texts: How is wallet balance from unspent transactions in cryptography terms?

texts:
There is already a good almost complete answer here (but missing the cryptography explanation):
How is a wallet's balance computed?

Is a bitcoin wallets balance calculated on the client computer app? eg. Leger Live

How is bitcoin wallet balance calculated cryptographically?

Does Ledger Live app check/compare each transaction+hash & transaction+signature hash like mempool nodes do?

Or does it only look at the unspent output addresses and check if they are children of wallet public key? If so how does it do this in cryptography terms?


texts: Where can I buy bitcoins with an American Express gift card?

texts: I recently got an American express gift card for my birthday. It has a value of $50. Where can I purchase bitcoins (or litecoins) with this giftcard?


texts: Bitcoin is not fungible...so why haven't the Bitcoin core devs upgraded the protocol to make it private by default?


texts: Why is 6 the number of confirms that is considered secure?

texts: Why is 6 is the number of confirmations that is considered secure? I haven't found any mathematical explanation or otherwise that explains why it is 6 and not 5 or 7. Is there a historical reason for 6? Is there a specific way to calculate it so 6 is just a number that was chosen?


texts:
I'm reading Andreas Antonopuolus's "Mastering Bitcoin" and I have some confusions regarding the derivation of child keys.

This picture is showing how private child keys are derived.

https://github.com/bitcoinbook/bitcoinbook/blob/develop/images/mbc2_0510.png

It all makes sense to me except for the fact that the parent private key points directly to the child private key. However the left side of the HMAC-SHA512 already provides the full 256 bits for the private key. How is the parent private key directly involved in creating the child private key?

I guess it also has to be directly involved, otherwise it would be possible to generate all the child private keys only with the Public Extended Key.

According to the book public Extended keys can only be used to generate the public keys of children.

https://github.com/bitcoinbook/bitcoinbook/blob/develop/images/mbc2_0511.png

In this image it seems more obvious that the Parent Public Key influences the Child Public key directly, not only because of the arrow pointing, but also as the left side of the HMAC-SHA512 function only provides 256 of the 264 bits, but unfortunately I cannot find any details of that interaction.

I would be happy if anyone can share some knowledge about the details of that interaction.

Thanks in advance and all the best :)


texts: funding and spending a "no-multisig/no segwit" P2SH tx

texts:
I got inspired by this thread:

Single signature P2SH redeem script

Assume I want to "hide" my address as long as can be. So I want a P2SH tx, which only shows a redeemscript (hash of my pubkey) on the blockchain until spent. I try to go analog to a multisig, but use just the pubkey as redeemscript. The funding tx would hash160 the public key, and use it as redeem script. This would be a payment to a "type 3 address", with this code in the "tx_out pkscript".

A9: OP_HASH160
14: OP_Data14 (= decimal 20 and the redeem hash)
87: OP_EQUAL

Would the spending tx have this in it's scriptsig?

<sig><pubkey><OP_CHECKSIG>

(instead of the way it is done in multisigs:
<sig><pubkey 1-n><OP_CHECKMULTISIG>)

Looking what happens on the stack:

sig
pubkey
<OP_CHECKSIG>

<OP_HASH160>
redeem hash
<OP_Equal>

For this to work, the <OP_HASH160> opcode would have to know, that the pubkey and the <OP_CHECKSIG> would need to be hashed together (to be compared to the redeemscript hash which follows for <OP_Equal>) ...

I think the same question applies to multisig. There is just two or more pubkeys followed by <OP_CHECKMULTISIG> (instead of <OP_CHECKSIG>).


texts: Are Bitcoin wallet apps on iOS truly decentralised

texts:
The only offering for p2p support on iOS that I’m aware of is the MultipeerConnectivity framework. Based on its documentation, it only seems to support nearby devices (ref: https://developer.apple.com/documentation/multipeerconnectivity).

Now, by “truly decentralised”, I mean no use of a backend whatsoever.

Perhaps there’s something I might be missing. If wallet apps are indeed, truly decentralised, how do they achieve this?


texts: What valid transactions are not broadcastable?

texts:
Many valid transactions are not broadcastable by default in bitcoin core to avoid attacks that could harm the network. These would rarely be found in a node's mempool but could, however, be found in blocks because they don't violate any consensus rules.
What transactions fit these criteria?


texts: What is my chance to find a block on a TestNet ?

texts: My gethashespersec is 4806082,  on the TestNet what is my real chance to find a block ?


texts: Can you encrypt not just the private key, but also the public keys (ie bitcoin addresses) in an Armory wallet?

texts: I would imagine that the paranoid darknety bitcoin user has an interest in keeping not only their private keys safe (so nobody can steal their bitcoins), but also has an interest in keeping their public keys safe (so nobody knows what addresses they control). With bitcoin armory, at least by default, a wallet's public information is available without any password protection when you load the program. Is there an option to encrypt all the wallet's information, so you can be safe in case, say, some jerk steals your computer and scrapes it for information about you?


texts: Is there a webpage showing some of the latest orphaned blocks?

texts:
Blockchain.info has a couple pages about orphans, but the chart page does not agree with the list page.

My admittedly brief search for a page that shows orphans didn't turn up anything that was useful, so I'm hoping someone has one.  It seems a valuable resource for anyone involved in a trade where one side claims that the payment was confirmed and the other disagrees.


texts: Importing private keys into wallet - does the bitcoin disappear from the original wallet?

texts:
If I import a bunch of private keys into a new wallet, will the funds be removed from the original wallet? Or do they both somehow point to the same money?

In my case, I wish to move funds from Bitcoin Core wallet to an Exodus wallet.


texts: How does a Bitcoin node connect to more than 65536 other nodes?

texts: I found on the internet that Bitcoin uses TCP to communicate with other nodes, connecting to them and sending messages. But a computer cannot bind more than 65536 sockets (because of TCP ports), so how can a node connect to more than 65536 nodes?


texts: How does the tx fee in sendmany method get calculated?

texts:
In sendmany there is a conf_target parameter with the comment "Confirmation target (in blocks)". Does that mean that Bitcoin Core implicitly calculates and sets a smart fee for a given block target?

If so what is the priorities if I:

Set TX fee explicitly before
Set conf_target == 1
Set estimate_mode == UNSET

What will be the resulting fee rate on the transaction in each case?


texts: Is there any logical way that a "cloud Bitcoin mining" operation could be anything but a scam?

texts:
A few years ago, I paid (don't remember now if it was in Bitcoin or fiat) for a subscription to this "Cloudhash" scam. Basically, they claimed that I was "renting" a miner in their big facility, or more likely, they used my money (together with many other customers' money) to buy a bunch of miners that they put into a data center or some sort of facility, and then I could "watch the Bitcoins roll in".
As you can imagine, the amount in my control panel never reached above $2, far below what was allowed to be withdrawn. I never made a single dime. As far as I'm concerned, that was a scam. But does it necessarily have to be a scam? Or is there some way that somebody could legitimate run such a thing and actually pay out any kind of meaningful amounts of Bitcoin to the customers?
I read so many stories of people never getting their miners from China, or getting them so late that they had already become obsolete when they arrived. I realized that the power would go out in my apartment even if I did buy one, got it and hooked it up here. Not to mention the noise and heat generated would've driven me insane. It simply was not practical in my situation (which has not changed) to mine myself. That's why that service seemed so attractive to me, requiring me to do nothing but let them mine for me and I would get at least some coins.
I will say that I was skeptical, but I assumed that I would at least get back the money I had put in. Nope. Not even that.
Is there something which mathematically prevents this from ever working out?
Is there such a thing as a non-scam project that does this? Somebody who perhaps has rented a big basement with free power next to their uncle's nuclear power plant or something like that? Wouldn't it make sense for them to use my amount to buy another miner (or part of one) and then I would regularly get "my share worth" of satoshis?
Or am I pipe-dreaming here? Am I a naive fool who fell for the oldest trick in the book? And you all find it funny that I could ever believe that such a thing could exist?


texts: Bitcoin Cash to CoPay Bitcoin Wallet - How to Recover?

texts:
We have an eCommerce website and a customer is purchasing an item using Bitcoin.

We provided the customer with our business Copay Wallet address, however the customer sent "Bitcoin Cash" - how can he, or we, recover his payment?  The Copay wallet is of course Bitcoin only.


texts: What is the difference between Trading Volume and Transaction Volume?

texts:
Looking at the Bitcoin Statistics summery from Blockchain.info

there are Trading Volume and Transaction Volume listed.
I understand that transaction volume represents the amount of bitcoin used for transactions, eg. user sends bitcoins over to another user.

What about trade though? How is the value for trading value determined?


texts: Bitcoin core 0.19.1 RPC, 'sendtoaddress' not working!

texts:
Suppose this scenario:

There are 2 wallets called wallet1 and wallet1 on the same node in testnet blockchain.
wallet1 balance: 0.001 BTC
wallet2 balance: 0 BTC

I am trying to send 0.001 BTCs from wallet1 to wallet2; so I use the sendtoaddress command like this:
bitcoin-cli -testnet -rpcwallet=wallet1 sendtoaddress <wallet2 address> 0.001 "" "" true.
This gives me a txid which none of the blockchain explorers like live.blockcypher.com/btc-testnet can't recognize it!

It deducts the coin from wallet1 and I don't know where does it go!?

For solving this, I tried to get the transaction hex to broadcast it via some other platforms to check if the raw transaction is correct and it was OK and after broadcasting it via the other platform, blockchain explorers could detect the transaction id.
Here are my question:

Isn't just using sendtoaddress enough for sending coins?
Why the broadcasting process doesn't complete on my node?

Here is my bitcoin.conf:
[test]
prune=600
blocksonly=1
maxconnections=15
testnet=1
regtest=0

deprecatedrpc=accounts
deprecatedrpc=addwitnessaddress
deprecatedrpc=signrawtransaction
deprecatedrpc=validateaddress

minrelaytxfee=0.0001
maxmempool=200
maxreceiverbuffer=2500
maxsendbuffer=500
dbcache=16000

rpcbind=0.0.0.0
rpcallowip=--

rpcuser=--
rpcpassword=--

server=1
rest=1
daemon=1


texts: Where can I find more resources that explain Bitcoin simply?

texts:
I have been learning crypto for a little bit now and have been helped a lot by pebwindkraft, Andrew Chow and Adam in particular.

I would like to ask about resources that help beginners like me to understand the crypto space, I have been following a guy on youtube and I believe that he deserves some credit for the github book he did and the youtube videos that explain bitcoin in a way that I can sort of understand.

If you have any other resources then please feel free to put them down below.

Edit:

The channel I was referring was : https://www.youtube.com/channel/UCHBWzcGSrtoLYcasLwGvsow


texts:
so i got a 0.8 btc on my paper wallet..and usually i checked the balance on daily basis on blockchain.info.

And weird thing happened yesterday,my paper wallet sent my btc with total amount of 0.2btc to unknown address..
And i swear i keep my paper wallet safely and never get exposed..after learning that ,i decide to transfer all remaining btc on my wallet on blockchain apps.

