmed-transactions, as I was writing up this question until now, the number has been rising and is now showing about 18k unmatched transactions which seems to point at abnormal network conditions (typically 2k-4k)

EDIT:
The transaction was eventually confirmed about 10 blocks later. The fact remains that it was seemingly never relayed to my node until its inclusion in a new block.


texts: Definition of confirmation time in blockchain.info, Part 2

texts:
In my previous question (Determinant of confirmation time), I asked

"What will be the definition of confirmation time and data used for

https://blockchain.info/charts ?"

Now I read

"The classic bitcoin client will show a transaction as "n/unconfirmed" until the transaction is 6 blocks deep. " (https://en.bitcoin.it/wiki/Confirmation)

Then is it correct to say that, in a simplest approximation it takes 6 times the confirmation time in the graph to get a transaction done?


texts: Unconfirmed transaction: the status is "0 / unacknowledged, not in memory pool "

texts:
I started a transaction with bitcoin-0.21.0-win64, a Windows client. It may be that the fee is set too low, which leads to the unsuccessful transaction. What should I do in the future? What do I need to do? How to implement the specific operation steps? Below is the transaction details, please help! Thank you very much！
Status: 0 / unacknowledged, not in memory pool
Date: 2021 / 3 / 8 12:31
To: coin an 1kgsxf7krv1ab99tex1wjm643tsilczbg6
Expenditure: - 0.05193365 BTC
Transaction fee: - 0.00120000 BTC
Net amount: - 0.05313365 BTC
Transaction ID: aceea84e8a72b24654cba7b1d042561d8a9d36f7828855b52012de8a5a0b9c12
Total transaction size: 11767 bytes
Transaction Virtual Size: 11767 bytes
Output index: 0


texts: What should I do if I change my BitCoin wallet?

texts:
At present, I use Electrum as my wallet, and I create private key and transfer some bitcoin to the Electrum wallet.

If I choose a new  wallet such as  BitGo wallet listed on https://bitcoin.org/en/choose-your-wallet, how can I pass bitcoin from old wallet to new wallet?

Do I must to send bitcoin from old Electrum wallet to the new address created by new BitGo wallet?


texts: Is the synchronization process supposed to be downloading at less than 5kB/s?

texts:
I've been running the bitcoin-qt client for over a week now trying to catch up with the block chain (closer to three weeks if I count the first time I had to synchronize everything).  Looking at my bandwidth usage, I'm only getting 2-5 kB/s at any given time.

I did a ton of Googling and noticed a lot of others were complaining about the long synchronization process, but none of them seemed to be as long as mine (and no one made mention of their speeds).  Is it supposed to be this slow, or have I set something up incorrectly?

I should further clarify that this is not a new issue, this has been persistent since I started using bitcoin over a year ago.

Further information:

The client is always at or below 8 connections to the Bitcoin network (if that is at all relevant/useful information).  I have UPnP enabled.

Computer: I'm using a laptop (OS: Win7 64-bit) from a few years back, so inherently the  specs aren't tops (but by no means terrible) - the CPU is an AMD Athlon II M300 (2 cores / 2 threads, 2.0 GHz, 1MB cache).

CPU Usage: According to perfmon, bitcoin-qt averages 7% CPU consumption.

Blocks processed: 124 in an hour (I also made a list breaking it up into 10-minute increments and it averaged 1.8-2.0 blocks per minute of those increments, so it agrees with the hourly rate without much fluctuation).


texts: Are bitcoin commands resistant to race conditions and thread-safe?

texts: Is concurrency a problem for commands like sendfrom,move,sendmany etc.? I suppose everything is fine after skimming source code, but I want to be sure about that.


texts: Transaction not showing up as confirmed on MultiBit

texts:
I tried to send a Bitcoin transfer yesterday at noon and after more than 120+ confirmations it's still unconfirmed.
I used MultiBit as wallet, I set fees but still nothing.
I was used to super-fast transaction, the maximum I've waited in the past was 15 mins.

