texts: How much is ripple decentralised and p2p

texts:
I don't understand this

  Even if Opencoin should close, the ripple network will continue. Because the ripple is a P2P >network, it is not operated by Opencoin but by the combined efforts of all the computers >running the ripple server software. The ripple network can not be shut down without shutting >down the entire Internet.

so what is there are still ripple users but no ripple servers?
Will all XRP and all stored money vanish?
is all ripple clients also a server so that they can process transactions.

Also, I would like to ask do all people that use ripple form a p2p network,
or only the ripple servers form a p2p network, and users connect into it?

Thank you :)


texts:
“If the number of nodes that agree exceeds 2/3, the blocks or transactions of clients will be accepted”

Practical Byzantine fault tolerance (pBFT) : (n - 1) / 3

I read those 2 things in a PDF that a friend of mine sent me.

The question is: are those numbers (2/3) or “(n-1)/3” constant? Or those numbers are established by the developers.

What makes those numbers? What’s the reason for 2/3 and not 2.5/3 ?  Or why not (n - 2 ) / 3


texts: What would happend if a country were backed by its own cryptocurrency?

texts:
What would happen if instead of depending on dollars or gold, a country were backed by its own cryptocurrency, would this benefit its citizens and the country itself? How?

I've read this answer but it's mostly about bitcoin, and not about a country's coin.
Sorry if the question is out of place.
Thanks!


texts: Why do you need the *complete* blockchain to mine bitcoins, why not just the last n blocks?

texts: I understand that to mine bitcoins you need the hash of the previous block, and in order to resolve possible forks. But why not just have the last 100 blocks (or more whatever is appropriate) and keep a sliding window of the last blocks?


texts:
Would anyone here please be able to tell me how to do RBF using the ledger nano- I can see the transaction was RBF and has been stuck for about 24 hours now. The TX is 5c119ce4b0bce440c16b2ad48e720c22422454118bf15ece0602904349d0b568 and it still has not been accepted.
I have been looking at accelerating it and also RBF, I have been unable to find anything for RBF in line with Ledger Live. I would really appreciate any help and if you could look at the transaction ID for me. I do not understand it unfortunately.
Many Thanks


texts: How to fix kernel paging request error on raspberry pi miner?

texts:
I'm mining Bitcoin and Litecoin using Gridseeds.

As a host/controller I'm running a Raspberry Pi with ArchLinuxARM.

I'm using the latest Arch image and compiled cgminer from this github repository:

https://github.com/girnyau/cgminer-gc3355

I'm running 10 Gridseeds. They are running well at 3.6 MH/s Scrypt (10x 360kH/s @ 850 MHz) until some point when it goes Oops:

[ 4565.377848] Unable to handle kernel paging request at virtual address 00002055
[ 4565.385255] pgd = c9df8000
[ 4565.393214] [00002055] *pgd=c9df8000, *pte=00000000, *ppte=00000000
[ 4565.404992] Internal error: Oops: 17 [#1] PREEMT ARM

Here is a screenshot:

Why? And how to fix this?


texts: Bitcoin P2PKH transaction - two questions

texts:
Trying to learn the basics of the bitcoin's standard transaction script here. For a transaction where Alice has sent coins to Bob, who is now trying to redeem them, we have the concatenated scriptSig and scriptPubKey as below

<Sig> <PubKey> OP_DUP OP_HASH160 <PubkeyHash> OP_EQUALVERIFY OP_CHECKSIG

When we say that the recipient must specify the PubKey and Sig in scriptSig, what exactly is in Sig? My understanding is that Bob is signing the entire transaction with his private key and then this is what OP_CHECKSIG verifies. In this case, the inputs to OP_CHECKSIG are the transaction data and the public key. Please let me know if this is correct and if not, then what exactly are the inputs that OP_CHECKSIG requires?

Secondly, what is the point of the first part of the script that checks the match between scriptSig's PubKey and scriptPubKey? Could we not instead get a simpler script where the outputs of a transaction specify the public key itself instead of the hash of the public key? In this case, we would simply have

<Sig> <PubKey> OP_CHECKSIG,

where Sig comes from the Bob and PubKey from Alice.


texts: Does using deterministic wallets reduce our anonymity?

texts: Is it possible to figure out that certain addresses belong to the same wallet? Say I have 2 or 3 addresses that I know were created by a deterministic wallet like Armory. Is there a way to find all the other addresses that have been used by that wallet? I mean by that instance of a wallet, not all the addresses created by the Armory software.


texts: How do I decrypt a password protected, BIP0038 address?

texts: Services like bitaddress.org allow you to password encrypt a paper wallet. How would I decrypt it?


texts: Conditional based Crypto based on Smart Contracts

texts:
Is it possible to store an encrypted message in the blockchain that reveals itself only when a particular condition is met?

I think that the conditional disclosure can be done with Smart Contracts, but I don’t know if it would be securely encrypted until the condition to disclosure is met.


texts: Mining Primecoin with one server and no pool?

texts:
Is it possible to mine with just one server (for learning about mining, not for making a living!) and one wallet?

I've configured a Ubuntu VPS on a server I had spare and run Primecoind. My primecoin.conf has a random RPC username and password that I generated but I haven't put server=1 in the configuration file. I'm not sure if I should/need to.

When viewing the information of the process running, I can see the following data:

Every 2.0s: primecoind listtransactions & primecoind getmininginfo

Thu Jul 11 22:43:27 2013
{
    "blocks" : 16149,
    "currentblocksize" : 1000,
    "currentblocktx" : 0,
    "errors" : "",
    "generate" : true,
    "genproclimit" : -1,
    "primespersec" : 7,
    "pooledtx" : 2,
    "testnet" : false
}
[
]

I'm confused by a couple of things.

Firstly, why does pooledtx fluxuate from 0 to 2 from time to time. Secondly, how would I now if I have successfully mined for the first time and if there was any balance at all?

I've got MultiBit setup on my Mac with a wallet ID available.

I'm just unsure on how it all fits together. Any pointers would be appreciated.


texts: When miners are working on their block, does everybody's block have the same transactions in them?

texts:
On Bitcoin-Wiki's page about Blocks, it says that "Bitcoin transactions are broadcast to the network by the sender, and all peers trying to solve blocks collect the transaction records and add them to the block they're working to solve.".

So, do all peers have the same transactions in their blocks at all times?


texts: Attack vectors for difficulty retargeting with BCH and BTC?

texts:
Since the existence of BCH, miners can now switch chains to mine on. Assuming they mine greedily based on price and difficulty. Can the following attack happen and how could it be mitigated:

Assuming BCH has a high market cap, in parity with BTC.

Since it take two weeks to adjust for difficulty most miners would mine BCH when bitcoin difficulty is unprofitable. Then lets say 20% of miners keep mining BTC such that the difficulty adjustment is triggered 1.5 months later and re sets to 1/5 difficulty. Then, miners would jump from BCH to BTC and mine 2 weeks worth of supply in 4 days, leave when difficulty readjusts, and BTC basically dies (because most of the time blocks are solved on average every 50mins rather than the usual 10mins, causing slow confirmation times).

How can this attack be mitigated?


texts: Hardware wallet - Claiming forked currencies

texts:
I'm considering purchasing a hardware wallet for my cryptos (ledger or trezor) and was wondering how one might claim a forked crypto if these devices don't provide the private keys or add support for it. Let's say bitcoin forks in the future, and for whatever reason ledger/trezor decides not to support it. How do I claim the new currency in this case?

One option might be to generate private keys using tools and then claim them on another wallet that does support the new currency. Thoughts?


texts: Extended Public Key 's mechanism misinterpreting in 'Mastering Bitcoin' by Andreas

texts: I am a newbie and start exploring from the 'Mastering Bitcoin' book. The figure below to me is a little inaccurate, I think the arrow from HMAC-SHA256 should point right to the child public key. Am I right??


texts: Difference between bitcoin-cli getnetworkinfo version and bitcoind --version

texts:
I tried to upgrade bitcoin core from 0.18.0 to 0.20.0.
When I ask for the version through bitcoind bitcoind --version it prints Bitcoin Core version v0.20.0 but if I ask for the version through bitcoin-cli bitcoin-cli getnetworkinfo it prints "subversion": "/Satoshi:0.18.0/"
How is this possible that this is not the same?


texts: How to confirm how many peers a node has?

texts:
When a node requests one of it's neighbours for a list of it's peers, that node responds with a list of all of it's neighbours. I'm just wondering is there a way to confirm that those nodes are actually his neighbours and not random/bad nodes?

Or is there an easier way to determine which of your neighbours is the most connected i.e has the most connections to it?


texts:
Hi people of North Cryptoland. I bought a couple of Bitcoin a few months ago with a long term view for my retirement, just to add to the portfolio. They are stored in a Bitcoin Multibit HD wallet (in brown leather nicely embossed I imagine!) Anyway I am just wondering how does one find the new BCC if I am entitled, and how do I download them into my Wallet or do I need a new Wallet? (you know in black leather - sort of bill fold style I imagine!). Be gentle with me, I'm 54 years old and my level of computer savvy, runs all the way up to being able to start my computer most days, if I've remembered to plug it in to the wall socket that is...

Thanxs in Advance.  Shady @ Australia


texts: How can I create a transaction that collects inputs from many addresses and sends them to one address in bitcoind?

texts:
I'm using bitcoind and would like to understand how to create transactions that send inputs from many specifically selected addresses (from my wallet) to one destination address. I want to do manually what the sendtoaddress command does automatically.

If this operation requires me to create a raw transaction could you please provide a working example? I already read bitcoin.it:raw_transactions, but it is hard to understand without an example and unfortunately the wiki article doesn't provide any.

I would appreciate help greatly.


texts: I have being mining BTC" on my computer. It does not show as TH/s but rather H/s... is it big or small?


texts: Will forks and alternative block chains cause hyper-inflation of decentralized digital money?

texts:
Great effort has been put into Bitcoin's concept of money supply and that there will never be more than 21 million units.

However, it's relatively easy to fork it and create alternate block chains. SolidCoin, IXCoin, IOCoin etc are much less worth, but they can easily be traded against Bitcoin. Does this increase the over-all supply of Bitcoin-like money to well beyond 21 million units? Some believe yes, and that this is one reason already for the recent price drop.

Also, the concept of open and decentralized P2P money is still young. Chances are that a lot of other such currencies will pop up in time. Is there a risk that Bitcoin will be thwarted by an inflation of other currencies, rendering it and all other open, "free", decentralized money worthless and useless?

EDIT: One thing to consider in this context is that the number of traditional currencies will always be limited as there are only so many nation states on this planet (and they are consolidating, e.g. Euro), but the number of decentralized digital currencies is potentially unlimited.


texts: Are the transactions displayed on "BitListen" really accurate?

texts:
Over the years, whenever there's unusual Bitcoin activity, I look at: https://www.bitlisten.com/
But can these transactions really be accurate? I just saw numerous 100+ BTC ones, and just now a gigantic one of 946.92 BTC (!!).
According to my exchange rate calculator, that is:
BTC 946.92 = $22,731,761.52 USD

Almost twenty-three million US dollars... at once?
I realize that a lot of money is being traded right now, but even if somebody has that many Bitcoin to trade, would they really do it all in one go? Isn't that very risk? Wouldn't you split it up into at least hundreds of different transactions?
I don't understand what kind of person or entity would make a single transaction of such a huge sum. Is this really accurate or faked somehow?


texts: Can a Ledger Nano X hold multiple BitCoin Wallets?

texts:
From my reading of Ledger Nano X, it can hold multiple types of currency, for instance, BitCoin and Ethereum.