Please anybody can answer here is my paper wallet address.
this.https://blockchain.info/address/14w344ohpe2M35BkScgcFdANuei5MPK49Z

And here the transaction.
https://blockchain.info/tx/8d1d918dcd045732c79541662309b9fe83e7faea99e3e0e757e3620167b2bb7a


texts: How to accept and detect altcoin payments?

texts: Similar to this question, How can a website detect when bitcoins have been deposited?, is there a way to accept altcoin deposits on a website and have the website automatically know when the altcoins have been sent to the website and update the user's balance accordingly?  Is there a procedure common to all altcoins or does each altcoin need a completely different approach?


texts: The role of governments when comparing Bitcoin and gold

texts:
I was reading the bitcoin wiki on myths and I completely agree that Bitcoin has the advantage of limited in supply like gold but it's a lot convenient and secure to use then gold. However, if you read further, one of the myth they are trying to debunk is

  Bitcoins are worthless because they aren't backed by anything

and they debunk with the argument

  One could argue that gold isn't backed by anything either. Bitcoins
  have properties resulting from the system's design that allows them to
  be subjectively valued by individuals.

However, I think the biggest difference is that gold is backed up by governments all around the world. All governments owns a huge sum of gold assets since it's been passed on generations after generations, so there is a huge motivation for the government to make the market subjectively perceive gold as valuable.

On the other hand, Bitcoin is only backed up by smart developers and early adopters. Governments owns of non of it and they can't control it like fiat currencies so they hate it. Countries like China even go to the extreme to outlaw trading cryptocurrencies in general. It makes logical sense for the US and EU governments to eventually follow China's steps to outlaw cryptocurrencies since it's to their advantage, Bitcoin's price will plummet when that day happens.

One could argue that the governors in US and EU are elected by a democratic process, but I would say the general public doesn't understand what Bitcoin is and they wouldn't care whether this candidate supports Bitcoin or not when they are voting.

It seems to me that in order for cryptocurrencies to succeed it needs to get the government on board somehow, but at the same time one of the biggest sell point of cryptocurrencies is they are not controllable by any central authority.

Is there any flaws in my arguments and logic?


texts: Bitcoin Unconfirmed Transaction Tiny Fee

texts:
I sent a huge amount of Bitcoin(.7) with a tiny fee. What can I do to get the transaction confirmed. Does it have to go through eventually? I can wait a week or two.

Otherwise I am looking for other ways to get it confirmed. Bitcoin was sent from Blockchain Info to Electrum. Electrum has a low fee warning sign next to the unconfirmed transaction.


texts:
I have BIP39 Seed:

5b56c417303faa3fcba7e57400e120a0ca83ec5a4fc9ffba757fbe63fbd77a89a1a3be4c67196f57c39a88b76373733891bfaba16ed27a813ceed498804c0570

I want to get Master private Key

Then I Have to use HMAC-SHA512, I can use this site, which secret I have to add ? I don't have any secret, for test  I choose "mnemonic", the same constant that I use to generate BIP39seed (is it correct? )

the result is:

  9744d0d7e168f725b6cc36a73c24dfc91bd6d80bf5a6871ad2c6c0b854e4e281b74049c41d25f0b338b3fc9b053b87b95636c3c94c31f37458fe98a09a4a94c9

and I can get

left 256 bits  => 9744d0d7e168f725b6cc36a73c24dfc91bd6d80bf5a6871ad2c6c0b854e4e281
right 256 bits  => b74049c41d25f0b338b3fc9b053b87b95636c3c94c31f37458fe98a09a4a94c9

And I can Get master private key in this way?

PKM = bx ec-to-wif 9744d0d7e168f725b6cc36a73c24dfc91bd6d80bf5a6871ad2c6c0b854e4e281

  result:
  L2Hku6wzwvWnHAct8TmtfvviE4QXBTXtZrae2buXwjq5mRG4doF2

but this result is not in https://iancoleman.io/bip39/ If I import my mnemonic phrase

  (army van defense carry jealous true garbage claim echo media make crunch)


texts:
I had created a script that creates a bitcoin private key, public key and address, for checking if all works fine I create one and check the private key on https://walletgenerator.net/, and it outputs a different address, every time I do that my script create a different addres that what walletgenerator returns.
Python script:
import secrets

import hashlib
import ecdsa
import codecs
import base64
class Address():
def init(self):
self.private_key = self.create_private_key()
self.public_key = self.private_key_to_public(self.private_key)
self.address = self.public_key_to_address(self.public_key)
@staticmethod
def create_private_key():
    bits = secrets.randbits(256)
    bits_hex = hex(bits)
    private_key = bits_hex[2:]
    return private_key

@staticmethod
def private_key_to_public(private_key):
    verify_key = ecdsa.SigningKey.from_string(codecs.decode(private_key, "hex"), curve=ecdsa.SECP256k1).verifying_key
    key_hex = codecs.encode(verify_key.to_string(), "hex")
    bitcoin_type = b'04'
    public_key = bitcoin_type + key_hex
    return public_key

@staticmethod
def public_key_to_address(public_key):
    public_key_bytes = codecs.decode(public_key, "hex")

    sha256_bpk = hashlib.sha256(public_key_bytes)
    sha256_bpk_digest = sha256_bpk.digest()

    ripemd160_bpk = hashlib.new("ripemd160")
    ripemd160_bpk.update(sha256_bpk_digest)
    ripemd160_bpk_digest = ripemd160_bpk.digest()
    ripemd160_bpk_hex = codecs.encode(ripemd160_bpk_digest, "hex")
    network_byte = b'00'
    network_bitcoin_public_key = network_byte + ripemd160_bpk_hex

    network_bitcoin_public_key_bytes = codecs.decode(network_bitcoin_public_key, 'hex')
    # Double SHA256 to get checksum
    sha256_nbpk = hashlib.sha256(network_bitcoin_public_key_bytes)
    sha256_nbpk_digest = sha256_nbpk.digest()
    sha256_2_nbpk = hashlib.sha256(sha256_nbpk_digest)
    sha256_2_nbpk_digest = sha256_2_nbpk.digest()
    sha256_2_hex = codecs.encode(sha256_2_nbpk_digest, "hex")
    checksum = sha256_2_hex[:8]

    address_hex = (network_bitcoin_public_key + checksum).decode('utf-8')
    return Address.base58(address_hex)

@staticmethod
def base58(address_hex):
    alphabet = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
    b58_string = ''
    # Get the number of leading zeros
    leading_zeros = len(address_hex) - len(address_hex.lstrip('0'))
    # Convert hex to decimal
    address_int = int(address_hex, 16)
    # Append digits to the start of string
    while address_int > 0:
        digit = address_int % 58
        digit_char = alphabet[digit]
        b58_string = digit_char + b58_string
        address_int //= 58
    # Add ‘1’ for each 2 leading zeros
    ones = leading_zeros // 2
    for _ in range(ones):
        b58_string = '1' + b58_string
    return b58_string

Doing
foo = Address()
print(foo.private_key, foo.public_key, foo.address)

returns
# 5598c164e8bcec667589267cdaf0f14a6b9399ae0b2a6b10972602a6feaf682d
# b'04cbeefab6ecfa84f5f120503de4574952f2d1fa5b11b8f6c80a13df02e6512090e6fede6dde3e65256c484162e38
# 39cf599c3d08a236432e8e307784b741ffca5' 18NFnELB9YpRiEbLMmRLKymYpvxC9yzkC2

And then, if I check the private key 5598c164e8bcec667589267cdaf0f14a6b9399ae0b2a6b10972602a6feaf682d on https://walletgenerator.net/, it returns:
Public address: 1LBLgjq3ntVdb8MqB41rHReWnrKgT41Lwv
Public address compressed: 1LBLgjq3ntVdb8MqB41rHReWnrKgT41Lwv


texts: What happens when bitcoin drops and i add more money to my wallet

texts:
If i have $1000 worth of bitcoin with the current price of bitcoin at $7000, then later on bitcoin dropa to $6500, normally i know ths money in my wallet will drop. But my question is what will happen if i add more money in my wallet then later bitcoin goes back to $7000, will i have more than $1000?

I have been wondering for a while and yet haven't come up with a clear explanation.


texts: How many api calls blocktrail allow per second. On official site mentioned only rate per minute(https://www.blocktrail.com/api/docs#rate_limits). Is this mean that I can make 5 requests per second(or can I do more)?


texts: Automated transactions to addresses from database

texts:
I want to create a website where people can submit their altcoin address and they receive some for free.

The addresses are saved in a MySQL database and the transactions are send from just one address.

How do I have to connect the database with the altcoin client so the transactions to the user addresses are processed automatically?

Thank you in advance!


texts: How do you get Sibling Hashed Values in a Merkle Proof?

texts:
Merkle Proofs are one of the main reasons that people attribute Bitcoin's use of Merkle Trees. But I'm struggling to understand how these work in practice. Please explain theoretically as well as practically.

Given that Lightweight Nodes only store Block Headers to limit the storage needed for their copies of the BlockChain, Nodes don't have access to the transactions in a Block; by definition of a Block Header, the only info they have about transactions is the Merkle Root.

But the Merkle Root is not enough to prove a transaction is in a block. All the sibling-values up the Merkle Tree are needed. Where do these values come from if they aren't already stored?

Example. Node 1 has a Block on its Blockchain with Merkle Root = H_ABC...P. It wishes to see if H_K is in the block. To do so, it needs the values H_L; H_IJK; H_MNOP; H_ABC..H. Where and how does it get these?


texts: Why is my Bitcoin transaction not confirming today?

texts:
Please don't tell me that this also has something to do with this stupid Corona virus. First, it slashes the Bitcoin value in (less than) half. Then I can't order any groceries and have to sit here and starve. And then it somehow affects the Bitcoin network's ability to make transfers?

Hopefully, it has nothing to do with the Corona virus, but if not, how can it be that I still have "0 confirmations" and it says the dreaded words "memory pool" in my Bitcoin Core?