Did I do something wrong or is it just the usual time it takes?

Here it is:
https://blockchain.info/tx-index/ba8c1f8e3c2b526a0ed842eda8e6c75650c9ac12ba093b79b023556edf8bcec7


texts: public key generated when importing PK different from original pub key

texts:
I used bitcoin core (latest 0.19) to create some addresses offline. When I dumped the privkey I was surprised to see all of them starting with L2 (and the addresses with 3), but I went for it. I take note of the private keys/addresses.

Next day, I import one of the privkeys into another bitcoin core wallet, it scans, but the noted address never shows up in my receiving address. But still it added another address to my list (starts with 1B).

So I also added this privkey into an electrum wallet. And surprise, that same address is showing up, not the original one that I got when I created the pair.

What's happening? Is that due to the L2 type?


texts: Is it possible to run two Lightning Network nodes on top of single Bitcoin Core node?

texts:
I would like to simultaneously run LND and Eclair nodes on top of single Bitcoin Core bitcoind node. Is it possible? I wasn't been able to pull it off so far.

If possible, how to set up ZMQ and listen-tcp?

Thanks Rene, I have managed to do it. Works flawlessly. :)

Listen addresses must be different, eg. 0.0.0.0:9735 and 0.0.0.0:9736, and both  need to be open in router. Also rpclisten must be different, eg: 127.0.0.1:10009 and 127.0.0.1:10019

When opening channel between them use localhost address, eg. 03di28did92d2dh92d29d229d299239r98398r@127.0.0.1:9736


texts: Is Namecoin actually being used for anything significant?

texts:
I have some idea of what Namecoin was trying to achieve, but as of yet I've never seen it actually used. Is it being used for anything of significance yet, or are there plans by anyone to do so in the short to medium term?

If I were to register a .bit domain name and host a website, can everybody with a standard internet connection setup access it, or is special software or other setup required?


texts: Can the blockchain be outpaced by a chain of low-difficulty blocks?

texts:
Let's say someone creates a blockchain fork starting from the genesis block, when the difficulty was absurdly low compared to today; then he starts mining new blocks from there up to the current block index.

Normally, this would require such an amount of time to make it completely impossibile to catch up with the real blockchain; even if he used today's powerful mining hardware, the difficulty increase would compensate for it quickly. But, here's the catch: he customizes his mining software to not ever increase the difficulty, even if it's mining hundreds of blocks per second; block timestamps are simply faked in order to make it seem they were generated at ~10 minutes interval.

When the fake blockchain is longer then the real one (currently ~300000 blocks), he starts broadcasting it; it appears to conform to all rules, and it's longer than the current one, thus all clients and miners treat this as a winning fork and switch to working on it. Of course, difficulty increases abruptly as soon as the full network hashing power is thrown at it, and after some time block generation resumes normal levels.

But now the creator of the fake blockchain owns all Bitcoins that have been generated from the genesis block to when he released it.

Is this scenario actually possible? If not, why? How would Bitcoin nodes reacts to a 300000-blocks-long fork? Is there a limit on how long a fork can be?


texts: Why can't Bitcoin use a very large blocksize such as 1GB?

texts:
In the current blocksize limit debate multiple proposals have been made. Bitcoin XT implements an increase to 8MB right away plus a doubling every two years. A competing approach used 20MB.

What specifically would make it a bad idea to go with a very high limit such as 1GB as opposed to increasing to a smaller limit such as 8MB?


texts: How do I access the Bitshares that I received from my Protoshares "snapshot"

texts:
I have had some Protoshares for a while.  At some point (according to my fuzzy memory) there was a "snapshot" which gave me the right to Bitshares.

I still have access to my Protoshares wallet but haven't installed a Bitshares wallet.  How do I access the Bitshares that I received from the "snapshot"?


texts:
Can you track your payment if you do a transaction from person to person for a house rental if the seller doesn't follow through with their end of the deal and doesn't send the keys can you get your money back?