Can it hold two or more separate BitCoin wallets with different balances?

Frank


texts: multiple input and output addresses in bitcoin transactions

texts:
I was checking transactions in blockchain.info. I have some questions about transaction information about input and output addresses.

block address:
https://blockchain.info/address/1NHv6qBxu6haWj8rqeLqw9eyJqm4JT26R6

why some of transactions have one input and one output? They don't have any change transaction?
If any transaction has two output, the second one is change transaction?
can we see fee transactions in output address?
Are multiple addresses in input part related to each address in wallet that has bitcoin?

and one more question about transaction scripts:

what is input and output script? do wallets produce them? how we can use them?

I'm new in bitcoin and I appreciate your clear explanations...


texts: I am trying to create a genesis block for a personal play coin. I get the correct output of assertion failed. However when compiling I noticed the ./altcoin folder is not created at all.


texts: How do deterministic wallets know how many keys to generate?

texts:
Say I backup the "seed/key" for a deterministic wallet. I then create 10,000 transactions, resulting in 10,000 new addresses being generated.

Say I then lose the wallet file and I restore from the "seed/key". How does the deterministic wallet know it has to generate 10,000 addresses to get the full balance?


texts:
I use Bitcoin-Qt. Decided to make another wallet and transfer some bitcoins there. Wanted to give that wallet to my friend as a gift. What I did was:

renamed wallet.dat file to 1_wallet.dat
started Bitcoin-Qt it created new wallet.dat file
copied address of new wallet
renamed wallet.dat to 2_wallet.dat and 1_wallet.dat back to wallet.dat
transferred some bitcoins to new wallet address

finally after transaction was confirmed I still didn't see bitcoins in a new wallet. What I did wrong? Is it possible to get back these bitcoins?


texts: How does blockchain.info access my wallet in MyWallet

texts:
I made a wallet at blockchain.info and enabled two-step authentication using Google Authenticator.

As I understand it, the operator of blockchain.info cannot access your wallet (unlike e.g. MtGox). Yet somehow blockchain.info can deposit coins in my wallet.

Also, I assume the two-step does not work for the offline backup files, but the password does?


texts: Can a Bitcoin response contain multiple Bitcoin messages?


texts: Do you need to download the entire blockchain in order to mine bitcoins? I'm downloading bitcoin-qt, and I'm afraid it will take up too much memory on my computer. Also, I just read that when another node downloads the blockchain from me, that will also tie speeds. Is this true?


texts: I tried to run bitcoin core and it is gone. Has anyone experienced this?

texts: I tried to run bitcoin core and it is gone.The folder is still there, but the exe is not there. Does that mean the local wallet is gone as well?


texts: Where is bitcoin.conf location on MacOS with Bitcoin core v0.15.1

texts:
After doing some research it is supposed to be under ~/Library/Application Support/Bitcoin/

But on my computer there is no Bitcoin.conf under ~/Library/Application Support/Bitcoin !

So where do I find Bitcoin.conf?


texts: Is there a way to transfer money from Dwolla to MtGox without paying BitInstant a 3.99% transaction fee?

texts: I want to transfer some money from Dwolla to MtGox however I've noticed that MtGox's Dwolla account isn't working. I've tried transferring using BitInstant to my MtGox account directly and that works fine, however BitInstant takes 3.99% of the amount I'm transferring as a fee which is pretty big when you start moving larger amounts. I'm wondering is there a way to transfer money to buy up some Bitcoins without losing so much to transaction fees?


texts: Bitcoin RawTransaction Json - what do all the variables mean

texts:
The below is the response we get. could someone please explain what each element is.

type RawTransaction struct {    Blockhash     string    BlockTS       uint32 json:"blocktime"    Confirmations int    Hex           string    Locktime      int    TXTS          uint32 json:"time"    TXID          string    Version       int    Vin           []struct {        ScriptSig struct {            Asm string            Hex string        }        Seqeuence int64        TXID      string        Vout      int    }    Vout []struct {        N            int        ScriptPubKey struct {            Addresses []string            Asm       string            Hex       string            ReqSigs   int            Type      string        }        Value Amount    } }


texts: Does a brokerage firm have its own price matching engine? or it is only that exchanges can do this all matching stuff?

texts:
Is the location of price matching for a trade can optionally decided ? i.e. Does a brokerage firm have its own price matching engine which gets the Market depth updates and runs price matching algorithms against that data for its customers? or it is only that exchanges can do this all matching stuff?

Which is the generally followed method in practice?


texts: Short-term capital gains taxes for crypto to crypto trades?

texts: If I were to profit off cryptocurrency to cryptocurrency trades throughout the year without ever cashing out my crypto position for USD, would I avoid paying any short-term capital gains taxes on all of my crypto to crypto trades? Would I ultimately only pay long-term capital gains tax once I convert my crypto to USD after the one year mark?


texts:
I have an Antminer S9 where one of the chains is not hashing. In the logs I see the following:

get nonces on chain[7]
require nonce number:912
require validnonce number:57456
asic[00]=00 asic[01]=00 asic[02]=00 asic[03]=00 asic[04]=00 asic[05]=00 asic[06]=00 asic[07]=00
asic[08]=00 asic[09]=00 asic[10]=00 asic[11]=00 asic[12]=00 asic[13]=00 asic[14]=00 asic[15]=00
asic[16]=00 asic[17]=00 asic[18]=00 asic[19]=00 asic[20]=00 asic[21]=00 asic[22]=00 asic[23]=00
asic[24]=00 asic[25]=00 asic[26]=00 asic[27]=00 asic[28]=00 asic[29]=00 asic[30]=00 asic[31]=00
asic[32]=00 asic[33]=00 asic[34]=00 asic[35]=00 asic[36]=00 asic[37]=00 asic[38]=00 asic[39]=00
asic[40]=00 asic[41]=00 asic[42]=00 asic[43]=00 asic[44]=00 asic[45]=00 asic[46]=00 asic[47]=00
asic[48]=00 asic[49]=00 asic[50]=00 asic[51]=00 asic[52]=00 asic[53]=00 asic[54]=00 asic[55]=00
asic[56]=00 asic[57]=00 asic[58]=00 asic[59]=00 asic[60]=00 asic[61]=00 asic[62]=00

followed by a whole stream of these (I don't think its necessary to paste all of them):

Below ASIC's core didn't receive all the nonce, they should receive 8 nonce each!

asic[00]=00
core[000]=0 core[001]=0 core[002]=0 core[003]=0 core[004]=0 core[005]=0
core[006]=0 core[007]=0

Later in the logs, I see the following:

last_nonce_num:0
chain[5]: All chip cores are opened OK!
Test Patten on chain[5]: OK!
chain[6]: some chip cores are not opened FAILED!
Test Patten on chain[6]: FAILED!
chain[7]: some chip cores are not opened FAILED!
Test Patten on chain[7]: FAILED!

Does anyone have any idea what the problem is, and a possible solution?


texts: Are there any Bitcoin block explorers still around that log First Seen by node data?

texts:
Title..  Hoping to find out when a historical tx went into the mempool.  I'm aware this is transient data and not in the blockchain.  However i'm pretty sure I remember in the old days explorers used to log it.
edit:
i would like to find a block explorer that logs the first time its node saw particular transactions in the mempool, as opposed to the first time they were in a block.   ie:  I would like to look up a tx and see how long it sat in the mempool before it was mined.


texts: What is the right way to restart bitcoind if it crashes?

texts:
I am very new to this and apologies if it has been asked before but I can't seem to find a clear answer after looking extensively.

I am trying to run a full node. I started bitcoind -daemon and everything worked fine, the blockchain was syncing. It crashed the next day because I hadn't set my options for swap memory correctly.

After fixing that issue, I did bitcoind -daemon again and it looked like everything was being done from the start. Should I be doing bitcoind -reindex-chainstate from now on if the process stops? Or did I not understand correctly and simply doing bitcoind will resume syncing but requires some verification first?

Also, in any of the above cases, is it the same process once the blockchain has synced?

This is on a Raspberry Pi 3B+ with an external HDD for storage.

Thanks a lot in advance.


texts: How to force bitcoind to include a specific transaction as an input of another transaction?

texts: I would want to force bitcoind to include a specific transaction as an input of another transaction. This is so as to prevent people front wanting to launch a double-spend attack on the website. The method is similar to the one used by SatoshiDice. How can I accomplish this task with the standard client?


texts: Was there ever a time when mining on Amazon EC2 was profitable? When the difficulty was low, so was the exchange rate, so I'm not sure.


texts: So the blockchain is a linked list structure, but the transaction chain is a DAG, that means that bitcoin works a bit like Git?


texts: Why are the BTC exchange rates different from website to website

texts: For instance here: http://bitcoinwatch.com/ one exchange lists the BTC-USD rate at 133, while the other one lists at 122.


texts:
I'm reading bitcoin core source code. I want to know how to get bitcoin address from CTxIn object.

I have a CTransaction object. I found the way how to get addresses from vout like the following. But I don't know about vin.

UniValue out(UniValue::VOBJ);
ScriptPubKeyToUniv(txout.scriptPubKey, out, true);

UniValue u = find_value(out, "addresses");
UniValue uv = u.getValues()[0];
newDestination = uv.get_str();

CTxIn has a scriptSig. I think I can get address from it.

CTxIn

https://dev.visucore.com/bitcoin/doxygen/class_c_tx_in.html

Update 1

I found how to get the pubkey by using ScriptToAsmStr. I know this works for only P2PKH address.

vector<string> array;
CScript s = _tx.vin[0].scriptSig;
string a = ScriptToAsmStr(s, true);
boost::algorithm::split(array, a, boost::is_any_of(" "));
if (array.size() == 2) {
    cout << array[1] << endl; // 0396f8781a4900372a5d72d84718d146170d5983e67dff8b4a28fef80690c09767
}

I'm now looking into how to convert the pubkey to bitcoin address on mainnet.

Update 2

I tried it like following but "invalid" is showed..

const char *cstr = "0396f8781a4900372a5d72d84718d146170d5983e67dff8b4a28fef80690c09767";
std::vector<unsigned char> vec(cstr, cstr + strlen(cstr));

CPubKey pubkey(vec);
if (pubkey.IsValid()) {
    cout << "valid" << endl;
} else {
    cout << "invalid" << endl;
}

Update 3

Thanks to the Andrew Chow's answer, I could make a CPubKey object. All that is left is to output the bitcoin address from the object.

#include "utilstrencodings.h"

std::vector<unsigned char> vec = ParseHex("0396f8781a4900372a5d72d84718d146170d5983e67dff8b4a28fef80690c09767");

CPubKey pubkey(vec);
if (pubkey.IsValid()) {
    cout << "valid" << endl;
} else {
    cout << "invalid" << endl;
}

Update 4

Finally, I got a bitcoin address from a CTxIn object. I think this is not smart way. There might be other ways.
And still not sure about CKeyID's meaning. I will look into it in detail.