For the last "many months", every Bitcoin transaction has been very fast to confirm fully for me. Why is it suddenly acting up? Is everyone trading tons now even though the price is so low? Isn't it when it goes up that there's network congestion?


texts: Funds were sent from another wallet to my wallet, but i didnt received the funds, please help


texts:
Is there a research, BIP proposal or simple discussion about possible improvement on the size required to run a full node and a way to shrink/prune the history of bitcoin and have fast sync?
Let me try to narrow a bit the topic: would be interesting to have a way to have fast node sync, with few memory required to store an updated "fullnode".
I was thinking if may be useful to have a kind of UTXO snapshot periodically (let say every 2016 blocks) where a node would generate a UTXO snapshot and put the hash (a merkle tree hash or whatever struct fits well) in the block header
having this, nodes may do a lot of different kind of sync based on their needs, e.g. they may validate "header first" by using these "snapshot headers", require a specific snapshot using something similar to "assumevalid" without the need to validate all prior transactions nor having to download blocks, because the utxo set is all what they need to validate next blocks on top of the snapshot height. Of course such nodes can't serve old blocks, similar to how pruned node ares, but they can validate and sync fast.
Of course my thought isn't indeep this is why I'm wondering what's current state about this topic because I'm quite sure it's something that periodically pops out.
Beside this, I've a more broader question, that may sound a bit rhetorical but still legit: is bitcoin history that important? Having snapshots (as consensus, every node has to generate it at the same height, its hash has to be stored on block header, etc...) could theoretically cause the block containing the snapshot act as a new genesis that move bitcoin ahead An utxo that's spent, isn't useful anymore like a transaction that have all its utxo spent, so removing them shouldn't cause any harm except probably transactions using OP_RETURN but they may be stored in another kind of "DATA Snapshot".
I can't think about a valid reason (except of course for initial sync) that makes the full history of bitcoin needed to be stored and served, did I miss something?
this kind of "dynamic genesis" still would allow a node that chose to store the whole chain compatible with a node that want to start from last snapshot, everyone can validate and serve blocks (of course the latter could serve only from snapshot genesis). It's kind of similar to what we have with checkpoint with the difference that's set in consensus and not hardcoded in code (that's one of the reason why checkpoint failed)
Open to criticisms that add something to the discussion.


texts: How soon does bitcoind incorporate locally solved blocks into its 'getwork' output?

texts: If one sends a solved block to bitcoind server using getmemorypool or getwork, and right after that requests a new block using the same API call, what will the server respond with? Assuming the data is correct, will bitcoind immediately create a new block to be solved with prev block field corresponding to the hash of the recently submitted work, or will it wait for the block to be accepted by its peers first?


texts: Is it possible to link one single LN node to Bitcoin addresses?

texts:
In René Pickhardt's presentation (slide 166) (here is the interesting talk), it's written that on-chain funds and addresses can be linked to LN nodes. How can this be achieved?

From my understanding, it is possible to link funds of a channel to two LN nodes, but it's not possible to tell which node funded the channel and how the funds get split among nodes in the settlement transaction.


texts: Can someone explain the output from running Bitcoin Core unit tests on Mac OS please?

texts:
When I build and run the unit tests on Mac OS using the make check command the output contains these two summaries (images uploaded below). Why does the testsuite summary initially summarize zero tests and then later only summarize a small number of the unit tests? I checked with another Bitcoin Core Mac OS user and they get similar outputs.

 and .


texts: Does MuSig have the same security as 2-2 multisig?

texts:
Disclaimer: This question is of theoretical importance to me trying to educate myself better on cryptographic principles and signature schemes. I don't intend to imply that in practice schnorr signatures are less secure than current 2-2 multisig transactions / scripts.

I am currently reading the musig paper and about scriptless scripts. In my understanding an important common idea in both cases seems to be able to have a single signature produced from several private keys.

Let us assume I can brute force the private key from a public key within reasonable time let's say 1 month (for example because I have a somewhat efficient algorithm for the discrete log in ecdsa (which I don't have). Also assume I can invert the hash function of Bitcoin addresses quickly. Or assume we just know the public keys because I am the third party in an escrow service)

Wouldn't I be able to break a MuSig address within 1 month (under the above assumption) by breaking the aggregated private key to the aggregated public key whereas in the setting of a common 2-2 multisig wallet I would need 2 months in order to be able to provide two valid signatures since I'd have to bruteforce both private keys independently of each other?


texts: Help! Unconfirmed transaction for the past 12 hours!

texts: I am a noob in the bitcoin world, I made a transfer of 0.0577201 BTC , with a transaction fee of 0.000221 BTC,  but the transaction has not yet been confirmed. Please help me! Here is the link for the transaction: https://blockchain.info/tx/72b2b1191693f5d916daf899ef6e43171599b065779e394fc7096c8fc5262091


texts: When will my Lightning channel be closed?

texts:
I have a force closed channel from lnbig.com and it has been pending in closing state for over 2 weeks (42600+ blocks).
When might it be closed so I can request a new one?
What are the default/average values for different channel closing types?
Is there any way for me to check force close wait period?


texts: Before you yell at me for how bad gpu mining is, its the only thing within my budget right now. But Im not sure what equipment to use, or how to set it up. I know I need to set up my mother board and power supply below the GPU rack up top, but how can I fit as many GPUs as possible? I was thinking of using a riser board with multiple slots, but Im not sure if that would work. Anybody mind helping me out here?


texts:
The following bitcoin addresses are involved in FRAUD...

[snip]

Where can I report bitcoin scammers?


texts: What happens to rejected transactions ( i.e double spend or invalid transactions)?

texts: Do they get put in an orphaned block or not get put into any block at all?


texts:
How can a government make people holding Bitcoin pay capital gains tax on their holdings if everyone is pseudonymous?

If crypto becomes widely adopted, will we have to rely more on sales taxes (e.g. at the point of sale), and less on wealth taxes?


texts: ANXBTC.com / MTGOX v2 API "Authentication"

texts:
I've signed up with ANXBTC.com and I'm trying to learn the API (based off MTGOX v2 API):

http://docs.anxv2.apiary.io/

In order to issue commands, there needs to be authentication.

I have a "Rest-Key", but I have no idea how to generate/find a "Rest-Sign".

On the link above, it says that "Rest-Sign is an HMAC hash constructed from your API secret, your API method path, your post data, and uses the SHA-512 algorithm."

Also on the above link, there is sample code (PHP, python etc) which can be tested - however it needs both the Rest-Key and Rest-Sign.

Part 2: Are these APIs meant to be run solely off a personal computer, or can it be used online? Eventually I want to try and create a website form where I can show the current exchange rate, as well as place orders. Is that possible?

If anyone has insight, help is greatly appreciated.

Thanks, Michael


texts: Who can change the code governing how much of BTC is released?

texts: I understand that BTC's will be continually released by the year 2040, when it will reach 21M coins. Actual numbers don't really matter, but I'm interested in who has the power to change this rule. Is this an individual, a "github community"?


texts: Can't connect Electrum to a Network so that I can receive my bitcoins

texts:
I've looked everywhere for an answer but can't find the right one for my situation. I'm using the linux based tails OS with persistent setup with my electrum wallet. Everything works fine and LBC shows my (test) funds of 0.0011 transferred, yet there's nothing in my wallet even after 45 minutes. Blockchain shows my transactions as complete with 17 confirmations yet still nothing in my electrum wallet. I'm guessing this is because my electrum wallet cannot connect to a network for some reason. I read similar stories but am not sure if it's particular to my problem since I'm using Tails.

Any advice would be welcome!


texts: Understand double spending through an example

texts:
Let’s suppose you have 1 BTC which you try to spend twice.

You made the 1 BTC transaction to a merchant (Transaction T1). Now, you again sign and send the same 1 BTC on another Bitcoin address to try and trick the merchant (Transaction T2).

1) Will every mining node that read from the pool both these 2 transactions discard the second one ? So as to put in a block only the first transaction (the correct one)

2) Suppose that for some reasons a mining node A mines the first transaction  in a block and propagate its blockchain to the network. At the same time a mining node B mines the second transaction in another block and propagates its blockchain to the network. This creates a fork in the blockchain. Will the other nodes of the network simply reject the B's blockchain because they know that transaction T1 is the correct one ?

3) To me it seems impossible that double spending can happen, every node will almost immediately read transactions T1 and T2 from the pool and discard T2, or discard a block if it contains T2. So i don't understand the need for waiting for 6 confirmations to be sure a transaction is correct.


texts: Visa, MasterCard or any other network copy Bitcoin blockchain tech?

texts:
I read an article (below) that explained how complicated the payment industry is and thus is why it is relatively expensive.

Could a network like Visa eventually copy Bitcoin, and thus cut everyone else out?

Would this potentially end Bitcoin?

This is the article: THE PAYMENTS INDUSTRY EXPLAINED: The Trends Creating New Winners And Losers In The Card-Processing Ecosystem


texts: Abrupt increase in difficulty of proof-of-work

texts:
I am simulating a private bitcoin network that I started with the initial difficulty set to (1/2)^16, however after about 20 blocks of mining on the network it increased to 1 and has been constant since then. As far as I understand from the source code, it is supposed to increase after every 2016 blocks, so how did it increase after only 20 blocks.

Change of powLimit in my bitcoind instances.

strNetworkID = "regtest";
        consensus.nSubsidyHalvingInterval = 210000;
        consensus.nMajorityEnforceBlockUpgrade = 51;
        consensus.nMajorityRejectBlockOutdated = 75;
        consensus.nMajorityWindow = 100;
        consensus.powLimit = uint256S("0000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.fPowAllowMinDifficultyBlocks = true;
        consensus.fPowNoRetargeting = false;


texts: How to get pending balance using bitcoin client/ bitcoin-cli?

texts: I want to get the pending balance for my bitcoin client but I don't see any RPC call for it.


texts:
The difficulty is adjusted such that a block is generated every 10 minutes.

What would be the consequences to lower the difficulty such that a block is generated every 5 minutes?


texts:
Accidentally/stupidly sent Btc to Ltc address.
On my Trezor I generated a Btc 'send payment', then I generated a 'receive payment'. Trezor asked for the Ltc address to be converted, which I did, then I pasted it and confirmed the lot...all steps done from my Trezor...I did wrong, because I forgot an important step, to convert the transaction on sites like Changelly before carrying on with the confirmation...The transaction is on the blockchain and the continuous rising number of confirmations indicate, at least to me, that it has been accepted. So, the funds are sitting on the blockchain in limbo! Is there anything I can do to retrieve the funds?
Cheers


texts: How to understand the first reply of a node

texts:
I have send my version message to a bitcoin node and the hexdump of his answer was this:
https://pastebin.com/QBNaeS0g
Maybe this is a network related question but I want to know the version used by this node and how did you come with it.


texts: How can I exactly use both the rpc API of Bitcoin and the rpc API of Bitcoin cash on the same server or machine?

texts:
I've looked for an exactly answer but I really couldn't find it.
So can someone let me know the why of doing what I'm asking correctly?


texts: Is it profitable to mine any Altcoin in the Cloud? Amazon aws has servers with GPU.

texts: As title says, I would like to mine in the cloud. Is it profitable? I don't mean bitcoin because the network hash power is too high at the moment. I'd like to mine, for example, Dogecoin in the cloud. Is it possible and profitable? Thanks!


texts: How to connect to a public node through json RPC?

texts:
I found a list of public bitcoin nodes here.  I am using a php library. How can I connect to these nodes via JSON RPC? Is it safe to connect to public nodes? What should I give as username and password?

I had tried a bitcoin node on my ec2 instance. It is taking too long to sync and blockchain size is also increasing. I want to communicate with bitcoin network without running a bitcoin daemon.


texts: Best practices for storing the bitcoin blockchain?

texts:
I have a few questions. One, is an SSD a good option to store the bitcoin blockchain. To unpack that question more, historically, has the blockchain size kept pace with Moore's law in relation to SSD technology?

