texts:
Does anyone else have this problem?  I have to restart that computer and mining rig about once a day.  More than half will err out over 12 hours.  They can't recover by themselves?

O.S.: Ubuntu Server 12.04
mining program: bfgminer 3.3.0

$tmux
$sudo ~/bfgminer/bfgminer -o stratum+tcp://stratum.bitcoin.cz:3333 -u MYWORKER -p MYPASS -S all

ctrl-B, ctrl-D
close terminal session

Nothing else is plugged into a USB port.  It's one of the simplest setups I can think to make.
Block erupters are less than a month old.  Block erupters have all the current they'd want at 5V (external power supply and their current demand doesn't get anywhere near the limit of the p.s.)

I'll try to come back as soon as I can find any specific error messages.

Should I not keep the mining executable in my home directory?


texts:
I have sent my only begotten BTC from my exchange currency account but not yet received in my blockchain wallet, and when I inquire with my transaction ID, I found my the transaction to be stuck for four days now... So, it seems to be there and but it is not clear when it will be released to my account. Should I be able to retrieve them back to a senders account.

Can we have that option please so that we can be safe and able to make some other options to use our money.

This thing of unspent outputs and stuff delays us to the business and for security being we won't trust the network for the fact that many are transaction awaited on an unknown same address. Those transactions stays for a long period of times.

Can we please given only an option to retrieve them back not anything else we may need on this. Maybe it could even ease the system to flow easy and transparent to us.


texts:
This may be a bad question, but I am just getting started and you have to start somewhere.
I have seen it discussed that generating the same public key as someone else is theoretically possible but has such a low probability that we don’t need to think about what would happen if this event occurred. I am content with this.
But, if I go and create a public key tomorrow (which I understand to be a completely offline thing) it seems that it could be simple to at least check and see if that public key has ever been used in a transaction before. I believe I have read that nodes keep a list of public keys with unspent Bitcoin for quick verification in processing transactions, this could theoretically be used for the check I describe. This would make me feel more certain that at that time I do indeed have a public key distinct from all other public keys (the only possibility being that someone might have that same public key, but has never received Bitcoin).
So I understand the probability is horrendously low, I’m not concerned about it actually happening, I just want to understand in a theoretical since but if that check would be simple enough to to perform as a just in case. Is such a check possible?


texts:
I was reading about the math behind bitcoins in this article, and one thing I can't seem to wrap my head around is how the said algorithm is used to sign "data". What exactly is this "data"? Is it my bitcoin? If so, how exactly is a bitcoin represented in terms of data? Say I have 5 bitcoins in my Coinbase wallet that I want to send my friend. How would that translate to the whole "gaining the private key and signing your data with it" process as described in the article?

Sorry if this is too novice a question, I'm new to cryptography concepts. Thanks in advance!


texts: Anyone tried building bitcoin core with visual studio 2019?

texts:
I followed the steps mentioned in the below link:
https://github.com/bitcoin/bitcoin/tree/master/build_msvc
Trying to build from https://github.com/bitcoin/bitcoin/tree/0.20

Errors:

Error   C1083   Cannot open include file: 'QApplication': No such file or directory bitcoin-qt  \bitcoin-0.20.1\src\qt\bitcoin.h    12

Error    MSB3073 The command "C:\Qt5.9.8_x64_static_vs2019\bin\moc.exe  "..\..\src\qt\test\addressbooktests.h" -o .\QtGeneratedFiles\qt\moc\moc_addressbooktests.cpp" exited with code 3.    test_bitcoin-qt \bitcoin-0.20.1\build_msvc\test_bitcoin-qt\test_bitcoin-qt.vcxproj  103

Error    MSB3073 The command "C:\Qt5.9.8_x64_static_vs2019\bin\moc.exe  "..\..\src\qt\bitcoinamountfield.cpp" -o .\QtGeneratedFiles\qt\bitcoinamountfield.moc" exited with code 3.   libbitcoin_qt   \bitcoin-0.20.1\build_msvc\libbitcoin_qt\libbitcoin_qt.vcxproj  168