CKeyID id = pubkey.GetID();
CBitcoinAddress address(id);
if (address.IsValid()) {
    cout << "valid" << endl;
} else {
    cout << "invalid" << endl;
}

cout << address.ToString() << endl; // 15L7U55PAsHLEpQkZqz62e3eqWd9AHb2DH


texts: What is ASIC hardware good for besides mining?

texts:
Are there any other uses for ASIC hardware besides mining crypto?
Also what are the consequences of the hashing power race?


texts: how much is the initial capital needed to start a bitcoin exchange?

texts:
For anyone who has done the math on opening their own bitcoin exchange, how much capital do you need to start an exchange, of course excluding the obvious variables like marketing budget, setup and legal fees? and where the money would go? for example, buy reserve bitcoins (if needed), infrastructure..etc
Thanks.


texts: How does Proof of Stake prevents dishonest behaviour compared to PoW?

texts:
I know that in Proof of Work (PoW) once a node has found the solution (the nonce) they announce it to the network. Then the rest of the nodes can easily verify the correctness of the block hash and append it to the chain.

But in case the solution is not correctly verified, the block is finally not appended to the longest chain and therefore the dishonest block is discarded.

I know that in case of PoS, the dishonest node would lose the stake, but,

How does this procedure works in the case of Proof of Stake (PoS)?

I mean how is the validity of a block checked and how the bad node lose the stake?


texts: Opening Lightning network channel: who is paying?

texts:
When opening a lightning network channel between two parties, which of the following is true:

1) They must both pay a fee to open the channel

2) They might both pay a fee to open the channel

3) Just one party pays a fee.

The fee here refers to the bitcoin mining fee, not to the amount of BTC the two parties are putting in the channel.


texts: Deriving the Bitcoin address from the raw block script

texts:
I'm just starting to write a bitcoin script parser and I am wondering how to get the address from the genesis block? blockexplorer.com shows the coinbase value to be

  04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73

in the raw block data. But it also shows the receiving address for this transaction to be

  1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa

How can I derive the address from the raw transaction? I found a page in the wiki that talks about creating an address, but this seems like it is going about the process in a back-to-front order. Surely the address must exist first before the raw block can allocate the mined coins to it? Otherwise, the blockchain would simply have to allocate mined funds into the ether. The receiving address must have been known to the mining algorithm before it generated the very first mining transaction.

Please could someone walk me through the steps of deriving the address from the raw transaction script.


texts:
On blockchain.info there is the charts that shows the mining difficulty over time and the hash rate over time. See:
Hash:  https://blockchain.info/nl/charts/hash-rate
Mining difficulty: https://www.quandl.com/data/BCHAIN/DIFF-Bitcoin-Difficulty

Can someone explain what the difference is between the two?
The reason I ask is that some paper argues that if more power is required to mine Bitcoins, the value should go up. As explanatory variable, they usually refer to hash rate. I'm trying to find out what the difference is between mining difficulty and hash rate in order to understand why those papers wouldn't use mining difficulty as explanatory variable.


texts: With SilkRoad shutting down, and BitCoins being seized, what does this mean for bitcoin?

texts:
Over the past 2 days, it has come to light that the online market place SilkRoad has been seized by the FBI. Also, they have seized $3.5m worth of BitCoin (which must've been in Escrow).
http://www.bbc.co.uk/news/technology-24381847
http://arstechnica.com/tech-policy/2013/10/feds-shut-down-silk-road-arrest-alleged-admin-dread-pirate-roberts/

What does this mean for the BitCoin cryptocurrency - can we expect a sudden increase in the value of a BitCoin? Or because BitCoins biggest source of transaction is shut down, will we see a sudden crash?

The above does not have to be strictly related to the amount that was seized - it can be influenced by peoples view of bitcoin after the seizure of the money.

Also, is BitCoin itself in trouble for "money laundering" or anything similar?


texts: We can generate and verify transactions without blockchain - why do we need it? I can generate a transaction, broadcast it to the network, it can be verified multiple times etc.


texts:
I use the blockchain.info API to generate unique addresses each time to receive bitcoins.

This works. However, when an address was generated but a payment only gets confirmed a few days later, even if you login to blockchain.info, it will not appear in the transaction list.

The gap is not regenerated. What can I do?


texts: in the Cryptocompare table I don't understand what the columns mean, e.g. there is Price, "Open 24H", "Range 24H", etc... Does anyone know what the different columns mean?


texts: What is the cheapest Cash-to-Bitcoin Service?

texts:
There seems to be a few services to purchase bitcoins from out there, as in bitinstant, MtGox, bitcoin.de, etc.

I would like to know if someone has looked around to find the one with the cheapest transaction fees for buying/selling bitcoins.


texts:
I've some questions about the technique of storing and restoring a wallet using Electrum.

I found out that Electrum stored a file on my PC. This file has my wallet's name so I think this file contains my bitcoins. If I deleted this file, my money will be lost forever, Am I right?
I have 12 words (The seed). Will those words restore the file if it is deleted? Or Are they just used to restore password?
What are all the things that I need to restore my wallet? (Eg. the file, the seed, the password, private keys, ... etc)

Thank you so much,


texts:
My PC, got burned entirely in a fire at my warehouse.
Luckily, I had create a backup of my bitcoin core  wallet.dat > 2 days before ! < ,so I bought a new pc, with Windows 7 on and now I'm downloading everything from the beginning.
In the 6th day, as I had 21 weeks left, my wallet popped up the message:
Number of blocks left : Unknown Syncing headers
So I believe, that it might take a lot longer, since it might need a -reindex
or a -rescan.
So I read about the article on migrating Bitcoin core to Electrum.
when I searched for the receiving addresses that had money in them, I found only a small fraction of the total amount in blochchain.info.

My Questions are :

A) Will I need a -reindex or a -rescan FOR SURE ? and what's the difference of these 2 ?

B) Why my addresses are almost empty ? OR why can't I find the addresses which have the correct balance inside them ?

Thank you in advance.


texts:
How high are transaction fees for "sendmany"?

Is it correct that using "sendmany" i can send Bitcoins to multiple addresses but only have to pay the transaction fee once?


texts: Is there a tool that searches for a specific BTC amount in a specific date range?

texts: Suppose I want to search for a transaction of exactly 445 BTC in the date range 27 July 2013 and Aug 3rd 2013 ... is there an (online?) tool that has this kind of search capabilities?


texts: While calculating merkle proof, where are the other hashes being stored?

texts:
Consider that I have a merkle root made up of transactions a,b,c,d,e,f,g,h.

The root is H( H(H(a)+H(b)) + H(H(b)+H(b)) ) + H( H(H(b)+H(b)) + H(H(b)+H(h)) ).

Now, I have to verify whether transaction C is part of this root (which it is).

I am supposed to get hash of c H(c), which I can using the one-way hash function.

But then, after that I must get hash of other values also: H(d), H(H(H(a)+(b))) and so on in order to verify that c is a part of the Merkle tree.... Where do these hash values come from? Are they stored somewhere? If not, how are they dynamically generated?

And if all hashes are stored, how do I know that my hash H(C) has to be paired with H(D) and not H(A). Similarly for other levels also.
Doesn't storing all hashes defeat the purpose of optimizing space?


texts: SegWit witness commitment merkle root location

texts:
BIP 141 defines the commitment structure here
What i am unsure about is the location of this data. I know it will be in scriptPubKey.
Does this mean Coinbase tx will have more than one output?
Also is there a testnet block with an example of a Coinbase tx with witness commitment?


texts: I need to make a request through cmd.exe (commandline), but the only .exe file I can find is bitcoin-qt.exe, which doesn't respond to "getinfo", "getaddressbalance", etc. How can I find bitcoin.exe to make these requests?


texts: Armory synchronization takes forever. How can I speed it up or retrieve my coins?

texts:
I have an Armory wallet that has been offline for a long time. When I start up that computer it runs just fine, however it is taking forever to download the blockchain. Based on my estimate of the blockchain size 116 gigs, and how much space is on my computer, I estimate it will take another 12 days to finish. I can however run Armory in offline mode and view my private keys.

What is the best way to spend my bitcoins. I would like to set up a new wallet that does not require me to download the blockchain and import the bitcoin addresses from Armory, but I can't find information on how.

Thanks a lot


texts: Walk me through buying 50k in BC using cash in Dallas and exchanging BC for cash in the SF bay area 3 days later. Specifically with attention  to costs and fees, and maintaining anonymity via in person transactions or whatever method is most relevant to maintaining anonymity.


texts: How do I move my dogecoins from my DOGE wallet into my VERGE wallet?

texts: I have been reading online about people who just backed up their DOGE wallet and then copied the wallet.dat file into their VERGE wallet installation and voilà! When the VERGE wallet was opened the coins showed up. But I can't figure out where this wallet.dat file needs to be copied to for the VERGE wallet installation? If anyone knows how I should be going about this I would be most appreciative.


texts: Three different HEX having same wallet address how possible?

texts:
HEX1:
1111111111111111111111111111111111111111111111111111111111111111
public key:

044f355bdcb7cc0af728ef3cceb9615d90684bb5b2ca5f859ab0f0b704075871aa385b6b1b8ead809ca67454d9683fcf2ba03456d6fe2c4abe2b07f0fbdbb2f1c1

Wallet Uncompressed:
                                    1MsHWS1BnwMc3tLE8G35UXsS58fKipzB7a

private key Wif:

5HwoXVkHoRM8sL2KmNRS217n1g8mPPBomrY7yehCuXC1115WWsh

public key compressed:

b'\x03O5[\xdc\xb7\xcc\n\xf7(\xef<\xce\xb9a]\x90hK\xb5\xb2\xca_\x85\x9a\xb0\xf0\xb7\x04\x07Xq\xaa'

Wallet Compressed:

1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nK9

HEX 2:
111111111111111111111111111111111111111111111111111111111111111101
public key:

034f355bdcb7cc0af728ef3cceb9615d90684bb5b2ca5f859ab0f0b704075871aa

Wallet Uncompressed:
                                 1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nK9

Private key wif:

5HwoXVkHoRM8sL2KmNRS217n1g8mPPBomrY7yehCuXC1115WWsh

public key comp:

b'\x03O5[\xdc\xb7\xcc\n\xf7(\xef<\xce\xb9a]\x90hK\xb5\xb2\xca_\x85\x9a\xb0\xf0\xb7\x04\x07Xq\xaa'

Wallet compressed:

1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nK9

HEX 3:
111111111111111111111111111111111111111111111111111111111111111100
Public key:

034f355bdcb7cc0af728ef3cceb9615d90684bb5b2ca5f859ab0f0b704075871aa

Wallet Uncompressed:

1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nK9

priv compressed:

5HwoXVkHoRM8sL2KmNRS217n1g8mPPBomrY7yehCuXC1115WWsh

public key compressed:

b'\x03O5[\xdc\xb7\xcc\n\xf7(\xef<\xce\xb9a]\x90hK\xb5\xb2\xca_\x85\x9a\xb0\xf0\xb7\x04\x07Xq\xaa'

Wallet compressed:

1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nK9

Pls i want to know how possible for the different hash to have same wallet.
NOTE: I am using bitcoin python library to generate the wallets
Only the first hash is valid on bitaddress.org when checked for details.


texts:
I bought some bitcoins a few years ago using Bitcoin Core.