Second, is a SAN drive array more appropriate to store bitcoin and other blockchains? I have done this before, it worked for my purpose as bitcoin is rather dynamic and slow compared to a typical database. The storage size is a clear upside. However, I wonder what is the impact with many big queries and also sync times?


texts: Hence BIP 342 proposes to enable opcodes like OP_MOD, OP_DIV, OP_MUL is it possible to perform advanced math operations like EC point addition/multiplication in a script size of up to 10kB?


texts: Does my node rebroadcast its mempool transactions on startup?

texts:
Say my node has transactions in its mempool and then gets shut down and restarted.

Does it save the mempool to disk and reload this mempool when it starts back up, or does its mempool get lost on shutdown?

If the mempool gets saved and loaded on restart, does my node rebroadcast these transactions out to the network once it starts back up?


texts:
Suppose you've created a random private key by rolling dices.
You've checked in the blockchain and nobody else has ever used the respective address of such private key.

Issue
Is this process reasonably safe to generate private keys?
Or, is there a subset of private keys that you should avoid due to known vulnerabilities in Bitcoin ECDSA (ie: something faster than brute force)?


texts: Where can I see the code of how the UTXO set is updated in case of a fork in Bitcoin Core?

texts: I am looking for a filename and a line, or multiple ones if necessary. My goal is to maintain an index of addresses to UTXOs.


texts: bitcoin-qt (master branch) shutdown delay on debian stretch

texts:
Following a bitcoin core issue on debian stretch which was resolved on the master branch, I am now running a pre-release test build. Each time I exit bitcoin-qt, I have to wait about 5 minutes until final shutdown occurs. My debug file is showing:

2016-12-20 19:58:55 AcceptToMemoryPool: peer=3: accepted 2b8c3...5c14 (poolsz ...
2016-12-20 19:58:56 AcceptToMemoryPool: peer=3: accepted 4a3d1...7e0e (poolsz ...
2016-12-20 19:58:56 tor: Thread interrupt
2016-12-20 19:58:56 scheduler thread interrupt
2016-12-20 19:58:56 torcontrol thread exit
2016-12-20 19:58:56 opencon thread interrupt
2016-12-20 19:58:56 addcon thread interrupt
2016-12-20 19:58:56 msghand thread interrupt
2016-12-20 19:58:56 net thread interrupt

This is where it hangs for a few minutes, then:

2016-12-20 20:05:58 Imported mempool transactions from disk: 10932 successes, 476 failed, 0 expired
2016-12-20 20:05:58 Shutdown: In progress...
2016-12-20 20:05:58 Stop
2016-12-20 20:05:59 Erased 1 orphan tx from peer 5
2016-12-20 20:06:01 Dumped mempool: 0.063746s to copy, 1.55051s to dump
2016-12-20 20:06:01 Shutdown: done

I have not experienced this before ever on any system. I am not seeing a similar issue when shutting down bitcoind (EDIT actually it does happen with bitcoind at times). I am wondering if anyone is aware of any pending change (on master branch for future release) which would explain such behavior (I worry this may be related to debian stretch, but my hardware is new, very cheap and hopelessly slow on known benchmarks, which may also be the cause of this).


texts: bitcoind: How to get rawblock data with ZeroMQ

texts:
I am trying to use the zeromq api for bitcoind to get rawblock but its not working with the code I've provided below. I am able to get hashtx and rawtx if I remove the filter but not hashblock and rawblock. Not sure if this is an important detail or not but my bitcoind is still syncing so I'm not sure if those topics are only triggered when bitcoind has synced up.
// Implementation of ZeroMQ in node.js.
// From the maintainers of the ZeroMQ protocol.
var zmq = require("zeromq");

// Create a subscriber socket.
const sock = new zmq.Subscriber();
var addr = "tcp://127.0.0.1:28332";

// Initiate connection to TCP socket.
sock.connect(addr);

// Subscribe to receive messages for a specific topic.
// This can be "rawblock", "hashblock", "rawtx", or "hashtx".
sock.subscribe("rawblock");

(async () => {
  for await (const [topic, msg] of sock) {
    console.log(topic.toString())
  }
})();

My bitcoin.conf file looks like:
server=1
txindex=1

# [zeromq]
zmqpubhashblock=tcp://127.0.0.1:28332
zmqpubhashtx=tcp://127.0.0.1:28332
zmqpubrawblock=tcp://127.0.0.1:28332
zmqpubrawtx=tcp://127.0.0.1:28332


texts: How to install a Bitcoin client on Ubuntu Server

texts:
I've googled a lot for this issue. Hehe. I have found some tutorials, but they were of no use because they are for systems that do have a GUI. I have no plans to install a GUI on that system, and I want to use bitcoin from the command line, or via RPC API. This is the system I run:

  Linux redacted 3.2.0-40-generic-pae #64-Ubuntu SMP Mon Mar 25 21:44:41 UTC 2013 i686 athlon i386 GNU/Linux

I found I can do this:

  sudo apt-get install bitcoind

But hardly I know what to do with it after that. It installs successfully. If you are going to ask a reason why I want this, it's because I want to communicate with it via PHP or I'll see how, but mostly it's for automating services with it. Please help. :-(


texts: How secure is calling bitcoind JSON-RPC?

texts: How secure is calling bitcoind through a JSON-RPC? For example, if I run it on one of my computers, and try calling it from another computer (provided neither of them are compromised), can someone intercept my communication and gain my RPC username and password?


texts: How can I load a specific private key into my wallet

texts:
Starting a Private Node using bitcoin-qt.
And then I generate a pair of keys for my own testing.
But unfortunately whenever I reset the node, it will generate a new pairs of keys, it makes my recursive test very tedious.
Is there a way for me to load a private key into my wallet instead of using getnewaddress every time and test with a new pair of keys?


texts: Does Ripple require users to input their ID and personal data?

texts: Currently all the USD to crypto currency exchanges require personal identification before withdrawing to USD. Does Ripple require this? How about the Ripple Gateways that do the currency conversions?


texts:
On page 2 of Bitcoin paper, it says:

  The problem of course is the payee can't verify that one of the owners
  did not  double-spend the coin. A common solution is to introduce a
  trusted central authority, or mint, that checks every transaction for
  double spending. After each transaction, the coin must be returned to
  the mint to issue a new coin,    and only coins issued directly from
  the mint are trusted not to be double-spent. The problem with this
  solution is that the fate of the entire money system depends on the
  company running the mint, with every transaction having to go through
  them, just like a bank.

  We need a way for the payee to know that the previous owners did not
  sign any earlier transactions.
  For our purposes, the earliest transaction is the one that counts, so we don't care about later attempts to double-spend. [emphasis added]
   The only way to confirm the absence of a transaction is to be aware
  of all transactions. In the mint based model, the mint was aware of
  all transactions and decided which arrived first. To accomplish this
  without a trusted party, transactions must be publicly announced [1],
  and we need a system for participants to agree on a single history of
  the order in which they were received. The payee needs proof that at
  the time of each transaction, the majority of nodes agreed it was the
  first received.

Why does only the earliest transaction matter for double spending?
I thought that it would be latest as previous owner would have checked till that. But even that is flawed... We need to check all.

Is it because the coin is a list of transactions and only first one is not verified?


texts: What is the meaning of the Bitcoin address version?

texts:
Bitcoin address versions are described on the Address wiki page:

  Normal addresses currently always start with 1, though this might change in a future version. Testnet addresses usually start with m or n.

The Protocol specification gives a bit more technical detail:

  Version = 1 byte of 0 (zero); on the test network, this is 1 byte of 111

Aside from distinguishing real and testnet addresses, what is the meaning and purpose of the address version? How and why will it change in future?


texts:
I have a 0.12 full node syncing in prune node.

This is what I get when I execute getblockchaininfo

pi@raspnode:~ $ bitcoin-cli getblockchaininfo {
    "chain" : "main",
    "blocks" : 276483,
    "headers" : 403136,
    "bestblockhash" : "00000000000000017871bf646ec12c1e2dedacef87dcd357cea0da1ddb0b64b5",
    "difficulty" : 1180923195.25802612,
    "verificationprogress" : 0.11950119,
    "chainwork" : "00000000000000000000000000000000000000000000084f5ed912538557eaa8",
    "pruned" : true,
    "softforks" : [
        {
            "id" : "bip34",
            "version" : 2,
            "enforce" : {
                "status" : true,
                "found" : 1000,
                "required" : 750,
                "window" : 1000
            },
            "reject" : {
                "status" : true,
                "found" : 1000,
                "required" : 950,
                "window" : 1000
            }
        },
        {
            "id" : "bip66",
            "version" : 3,
            "enforce" : {
                "status" : false,
                "found" : 0,
                "required" : 750,
                "window" : 1000
            },
            "reject" : {
                "status" : false,
                "found" : 0,
                "required" : 950,
                "window" : 1000
            }
        },
        {
            "id" : "bip65",
            "version" : 4,
            "enforce" : {
                "status" : false,
                "found" : 0,
                "required" : 750,
                "window" : 1000
            },
            "reject" : {
                "status" : false,
                "found" : 0,
                "required" : 950,
                "window" : 1000
            }
        }
    ],
    "pruneheight" : 0 }

I would like to understand the new specs about softforks. I know id is the BIP id. But what about this block of code?

                "enforce" : {
                    "status" : false,
                    "found" : 0,
                    "required" : 750,
                    "window" : 1000
                },
                "reject" : {
                    "status" : false,
                    "found" : 0,
                    "required" : 950,
                    "window" : 1000
                }


texts:
Hi I'm looking for a way to make a automated trading robot. I know there is btc robot but it is too rapid, I only want to make long term trades. like making a trading robot where i can set the limit for buying and selling.
Buy when price is at 300$ and sell all my BTC when price is at 600$. maybe some alert/notification system when the price is at the "set sell price" and when the price is at "set buying price".

does anyone know such kind of trading robot?


texts: Calculating EMA on multiple time periods - right or wrong?

texts:
I'm writing a bot that acts on market signals - currently just based on exponential moving averages. At the moment, I have the program watching the market on multiple different period lengths. For example, it will grab the last price right now, calculate and log a moving average if there is enough data, and then 60 minutes from now do the same. It can be doing this for 5min, 15min, 30min, 2h, 4h, etc. etc. time periods.

However, If I have an algorithm making decisions every 60 minutes, It could very easily lose a lot of money in between the two calculations. My thought is that I should be grabbing market data and calculating values every 1 or 2 minutes, and base those calculations on data from period_length time ago. It still obviously charts a 60 min or 2h or w/e chart, but does so every 1 min in order to react as fast as possibly to changes.