Related Questions:
building bitcoin-qt.exe using Visual Studio 2017
Environment for building Bitcoin core in Windows
https://bitcointalk.org/index.php?topic=5264661.0
https://github.com/bitcoin/bitcoin/issues/17864


texts: Why does this transaction give me an error?

texts:
I am trying to script automatic payments without hosting a full node (my server doesn't have enough harddrive space). To do this I'm using electrum's python interface, and I have created a transaction, but when I try to send it, I get the error message: "TX rejected", "code: -22". Looking that up here, it appears that's an error either parsing or validating the transaction. It appears the error was thrown here.

But I cannot determine why. The transaction contains 2 inputs, 2 outputs, and the outputs + fee of 0.0001 = the size of the inputs (as of now) as verified via blockchain.info. The size of the transaction is under 1kb, so the fee is as I understand .0001. I sent an earlier transaction of .0001 with a .0001 fee through the electrum UI and it went through fine. So why is this transaction failing?

The raw transaction is:

01000000029802316bd53cdef6741b40b0a75cbffdfab270b0804f32096dda42594e19d179010000008b483045022100bd8bebb8491689604203806b66dc8c785cfb2362f2af630550bcd08d8789311c0220762ed5f310a15294e4fa9a5da9c4baff19e0f7c74a37430676fa3f7af3b50bb6014104f58c3d2d51eebf504ce13e1f5d3bb6f80c3df2e60212fef826dc2ce5bbe5f833b7ef684005fc6c28f80d7f27f70333471099edd4d41f4176261ae345a4128c46ffffffffd133f259c5e4bc4213136acb2fc4dbe5234732cfbfcc6a2845b83a744ea90e000e0000008b483045022100ec66b8827e4827b63a66840b1976cfc244a5ab20a047dd0d23e33285f63d7967022030c8f4b78277747dce2b085cf84acdd990704b0568c4d6e130a2361892b58e8d014104f58c3d2d51eebf504ce13e1f5d3bb6f80c3df2e60212fef826dc2ce5bbe5f833b7ef684005fc6c28f80d7f27f70333471099edd4d41f4176261ae345a4128c46ffffffff02a00f0000000000001976a9147d7cc528123aca5b820013445abbdff7530db71488ace01f0000000000001976a914742415bbd2c023df6f47e1fb6f5dac5316dc437588ac00000000

and I uploaded the decoded version (using electrum decoderawtransaction ... or https://coinb.in/decode-raw-transaction.html - both give the same output) here


texts: Is RPC Miner still the preferred BTC mining software for a Mac?

texts: I'd like to get a sense of how impossible it is to mine BTC as part of a pool on a MacBook Pro.  I figured there was some mining software out there but Uncle Google only showed some stuff from 2013.  I eventually clicked around to something called "RPC Miner", which led to this link (http://uploaded.net/file/49dw65r3), which I sure hope isn't a virus.  Is RPC Miner still the preferred mining software of choice for Mac?


texts: Security implications of bitcoin.conf location

texts:
I'm setting up and hardening a dedicated headless bitcoind and lightning daemon and wanted to have a discussion about location of the bitcoin.conf.

Item #1:

Bitcoind defaults to using ~/.bitcoin/bitcoin.conf, presumably because keeping all relevant files in one location makes it easier to copy and/or share the blockchain between different machines. Are there security implications to this? Is it substantively safer to store bitcoin.conf in /etc instead (such as /etc/bitcoind/bitcoin.conf)?

One argument against using ~/home/.bitcoin/bitcoin.conf I thought of is the RPC Password is be stored in the .conf file and could be viewed by anyone with read access. So it is less readable in ~/home or in /etc?

I'd get +1 POSIX-style-points for using /etc...

One argument against using /etc/bitcoind/bitcoin.conf is portability. It is less convenient to have the .conf file in a separate location. Less convenient means greater chance of mistake or error sometime down the road.