I have since discarded my computer as it broke.

Where/how can I find my bitcoins?


texts: Verifying a P2SH transaction script by hand. How should I concatenate OP CODES in order to hash the script?

texts:
I'm reading this:

  Transaction
  40eee3ae1760e3a8532263678cdf64569e6ad06abc133af64f735e52562bccc8 paid
  to P2SH address 3P14159f73E4gFr7JterCCQh9QjiTjiZrG. You can see the
  redeem script in transaction
  7edb32d4ffd7a385b763c7a8e56b6358bcd729e747290624e18acdbe6209fc45 which
  spends that output, using OP_FALSE  { OP_1  OP_1
  OP_CHECKMULTISIG }.

from https://en.bitcoin.it/wiki/Pay_to_script_hash

I'm trying to check the validity of the transactions by hand to see if I understand what's happening. I first found the first transaction: https://blockchain.info/tx/40eee3ae1760e3a8532263678cdf64569e6ad06abc133af64f735e52562bccc8

As I understood, it is locking these outputs to the output script

OP_HASH160 e9c3dd0c07aac76179ebc76a6c78d4d67c6c160a OP_EQUAL

The text tells me to look at the other transaction: https://blockchain.info/tx/7edb32d4ffd7a385b763c7a8e56b6358bcd729e747290624e18acdbe6209fc45

which spends this output. It means that this transaction presents a script (with data) that satisfies OP_HASH160 e9c3dd0c07aac76179ebc76a6c78d4d67c6c160a OP_EQUAL. Let's see the input of this transaction:

OP_FALSE 3045022100ad0851c69dd756b45190b5a8e97cb4ac3c2b0fa2f2aae23aed6ca97ab33bf88302200b248593abc1259512793e7dea61036c601775ebb23640a0120b0dba2c34b79001 5141042f90074d7a5bf30c72cf3a8dfd1381bdbd30407010e878f3a11269d5f74a58788505cdca22ea6eab7cfb40dc0e07aba200424ab0d79122a653ad0c7ec9896bdf51ae

I should take the OP_HASH160 of this to verify it's equal to e9c3dd0c07aac76179ebc76a6c78d4d67c6c160a, right? Remember that OP_HASH160 means: ripemd160(sha256(something)). Should I concatenate that OP_FALSE int he beggining? Also, shouldn't it be a script? Where are the other op_codes beasides OP_FALSE?


texts: Why different coins have different number of confirmations?

texts: Does it have to do with the block difficulty? What factors impact the number of confirmations that is considered to be safe in a bloc


texts: Issues connecting a Bitcoin-Qt Wallet to a local node

texts:
I have a bitcoin-core node running on a Raspberry Pi on my local network.   The node is publically visible and running fine (I can see it on bitnodes.21.co - it has connections and is synced to the latest block).

I have a Windows PC with a Bitcoin-Qt installation that I would like to connect only to the local node, only when I start it up it doesn't seem to connect. I'm starting it from a command line with

bitcoin-qt.exe -connect 192.168.0.6

The GUI just says "Connecting to peers" and Help > Debug shows 0 connections.

I can ping the Pi from the Windows machine and I can telnet to port 8333 on the Pi from the Windows machine, so I believe the network connectivity isn't the issue.

Any advice on how to diagnose what's going on? (RPC commands? Logs?)

Am I using the right command to connect?


texts: What differences exist between the Lightning Network implementation versus the white paper?

texts:
I'm reading the Lightning Network WP and came across SIGHASH_NOINPUT, then came across this: Lightning network: how was malleability actually fixed?

Are there any other design considerations in the White Paper that have changed in the actual implementation?


texts: bitcoin-qt keeps on quitting with "failed to read block"

texts:
I just wanted to install bitcoin-qt on another machine (all others are working fine) but I cannot seem to retrieve the block chain using bitcoin-qt 0.8.6-beta (as downloaded from http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.8.6/bitcoin-0.8.6-win32-setup.exe/download).

I'm running bitcoin-qt (started as as administrator) on Windows 8 using a 3G data connection. After downloading a few thousand blocks the software keeps on quitting with the error "failed to read block". When I restart the software it fetches another thounsand blocks and quits with the same error soon.

Even a full reinstall (I additionally deleted the whole data directory in %APPDATA\Bitcoin) doesn's seem to help. Starting bitcoin-qt with "-reindex" didn't help either. I checked the hd-drive for errors but didn't find any.

What am I dong wrong?


texts:
I'm running a bitcoin core full node with Tor and I've configured a hidden service for that.
The point is: bitcoin core log shows me an onion address which is very smaller than the one I found in /var/lib/tor/bitcoin-service/hostname.
I noticed that other peers in the network connect with me using the small .onion address.
Which is the difference between these two types of onion address? Are they correlated eachother in some way?
I've also tried to use the longer . onion address in the externalip option inside bitcoin.conf, but it gave me an error.


texts: sent btc to bcc address. what can i do to stop swearing?

texts: Both are my accounts. Two hours ago i sent 0.2 btc from breadwallet to wirex in orden to add funds to my debit card. But I mixed up addresses and they went to a bcc one. I wrote to both supports, with no answer yet. I did not know a thing about replay protection. Is it by default or should I do something to get my transaction rejected. I don't even know if it's anything I could do, in fact.


texts: Bitcoin Core transaction stay unconfirmed

texts:
My transaction from Bitcoin Core to Trezor Wallet stays unconfirmed. Because of too low transaction fee ? How do I resolve ?

Status: 0/unconfirmed, in memory pool, broadcast through 9 node(s)
Date: 23.08.2017 11:39
...
Transaction fee: -0.00005760 BTC
...
Transaction ID: 3d9a0ab7d39bf553584a19433280e61065225891f257cca4f9f00811939d2189
Transaction total size: 192 bytes
Output index: 0


texts: How do Bitcoin and Litecoin compare in scalability?

texts: Bitcoin and Litecoin are very similar, however they differ in the hash algorithm, the block interval and reward schedule. How do these characteristics impact the scalability in terms of e.g. transaction capacity, IBD, CONOP, light weight node requirements, and block verification times?


texts: Where is the public key corresponding to my address stored?

texts:
Some simplified explanations of Bitcoin say, that the Bitcoin address is the public key, and anybody can easily verify that a signed transaction is valid since it was signed with corresponding private key.

But in reality, the address is the hash of another hash of the public key.

So, it's not possible to derive the public key from the address alone.

How do miners obtain my public key, then?
Is the public key included in the transaction I am sending ?


texts: Transaction fees and transactions with bitcoin-cli. Wallet address balance negative

texts:
I'm trying to make a bitcoin website and I tried to implement a sort of 'withdraw' button which would allow you to send your money in the wallet address to some other address. The problem I am facing is that post-transaction it is taking making the address balance negative.
This is the setup:

There is bitcoind running in the background so I have one wallet on the server. It has a default account name of "" (empty string) with some address.
I generate a new address for each user in the wallet. Let's say each user gets his/her own account named "user_1", "user_2", etc. I generate addresses by basically doing bitcoin-cli getaccountaddress user_1.
Users can deposit/withdraw money to/from this address.
If I withdraw too much money from this address it'll make the address balance negative and I presume it is also taking out coins from the master account, i.e. the "" account.

For the transfers I am using the following command bitcoin-cli sendfrom user_1 <some_other_bitcoin_address> <amount> <min_confirmations> <comment> <comment_to>. If I truly pick more money than is available in the wallet then it'll error and tell me that I don't have enough balance. But in a certain edge case it goes through and make the address balance negative.
I figure that there are two approaches to this solution:

Option 1: Calculate the precise transaction fee and based on that fee make a check.
Option 2: Use bitcoin-cli move "" "user_1" <amount_that_is_negative> so it seems that the balance it not actually negative and that the site owner has decided to pay for the excess fee.

So basically, I need to solve the negative address balance problem and could also some clarification on the following:

How to do #1? i.e. How to calculate the size of the transaction (in bytes) + transaction fee in advance?
Using bitcoin-cli settxfee <amount> seems to return true but the actual transaction fee that is applied to me was much higher. Why was this the case?
I need to know more details about how the move command works. Is move an actual transaction that will incur transaction fees?
Is option 2 a good option to hide/solve my problem?
What are other options / correct implementation for implementing a withdraw button?
Can sendfrom take out money from other accounts other than the "" account?

Thanks!


texts:
How can I convert a bitcoin public key to a bitcoin address?

Note: I am using PHP.

Is there an existing bitcoin API or PHP-API to do that converting ?


texts: Why does Bitcoin block 526,591 have a 6.25 (instead of 12.5) block reward?

texts:
https://chain.so/block/BTC/0000000000000000002ba5a1fb96f93e6c215d62db4280f1cbd30e82c7c71fba
https://blockchair.com/bitcoin/block/526591

It's an empty block (zero transactions), but the coinbase transaction is 6.25

The blockchain.com explorer shows this as having a -6.25 fee (despite having no transactions) https://www.blockchain.com/btc/block/0000000000000000002ba5a1fb96f93e6c215d62db4280f1cbd30e82c7c71fba


texts: Is there A Mechanism In Place that Prevent Address 'Squatting'?

texts: Is there a function or mechanism in the bitcoin protocol that prevents someone from creating millions or billions of bitcoin addresses and just sitting on them? Do the addresses need a minimum balance of outputs? or Does that distributed DB save each address? (And if it is saved....what is saved?  The base58 address or the full Public Key? I am also familiar with the ecdsa algorithm.)


texts: Can you send amounts that would typically be considered 'dust' through the Lightning Network?

texts:
Reading through the Lightning Network Paper, it seems that amounts sent through an intermediate node use the Hash Timelocked Output construction. The thing I'm concerned about with HTLCs is that they actually require their own output. Simultaneously, the transactions they are in must also be broadcast-able if the other party goes offline or become uncooperative.

So, let's look at a scenario where Alice wants to send 1 satoshi to Carol, through Bob, with whom Alice and Carol both already have payment channels open. Alice sends bob a new commitment transaction with 1 satoshi deducted from her balance and a new HTLC output for 1 satoshi. Bob sends the same type of channel update transactions to Carol. The problem is, though, that HLTC output would be considered dust if it ever did actually need to be broadcasted! So this cannot be considered a valid guarantee of payment, since the transaction would not even propagate on the network.

Is that a problem? Part of the excitement over the LN is that you can send really small amounts, but it seems to me that you can't actually send smaller amounts than you could in a real bitcoin transaction, because you have to be able to broadcast the transactions if the other party doesn't cooperate or goes offline.


texts: blockchain.info wallet doesn't show transactions made through api

texts:
I've been accepting orders on my website for several months using blockchain.info api. Everything worked smoothly until few days ago. At the moment I have two transactions made through api, both seem to get through, but I can't see them in my main wallet. Sent an email to customer support, no answer yet.

https://blockchain.info/address/19USdV4ENhRkcRbmjL2gZWBUPJqhc7xyuW

https://blockchain.info/address/1FApdPwewC8VCNzEJ9SCbECFqf2cPQyqZG

How is it working? How do I get those funds in my main wallet? Am I doing something wrong?