Is this the correct approach, or am I way off on this?


texts: What's to prevent someone from using bitcoin at a store like subway and double spending to buy the sandwich before a confirmation is made? Since subway obviously isn't going to wait for a confirmation, can't a person send bitcoin to subway and at the same time send that bitcoin to another address?


texts: What percentage of Bitcoin use is legitimate?

texts:
I wasn't able to find actual data on this. I'm under the impression that

the majority of transactions represent ownership transfer between investors, traders and exchanges
the majority of remaining transactions represent purchases of goods and services
the majority of purchases made with Bitcoin are for something illegal

It's very easy to see why someone would want to buy drugs with Bitcoin. It's not easy to see why someone would want to buy coffee with Bitcoin. If I want to buy coffee with Bitcoin, isn't it easier to first exchange that Bitcoin into fiat currency, and pay for coffee with that?

Does anyone have any data regarding what percentage of Bitcoin use is legitimate?


texts: Do I need to hire miners if I don't know how to mine?

texts: I am studying Blockchain technology and found out that miners are the ones that provide Proof of Work and verify the transactions on the Blockchain. If I were to build an app that would involve the release of verified documents, would the verifying authorities need to have hired miners to be able to provide verification or are verification and mining 2 separate processes?


texts: Can Lightning Network be used for individual small transactions?

texts:
Today I went to use shapeshift.io to trade some BTC for IOTA. I only have a small amount of BTC, and I will only be performing a single transaction. Due to congestion on the network coupled with impractical fees the aforementioned operation is infeasible.

My question is, in theory, does the lightning network help me in this situation?

I get that it can help me pay merchants several times without bloating the network/incurring multiple fees, but does it help an individual user in a single transaction like the one above? I feel like I'm missing something, because lightning is supposed to solve both congestion and fees, but in my limited understanding, it seems to do this only indirectly. It clearly would unclog the mempool a great deal, and thereby, because of a decrease in congestion result in a concurrent decrease in transaction fees. Right? But is there a direct application for single transactions not involving multiple small in/outputs like my very real world example above?

Thanks a lot for your responses.


texts: Do you have to pay taxes on Bitcoin revenues?

texts:
Disclaimer: this is not legal advice, and this varies from country to country.

If you accept bitcoins as payment, do you have to pay taxes on that? And would you have to write an invoice? Since they are not an official currency, such a trade would be considered a barter or what?

I.e. what's the legal status of someone accepting bitcoins as payment, and what is him required to do?


texts: How does the miner efficiently check that an address has required amount of data?

texts:
I've read this question.

As the answer said, the miner "looks up the outputs that a transaction is spending from and makes sure that no other transaction has spent those outputs already."

So the miner has to look up all the blocks form block 1 to the end, which has over 500,000 blocks (and will grow even bigger), for each transaction. And a block contains thousand of transactions. This sounds impossible to me.

"A node maintains a list of all unspent transaction outputs." This request each node to maintain billions of address and their unspent transaction outputs. Is this even possible? If yes, what about the future?


texts: clients that support the Lightning Network?

texts: Which clients, besides Electrum, support the Lightning Network?


texts: Is there developer documentation for the Bitcoin Core source code?

texts: Is there a documentation somewhere to understand the C++ code of Bitcoin Core (available on Github) "from a to z" and being able to recreate it ?


texts: How does Ripple decide on the exchange rate between different currencies?

texts: When A pays in USD but B receives EUR, how exactly does Ripple decide on the EUR/USD exchange rate?


texts: Can a Trezor seed be used in any other HD wallet?

texts:
Trezor FAQ says

  If you do not use a passphrase, your recovery seed is all that is needed to access your bitcoins.

If you do not use a passphrase, can the Trezor seed be used to recreate a hierarchical deterministic wallet?


texts: (How/Why) - Work vs Block Size Limit and Leading Zeros

texts:
Tl:dr
How did Satoshi/the community decide an appropriate block-size-limit?
Why does the protocol increase mining difficulty by adding zeros?

I've some limited experience with some of the cryptographic concepts underlying bitcoins protocols.
I have two questions.
Given the fact that there is an upper limit on block size, perhaps the easiest way to breach this is to arrive at an some exceedingly large nonce which will become necessary due to other block contents.
The question is, how do you set an appropriate limit for arbitrary blocks?
Would you need to know about inverting the hashing-algorithm in order to prove the efficacy of a given limit for an arbitrary ledger/header/nonce set?

Second question is about the relevance of increasing the leading zeros over time.
Would it not be equivalent (wrt work done) to set a total number of zeros?
That is, would you need to know about inverting the hash algorithm in order to prove that difficulty is increasing by adding leading zeros as opposed to any other "pattern" of any other hex character of the same cardinality?
Please forgive and correct my understanding of the issues in question.


texts: What are the legal processes that someone would have to go through in order to get a Bitcoin exchange operational?

texts:
One of the main perceived difficulties in getting started with Bitcoin is obtaining some in the first place.

Naturally, for an exchange to be accepted into the mainstream it needs to be a recognised and approved legal entity within the country it is operating in.

So my question is this - what are the legal processes that someone would have to go through in order to get a Bitcoin exchange operational?

If possible, it would be useful to have each answer target a particular country with suitable edits to become a solid reference.


texts:
The before transaction is @ https://www.blocktrail.com/tBTC/tx/da58f6688b0727a7f1bf3eec899099bde1f18b9c7099f9d2c79556db238e623d

Its output script is "OP_HASH160 da1745e9b549bd0bfa1a569971c77eba30cd5a4b OP_EQUAL".

The current transaction is @
https://www.blocktrail.com/tBTC/tx/839b903b9f79c3372792ceb95917047c46d1b919ed1f6471f5a19d7c865ab32c?txinIdx=0

Its input script is "51".

I verified the transaction manually but it failed.
Why the transaction was accepted and confirmed?

The evolved stack is as below. What's wrong?
628850cb844fe63c308c62afc8bc5351f1952a7f = RIPEMD160(SHA256(1))


texts: Has anyone proposed a human only proof of work system?

texts:
There have been suggestions of proof of work requirements that exclude GPUs or ASICS (or try to) but I was wondering if anyone had suggested a proof of work that is not suited to being solved by computer at all, so that the miners would be humans working on proving their own work done - work that cannot (currently) be performed by a computer in a competitive amount of time.

This would presumably need to be quickly verifiable by computer, but not independently solvable by computer.

If this hasn't yet been proposed, is there any apparent reason this would not work?


texts: Why is segwit support rising so smoothly?

texts:
I expect to see some noticeable random steps (e. g. when some relatively large pool on miner starts to support segwit). Instead I see almost perfect linear dependency. Why is that? I am afraid that I miss something fundamental about segwit.

I painted in red what (approximately) I expect to see, while blue line is the real one. Graph is taken from https://blockchain.info/charts/bip-9-segwit


texts: What other decentralized bitcoin / altcoin exchanges are there besides Bitsquare?

texts: I recently found out about Bitsquare's decentralized exchange that lets you trade altcoin or fiat. But are there other decentralized altcoin exchanges out there like bitsquare?


texts: Ubuntu Linux, Unable to set bitcoin datadir to a folder in different drive

texts:
I am trying to run a bitcoin node. I want to set the datadir to a folder located on drive other than on which I have installed ubuntu.
Folder I want to set as datadir:
/media/spider/Utils/bitcoin

with permissions
drwxrwxrwx 1 spider spider 448 اپریل   2 17:25 bitcoin

But when i try to run bitcoin-core i get this error
$  bitcoin bitcoin-core.daemon --datadir=/media/spider/Utils/bitcoin
Error: Failed saving settings file:
- Error: Unable to open settings file /media/spider/Utils/bitcoin/settings.json.tmp for writing


texts: How do I run two instances of bitcoind on the same linux machine with different conf files?

texts:
I want to run two instances of bitcoind on my machine.

I know my bitcoin.conf file is in ./bitcoin/bitcoin.conf, and I know (thanks to this thread) that I need to change my .conf file to point to different data dirs and RPC ports, etc.

However there is only one .conf file.

How do I go about pointing my second bitcoind instance to a new bitcoin.conf file? I copied the directory with the compiled code to a new directory, I am making the assumption that compiled code can be copied into another directory and it will work without problems.


texts: Can transactions scale sufficiently to compensate the diminishing block reward by fees?

texts:
Today, the bitcoin network is secured by massive computing power, which is expended in the process of mining. The miners are rewarded by newly mined bitcoins, plus transactions fees.

The security of the network relies on the computing power being so expensive, that no one group can afford to gain 51% share.

Eventually, the amount of newly mined bitcoins will diminish, and the mining  reward by itself would cause mining to become unprofitable.

Will the fees be able to pay the expenses for the huge expensive computing power?

I can see two extreme situations where it might work:

a) either the transaction fees will be astronomical
b) or there will have to be huge amount of transactions

option a) is clearly not viable, which leaves option b).

What would this mean for the bitcoin economy?

Will bitcoin need to become "high-velocity" money?
How could that be enforced? And how would we prevent the blockchain growing out of control?

Is my analysis correct?


texts: I am using https://github.com/bumi/bip70-example to make signed payment request. I bought COMODO Wildcard certificate. And creating certificates bundle in following order: mydomain_origin.com.crt, comodorsadomainvalidationsecureserverca.crt, comodorsaaddtrustca.crt, addtrustexternalcaroot.crt. And specifying this bundle and private key to the code. But when trying to make a payment wallet(Bread wallet for this example) giving me: "payee identity isn't cerfied. This operation couldn't be completed. (OSStatusError -9809)."


texts: When you pay from a P2SH address, does its change go into a P2SH address too?

texts: Because that means you must always keep the redeem script around to make the change addresses, and if it's a multisignature script, then you'll need to have the script with those public keys around, ready to go too.


texts: What is the age of the youngest known Bitcoin developer?

texts: What is the youngest age of someone known to have submitted a Pull Request to Bitcoin Core?


texts: Who added the 21 million limit to Bitcoin?

texts:
After reading the white paper of Satoshi Nakamoto. The white paper does not mention anything about a limit of money supply.
I think I have read somewhere mentioned the name, but unfortunately I cannot remember it.
If I look in the main resources available online (Wikipedia, bitcoin.org, ..) they all mention Satoshi Nakamoto as the one who added this feature.
If Satoshi was not the one to add this feature, I think it is very important that we know who came up with this, and why the bitcoin dev community at the moment decided to adopt it.


texts: Does P2PKH substitute P2PK in any circumstances? Why? I know address(public key hash) was invented later than the official implementation released. Is it the reason?


texts: In what line of what file does the block reward depend on?

texts: I want to make an altcoin and since I am new, I wanted to know what sets the reward of a block after being mined.


texts:
Hey guys been looking through the forums and I'm still not quite sure how to speed things up or fix it. (Not very good with this kind of stuff)

Here's my wallet address - 1GZK3NYHCAScGRb4awAkXGVXszstwCVEEh

Initial problem:

Both transactions say they have been seen by 50+ peers
But hadn't been confirmed for 24hrs

I used the standard multi bit classic fee 0.0001
Which has never slowed me down in past.

i figured it was too low of a fee. Changed my settings for next time

New problem:

I did a 'reset blockchain and transaction' (did it twice) on multibit classic - seems to be no way to change date etc. in an attempt to get my coins back and start again

Now the amount of 1 of the 2 transactions is showing in my balance (but isn't spendable) and the other seems to have made no change (still sending to the same address, just the peers have reset)

I've looked on blockchain.info and nothing seems to have changed at all.