Item #2
Similar to #1, besides +1 style points, is there any advantage to moving logs to /var/log? My understanding is bitcoind already rotates logs, but is there an advantage to how systemd does log rotation in /var/log?

Thanks, these are good points. You're right about bitcoin.conf being in /etc and it causing difficulty accessing the daemon on a day-to-day basis. In my case this server is meant to serve a small local workgroup on the same machine and on the LAN and has bitcoind running without a wallet to serve a local lnd and electrumx instance. Both of these access bitcoind through RPC via localhost, so the location of bitcoin.conf is irrelevant to them.

Even if bitcoind was run as a system-level service to be used as a wallet, users wouldn't necessarily need to access bitcoin.conf if they used RPC. Local users could each have their own bitcoin.conf in their home folders with RPC credentials. This would eliminate their need to specify bitcoin.conf at the command line.

  You may then secure the file with "chmod 600", so only the owner can read/write >the bitcoind.conf file (and root and/or the admins after tweaking the >permissions).

^^This would do more for security than just moving to /etc.

So there is no one right answer, but that if running bitcoind as a system-level service it might make more sense (if not actually increase security) and get +1 POSIX style points to put bitcoin.conf in /etc, but if running bitcoind in the user space for a single local user it makes more sense just to keep everything in ~/home to save RPC credentialing hassles.


texts: bitcoin mssql decimal/money storage size

texts:
What's the decimal storage requirement in ms sql for bitcoin?

GAAP standard quotes decimal (13, 4) for money.

Is decimal (13,8) preferred for bitcoin or something else?


texts:
Say I have an account with MtGox, and I put $5k worth of bitcoins in there. The exchange rate subsequently goes up by 10%. Now my MtGox bitcoins are worth 5.5k. Can I exchange this for USD in my MtGox account, but let it sit in my MtGox account until I want to buy bitcoins again?

The reason I ask is because I am in Australia, and MtGox charges a $10 fee (plus the 0.6%) to send to my bank account, and more importantly, it takes a few days to transfer. This means if I choose to buy BTC again, I have to transfer money from my bank account back into my MtGox account which also takes a few days. That's a turnaround time of almost a week, which would make "day trading" impossible!

Can I have usd in my MtGox account without transferring it to my bank account, or having it in bitcoins?

I'm a newbie, obviously...


texts: Payment confirmation (3rd's party point of view)

texts:
On my site I want to allow two parties to trade between each other without me posing as a middle man. That means that vendor would provide his own address to which a negotiated amount would be deposited. My site would only scrape the public bitcoin transaction list for given address to find out if the payment was done to trigger post processing on my site.

Since people generally reuse bitcoin addresses, checking an immediate balance will not give me a proof that transaction really came through, thus I want to parse all transactions for a given address, filter out those transactions that are older than defined time frame (assume I have timestamp of offer's creation time) and calculate the sum from the rest.

Is this a valid solution or am I missing something?


texts: Is it possible to earn BTC by processing transactions?

texts: Where does the money go? Is it possible for any person to setup his wallet application to process transactions and make some more BTC?


texts: New to Bitcoin - tips on securing my server

texts:
I regard myself as being a competent programmer and have good general IT knowledge; however I know very little about BTC. I just want to make sure that my setup is "generally secure" and that I'm grasping as much of the low hanging fruit as possible (from a security point of view).

So I installed bitcoin-cli on my Ubuntu 14.04 VPS (I am quite trustworthy of the company who provide the VPS):

sudo add-apt-repository ppa:bitcoin/bitcoin
sudo apt-get update
sudo apt-get install bitcoind

Here's my init script:

description "bitcoind"

start on filesystem
stop on runlevel [!2345]
oom never
expect daemon
respawn
respawn limit 10 60 # 10 times in 60 seconds

script
exec 2>>/var/log/bitcoind.log
set -x
user=eamorr
home=/home/$user
cmd=/usr/bin/bitcoind
pidfile=$home/.bitcoin/bitcoind.pid
# Don't change anything below here unless you know what you're doing
[[ -e $pidfile && ! -d "/proc/$(cat $pidfile)" ]] && rm $pidfile
[[ -e $pidfile && "$(cat /proc/$(cat $pidfile)/cmdline)" != $cmd* ]] && rm $pidfile
exec start-stop-daemon --start -c $user --chdir $home --pidfile $pidfile --startas $cmd -b -m
end script

Saved init script to /etc/init/bitcoind.conf

service bitcoind start

OK great.