Actually, I recently had the problem with the gap limit. I changed the gap limit to 50 (default is 20) and then made a small payment from my main wallet back to myself to make the gap=0. And after that, these two transactions appeared.

Please advice. Appreciate your assistance.


texts: Can I sign and redeem many outputs at the same time? (shrink the size of a tx Input)

texts:
I'm looking at this transaction that is redeeming many historical outputs from the same address.

When I look at the blockchain, it seems pretty clear there is redundancy here of the public key being repeated over and over again.  If I could consolidate that, I could save on transaction fees, and bloat in the blockchain by signing all of them at once.

Is there a way to have one signature redeem many inputs at once?  Perhaps using P2SH?


texts:
My parent's have Windows Vista and recently we had a power outage and Bitcoin started from beginning loading blocks however for a week now it doesn't go below 1 year 13 months? As an inexperienced Bitcoiner, I could use some advice. Please help if you can. Thank you.Please make it simple as I'm new and don't understand all the Bitcoin terminology.
David


texts: What makes blockchain technology so attractive to non cryptocurrency applications?

texts: I have often seen articles claiming bitcoin's demise is iminent but yet others state the blockchain technology that powers it is being considered for other uses. What features make it attractive for those purposes versus alternatives?


texts:
Was there a recent change where it is no longer possible to specify rpcport?

I noticed these two warnings:
Warning: Config setting for -addnode only applied on test network when in [test] section.
Warning: Config setting for -rpcport only applied on test network when in [test] section.

After trying adding a [test] section I got very mixed results as some times it disregarded all options and in general rpcport was still not set.

I could not find any documentation on how to do this.


texts: Changing from the standard directory Bitcoin-Qt/Bitcoin-Core uses, to a remote disk (MacOSX)

texts:
I'm currently downloading the Blockchain on Bitcoin-Qt and i'd like to change from the standard directory Bitcoin-Qt stores the data (on mac) =

  ~/Library/Application Support/Bitcoin/

to a harddrive, but can you do this without re-installing bitcoin core and choosing a different directory? If not, can you just drag and drop the data you've already downloaded/synced in to the new directory so that bitcoin core identifies that as the real blockchain, and that you don't have to re-download/re-sync everything?

It does not answer my question, i want to know how to change directory of the blockchain data on a Mac, not on Windows.


texts: Does each miner in a bitcoin mining pool has a chance to win the block reward?

texts:
Suppose there is mining pool XYZ. 10 miners 1 through 10 are subscribed to it and miners have varying hash power, some have 10 GPU mining rig while others have just a single CPU running 24 hours a day seven days a week. Suppose 12.5 BTC are won by XYZ each week.

Does it mean that each week one of those 10 miners win 12.5 BTC and XYZ then distributes BTC to each of the 10 miners in accordance with their contribution of hashing power?

OR XYZ gathers together hashing power of miners 1 to 10 to try to be the first to solve the puzzle to win 12.5 BTC ?

Is it possible for a solo miner with 10+ GPU rig to win 12.5 BTC block reward even though mining pool XYZ has much greater combined hashing power? I mean is there randomness also involved in wining block reward in addition to hashing power?


texts: Why does Bitcoin Core not produce a Reject message for Conflict TXs?

texts:
From the perspective of a full node participant in the network, why is it a bad idea to convey to a peer that a transaction has been rejected because its either a conflict transaction/high fee transaction or a transaction which already known to it?

I noticed that in the Bitcoin Core source code that REJECT_CONFLICT is set at 0x102 which is greater than REJECT_INTERNAL.

if (state.GetRejectCode() < REJECT_INTERNAL) // Never send AcceptToMemoryPool's internal codes over P2P
    pfrom->PushMessage(NetMsgType::REJECT, strCommand, (unsigned char)state.GetRejectCode(),
                       state.GetRejectReason().substr(0, MAX_REJECT_MESSAGE_LENGTH), inv.hash);

Bitcoin Core code excerpt from src/main.cpp.


texts: Does the inability to spend only part of a transaction result in "too many" extra transactions?

texts:
I understand that I can only spend the amount of a full transaction associated with an address. Often this will result in change being sent to a change address that I provide. One question at this point is, why does the receiver bother sending back the change. Do you send way more than the original cost for an item?

Say they do, don't they have the same problem, not having a transaction for the exact amount so that they too might end up sending too much to you, so that a cycle of change happens - what could have been one transaction ends up being many which seems like this is a burden on the system?


texts: how Bitcoin Benefits from giving u s currency(other then money from ads)

texts: Now, I have a pretty simple question to ask , How does Bitcoin benefit from giving us money for solving math problems? Another question is that why does it want us to do it? & is there a bigger purpose behind it???


texts:
I am a noob, so please bear with me.

I'm wondering whether the Bitcoin Core team plans to integrate a smart contract feature evolving the Bitcoin scripting language in a more sophisticated one in the near for far future.

Afaik, the only work currently done is on sidechains. Any clues?


texts: Are there any API servers available for alt-coins that allow for transactions to be broadcast into their networks?

texts: With blockchain.info we have the pushtx API that allow one to broadcast raw transactions into the network. It appears to be one of few services that offer such functionality. Are there any servers that offer such APIs for altcoins, or does one need to create their own / run their own version of altcoin'd to have access to such functionality?


texts: Why are hashes in the bitcoin protocol typically computed twice (double computed)?

texts:
According to the wiki specification of the bitcoin protocol, hashes are typically "computed twice". For example:

hello
2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824 (first round of sha-256)
9595c9df90075148eb06860365df33584b75bff782a510c6cd4883a419833d50 (second round of sha-256)

What is the reasoning for this? I imagine it somehow provides additional security, or protection against potential attack vectors, but I can't reason what those attacks might be.


texts:
How many coins been mined on the Testnet?
How can I check how many coins have been mined?


texts: Where exactly is the "off-by-one" difficulty bug?

texts:
I read through How is difficulty calculated? and want to understand where the "off-by-one" bug is in calculating difficulty. Here is a Matlab snipet I wrote to calculate difficulty. What are the correct block step intervals that I should use? Note: minv and maxv are the block heights (plus 1) of the interval. Thus, time stamps from block heights 0 and 2015 are used in the first difficulty calculation.

% Calculate difficulty
num = floor(length(block_chain)/2016);
minv = 1;
maxv = 2016;
target = 1209600;
difficulty = ones(num,4);
delta = zeros(num,1);
timedif = delta;

for i = 1:num
    if i == 1
        difficulty(1,3) = 1;
        timedif(i) = block_chain(maxv,2) - block_chain(minv,2);
    else
        timedif(i) = block_chain(maxv,2) - block_chain(minv,2);
        delta(i) = max(0.25,min(target/timedif(i),4));
        difficulty(i,3) = max(1,difficulty(i-1,3)*delta(i));
    end
    difficulty(i,:) = [block_chain(minv,1), block_chain(maxv,1),...
        difficulty(i,3), timedif(i)];
    minv = maxv + 1;
    maxv = maxv + 2016;
end


texts:
When I'm sending my transaction, it's "competing" with other transactions for being mined. Are there any mining pools with the following service:

I'm giving them my address
I'm topping up my balance on their service
I'm sending some transaction from my address
The pool checks transaction pool and sees the transaction with my address in inputs
The pool mines my transaction in the next block (without sorting by priority, comparing fees, etc) and takes some "reward" for it from my balance


texts: Searching for the comprehensive guide to creating Crypto Currency

texts:
A few months ago I came across (by accident) a very detailed and well written guide on how to create your own crypto-currency from the bitcoin source code.  I skimmed through it and "Stared" in Firefox for future reference.

Now that I want to read through it I can't find it in my bookmarks. (I sometimes think Firefox is not saving them), anyway...

The guide had highlighted source code, complete explanations of what was necessary, how to generate the genesis block, etc.  He even offered a service were he would do it all for you.

Does any one have the link to that site?


texts: How do coinjoin and sharedcoin work? How to make it make it hard to pinpoint bitcoin sender wallet

texts:
I would like to implement a way for bitcoin transactions to be untraceable. EX. user1 on my site wants to send bitcoins to user2. How would I go about mixing the coins so user2 doesn't get user1's sent from address.

All open source bitcoin washers are javascript or python or something, I need to do this on my server and prefer not to use javascript on user end like SharedCoin.com does.

Would I be fine just sending the coins through 50 or so addresses with the values of the coins jumbled (I mean jumbled like, if user1 sents 1 btc, before the bitcoins get to user2 wallet, the coins would pass through the 50 or so btc addresses in mixed values, not just 1btc, but like 0.23 and 0.77 sent to two different addresses and then like 0.02 and 0.21 goto 1 address and 0.75 and 0.02 goes to another and it just continues to split more from their?)

I am aware of darkcoin, and that these bitcoin washers can be traced back, but this is something I need for bitcoin.

Thanks for any help at all.


texts:
Can I generate a bitcoin address with my RSA private key?

Explain also how and why.


texts: How can I know which user made which BTC transaction?

texts:
I am making an app, and I want my users to deposit BTC coin to my address which is an exchange address (I don't have the private keys).

How can I know which user made which transaction?

I have a way, which is to add the numeric user ID to the amount , for example if an user wants to deposit 100.00 BTC coin , and the ID is 158769, I can add the ID in the amount like this: 100.0000158769 and make it as a QR-code so the user should deposit the exact amount so I can know that he made this transaction.

But is there any other way to do it , any idea?

Thanks in advance


texts: When creating a Bitcoin Farm, how do you evade having 20,000 modems

texts:
How do you evade having to have 20,000 modems for all the Bitcoin Miners (utilising Antminer S9's)?

Thanks!


texts: Generating addresses starting with certain characters such as "JoeAnonymousUserB7pMqyVa8JRcpZdCQLQ"

texts:
Similar to how the SHA256 hash competition exists to validate a transaction, I wonder if this concept can be ported to addresses, so that the first few characters is significant to a human reader.

Is there value in making a public key address start with human readable text?
What approaches exist to accomplish this?  Must the key pair be re-generated continuously or there there space to place a nonce?
Could this cause legal issues?  ...such as a key that contains text matching censored information which is replicated to countries that ban that information


texts: How to set Bitcoin-Qt setgenerate mining recipient?

texts: I know it's inefficient and a bad idea and all that, but I just discovered the setgenerate console command in Bitcoin-Qt (v0.8.1-beta, MAC) and I was wondering how to set the recipient address of "all those" Bitcoins I'm about to generate?


texts: What values are hashed in the SHA-256 algorithm, and what would be the next iteration until a possible header is found?

texts:
I've been doing a lot of reading on mining and software related to mining but I can't quite get my head wrapped around the specific nature of what is being hashed together. So far I feel like the current block header, and a nonce are hashed together in hopes of finding a hash that is less than the current target, if it is, you get 25BTC. Here's where I am confused, according to the psuedocode https://bitcoin.stackexchange.com/a/3047 . The only value that changes is the nonce, and that is a fixed possible hex/integer ex: from 0 to 0xFFFFFFFF.