Do I need to just be patient?

I just don't really understand what's happening or what I'm looking at.

If someone could help me fix it or explain what's going on that would be appreciated

I'm confident once I get my coins back and send with a higher fee it'll all be fine. Just can't seem to get them a back

Cheers!

Ps. Sorry I'm a noob and stressing


texts: Why do we need bitcoins in the bitcoin network?

texts:
I am new to the bitcoin world and I am just wondering why don't we simply use the US currency (or any fiat currency) to transfer money using the bitcoin network? Why do we need crypto currencies as a must to deal with that network?

Edit: why do we need (in the bitcoin network) to change our US dollers to bitcoins so as to be able to transfer our dollers to someone else? Or can we use the technology of the bitcoin network to transfer dollers without the need to convert the dollers to bitcoins, like what banks do?


texts: How would you store a bitcoin wallet for a small bitcoin exchange?

texts: How would you store a bitcoin wallet with the security of the wallet being a priority for a small bitcoin exchange? Offline wallets are the safest though how would a client be able to withdraw their coins if the wallet is offline?


texts: How can I test if a bitcoin address is compressed or not?

texts:
I have two bitcoin addresses:

1D8VSXHFAWNhAbruwUMbNp4hsXAnRNkYvX
12T15tvMGaymMX97X9KxVzyLF323r8v6Hg

One is compressed, one is not.

How can I test which is which? (Preferably using python 2.7)

Thanks in advance :)


texts: Why did bitcoin programmers release mining code?

texts:
Why did anyone ever release bitcoin mining code, aside from promoting bitcoin and eventually raising investor awareness?

Looking at a price chart, bitcoins were valued at just a fraction of a dollar until it was better explained to people. Was this because

a) a lack of trust in fiat currencies during a recession, or
 b) release of mining code solely to get bitcoins to have any value in the collective at all.

Was the global liquidity crisis and recession merely coincidence?

I'm curious because bitcoins have offered a really great return for people that were mining before the promotions or at other points in time.


texts:
I want to create ECDSA signature {r,s} where r is very low (for example 1) and can be encoded in DER-format in one byte.

How to calculate k value? Seems to me that it does not depend of anything. What is the value of k which produces r=1 ?

Note: I do not worry for the safety of my private key while publishing this signature.


texts: Who is the programmer behind SatoshiDice?

texts: I have talked with Erik Voorhees and I learned that he is not the person that programmed SatoshiDice. Does anyone know who is the developer behind this game is?


texts: Is Bitcoin Days Destroyed a measure of hoarding? Also, is it possible to derive  velocity of money (i.e. bitcoin) from Bitcoin Days Destroyed?


texts:
I guess they took off this function, so any alternative?

what i'm looking to do is exactly like this

sweepprivkey privkey minconfirms [destinationtype destination] [fee] [amount changeaddress]


texts:
Does Bitcoin have a legal expert/team that does their work? (yes, they - a group of interested individuals (the Bitcoin team) even though they have no formal association - are a decentralized network but some of those decentralized networks do have offices, etc., and may have a legal team.)

Are there any private individuals who have (ever) started an action on behalf of Bitcoin?


texts: What information does a lightning network node hold?

texts: Just setup my first lightning network node, what information exactly am I downloading when syncing?


texts: What happens if Bitcoin itself is obsoleted by another digital currency?

texts:
Unless Bitcoin is replaced with a Bitcoin-compatible currency, I believe that all holders of Bitcoin will be out of luck when the day comes that it is obsoleted by a superior system, as inevitably happens in almost everything electronic.

Normally if a new commodity type is introduced into the market (such as the discovery of petroleum), the market will naturally find a new equilibrium, and this is not a problem. Normally when a new fiat currency is created, there is usually an exchange policy in which holders of the old currency are issued units of the new currency, but I don't see how this is possible in systems like Bitcoin. Nobody is going to want to trade units of the superior new system for units of the inferior system if they know that everyone in the world is going to stop accepting the old system soon, so everyone holding Bitcoin at that time will find that their savings are suddenly worthless if they cannot somehow be "brought in" to the new system.

As we know, the entire Bitcoin infrastructure is limited in currency units, which is normally an advantage because it prevents "money printing". Because of this, the only ways I can think of to solve this potential problem is if the new currency system has more units than the old, and when the old system is to be replaced, the developers of both systems coordinate to release a new version of their systems in which the new system is made to be downward compatible with the Bitcoin network, and somehow one unit in the new system is marked as unmineable and is instead replaced with the already mined units from the old currency system, which will probably result in forking both currency systems.

The consequence of NOT replacing one digital currency system with another is that either every new system or fork which gets popular will "print money" due to their creation increasing supply without proportionally increasing, or that innovation in digital currencies must be limited to things which are reasonably compatible with the existing systems. So if this problem cannot be resolved, it either means a slowing of the progress of humanity, or an occasional massive loss of purchasing power punishing whoever is unlucky enough to be a large holder of the old currency at the time that it becomes discontinued.

Is someone working on this problem, or are all the developers of digital currencies like Ripple, Bitcoin, Litecoin, and others simply betting that their system will be the victor for all time?


texts: In various places on Ripple Wiki we can see the type Hash256 (for example here). What data structure is it exactly? Is it just a 256 byte array, or are there some rules governing this type (and preventing potential misuse)?


texts:
I want to start a BTC market.  I understand all the ways to go about creating a site, it's just the payment implementation which confuses me.  I want multi-sig transactions capable between my users on site.  If I understand correctly, multi-sig addresses are just special wallets anyways which require a certain fulfillment (2 out of three keys, for example) to go through.

How can I implement a system like this for my users on my server?  So I can allow users to trade without the middle man if possible, yet also have the opportunity for an escrow moderation in case something happens?  In the end a small percentage of market fees can be charged?

I'm new to Bitcoin programming but I'm assuming you simply have your web application interact with server daemons which dynamically create multi-sig addresses on demand for your users and somehow give them each a key, and leave a key for escrow moderation?  And that would probably be all you'd have to do?


texts: BitcoinJ seems to be calculating balance incorrectly

texts:
My application is using bitcoinj-0.11.3. I am using Wallet.getBalance(balanceType) to read wallet balance.

For AVAILABLE I get 8.94106037
This is supposed to include all confirmed transactions.
For ESTIMATED I get 22.43822671.
This mode assumes that all of the transactions in the memory pool are included into the blockchain.

Knowing my transactions this looks inaccurate as confirmed by blockr which indicates a balance of 24.48442767. Note that this doesn't include unconfirmed transactions.

So, there are two inaccuracies here:

22.43822671 vs 24.48442767
AVAILABLE shows ~9 when it should show ~24.

While blockr balance seems right my funds keep in pending state. I suspect that wallet balance calculation is somehow wrong.

[Edit]:
Might also help the output of Wallet.toString :

Wallet containing 22.43822671 BTC (available: 8.94106037 BTC) in:
  5 pending transactions
  79 unspent transactions
  390 spent transactions
  0 dead transactions

I think this also answers to Nick question that I am not scrambling numbers while converting the BigInteger.


texts: Multi-signature with no address reuse . How coordination is done?

texts:
I would like to have both 2-of-3 multi-signature and no address reuse.
For example,
3 BTC belong to multi-sig user1 (Officer),user2 (Manager), user3 (CEO) (2of3 multisig) with pubkey1,pubkey2,pubkey3.
They send 1 BTC to user 5. Assume zero fees. The change of 2 BTC should be sent to user1,user2,user3 (multi-sig) with pubkey1.1, pubkey2.1, pubkey3.1
Well, this is easy to say here! but
In real life, how do the users in multi-sig coordinate their next pub key? Would it be a coordination nightmare? What happens when one of the user (CEO) always not available for any communication? We will be stuck with an old Public Key for (user3)? Is there any automatic coordination like BIP32 ? etc.


texts: How to get unspents for inputs using bitcoinjs-lib?

texts: I would like my simple wallet app to automatically select UTXOs for inputs. I realize that I can't accomplish this with just bitcoinjs, but is there something I can add to it to keep track of unspents? Or is there a way to use some sort of API to automatically select unspents? I do see that it is fairly easily done with btc.com, but I would like to be able to do this with altcoins as well. Thanks in advance!


texts: Is my wallet at blockchain.info still mine if the website shuts down

texts:
I'm a really beginner, I have no client on my computer. I puchased bicoin and store them in my wallet at blockchain.info, and I have downloaded the "backup file" named "wallet.aes.json".
My concern is if someday the website of blockchain.info shuts down, can I get my bitcoins by importing the backup file into a client software? I also have my "key" which is a long code that looks like an bitcoin address, and my understanding is that the backup file also only consist of my address and that key.
Thanks!


texts: Blockchain.info send may transactions API v2

texts:
I'm currently using v2 of Blockchain.info's API and am wanting to utilise "Send Many Transaction" and am having some issues.

I have 1 wallet with many addresses, I am trying to send 2 transactions within 1 payment, their API documentation is still from v1 and is missing the '&from' from their api example, and have spent more time than I'd like to admit to get this working.

this is from there website:

http://localhost:3000/merchant/$guid/sendmany?password=$main_password&second_password=$second_password&recipients=$recipients&fee=$fee

$main_password Your Main Blockchain wallet password
$second_password Your second Blockchain Wallet password if double encryption  is enabled.
$recipients Is a JSON Object using Bitcoin Addresses as keys and the amounts to send as values (See below).
$from Send from a specific Bitcoin Address (Optional)
$fee Transaction fee value in satoshi (Must be greater than default fee) (Optional)
$note A public note to include with the transaction -- can only be attached to transactions where all outputs are greater than 0.005 BTC.(Optional)

The result I get is:

failed to open stream:HTTP request failed!

Fatal error:Maximum execution time of 120 seconds exceeded

I now the url is wrong but can anyone please help advise me what it is specifically.

So far this is what I have

// Sending addresses
$Address1 = 'Address1';
$Address2 = 'Address2';

//Amount coming from
$From = 'Address3';

//Amounts being sent in satoshi
$Amount1 = 100000;  // 0.001 of a btc
$Amount2 = 100000;

$recipients = urlencode(' {
    "'.$Address1.'": '.$Amount1.',
    "'.$Address2.'": '.$Amount2.'
}');

$Guid = 'MY_GUID';
$Password = 'MY_PASSWORD';

$url = 'http://localhost:3000/merchant/'.$Guid.'/sendmany?password='.$Password.'&from='.$From.'&recipients='.$recipients.'';
// I've also tried to remove $data and put '&api_code=MY_API_CODE' after
// $recipients as this also works for other api calls for v2

$data = array('api_code' => 'MY_API_CODE');

$result = sendAmounts($url, $data);

function sendAmounts($url, $data) {
$options = array(
    'http' => array(
        'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
        'method'  => 'POST',  // Also tried GET
        'content' => http_build_query($data),
    ),
);
$context  = stream_context_create($options);
$result = file_get_contents($url, false, $context);

return $result;
}

Thank you in advance.


texts:
I have ubuntu server running Bitcoin core v0.16.