* Now what? *

(Bearing in mind that I don't want to use a third party website)

Do I need to open port 8333 on my firewall? Is that ok?

Is there some "private key" I should store somewhere safe? Do I need to store this on my VPS?

Is there anything else I should do?

I want to buy €50 of BTC. I guess I need an address. How do I create an address? I will tell the folks at bittylicious.com to send €50 worth of BTC to my newly created address, right?

Finally, how do I create multiple BTC addresses, receive money at those and transfer into my "master" BTC address?

Here's some command outputs for your information:

>> bitcoin-cli getnetworkinfo
{
    "version" : 90201,
    "protocolversion" : 70002,
    "timeoffset" : 0,
    "connections" : 8,
    "proxy" : "",
    "relayfee" : 0.00001000,
    "localaddresses" : [
        {
            "address" : "xxxxxxxxxxxxxxx - IPv4 address",
            "port" : 8333,
            "score" : 9
        },
        {
            "address" : "xxxxxxxxxxxxxxx - IPv6 address",
            "port" : 8333,
            "score" : 1
        }
    ]
}

>> bitcoin-cli getinfo
{
    "version" : 90201,
    "protocolversion" : 70002,
    "walletversion" : 60000,
    "balance" : 0.00000000,
    "blocks" : 172082,
    "timeoffset" : 0,
    "connections" : 10,
    "proxy" : "",
    "difficulty" : 1498294.36281651,
    "testnet" : false,
    "keypoololdest" : 1409306527,
    "keypoolsize" : 101,
    "paytxfee" : 0.00000000,
    "relayfee" : 0.00001000,
    "errors" : ""
}

>> bitcoin-cli listaccounts
{
    "" : 0.00000000
}

>> bitcoin-cli listreceivedbyaddress
[
]

Thanks for your help guys,

Update:

There's an init script for Debian (works on my Ubuntu 14.04) in the offical repo:

https://github.com/bitcoin/bitcoin/blob/master/contrib/init/bitcoind.conf

So, all you have to do to get bitcoin up and running headless (from a fresh install) is:

sudo apt-add-repository ppa:bitcoin/bitcoin
sudo apt-get update
sudo apt-get install bitcoind
sudo curl https://github.com/bitcoin/bitcoin/blob/master/contrib/init/bitcoind.conf > /etc/init/bitcoind.conf
sudo vim /etc/init/bitcoin.conf
#Delete the line "disablewallet" (part of "exec start-stop-daemon" command) - don't delete if you don't want a wallet
adduser bitcoin
sudo mkdir /var/run/bitcoind
sudo chown bitcoin:bitcoin /var/run/bitcoind
sudo mkdir /var/lib/bitcoind
sudo chown bitcoin:bitcoin /var/lib/bitcoind
sudo mkdir /etc/bitcoin
sudo touch /etc/bitcoin/bitcoin.conf   #put your config in here: rpcuser, rpcpassword, etc.
sudo apt-get install ufw
sudo ufw allow 22
sudo ufw enable

This installation is maintainable and gives a "good" level of security.


texts: New params of chainparams.cpp. What put on them and how generate?

texts:
What do these parameters do and what to insert there

        uint256S("00000fffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"); //what this do ? end what put to here

        consensus.nRuleChangeActivationThreshold = 6048; // 75% of 8064 //what this do end what put ?
        consensus.nMinerConfirmationWindow = 8064; // nPowTargetTimespan / nPowTargetSpacing * 4  //what this do ?
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28; //what this setting's do ?
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 1199145601; // January 1, 2008
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = 1230767999; // December 31, 2008