Or in other words is there a record of your transaction so you can claim a dispute or track down the person who didn't follow through?

What safety do i have in this aspect for example i am applying for  rental house but i found out they're in the states and I'm in Canada so they have to send me they keys but they want the payment first through btc wallet so if i do this and send the bitcoins and he doesn't send me the keys and i find out it was a scam is there a way for me to recover my payment?


texts: Can anyone shed any light on this error? Bitcore Multisig - bad-txns-in-belowout

texts:
Code:

var utxo = new bitcore.Transaction.UnspentOutput({
  "txid" : "e0c6b736e86e8dccd63bbc27f35142b413bd991a410ef50f14cd56fa1a783a1e",
  "vout" : 0,
  "address" : "2NCAeo5p1Pg8VVupFFumCd3PYz551VAZWLJ",
  "scriptPubKey" : "OP_HASH160 20 0xcf8d0490cba6d7ca817323cf0c337fbd0a3de539 OP_EQUAL",
  "amount" : 10000000
});

var multiSigTx = new bitcore.Transaction()
    .from(utxo, pubKeys, 2)
    .to("mwFLeaw5LMAPvoz1hP6qQhHbHkHq8WxM2t", 90000)
    .fee(9000)
    .change("mwFLeaw5LMAPvoz1hP6qQhHbHkHq8WxM2t")
    .sign(privKeys);

var txSerialized = multiSigTx.serialize(true);
insight.broadcast(txSerialized, function(err, returnedTxId) {
  if (err) {
    console.log(err);
  } else {
    console.log("Sent coins, tx id is: ");
    console.log(returnedTxId);
  }
});

Result:

Transaction rejected by network (code -26). Reason: 16: bad-txns-in-belowout


texts: Do any of the Bitcoin exchanges implement trading curbs?

texts:
After the big hack of Mt Gox we all became aware that there is nothing in place to prevent "flash crashes." Most stock, FOREX and other exchanges have features like trading curbs or other market volatility procedures to prevent such crashes - so do any of the Bitcoin exchanges have such curbs in place?

Also, if one exchange were to implement such a procedure would it still be effective if other exchanges did not? In other words, if Mt Gox implemented a trading curb and TradeHill did not, would this non-universal curb be effective? Would the effectiveness hold if the scenario were reversed? (i.e. TH has a curb and Mt Gox does not)


texts: How does Exodus wallet (or other wallet) exchange bitcoin to other cryptocurrency?

texts:
I have been using Exodus wallet for a very short time. And it shows that I can exchange bitcoin to many other cryptocurrencies and wise versa. I still couldn't find a good answer on how this exchange of currencies works and if there are any risks associated with it. Please excuse me if any of the questions don't make much sense to you.

If anyone knows about it, please help me to understand this process better?

If I exchange bitcoin to litecoin/ethereum, does the wallet software itself
send the request the buy order of litecoin/ethereum to some other exchange?
If there is no litecoin/ethereum exchange in my country (Australia) what will
happen in exchanging litecoin/ethereum back to bitcoin? I don't know whether it needs to have a litecoin/ethereum exchange in the country to do so...
In case if I want to exchange litecoin/ethereum back to bitcoin, how does the
Exodus wallet software handle it OR how does a wallet software generally handle it?
Basically, what are the risks associated with the exchange between
cryptocurrencies, other than their price going down?


texts: bitcoin core wallet and python bitcoin-lib

texts:
I have a regtest bitcoin environment with nodes and wallets. I'm running bitcoind and bitcoin-cli, version v0.21.0.0.
So in my node i created my wallet with a bitcoin-cli -regtest createwallet node1 "w1", my question is, how can i import my wallet into https://bitcoinlib.readthedocs.io/en/latest/source/bitcoinlib.wallets.html ?
I thought that I had to export my master key, with something like:
bitcoin-cli dumpwallet /tmp/wallet.dump >/dev/null && grep "extended private masterkey" /tmp/wallet.dump
And dump a private key with:
bitcoin-cli -regtest dumpprivkey $(bitcoin-cli -regtest getnewaddress)