I'm sending RPC calls asynchronously using Guzzle (PHP library), but, e.g., if I'm importing 1000 address using importmulti command, any further requests are waits until that command finish.

Even though I have set rpcthreads=100
rpcworkqueue=50 and I've powerful server.


texts: How to calculate the average worker hashrate on a pool?

texts:
I just calculated the average hashrate of all poolminers on Slushpool by dividing the Pool Scoring Hash Rate by the amount of active workers:

So with current values that is: 641.1 Ph/s / 30287 ~= 21,2 TH/s

Is this the right way to do it, or am I missing something?
That seems to be pretty high ...


texts:
New to this (obvious)
Using armory.
To send/receive BC's I need and address for the wallet.
How do I get this address?
Simple question and have searched but no direct answer??

Thanks


texts: What benefit does bitcoin provide over using a credit card?

texts:
I am brand new to Bitcoin. I am retired investor.

What benefit would using Bitcoin have over, say, using a credit card, etc.? It appears that Bitcoin is primarily designed for businesses, buying, selling, and using Bitcoin as the exchange medium.

I saw a chart which showed the Bitcoin/USD value at approximately $32 and then dropped to $2 and now is back around $15 as of August 18, 2012.


texts: Javascript library to explore bitcoin blockchain data by connecting to a local running node

texts:
I need to get data of a block using the block height.

Is there a javascript library to get block data from the Bitcoin blockchain, by connecting to local running node or a 3rd party blockchain provider?


texts:
I'm working on a project that involves constructing raw transactions and signing them locally before pushing to the network. I keep getting Unable To Find Transaction Outpoint 1a67415e9f892c31cdaec29f6bf7e8e7ffd5a7cdca52fc565ad345313f85b222:90463999.

Here's my tx hash

010000000122b2853f3145d35a56fc52cacda7d5ffe7e8f76b9fc2aecd312c899f5e41671aff5e64058a473044022052576f11b965d4b0a712b91e04377e25acebfad8093f3296deecb05ad429281502201ede7fb35f495985bb67d302465c6419fc1c683d26f7111d4e70cceac2dc86910141047920bd57b7b0dbf7ac242879ee1f1c4b87cbe30a1c31baa4d111850865042415d84f0a433174b3b17f41e280bfef85ff885dd8a1f25bf0823cfd77ec81bfc080ffffffff0101000000000000001976a914221382696ab041ff0bce2aceeea15132d9336fd488ac00000000

which decodes to

{
   "lock_time":0,
   "size":223,
   "inputs":[
      {
         "prev_out":{
            "index":90463999,
            "hash":"1a67415e9f892c31cdaec29f6bf7e8e7ffd5a7cdca52fc565ad345313f85b222"
         },
         "script":"473044022052576f11b965d4b0a712b91e04377e25acebfad8093f3296deecb05ad429281502201ede7fb35f495985bb67d302465c6419fc1c683d26f7111d4e70cceac2dc86910141047920bd57b7b0dbf7ac242879ee1f1c4b87cbe30a1c31baa4d111850865042415d84f0a433174b3b17f41e280bfef85ff885dd8a1f25bf0823cfd77ec81bfc080"
      }
   ],
   "version":1,
   "vin_sz":1,
   "hash":"a1981a142ba4966939d27e2cb78ae0a4d9550c91448105defdbed7ec71f2b351",
   "vout_sz":1,
   "out":[
      {
         "script_string":"OP_DUP OP_HASH160 221382696ab041ff0bce2aceeea15132d9336fd4 OP_EQUALVERIFY OP_CHECKSIG",
         "address":"147BM4WmH17PPxhiH1kyNppWuyCAwn3Jm4",
         "value":1,
         "script":"76a914221382696ab041ff0bce2aceeea15132d9336fd488ac"
      }
   ]
}

which seems to match the unspent ountput I see here: https://blockchain.info/unspent?address=1LCrg6DSqbcK5vh7XRAGEQA4jBpNigjwyV

So what am I doing wrong?


texts: What good is to store all the transactions in the history

texts:
Bitcoin stores all the transactions that happened
in the blockchain.

Are really all the transactions needed? What good is it
to have transactions ten years old stored. Isn't it a waste
of discspace?


texts:
When I read this book Master Bitcoin, I have a problem in understanding the "Difficulty" in Chapter 8.

There is a equation of difficulty:

New Difficulty = Old Difficulty * (Actual Time of Last 2016 Blocks / 20160 minutes)

I feel confused.
According to the formula, if Actual Time was longer than 20160 minutes, the New Difficulty would be bigger than Old Difficulty, and then Actual Time would be longer and longer.

It looks very strange. For me the equation should be:

New Difficulty = Old Difficulty * (20160 minutes / Actual Time of Last 2016 Blocks)

However, I found this fomula is consistent with that in bitcoin code.

unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params& params)
{
    if (params.fPowNoRetargeting)
        return pindexLast->nBits;

    // Limit adjustment step
    int64_t nActualTimespan = pindexLast->GetBlockTime() - nFirstBlockTime;
    if (nActualTimespan < params.nPowTargetTimespan/4)
        nActualTimespan = params.nPowTargetTimespan/4;
    if (nActualTimespan > params.nPowTargetTimespan*4)
        nActualTimespan = params.nPowTargetTimespan*4;

    // Retarget
    const arith_uint256 bnPowLimit = UintToArith256(params.powLimit);
    arith_uint256 bnNew;
    bnNew.SetCompact(pindexLast->nBits);
    bnNew *= nActualTimespan;
    bnNew /= params.nPowTargetTimespan;

    if (bnNew > bnPowLimit)
        bnNew = bnPowLimit;

    return bnNew.GetCompact();
}

Then I found this answer.
This is what I understand, but why it is different from the equation of the book and the code.

update

I think this was just an ambiguous expression.
The better expression should be:

New Difficulty Target = Old Difficulty Target * (Actual Time of Last 2016 Blocks / 20160 minutes)


texts: Is there any plan to add a feature so that you can perform transactions that will be spent in the future and stored on the network? For example, I want to send some bitcoin to my kids after each N block so they will slowly receive a long time after I may already be dead. But I don’t want to send them the whole balance at once.


texts: Minimum transaction fee to COMPLETE when mempool is +50 MB

texts:
As of June 11, 2017:

Mempool History  - < Blockchain.info

the mempool is currently about 50 MB, and
a week ago, the mempool was about 100 MB.
The blocks mined per day are about 150, so at 1 MB / block = 150 MB / day of data is added.

This tells me that, if demand for transactions decreases as it has for the last week, from a mempool of ~100MB, it may reach a mempool of zero within a week from today's ~50 MB.
-- Note that the mempool hasn't approached zero since April 16 this year.

Once it reaches zero, I'm assuming that even if the fee is set to zero, transactions will get confirmed "soon", and definitely within a day.  Yes?
If I'm moving .001 (= $3 US) and specify 3 satoshi as a fee, at what point in time, and is is likely that it will be confirmed at all, when the mempool is at 50 MB?

I know that it increases probability as it ages.  However many miners won't touch transactions at all, unless there's a fee attached, OR all the fee-based transactions have been satisfied.  Correct?

So, what is PROBABLE TIME with the following mempool sizes would a $3 value / .001 transaction be confirmed with a 3 satoshi fee?

50 MB mempool -- =  how many days or hours?
25 MB   "
10 MB   "
5  MB   "


texts: What is a Key pair? & relationship with adresses?

texts:
does a generated private key, provide 1 public key? I mean, the pair is generated practically at once?
Then this only public key is used to create multiples “adresses” which will be used to make transactions?

Thank you a lot.


texts: Where can I find records of blockchain branches?

texts:
I plan to analyze blockchain branches to satisfy my own curiosity: how often do they occur, are they increasing in frequency, etc. To clarify my earlier mistaken terminology: I am talking about "garden variety" blockchain branches that occur when two miners succeed in mining a new block "at the same time."

Where can I find a record of blockchain branches? I'd love to find a handy webpage with the data, though I am running a full node if someone can walk me through generating the data.

Thanks in advance! Bruce


texts: Is there really this big a difference between AMD and NVIDIA?

texts:
As i am thinking of builing a system with a evga 670 i was wondering how much better a similarly priced AMD card would be in mining?
The bitcoin wiki
shows a hashrate of 406MH/s for the GV-R787OC-2GD  (a $250 card) while the EVGA GTX670FTW 2GB gets only 112 MH/s (a $400 card).

This seems really off to me. Is there really this big a difference?

As on many websites it says AMD is so much better for mining while because NVIDIA has Cuda everyone says its best for editing why doesn't cuda drive up Mhash/s?


texts: What is a Mining Pool, what is it good for?

texts: What advantages / disadvantages does it offer over solo mining?


texts: Does AUTHORIZATION_REVOCABLE flag affects all credits help or up to any amount?

texts: If one issues currency with AUTHORIZATION_REVOCABLE flag, and account A hold 100 credits of it, can issuer revoke only 13 credits? Can account A spend the rest 87 credits as normal?


texts:
I'm a noob in cryptocurrency and may ask really a stupid question.

Why no site covering everything(Wallet+Exchange+In-house Pool+Mining Cloud Marketplace+ICO) at once, so I can just join and get wallet and start investing my money either,

To buy cryptocurrency or
To buy miner to mine on in-house pool (option to use outside) or
To ICO

in a single site even an app by touching some actions?

Regarding wallet+mining cloud, I know Nicehash, which seems the closest but still I need to set up a pool and understand how their reverse bidding works.

I'm looking for a site where a user doesn't need to know about detail of crypto algorithm or concept of pool or anything but UI for invest X amount then you can earn Y per day/month by selecting currency and mining cloud sorted by ROI.


texts:
I'm interested in building a Bitcoinica replacement and wondered how did they get their pricing information.

Was it from Mt.Gox and was it verifiable, I mean could you have gone to a web site and seen a history of prices and therefore know why your position may have been liquidated ?


texts: Is it safe to keep a compromised private key in my wallet?

texts:
I'm using bitcoin-qt.  Suppose that one of the private keys in my wallet is compromised somehow, and is released to an attacker or the public.  Of course, I can transfer all the coins from the compromised address to a new one (unless the attacker does it first).  However, bitcoin-qt apparently doesn't provide a way to delete or disable a private key from a wallet.   (This is understandable; it would be pretty bad to accidentally delete a private key for an address that had coins in it.)

Is it safe to leave the key in the wallet, assuming I never again intentionally transfer any coins to that address?  (I could label it DONOTUSE or something.)  Or are there situations (e.g. change) where the client might automatically transfer coins there without asking me?


texts: If a user recovered data directory of LN node software with an old backup, what would happen? Would cooperative channel closing be possible?

texts:
As far as I know, the "Data Loss Protection" feature would just request the counterparty to unilaterally close the channel. I wonder if mutual closing is still possible, with old channel states?