        // Deployment of BIP68, BIP112, and BIP113.
        consensus.vDeployments[Consensus::DEPLOYMENT_CSV].bit = 0;
        consensus.vDeployments[Consensus::DEPLOYMENT_CSV].nStartTime = 1485561600; // January 28, 2017
        consensus.vDeployments[Consensus::DEPLOYMENT_CSV].nTimeout = 1517356801; // January 31st, 2018

        // Deployment of SegWit (BIP141, BIP143, and BIP147)
        consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].bit = 1;
        consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nStartTime = 1485561600; // January 28, 2017
        consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout = 1517356801; // January 31st, 2018

        // The best chain should have at least this much work.
        consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000000000006805c7318ce2736c0"); //what this do end what put here ?

        // By default assume that the signatures in ancestors of this block are valid.
        consensus.defaultAssumeValid = uint256S("0x1673fa904a93848eca83d5ca82c7af974511a7e640e22edc2976420744f2e56a"); //1155631  //what this do ?

        nPruneAfterHeight = 100000;  //what this do ?

i need to reconfigure exist coin to new wallet but stuck on this param's.

For all who down vote question, i try find about this param info , but do not find anything, or you simple down vote what you do not understand ?

I understand it's start end time out time. But how it work's.


texts: Why should SPV nodes operate on the P2P network?

texts:
I understand there are advantages for the SPV client to acquire header-chain and subsequent inclusion proofs over the p2p network:

Peer discovery
P2P node interface is public
Reuse of P2P messaging protocol

But this must come at a cost for full-validating nodes:

Reduced channel bandwidth with full-nodes
Therefore, increased tx/block propagation times

Why are SPV nodes/clients not serviced over separate server-client interface rather than the P2P protocol? What are the justifications for this?

Thanks in advance.


texts: Do forum or website exist where can buy things not usually sold with bitcoin?

texts: Something like "wanted" classified advertisements is needed. Silk Road only sell offensive merchandise, no method to post wanted ads. Interested in purchase electronics, other legal unobjectionable products. Does website like this exist?


texts: Can Bitcoin scripting be used for double spending attacks?

texts:
A standard Bitcoin transaction deposits coins into an address and then, using Bitcoin's scripting language, states that whoever wants to spend this output must be in possess of the private key corresponding to that address.

However, it's possible to deviate from this base template to create more complex transactions, where other conditions must be met in order to spend the transaction output.

Is it possible to create a transaction where a sum is deposited into an address, but only the owner of another private key is allowed to spend it? I'm not a Bitcoin scripting expert, but this looks at least possible.

In this case, can such a crafted transaction be used to mount a double-spending attack, where address A sends sum X to address B, but after the transaction is completed address A retains ownership of the sum and can send it elsewhere, while address B can actually do nothing about it even if the sum is credited to its balance?

How would a standard wallet treat such a transaction? Would it even recognize there's something strange going on, or would it blindly display that X BTC entered address B, regardless of the transaction script?

Edit:

Sorry, I was misled by how sites such as blockchain.info display transactions: a transaction doesn't actually contain any "output address", it only contains outputs which state the conditions necessary to spend them; the "output address" is computed by checking which address's signature is requested by the output script; thus it's impossible to "send money to address B" without actually placing address B in the output script.

However, the question somewhat remains: could a transaction be crafted to fool a wallet into telling its user "I received X BTC" while someone else can actually claim the sum using another private key?


texts: Accessing a wallet from multiple devices

texts:
I'm using an Electrum wallet on my laptop. I'd like to have the functionality available on my phone (i.e. send/receive bitcoins - to the same wallet).

Is there a way to install one of the myriad of Android wallets, and "import" my wallet into them? Is that even the right approach? If not, what's the best way to use wallets on multiple devices?


texts: getnewaddress won't generate bech32 or p2sh-segwit addresses

texts:
We are only able to generate "legacy" addresses that begin with a "1". This is a long standing problem generating new addresses using bitcoind and has persisted through a few recent versions of bitcoin core.