Then would just matter of use them to create a new wallet like:

from bitcoinlib.wallets import Wallet, wallet_create_or_open, HDKey

# all data from regtest, no leak or so ever

private_keys = [
    # priv key
    "cPErqVBuHrWSAtqvRwHu3ZF9vbGJYnE3C1DmAL8RUgGLkRJsLh5y",
]
# regtest and testnet are the same
# the imported_key is the master key extracted with dumpprivkey.

hd_key =
HDKey(import_key="tprv8ZgxMBicQKsPf98zVnDSA3CH5LvexysRGWq1MGUdR6xTLrky41yhJ3j4RaSdXDFHi7L6KWwoozYcHTufX3y75NxuyVu7oSQE7KsPXoXFAcx", network="testnet", key=private_keys[1])

w = wallet_create_or_open("node_1", keys=hd_key, network="testnet")
print(w.addresslist())

Which prints me an address, but in a totally different format, stating with mxxxx therefore WIF, instead of bcxxx segwit.. which makes me unsure if I'm doing the right thing
Question:
Any documented way to migrate bitcoin core wallets (which i believe are segwit) to bitcoinlib format?


texts: how to activate BIP148 in bcoin configuration

texts: I cannot find any documentation about activating BIP148 on a bcoin node. Is there anything similar to BIP151=true in the bcoin.conf or is it enabled by default?


texts: Why Bitcoin does not user bcrypt for hashing?

texts:
I've read that bcrypt is a hashing library that can adapt to Moore's Law and I thought that would be great for the network to adapt in a flexible manner its security to its respective growing computing power.

As far as I know, bitcoin already adapts its mining difficulty to the frequency of block generation, I wonder if some kind of similar automatic protection would be possible to do regarding the security of the hashing algorithm itself.

So, can someone with more knowledge on cryptography clarify this?


texts: How to recover bitcoin wallet from messed up seeds

texts:
I have a ledger nano s wallet that is broken , when i tried to recover wallet from 24 recovery word i got error that says the recovery phrase is incorrect, i think the place of some words is incorrect and one weird thing is one of the words is duplicated in phrase, which i think is wrong.
So far i wrote a program in C# with nbitcoin library that checks all 2048 words of BIP39 wordlist in one place of 24 place and tried to generate its deposit address and compare it to lost wallet address like (i checked the code with new ledger wallet address and it worked) and i couldn't the correct phrase.
Write now i want to generate every possible combinition of these word and check them, i think it's around 24! Possibilities which is almost impossible to check, but i also know that every combinition of words in wordlist is not true and there is a checksum which i hope limit the possibilities.
Right now i need a code preferably in C# with nbitcoin library to generate every possible and true phrases of mnemonic and a suggestion for fast checking the phrase against the wallet.


texts: Which trading plateform to make cavalry?

texts:
There are many companies offering crypto-currencies exchange service.

But many of them have a gap in their currency list. Some other have a strange complexity.

All wallets are not systematically stored in the same point making things complicated.

Is there a good list of companies (websites) offering a simple exchange service, optionally giving wallet storage and not requiring a PhD to use?

The goal is to make currency exchange relatively offend.

(after comparison, the only that makes the difference is Kraken)


texts: Does my segwit node only have segwit blocks?

texts:
My segwit node makes a gettxout RPC query and checks the scriptPubKey.type is "witness_v0_keyhash" and does things accordingly.