How is it that the difficulty can increase if there are a finite number of attempts to change the nonce?

Am I right about hashing together the block header with the nonce?

I referenced this https://en.bitcoin.it/wiki/Proof_of_work and it makes perfect sense.. except for the fact that I still feel like the nonce is the only value that changes.

Maybe the 32-bit nonce yields way more possibilities that I can fathom and hashing together every possible nonce value is actually what is done.

Thanks!


texts: How can I get CGMiner to connect to mining_proxy.exe

texts:
I'm trying to get my CGMiner to connect to my mining_proxy.exe which I have my network ASICminers running through.

I have tried these (below) in every combination I could think of, local ip, 127.0.0.1, local host, connecting directly to eclipse. you name it and it won't show the hashrate or what is happening in the mining operation.

- cgminer.exe -o  stratum+tcp://127.0.0.1:8332 -u worker -p 123456
- cgminer -o "http://127.0.0.1:8332|http://us.eclipsemc.com:3333" -u worker -p 123456
- cgminer -o http://127.0.0.1:8332 -u worker -p worker

I need CGminer showing my hashrate and have some control over the mining operation.

thanks for the help


texts:
I am wondering where do I find the bitcoin address?
I want to buy some bitcoins but I don't know what to put in for bitcoin adress.


texts: I Want To Confirm That My Bitcoins Are Being Held In New Wallet

texts:
I sent a couple bitcoin from one of my trezor wallets to a different trezor wallet.

I don't know the details about how bitcoin "sending" between wallets work, and now I feel the need to confirm that it all went smoothly. Essentially, I'd like to see confirmation that all my bitcoin transfered to to my new wallet.

the receiving address of the new wallet, (the one thats supposed to be holding the bitcoin now), is: 1HyETxKBZshfu2cdjEWMYntDFabFXsrHe2

Can someone help me out here? How do I check to see if everything went over to the new wallet?

Thanks!


texts: 0 Payout at litecoin pool with a processing power of 1.6 Mh/s. Why?

texts:
Recently I managed to get my hands on 10 servers with 32 cores each and 128GB ram each. I realised that in 10 hours of working at 100% I had mined exactly 0 litecoins using a p2pool. I think it's called mint.

I was delivering an average of 1,6 MH/s to the pool. I was in the TOP 3 active miners of the pool.

My mining layout is: One CPUminer (minerd) per server with one thread per core all pointing to the same pool with the same username (litecoin wallet address).

Does anyone have any clue why this is happening? Is it a technical problem or was I just purely and simply tricked?


texts: Total amount of nodes and avarage active peer number

texts:
I have 2 questions:

Does anyone know where to find a reliable source for finding out a total amount of active bitcoin nodes?
How many peers does each active node have in avarage? Is there a limit to how many peers one node can have?


texts: European online stores selling electronics

texts:
I know bitcoinstore.com is the heaven for bitcoin loving geeks to buy their gadget. However I'd like to find similar electronics stores in European Union area to avoid extra custom fees.

Are there any bitcoin-friendly stores in EU?


texts:
I am still very new to Bitcoin.
I installed bitcoind on my Ubuntu server as described on bitcoin.org.

After installation I issued

  bitcoind -daemon

and the tool started to download/get the blockchain (which is finished meanwhile).

Three questions:

In contrast to what the setup guide says, the tool did not complain about a missing rpcuser and rpcpassword in the bitcoin.conf file. Is that an issue with the documentation or is there something wrong with my installation?
In case my node gets the chance to process a block, I would be rewarded those 25 BTCs. But to which account would the be sent? Is there a default or do I need to do some configuration for that?
As the process to become the node to mine the next block is computational very heavy, I would have expected that the CPU usage of my server should always be very high - but it's only at <10%. How can I make sure that my node participates to become the one to process the next block? Is there some configuration that I missed?


texts: Why does Bitcoin use two rounds of SHA256?

texts: Each blocked is hashed twice. Why isn't one application of SHA256 enough?


texts:
Can bitcoin address be longer than 35?

Does longer address indicate much lower chance of collision and/or higher security?


texts: How to transfer my wallet.dat to dedicated Ubuntu server

texts:
Sorry for dummy question at first.

I have developed an application on my local dev machine. Now I want to make a realease on production server located elsewhere to which I have ssh access.

I dont want to put my wallet.dat in git. Of course.
But dedicated server doesnt have access to my local virtual ubuntu developer machine where wallet.dat is kept.

So I have to copy my wallet.dat from one virtual machine it terminal to another terminal. I thought I could dump keys to some text file and simply copypast it between servers. But dumpwallet command creates file with hundreeds of addresses and each one of them should be than imported on by one by importprivkey and there is no option to import dumped file (weird, no?)


texts:
I have written this code to create and submit a new minned block to the bitcoin network:

  unsigned long magic_number = 0xD9B4BEF9;
  unsigned long block_size = 89 + (strlen(coinbase_transaction)-1) + (length*(strlen(root[0])-1));
  unsigned char transaction_counter = length;

  char* block = malloc(block_size);
  memcpy(block, &magic_number, 4); block += 4;
  memcpy(block, &block_size, 4); block += 4;
  memcpy(block, &header, 80); block += 80;
  memcpy(block, &transaction_counter, 1); block += 1;
  memcpy(block, &coinbase_transaction, strlen(coinbase_transaction)-1); block += strlen(coinbase_transaction)-1;
  for(int x=0; x<length; x++) { memcpy(block, &root[x], strlen(root[x])-1); block += strlen(root[x])-1; }

  char* content1 = curl_submitblock(block);
  int size1 = strlen(content1);
  json_char* json1 = (json_char*) content1;
  json_value* value1 = json_parse(json1,size1);
  printf("%s\n", content);

but, according to the documentation, I need submit a hex string of this block. For what I understand, the first 89 characters of the string block in this code is not a hex string.

What the way to make a hex string of all the block content, given the code above (if it's correct)?


texts: best way to generate btc wallet with mnemonic phrase

texts:
Im fairly new to crypto but after some further exposure it seems like it should be possible to do what im trying to do
I want to gift a small amount of btc to my nieces and nephews. My idea was to laminate a small card with their wallet id and a mnemonic phrase; then transfer some btc to this wallet from my own accounts
then when they are all grown up they can withdraw these funds
what is the best way (or software) to create multiple btc accounts using mnemonic phrases?


texts: Can't perform remote JSON RPC to my Bitcoin node (C#)

texts:
I'm trying to perform a remote JSON RPC. It works fine using localhost but not if I try to do it from another computer.

Here's what I have so far:

            int index = 0;
        HttpWebRequest webRequest = (HttpWebRequest).Create("http://fakeip:8332");

        webRequest.Credentials = new NetworkCredential("fakeuser", "fakepw");
        /// important, otherwise the service can't desirialse your request properly
        webRequest.ContentType = "application/json-rpc";
        webRequest.Method = "POST";

        JObject joe = new JObject();
        joe.Add(new JProperty("jsonrpc", "1.0"));
        joe.Add(new JProperty("id", "1"));
        joe.Add(new JProperty("method", "getinfo"));
        // params is a collection values which the method requires..
        Dictionary<string, string> Params = new Dictionary<string, string>();
        if (Params.Keys.Count == 0) {
            joe.Add(new JProperty("params", new JArray()));
        } else {
            JArray props = new JArray();
            // add the props in the reverse order!
            for (int i = Params.Keys.Count - 1; i >= 0; i--) {
            }
            joe.Add(new JProperty("params", props));
        }

        // serialize json for the request
        string s = JsonConvert.SerializeObject(joe);
        byte[] byteArray = Encoding.UTF8.GetBytes(s);
        webRequest.ContentLength = byteArray.Length;
        Stream dataStream = webRequest.GetRequestStream();
        dataStream.Write(byteArray, 0, byteArray.Length);
        dataStream.Close();

        WebResponse webResponse = webRequest.GetResponse();

which gives this exception:

    Unable to connect to the remote server ---> System.Net.Sockets.SocketException:
A connection attempt failed because the connected party did not properly respond
after a period of time, or established connection failed because connected host
 has failed to respond fakeip:8332

I've tried using curl too:

   curl --data-binary
    '{"jsonrpc":"1.0","id":"curltext","method":"getnetworkinfo","params":[]}'
-H 'content-type:text/plain;' http://fakeuser:fakepw@fakeip:8332

curl: (7) Failed to connect to fakeip port 8332: Timed out

My bitcoin.conf:

testnet=0
server=1
rpcuser=fakeuser
rpcpassword=fakepw
rpcallowip=0.0.0.0/0
txindex=1

Anyone have any ideas?

Edit: rpcbind allows me to make the RPC query using C# but the curl method is still not working.

Running the following:

curl --data-binary
'{"jsonrpc":"1.0","id":"curltext","method":"getnetworkinfo","params":[]}' -H
 'content-type:text/plain;' http://fakeuser:fakepw@fakeip:8332

results in:

{"result":null,"error":{"code":-32700,"message":"Parse error"},"id":null}

I get the same error for any command.


texts: How to set custom segwit change address in v0.15 Core via config

texts:
We generated segwit addressess via addwitnessaddress command in v0.15 core client. Therefore receiving funds to our segwit addresses.

When spending those segwit UTXO, wallet creates a standard change address starting with 1. Is there a way to set custom change address (segwit preferable) in bitcoin core via config or some parameter (not via GUI). We wanted to contribute to segwit addoption, but this behavior is contraproductive. Any thoughts how to solve this?

The other problem is related to coin control feature on segwit addresses:
I used coin control feature to consolidate UTXO and send it to a single address (saving data on the blockchain becasue no change was created). However when using the wallet with segwit addresses it does not calculate size of transaction correctly - causing dust change.

Is there a way how to report this to core developers or any plans to solve this with core v16.?


texts: in the united states if i buy or sell btc should i pay sales tax and captital gain tax?

texts: As the title.suggests. I understand if I sell bitcoins, or make purchases (say I briefly sell for use then purchase good) I should pay capital gain if there was one. But should I also pay sales tax if I purchase btc for usd? Technically am I liable for sales tax?


texts: How to get BIP34Hash and nMinimumChainWork?

texts:
I'm interested in the technical question of how you got BIP34Hash and nMinimumChainWork.

The changes were introduced here:

nMinimumChainWork: https://github.com/bitcoin/bitcoin/commit/ad20cddce2097c6561202777fccd257deb1a9810

BIP34Hash and BIP34Height: https://github.com/bitcoin/bitcoin/commit/33c90cf197223fb95f858db80d090d570d70498a


texts: If bitcoin fails as a currency, how will blockchain tech still be secure for other applications?

texts:
We often hear proponents, like Andreas Antonopoulos, say things along the lines of Bitcoin being an application of the Blockchain technology and that Bitcoin as a currency can fail, but blockchain technology will continue.

But the blockchain is only secure (and therefore useful) if there is a large enough and diverse enough (e.g. no one with >50% of the mining power) network of miners securing the network.