This might be a possible bug in bitcoind 64-bit linux.

We are currently running core 19.1 taken from here: https://bitcoincore.org/bin/bitcoin-core-0.19.1/

And our linux version is: Ubuntu 18.04.3 LTS x86_64

We have "addresstype=bech32" set in our bitcoin.conf.

Has anyone else seen this problem before?

Here is our bitcoin.conf:

addnode=**.***.***.***

server=1

rpcport=****

walletnotify=/btc_notify.sh %s

# OpenSSL settings used when rpcssl=1
rpcsslciphers=TLSv1+HIGH:!SSLv2:!aNULL:!eNULL:!AH:!3DES:@STRENGTH
rpcsslcertificatechainfile=server.cert
rpcsslprivatekeyfile=server.pem

gen=0

keypool=100

paytxfee=0.00005000

addresstype=bech32

And here is an example of how the problem manifests itself:


texts: Are all 'metal wallets' functionally equivalent?

texts:
Within the context of wallets, is it correct that a metal bitcoin wallet needs to store both public and private keys?
I'm looking at some metal wallets and want to clarify that the're all basically the same in that they'll give you different bits and bobs which are then must be physically arranged?
Or, are some metal wallets etched or otherwise "written" and then sent to the user?  Because that seems a very trusting act, to provide a private key to some third party.
Just dealing with bitcoin.  Perhaps naively thinking of storing public/private key "written" down with metal.
I would think something like:

minting physical bitcoins

would the point of such a wallet.  Obviously not minted, but just storing the public/private key on metal for reference.


texts: Just curious, if I send a transaction from one address to another, how do they verify it without knowing my private key?


texts: Ransomware requesting payment through Bitcoin

texts:
I read this article recently, talking about the emergence of "ransomware". An excerpt is:

The newer CryptoLocker differs by taking the ransom to a whole new level. Upon infection it doesn't make a fanfare, to the contrary, it acts in stealth performing a nefarious task in the background. You probably won't even notice the task running, as CryptoLocker silently encrypts your data files, including your precious family photos, vital Microsoft Word documents, spreadsheets, and email.
Upon completing the encryption of your files, it sends the unique key required for decrypting and unlocking your files over the internet to a secure remote server, and then the ransom begins. Immediately the CryptoLocker window displays containing the image of a shield, instructional text, and a countdown timer.
It's important to understand that the ransomware is not bluffing. Unless you pay the ransom, you will lose access to any files that have been encrypted. Once the countdown starts you have about three days to make payment, otherwise the key is destroyed and you permanently lose the ability to decrypt your files.

It seems like a logical step to request payment through Bitcoin, given that it would be much harder to track down the person receiving the payment than most other options. Sure enough, it's been done already! Admittedly, it could be a pretty daunting task for your average Joe Bloggs to figure out how to safely pay within 3 days using Bitcoin, but obviously the time limit can be made flexible.
Has any malware successfully used this technique yet, using Bitcoin? If so, does anyone know of a receiving address used more than once, thus giving an indication of how many people are paying a ransom?
Are there any websites that have statistics on such incidents?


texts: Editing bitcoinJ for Android Altcoin App

texts:
So there is an altcoin created by another party and i want to edit the bitcoin-wallet app for android so that it connects to the new network.

Is it enough to edit core/params/MainNetParams.java in order for the core functionalities of the app to work?

Thanks in advance!


texts: Can a smart mind explain block difficulty calculation in lay terms?

texts:
I tried to read it here: https://en.bitcoin.it/wiki/Difficulty

But it is closer to a rigorous math proof than to an explanation.

I am interested to understand that so I can understand what makes a block or a block chain more difficult than another. It is said that when a bitcoin client starts it chooses the most difficult block chain it sees.

Can a smart mind explain that in simple terms?


texts: How to store private data in blockchain and smart contract

texts:
Following my previous question on this topic Is there a way to store and share a private key through blockchain?, I might have a solution but I would like to improve the process.