To my understanding old nodes have different blocks and if I happened to fetch a block from an old node, what will my node do? Will it simply store it as is and ultimately result in not getting the desired "witness_v0_keyhash" response when I expect?


texts: worker keeps getting temp banned with sgminer

texts:
I have 3 R9 280x sapphires I use with sgminer

On almost every single pool, with or without --no-submit-stale, after about 5 min of hashing, my worker get's banned and hashing drops to zero. If I lower the intensity, I barely get 500mh/s if that. If I set it to 13, it runs normal, but I get banned?

sgminer -o stratum+tcp://neo.cryptcoins.net:3331 -u user.worker -p x -I 13 -D -P --no-submit-stale

How can I prevent from getting banned with a decent hash rate?

[18:58:33] RECVD: , "Worker is temporarily banned", null], "id": 666, "result":


texts: Is there a service providing historical data for crypto exchanges?

texts: I mean not just prices but candlestick and other data that usually is available on FX platforms?


texts: Probabilty of a Race Attack in time t with hashing power q

texts:
I read the original Satoshi's paper on bitcoin as well as Rosenfeld's paper on "Analysis of hashrate-based double-spending". However, they don't answer my question, which is as follows.

Let's assume attacker has q hash power (less or more than 50%) and that the merchant is waiting k confirmations (e.g. 6). What is the probability that after time t (e.g. 12 hours), the attacker will produce longer chain in order to double-spend money?

I have seen formulas to calculate the probability, that the attacker will eventually produce the chain, but what I am looking for is, what happens if the attacker is constrainted by time t. I know that the attacker has 100% chance on eventually getting the longer chain, but I also know that when the hashing power q is around 50%, it would take a lot of time and you would normally need around 60-70% of hashing power.


texts:
I understand how a new block gets created, and verified by the miner that created it.

But then, does it advertise this new block to near nodes? And how do these nodes go about verifying this? Do they stop mining their own blocks?

How do you prevent from other nodes stealing the new block and pretending its their own? (I guess the transfer included with their own address prevents this?)

I understand there can be multiple branches at the same time, and eventually one survives, but how is it prevented that multiple branches keep living for an extended period?


texts: Checking my balance of my btc public adress outside of my Xapo account

texts:
I have a doubt regarding my balance account in my Xapo wallet. I have checked in blockchain.info and other pages with my btc public address and all of them gave me zero founds.. According to Xapo i have 0.00649539 btc (just as an example).

I havent made any transactions yet but shouldnt be at least one with my original founds transferred by this company to my bitcoin address ????


texts: How to find out the ECDSA private key perfix version for Altcoins?

texts:
I want to create a paperwallet for an altcoin (Protoshares).

I know the public key version byte is 0x38 (56) and the addresses start with P...

But how do I find out the ECDSA private key prefix? For bitcoin it's 0x80, for litecoin it's 0xb0.

The Protoshares private keys start with 7... if that helps. Any idea where to look at?


texts: If a block chain is considered invalid, how about transactions in this block chain?

texts: Say if at current time there exist split of block chain, we call them A and B. A is "longer" then B, as the result B will be eventually forgotten, but what happened about the transactions in blocks on B? The block which is different between A will be unpacked, reconfirm the transaction then create new block, add new block on A?


texts: Master Seed from Mycellium does not concord with address Mycellium app generated for me

texts:
Created MYCELLIUM wallet in 2017 - copied down Master Seed, been transacting ever since.
Upgrades of various phones, always reinstalled latest Mycellium and used master-seed to restore, no issues.
Last week, app was "acting up" -- didn't want to sync and seemed to hang.  I decided to delete it and reinstall/restore from master-seed.  This time, incorrect balance is shown, and transaction log as well as looking on blockchain of public key shows no more transactions after 2018 ?!  (even though been busy until last week!)
Used this site https://iancoleman.io/bip39/ to generate the derived addresses from my master seed.  Seems to be accurate as the first 10 addresses are indeed mine and show me what MyCellium shows me.  However, when I do a search (in the pool of derived addresses) for a Mycellium generated receiving address I successfully used last week ... that address is NOT found ?!   I assume the addresses are used sequentially?  I generated 5000 addresses and still can't find that address in there!
Any insight/help/etc would be greatly appreciated!  I've never imported other private keys into MyCellium, only used the addresses provided by the app, and created another HD wallet from within the app.
Any chance to recover my lost coins ?