If the USD to BTC value goes down too low, or Bitcoin as a currency (for whatever reason) fails, the miners will stop mining. Is it therefore possible that this could then make the bitcoin blockchain technology insecure and put the other applications built on top of the blockchain technology at risk?

I guess one might say, what Andreas means is that new blockchain mining networks, independent of bitcoin could be setup. But what makes the bitcoin blockchain so good, is because the network of miners is so large (and therefore so secure), is it not?


texts:
What's the most foolproof way to ensure your bitcoins can be passed on safely to your heirs in the event of your death? Note this question has two levels of difficulty:

safely passing on bitcoins to someone and
passing them on according to the terms of your will, which may
split the "bitcoin estate" two or more ways, and not necessarily in
the same proportion.

Point 2) implies giving control of the wallet to a Trustee in a sufficiently transparent way that the heirs can check the wallet amounts to ensure they receive all the bitcoins available.

A complication I'm aware of is that as I'm using my bitcoin wallet, any transaction wipes the existing key and transfers the balance to a new key. So storing a paper wallet is not really an option unless I intend to never touch the bitcoins in it during my lifetime.


texts: Feasibility of using Ring Signatures with CoinJoin Technique

texts: There is a Ring Signature implementation in C++ by Libbitcoin team. We can find the details in the following GitHub repository. Is it feasible to use Monero like Ring Signatures together with the CoinJoin Technique in Bitcoin without a soft fork on the core protocol.


texts: What is 'birthday' in the context of BIP39 / Lightning seed generation?

texts:
In this talk about Lightning Network, roasbeef speaks about BIP39 as having no support for 'birthdays'. What does that mean?

https://www.youtube.com/watch?v=LXY0L8eeG3k minute 22


texts: What would be an estimate of the value gained if the whole world started using Bitcoins?

texts:
I remember that before the Euro was first introduced, I read estimates on how much economical benefit every person would get (GDP per capita) once the Euro was fully implemented. Estimates like these were used in the cost/benefit analysis used for deciding whether or not it was worth the trouble of creating the Euro at all.

I guess they didn't include the risk of a Euro-collapse and the related costs, but nevertheless, it was an estimate. I do not know whether this question is too speculative, but it is truly the most interesting question I can think of. If it would be too difficult to estimate for the whole world, then an estimate for a region would also be interesting.


texts: What are the "Know Your Customer" challenges that Bitcoin faces?

texts:
Can anyone explain what KYC (Know Your Customer) regulations are "missing", tough or impossible to implement with Bitcoin?

I will offer a bounty to the most detailed answer
(However this question is too new for me to do so)


texts: Is creating a long password for my coinbase account enough to keep my bitcoins secure?

texts: I've made an account with coinbase and purchased some bitcoin. Only after to start reading people talk about getting hacked and how bitcoins are not secure unless you put them in a "wallet".To be frank this wallet stuff confuses me a bit, I rather just keep it simple and keep the coins directly in the place they go when I buy them, which I guess would be on the "exchange"? So I'm wondering If I create an incredibly long password for my coinbase account, Is this enough security to protect my bitcoins? Just "walletless" and in the hands of coinbase.  I realize if coinbase was hacked as a whole , there would be issues since they act as the bank basically. but aside from that is there really any risk leaving my bitcoin on their if I have like lets say a 45 character long password?


texts:
Here's my code:

from bitcoin.rpc import RawProxy
# Create a connection to local Bitcoin Core node
p = RawProxy()
# Run the getinfo command, store the resulting data in info
info = p.getinfo()
# Retrieve the 'blocks' element from the info
print(info['blocks'])

I could execute the RPC using curl:

➜  bitcoin git:(master) curl --user glaksmono --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getwalletinfo", "params": [] }' -H 'content-type: text/plain;' http://127.0.0.1:18332
Enter host password for user 'glaksmono':
{"result":{"walletname":"wallet.dat","walletversion":159900,"balance":0.00000000,"unconfirmed_balance":0.00000000,"immature_balance":0.00000000,"txcount":0,"keypoololdest":1523932637,"keypoolsize":999,"keypoolsize_hd_internal":1000,"paytxfee":0.00000000,"hdmasterkeyid":"6e64f10c7c94532b597feaec70369df40ae84023"},"error":null,"id":"curltest"}

I've also installed python-bitcoinlib successfully:

➜  Sandbox pip install python-bitcoinlib
Collecting python-bitcoinlib
  Downloading https://files.pythonhosted.org/packages/30/03/fb7df95fe89baede202cf3fe65e65bea4bf863061b5e8f59b12dab538240/python_bitcoinlib-0.10.1-py2.py3-none-any.whl (88kB)
    100% |████████████████████████████████| 92kB 1.5MB/s
Installing collected packages: python-bitcoinlib

Ideas how should I execute the RPC through the Python code?

The result of my script and the python and pip versions are below:

➜  Sandbox pip --version
pip 10.0.0 from /Library/Python/2.7/site-packages/pip (python 2.7)
➜  Sandbox python --version
Python 3.6.4

➜  Sandbox python rpc_example.py
Traceback (most recent call last):
  File "rpc_example.py", line 1, in <module>
    from bitcoin.rpc import RawProxy
ModuleNotFoundError: No module named 'bitcoin'


texts: Where can I get a list of all the 72 initial NXT stakeholder addresses to see distribution?

texts: Where can I find a list of all the nxt accounts that were the initial 72 seeders? I want to find out to see how many of these accounts have moved their funds and dispersed it to the public.


texts: Need a cold wallet. Segwit, Lightning, Fees?

texts:
I have all my coins on exchanges. I'd like to keep some in cold storage. I know I can create one at walletgenerator.net. But I'm scared because I think there might be a better way or it may not be worth it at all. If I'm going to lose 20% sending it there and 20% sending it somewhere else it's not worth it. What fees could I expect sending .1 BTC from an exchange to that wallet and the fee sending off there? I hear about segwit and lightning all the time, but have no idea how that works.

I don't think the wallet from walletgenerator.net is segwit or lighting, so is there a better wallet to use? Is it even worth it, or am I better off with LTC? Can you recommend an exerciser I can do with a small amount to quell my stress? Trading advice is everywhere, but finding reliable answers to wallet and security questions is near impossible.


texts:
why all the sellers whom selling bitcoin with Amazon gift card are asking for physical cards with a receipt for it.
Thanks


texts: how coin exchanges protect them self against stealing coins?

texts:
Let suppose we have e-shop where you can buy with bitcoins. In this case, there is bitcoind that have locked wallet. In fact this wallet is never unlocked, because you can have another wallet on different computer with same wallet.dat file.

So in case of e-shops, even website is hacked and the hacker have full access of the server, he / she will not be able to steal any coins.

However in case of coin exchanges, there must be automatic withdrawal process. I am sure some exchanges withdraw money manually, but exchanges like Bitstamp, Bittrex, Binance, CoinExchange.io and others have such high volumes and this definitely can not be done manually.

How these exchanges protects against hacks?

Because the wallets must be unlocked, so all hacker need to do is to type bitcoin-cli send ....

If the wallet is locked, hacker might find the password somewhere on the server. Then he / she might unlock the wallet and send the coins.

Other way is hacker to "insert" his payment in payment queue and the system will send the coins for him.


texts: How can I fix this: (Non-canonical signature: S value is unnecessarily high)

texts:
I've written a small script that will create a bitcoin transaction from scratch, using an ECDSA library. It works, but sometimes I get this error:

64: non-mandatory-script-verify-flag (Non-canonical signature: S value is unnecessarily high)

I found this reply answer on bitcoin talk:

  The signature is composed of two values, the r value and the s value.
  In your third input, the s value is greater than N/2, which is not
  allowed.  Just add in some code that if s is greater than N/2, then s
  = N - s.

But what exactly is N?


texts: Solution to the same TXID from 3 different client

texts: Someone sent me some bitcoins.... then I had some other clients sending me the same txid that they also made a payment, but I received only one payment.


texts: When does a miner exactly start to create a block?

texts:
As far as I know, a miner begins creating a new block as soon as it receives a valid block from another miner. It then begins to construct and hash the next block on top of the block it just received.

However, in case of existence of orphan blocks, I suppose it starts mining after processing orphan blocks, right? Can anyone tell when exactly a miner would start working on a new block?


texts: There are any guidelines about how to create my own currency from Ripple?


texts: JSON-RPC call to bitcoind error, 403 failed to open stream

texts:
I am trying to make a json-call to a VPS server that hosts my wallet and it is failing with the following error message :

Warning:  fopen(http://user:pass@ip:port): failed to open stream: HTTP request           failed! HTTP/1.1 403 Forbidden
in C:\Users\Owner\Desktop\USBWebServer\root\php\jsonRPCClient.php on line 132

Fatal error:  Uncaught exception 'Exception' with message 'Unable to connect to     http://user:pass@ip:port' in     C:\Users\Owner\Desktop\USBWebServer\root\php\jsonRPCClient.php:140
Stack trace:
#0 C:\Users\Owner\Desktop\USBWebServer\root\php\testrpc.php(15): jsonRPCClient- >__call('getinfo', Array)
#1 C:\Users\Owner\Desktop\USBWebServer\root\php\testrpc.php(15): jsonRPCClient-   >getinfo()
#2 C:\Users\Owner\Desktop\USBWebServer\root\index.php(154): include('C:\Users\Owner\...')
#3 {main}
thrown in C:\Users\Owner\Desktop\USBWebServer\root\php\jsonRPCClient.php on line 140

i got my JsonRPCClinet.php file from here http://jsonrpcphp.org/code.php?file=jsonRPCClient

my bitcoin.conf file is as follows:

server=1
daemon=1
listen=1
rpcuser=user
rpcpassword=pass
rpctimeout=16
rpcallowip=0.0.0.0
rpcport=8332

i am aware that 0.0.0.0 is dangerous , i will change it once i can get things working

i am calling json-rpc using this php code

<?php
  require_once 'jsonRPCClient.php';

  /* Configuration variables for the JSON-RPC server */
    $rpc_host = 'ip';
    $rpc_port = '8332';
    $rpc_user = 'user';
    $rpc_pass = 'pass';

    $btc = new jsonRPCClient('http://' . $rpc_user . ':' . $rpc_pass . '@' . $rpc_host . ':' . $rpc_port);

  echo "<pre>\n";
  print_r($btc->getinfo()); echo "\n";
  echo "Received: ".$btc->getreceivedbylabel("BEkpbpYLpwacchSQFRCL7ZSWw3VwB8k7WN")."\n";
  echo "</pre>";
?>

additionally i have opened port 8332 on my VPS

can anyone see any reason why this error is occurring, i would greatly appreciate the help


texts:
I wonder if you can help me.
I have my 17 word seed (yes 17 words) and my wallet crypto address and I can see my crypto on the blockchain under that address.
How do I restore my wallet with the above two things because my previous device failed and is dead.


texts:
I have cloned litecoin to make my own altcoin for fun and i want to solo mine the new coin using cpuminer on mainnet. I have compiled and installed cpu miner in my Mac OSX and i am running the altcoin daemon and opened the port as well.