By the way, I roughly remember that I once seen a comment like this:

Before the "Static Channel Backup" feature was introduced, there was once a bad situation that the funds could be permanently lost, even if the channel counterparty unilaterally closed the channel. However, this bad situation was a trade-off in exchange for better (or easier) watchtower implementation.


texts:
I was curious to know if anyone knows of any bitcoin business that stores people's wallets offline?

I'm looking to diversify my backup methods for cold storage and am wanting to send my backups to a company that can store it for me securely.


texts: How do I generate the Bitcoin Cash hash preimage?

texts:
I am attempting to manually generate a signed transaction which is to be sent from my address 1GiJZtN7wjUuL4V5i7ZYYDAvFtqi5AhCDr which is bitcoincash:qzk9nxh6qpd9yt3hvv6vvun78s834f3escdhu2vdjp in the new address format. I am using an uncompressed public key in this transaction.

I have the following unsigned Bitcoin Cash transaction. How do I find its hash preimage which is the hash used in the signing of this transaction?

  0100000001fb4a8e5c7ac5311f32fbe127f031134ee3e7490f3308ca19c567f78d6aa96d770000000000ffffffff0100a00700000000001976a914a8e181e0847b495df439066ca8fb36ce093692be88ac00000000

Breaking it up, it looks like this:

01000000 - nVersion

01 - num of inputs

fb4a8e5c7ac5311f32fbe127f031134ee3e7490f3308ca19c567f78d6aa96d77 - txid (little-endian)

00000000 - vout

00 - size of sigScript

ffffffff - sequence number

01 - num of outputs

00a0070000000000 - amount (hex, little-endian)

1976a914a8e181e0847b495df439066ca8fb36ce093692be88ac - scriptPubKey

00000000 - timeLock

I am attempting to consume output 0 from the transaction with txid: 776da96a8df767c519ca08330f49e7e34e1331f027e1fb321f31c57a5c8e4afb,
The scriptPubKey for that transaction's output 0 is:

1976a914ac599afa005a522e376334c6727e3c0f1aa6398688ac

The value of the received output is 0.005 BCH

The transaction I am attempting to consume can be found here:
https://bch.btc.com/776da96a8df767c519ca08330f49e7e34e1331f027e1fb321f31c57a5c8e4afb
And the rawtx for the transaction I want to consume is here:
https://bch.btc.com/776da96a8df767c519ca08330f49e7e34e1331f027e1fb321f31c57a5c8e4afb.rawhex

Can anybody help me?


texts: bitcoin-cli createrawtransaction and purpose of "scriptPubKey"?

texts:
I am playing with P2SH on regtest and try to understand the logic of creating and signing tx with bitcoin daemon. I am on version 0.15.1, and try to create a tx.

The used  scriptPubKey results from a simple if/else/endif statement, not from a standard multisig approach. So I manually created the redeem script, and turned it into an address (beginning with "2"). I then created a transaction, that funds this address. Now I want to spend these funds. While creating the transaction, I discovered that the usage of "scriptPubKey" does not change anything in my output.

Example without "scriptPubKey":

bitcoin-cli -regtest createrawtransaction '''[{"txid":"'b5b67997f36627a461cd5ee1951aa775a68faa0c11c50b8f068ea1c7f4a9b087'","vout":'0'}]''' '''{"'mgpe9b44YYYbhDE1dbWosCSQDPYFkkoHjt'":'9.99995000'}'''
020000000187b0a9f4c7a18e068f0bc5110caa8fa675a71a95e15ecd61a42766f39779b6b50000000000ffffffff0178b69a3b000000001976a9140e507731ec9a94d454424f3ca65917a2abb45f4988ac00000000

Example with "scriptPubKey":

bitcoin-cli -regtest createrawtransaction '''[{"txid":"'b5b67997f36627a461cd5ee1951aa775a68faa0c11c50b8f068ea1c7f4a9b087'","vout":'0',"scriptPubKey":"'a914d53c738d730d8623eb2a070833599157beb3f6f687'"}]''' '''{"'mgpe9b44YYYbhDE1dbWosCSQDPYFkkoHjt'":'9.99995000'}'''
020000000187b0a9f4c7a18e068f0bc5110caa8fa675a71a95e15ecd61a42766f39779b6b50000000000ffffffff0178b69a3b000000001976a9140e507731ec9a94d454424f3ca65917a2abb45f4988ac00000000

The result is exactly the same. When the result is the same, what is the purpose of using this field as a parameter to "createrawtransaction"?


texts: What is the difference between a cryptocurrency, a digital currency, and a virtual currency?

texts:
I'm wondering what are the differences between the three terms.

I have the impression that they are used somewhat interchangeably, with people talking about Bitcoin being the most popular "virtual currency" etc.

Some people say virtual currency is the subset of digital currency, while others argue conversely.

Any suggestions will be appreciated.

Thank you.


texts: How to generate multiple public addresses using one private key?

texts: I want to generate multiple btc addresses using one private key. I am using pywallet library but each child address also have the private key. Can I use one private key for multiple addresses (if they derived from the same private key) to create a transaction?


texts: Is it technically possible to send a transaction with two identical destination output addresses?

texts:
Is it technically possible to send a payment consisting of several outputs, of which two (or more) are the same?

ie input collected 10 btc -> output to 1abc 1btc, output to 1abc 1btc, output to self 8btc (change)?

Will the client allow it? Can it be handcrafted?

I'm building a merchant-type app, and am trying to account for strange, non-standard transactions.

Thanks!


texts: Create Raw Transaction in BitcoinJ offline starting from UTXO info

texts:
I would to create offline Raw Transaction (without signing it) in BitcoinJ. The information I know about the inout is UTXO's hash, index, amount, address, and script. I also know the receiver address of the final transaction, the change address, the amount and the fee.
I'm fighting with the TransactionOutput constructors to build the input for my transaction. I don't know where to set UTXO hash and index - i think in the "parent" parameter, but i'm failing. This is my snippet:
Transaction parent = ???
Coin value = Coin.valueOf(satoshi(utxo.getAmount()));
Address to = Address.fromBase58(params, utxo.getOwnerAddress());
//where do i put utxo hash and index?
TransactionOutput input = new TransactionOutput(params, parent, value, to);
tx.addInput(input)


texts: Why is the signature hash different for each input in a multi-input transaction?

texts:
In pre-BIP143 signature hashes, I know that the signature hash differs because you have to substitute the previous scriptPubKey for each input and thus the serialization changes.

The question is why? If the HASH_TYPE is SIGHASH_ALL, why does the signature hash need to change for each input? Why not sign the same "blanked" transaction or the same transaction with the scriptPubKeys?


texts: What's the advantages of using the block chain as opposed to L2 solutions

texts:
I'm looking for a good example and explanation from a software architecture perspective BUT for general audience about the benefits of solving and having blockchain features on Layer 1 not disregarding any Layer 2 solution or blockchain but in fact comparing.
In example any scaling solution for off-chain transaction will definitely face speed issues in comparison to one that was solved on the original design of the blockchain.
It's not a fair comparison because both have their reasons, their strengths and their fame but if you take lightning or æternity state channels you will have some design flaws that should be talked about to help people to understand and decide based on more than just marketing.
Again this isn't in any way a critic towards any of the solution but an example to talk about design and architecture and not about which had better marketing.


texts: cgminer with two R9 290 giving me headaches

texts:
I've got two R9 290, using cgminer I'm getting nothing but trouble. I'm using the 13.12 driver and installed the 2.8 SDK.

When I launch cgminer it sees both cards, GPU0 and GPU1. They both happily start mining, but after about 30 seconds cgminer hangs for a few seconds and GPU0 starts dropping its hashrate (it gives HW:1). I'm not sure what's causing the issue since both cards are identitical and I've only defined the settings once using -g 2.

I've seen that there are some difficulties with the particular card (had to define --no-asl to stop it from crashing the display drivers). Does anyone have any tips or clues to find the problem?

I'm running two Gigabyte R9 290 with an i7-930, 18 GB memory and a 1000w PSU on Windows 7 professional x64.

Is there an alternative to cgminer for ATI cards which can succesfully use the ASL api?


texts: How could an inflation bug be spotted in grin?

texts: Looking at the transactions within the block explorer I can't see any transaction amounts. How could an inflation bug be detected if all transactions are private?


texts:
I'm using the Golang btcsuite/btcd library to write a Bitcoin app that creates custom OP_RETURN TXs in the blockchain.

I understand Bitcoin at a high-level (proof-of-work consensus, Merkle trees, membership, signatures, etc.), but I'm getting lost in the (unnecessarily?) complicated details of its RPC interface.

I was writing code in Go for creating a custom transaction with 1 input and 2 outputs (an OP_RETURN output and a change output). Here are my questions:

Is this considered a raw transaction? (If so, what exactly constitutes a raw transaction? Is it all transactions that don't get created via the sendfrom/sendmany/sendtoaddress RPC?)
What's the difference between getnewaddress and getrawchangeaddress at a semantic level? It seems that both generate a key-pair, but why is there a need for two different calls?
If I'm creating a raw transaction as described above, should I send the change to a getnewaddress key or a getrawchangeaddress key?

Thank you,
Alin


texts:
I tried stopping bitcoind using bitcoin-cli stop and got the following error.

bitcoin-cli stop
error: Could not locate RPC credentials. No authentication cookie could be found, and RPC password is not set.  See -rpcpassword and -stdinrpcpass.  Configuration file: (/home/user/.bitcoin/bitcoin.conf)

I confirmed that bitcoind is running (using ps -A).

ps -A | grep bitcoind
643 pts/0    00:17:23 bitcoind

bitcoind was started in a datadir on the usb storage. I can kill the process but i want to shut it down in a correct way.


texts: Bitcoin 0.10 uses getheaders to synchronize. How long has this message been supported by other clients? How many existing nodes support it?


texts: Is the getnewaddress command available before synchronization is completed?

texts: Can I expect the getnewaddress command to work before my bitcoind has finished synchronizing?


texts: Bitcoin i have been asked to send money for a private key

texts: Hi i have been asked to send money for funds that are nonspendable to receive a private key to unlock it, it's from bitcoin investing. How safe is this as i'm worried i wont receive the payment. It's currently sitting in my blockchain wallet account and it displays the funds as nonspendable until unlocked with a private key


texts: The amount of lost Bitcoin is well-known, but is it reported anywhere how many user accounts Mt. Gox had before its downfall?


texts: 0.00603581 is in my bit coin wallet how much do I own?

texts: If I have 0.00603581 in my bitcoin wallet who much do I accually own ?


texts: Can I recover bitcoins from an Armory wallet.lmdb file?

texts:
I did a super deep disk clean to see if I could recover the wallet file but I was unable to find it. Only file I was able to find that is armory_*****_wallet.lmdb. Does this file have any connection with the original wallet (.wallet) file itself?
If yes, is it possible to rescue the wallet from it?