texts: How return transaction hash from wallet to android app after payment?

texts:
Scenario: I have my android app where customers can pay by bitcoins.
For this I created intent with uri like:

  bitcoin:[address]?amount=..

and using startActivityForResult  it opens wallet with pre-filled destination address and amount. After payment was sent, wallet back to my app transaction_hash and I can "catch" it in response(onActivityResult).

I tried few wallets and it works only in Mycelium.
I want to implement the same for other currencies, like BCH and LTC and wonder if any other wallets support it in the way above or there are other better approaches exist.

Update: it called InAppPayments https://github.com/bitcoin-wallet/bitcoin-wallet/wiki/InAppPayments.

So, I am looking for wallets which support InAppPayments for btc, bch and ltc.


texts: How Extracting address Bitcoin to script multi signature

texts:
I want to extract the correct address from a script multi-signature.

I have this real script multi-signature from this ScriptSig (tx index 1), so this is a readme script for this address

OP_2
    03385adff37fd3d0a620ebc4e9866e81dda8ba8616e5ebcae899c7f51899267ae7
    034c08511718f947d1a3e152195c5e2756588e3e0c2c7730927eb6647af4942107
    033da9f8938a5b947a723df21b73fbd3985b719249324d2c705acfb97d63a5df9e
OP_3 OP_CHECKMULTISIG

Now from this resource these value 03385adff37fd3d0a620ebc4e9866e81dda8ba8616e5ebcae899c7f51899267ae7, 034c08511718f947d1a3e152195c5e2756588e3e0c2c7730927eb6647af4942107, 033da9f8938a5b947a723df21b73fbd3985b719249324d2c705acfb97d63a5df9e are the public keys, so this value is a pure public key? and for exstract the address form these I can execute the procedure for build bitcoin primitive address ?

or I'm lost some information for this argument?

an example if I suppose this value is a public key 03385adff37fd3d0a620ebc4e9866e81dda8ba8616e5ebcae899c7f51899267ae7

This should be the compressed public key because it starts with "03" if apply the HASH160 I get this address "14r7XjPtqVijLRhY9BkGAtDqVDp4txsK1X"

Is my reasoning right?

More Information on the why I want to get the address to P2MSH

I don't want to break the privacy of the address 3CD1QW6fjgTwKq3Pj97nty28WZAVkziNom, I'm reading this article and it catalogated the address 3CD1QW6fjgTwKq3Pj97nty28WZAVkziNom how an scam address, but I think this is restrictive affermation, because the address with "3" can to hide more people/address.

I'm only learning and I don't want break the privacy of the people


texts:
The size of the Bitcoin network is available here:

http://bitcoinstatus.rowit.co.uk/

As the page says, they do this by listening for Address messages that are broadcast over the network.

Since the Ripple server is now open-source, we can expect a number of individuals and companies to start running their own nodes. Is there a way to estimate the size of the network, either using an RPC command on the server, or by modifying the server code itself to collect some information about the peers?

I would be interested in the following numbers:

Number of public servers
Number of validators

I imagine the first one could be obtained by querying peers recursively. Unfortunately the RPC interface is only available to 127.0.0.1 by default. As for the second metric, I'm guessing we can get this by looking at the ledger.


texts: Would it be visible that someone moved bitcoins to or from tumblebit?

texts:
If I want to make a transaction with someone via Tumblebit, would it be visible on the blockchain?

If a have a known public bitcoin address and I will move bitcoins from there to pay someone via Tubmlebit, will it be recognizable?

If I receive payment that went through tumblebit, would that be recognizable from the history of transactions?

How exactly would that look?