./src/altcoind -daemon

When i run cpuminer i get this error.

./minerd -o http://127.0.0.1:26201 -O litecoinrpc:9eac7ba52764a6d42aa48386e8f435f8 -a scrypt --no-longpoll --no-getwork --no-stratum --coinbase-addr=xxxxxx

[2018-02-27 17:55:48] Binding thread 2 to cpu 2
[2018-02-27 17:55:48] Binding thread 0 to cpu 0
[2018-02-27 17:55:48] Binding thread 1 to cpu 1
[2018-02-27 17:55:48] Binding thread 4 to cpu 4
[2018-02-27 17:55:48] Binding thread 3 to cpu 3
[2018-02-27 17:55:48] Binding thread 5 to cpu 5
[2018-02-27 17:55:48] 8 miner threads started, using 'scrypt' algorithm.
[2018-02-27 17:55:48] Binding thread 6 to cpu 6
[2018-02-27 17:55:48] Binding thread 7 to cpu 7
[2018-02-27 17:55:48] HTTP request failed: Failed to connect to 127.0.0.1 port 26201: Connection refused
[2018-02-27 17:55:48] json_rpc_call failed, retry after 30 seconds

Here is my altcoin.conf

rpcuser=litecoinrpc
rpcpassword=xxxxxx
rpcport=262012
rpcallowip=127.0.0.1
server=1
gen=1
listen=1

Why is cpuminer not working?

Another attempt: I changed the conf file removing port

rpcuser=litecoinrpc
rpcpassword=xxxx
rpcallowip=127.0.0.1
listen=1
server=1
daemon=1

and now it seems to connect to the port but i receive, empty reply from server

[2018-02-27 18:23:11] Binding thread 4 to cpu 4
[2018-02-27 18:23:11] Binding thread 5 to cpu 5
[2018-02-27 18:23:11] Binding thread 6 to cpu 6
[2018-02-27 18:23:11] 8 miner threads started, using 'scrypt' algorithm.
[2018-02-27 18:23:11] Binding thread 7 to cpu 7
[2018-02-27 18:23:11] HTTP request failed: Empty reply from server
[2018-02-27 18:23:11] json_rpc_call failed, retry after 30 seconds

Any help or advise is much appreciated.


texts: Chain with most proof of work - hash target or block header hash?

texts:
What is calculated towards the sum of PoW of the chain? Is it the target difficulty that has been met or is it the actual block header hash?

Say the target is 000000ABC00000000... and I mine block with hash 00000012300000000... - do I count 000000ABC00000000... amount of work for my block or do I count 00000012300000000... ?

In other words: if someone else mines a block at the same time, extending the same chain as my block (i.e. natural fork) and his hash is 00000002300000000... is his chain's cumulative PoW greater than mine or are we same?


texts: If nonce can change the hash then it should be changing the next block's previous hash?

texts:
I am studing blockhain and i know that a block hash is linked to the next block in previous hash and it cant be changed for valid reason.
Reason is : because if someone have changed hash then then he/she would have to change in hundreds or millions of nodes/system also otherwise it wont be valid.
My question is :
If nonce will be changed by some miner then the hash will also get changed and it should be changing the next block's previous hash.
correct me if i am wrong. I mean if a miner can change the hash of a block then how he can replicate that hash in all the nodes or system for that block? this is confusing.


texts: Why there are blocks with single transaction in blockchain?

texts:
Just opened blockchain.info and found two blocks with single transaction on the main page:

292942
292947

Isn't it strange?
More than this, block 292941 was issued just minute before 292942 and has 128 transactions.
Block 292946 was issued just minute before 292947 and has 238 transactions in it.

So the question is: why there are such empty blocks in blockchain even if there are some transactions to be included? Is this some kind of misuse?

UPD:
Using this little script

for b in {292000..292999} ; do
  curl -s https://blockchain.info/block-height/$b?format=json \
    | jq -c -r '.blocks[] | "echo `date +%FT%T -d @\(.time)` \(.n_tx)"' \
    | bash
done

I found 10 empty blocks. It does not looks like a coincidence. Seems like someone thinks that this is more profitable to mine for empty block. If this is the case, it will ruin bitcoin.


texts: Does blockchain.info wallet or mycelium wallet use Bitcoin core?

texts:
And if so what version? I am asking because on a website it was talking about invalid blocks and how you should have a newer version of bitcoin core for some reason.
https://bitcoin.org/en/alert/2015-07-04-spv-mining


texts: How long does it take for a SPV to intermittently sync (order of magnitude)?

texts:
Say I have a device that is mostly offline, with a SPV on it.

Say once in a while (for instance once a week) I go online for about 20 minutes, and make a large number of transactions (which are based on transactions I might have received while I was offline).

How long, would you say, does a SPV (e.g., BitcoinJ, bitc or  others) need, upon getting online, to be fully operational in these circumstances?

I confess: I am not yet familiar with SPVs (although I did read about them, I have not had time to fully understand them yet). The steps a SPV follows to sync are outlined here, but no timeline is given.

Thanks


texts: Can miners be paid transaction fees even if they don't solve the current block?

texts:
I was recently mining on ltc.tbdice site which is a solo type site. They only pay out when a block is found and nearly all goes straight to the miner.

I had set up a specific wallet address for this mining pool and I recently had a very small payment show up in there even though I have never gotten a block on that site.

It was about 0.00065 LTC (sorry, don't have wallet with me right now).

So is this a correct payment or maybe just a bug on that specific website? It doesn't really make sense to me.
Thanks


texts: How does one find places that accept Bitcoin in the US?

texts: How does one find companies or stores that accept Bitcoin in the US?


texts:
I put my btc qt wallet.dat file on a USB and would like to open it on a software wallet. Preferably electrum. Is that possible?

If so how?

Too many problems with btc qt and takes forever to sync.


texts: Is it possible to use Electrum to create a multisig wallet with a trezor and an airgapped coldcard?

texts:
I set up a 2-of-3 multisig using Electrum, a Trezor, and a Coldcard. During testing, I ran into issues using the Coldcard to sign.

My approach:

(On Electrum) File -> New/Restore -> Multi-signature wallet -> Use a hardware device
Plug in Trezor, unlock, and set up as p2wsh.
Repeat steps 1 and 2 for second Trezor.
Plug MicroSD card into Coldcard.
(On Coldcard) Settings -> Multisig Wallets -> Export XPUB
Plug MicroSD card into computer running Electrum.
(On Electrum) Enter cosigner key
Paste p2wsh xpub from MicroSD card into text box.

This worked and my wallet was set up. I sent a small amount of bitcoin into it to test that I could sign transactions with Electrum. I was expecting the UX to be similar to that of a singlesig airgapped Coldcard used with Electrum, meaning I would create a transaction and click the "Export PSBT" button. Bring that to my Coldcard and sign the transaction. However, the transaction popup only has an "Export" button and no "Export PSBT" button. The "Export" button gives me a .txn file that is json containing the tx hex. Coldcard does not recognize this file and therefore cannot sign it. I was able to find these docs, specifically the section titled "Air-Gapped Creation of a Multisig Wallet". However, those docs seem specific to Coldcard-only multisig setups.

Is it possible to export multisig PSBTs from Electrum for signing on an airgapped Coldcard or is this something that is simply not currently supported? If it's supported, what do I need to do?


texts: Can I have a bitcoin pool joining another bitcoin pool

texts:
I currently having some idea of starting up a bitcoin pool company with my unique strategy pattern. However, I wouldn't have enough hash power at the start.

Hence, it is possible for one mining pool to join another mining pool? Or is there any ways that I can go about doing this?

Thanks


texts:
My goal is to manage the investments of a huge group of people. Let's say that each month each one puts in a different amount of dollars (it may even be $1) and I need to send to his wallet that amount in bitcoin. If I'll send to each person his own share of bitcoin, I'll lose a lot of money because of fees, there are a lot of micro transactions.

Is there any suggestions how I can manage this the best way?
When you come to think about it, any chance it's similar to how stock exchanges dealing with managing accounts balances? no way they are paying the bitcoin transfer fee on each transaction inside the exchange. it's not sustainable.

I thought about maybe purchasing the bitcoin in bulk, and save it, and to write each account balance in my own ledger, that way each user doesn't really have a wallet.

pros: no transactions fees.

cons: user doesn't really have a wallet, I'm fully in charge of his money in case his getting hacked.

How does the exchanges handle keeping all that crypto assets??

I thought about creating each user a wallet, but it means I can't support small investments.

I'd love some help here.


texts: Where do i get a good hands-on Bitcoin learning experience as a newbie?

texts:
I understand that bitcoin is a virtual form of money. It fascinates me. I have been to the site and seen numerous videos on youtube, but none seems to capture the vast enormity of the workings of bitcoin.

I would like to know how bitcoin is used, whether i can see the blockchain (since it is open source), how bitcoin to currency rates change, where and when and how bitcoin was created, why it is so successfull, if there is a way to see every step of a bitcoin transaction AND everything else that concerns the real life application of bitcoin.

I am a newbie, and i find most of the introductory documents of bitcoin working online too technical or too simple. How can i begin?


texts: verifying my modifications to bitcoind w/o broadcasting anything

texts:
I want to verify that my updates to the bitcoind source code don't break anything. One way that I thought of doing that was through loading the mainnet data into a regtest instance. To do that I first copied the good data folder and then ran my newly-compiled server in regtest mode pointing to my copy. I.e:

./bitcoind -server -regtest -datadir=.../my_data_copy

When I query the server it does not return any data. The debug.log file shows a number of block rollbacks. Why doesn't that work?

Is it possible to run the daemon in a way that it verifies the current code against the data on disk, such that the the current code would generate the same data? Is it possible to copy data from main or test networks and load that in the regtest mode?

I was thinking I needed to use regtest to avoid connecting to the live network. I don't need to connect to the network at all to verify the data, and I certainly don't want to broadcast anything in my test scenario.


texts:
Since full nodes must store the entire blockchain, and it seems to currently be 9 gb in size, it seems that sooner or later, it will be too large to handle ( if 9gb isn't already absurdly large ).  Is there no provision to ever restart the chain?  Certainly it can't just keep growing for all time?

It seems to me that sooner or later, a second genesis block will have to be created and unspent transactions will need to be converted from the first generation, then new transactions to the first genesis rejected, before finally discarding the first chain once all unspent transactions have been converted.


texts: How do many public keys correspond to one private key?

texts:
I have read online that hardware wallets can generate new public keys to facilitate transactions. Ie if someone has BTC on an exchange and they want to send that BTC in different installments to a single private key/hardware wallet, that hardware wallet can generate a different public key for each transaction. I'm a bit confused on how this works? Would the ledger not indicate that each of those installments now belongs to a different address? Or is it simply that each time a new public key is generated, the private key in the hardware wallet has the ability to sign for all of those? (Thus creating a persistent, growing list of public keys associated with one private key?).
Additionally, what is displayed on the ledger if that hardware wallet, after multiple installments with different public keys, now wants to send BTC elsewhere? Which of the previous public keys is used? Does it create a new one? Wouldn't this show up on the ledger as a public key sending more BTC than it ever acquired?