Image that A is the owner of some private data, and want to give the ownership of this data to B, another member of the blockchain. The data is a private key so it can not be public, but it can be encoded using A or B public key.

So:

Secret data is encoded with A public key, and stored in A informations data /
B want to by A secret data
A decode the secret data (using his private wallet key) and encode the secret data with B public key
Ownership of the data is given to B
Now only B (and A also but that's a different story) can decode secret data.

Is there a way to simplify this process using smart contract? I assume a smart contract have access to A and B public key, but can a data be encoded/decoded with private key of the one executing the smart contract?


texts: getbalance says 0 for incoming TX even though 0-conf is allowed

texts:
> $bitcoin_rpc.getnewaddress("myaddress", "bech32")
 => "bc1q9kvfyjxtk9tvkzgpkf4x8zs42sddwlyanz3z6z"
> $bitcoin_rpc.getbalance
 => 0.0
> $bitcoin_rpc.getbalance("*", 0)
 => 0.0
> $bitcoin_rpc.listtransactions
 => [{"address"=>"bc1q9kvfyjxtk9tvkzgpkf4x8zs42sddwlyanz3z6z", "category"=>"receive", "amount"=>0.00025, "label"=>"myaddress", "vout"=>1, "confirmations"=>0, "trusted"=>false, "txid"=>"ad922349668c17c3ab47081f6dbc6e7e8f68473840146bfdd18f35f7d0bca216", "walletconflicts"=>[], "time"=>1574217056, "timereceived"=>1574217056, "bip125-replaceable"=>"yes"}]
> Time.now.to_i
 => 1574217344

What's the magic behind it? Since confirmation=0 is default, I would expect a return value of 0.00025.


texts: How many characters you need to mistype at minimum to get another valid address?

texts:
Is it known the minimum amount of characters you need to mistype to get another valid address?

Addresses contain checksums, and also must follow some specific rules, so I guess this could be calculated: I wonder if someone did.


texts: How does a merchant ensure sufficient value in light of the price volatility?

texts:
When a merchant accepts bitcoin payment (for example 10 btc for the purchase), the buyer send the payment of 10 btc and it is settled.

However, the 10 btc value will fluctuate every minute (up to 20% or more sometimes on a daily basis).  Let's say 1 btc = $2000 at the time of the payment and 1 btc = $1900 at the time when the merchant exchanged it for US dollars. The merchant lost $100 in this case and the opposite could happen.

How does a merchant ensure that the btc payment satisfies the cost of the product?

Please help me understand how this works. Otherwise, it does not make sense to me why Merchants need to accept btc payments.


texts: Setup cgminer on Ubuntu 12.04 (im getting libudev.so.1 not found error)

texts:
I have read and read and read over the internet but noone seems to have problem like this.

Im trying to setup cgminer on my Ubuntu 12.04 (64 bit) desktop but i failed. Downloaded cgminer from url http://ck.kolivas.org/apps/cgminer/ read all the instructions but not working.

The error im getting when i try to start it is

./cgminer: error while loading shared libraries: libudev.so.1: cannot open shared object file: No such file or directory

Any help? btw im on Nvidia graphic if that makes a difference.


texts: Import/Export wallet vi bitcoin-cli. Bitcoin abc node

texts:
I'd like move my bitcoin cash wallet from one server to the other using the cli.

Server 1: bitcoin abc: 0.17.2.
Server 2: bitcoin abc: 0.18.0

I have done the following:

ran the command: backupwwallet "myfile.dat" on server 1 successfully.
copy the "myfile.dat" to server 2.
rand the command: importwallet "myfile.dat".

I get the following the error when trying to import the wallet:

error code: -8
error message:
Cannot open wallet dump file.

I have also tried to replace stop the node on server 2 and copy the wallet.dat over to the other server and then start the wallet up again on server 2.
I get the following error in the logs:

CDBEnv::Open: LogDir=/home/cryptodaemon/.bitcoincash/database ErrorFile=/home/cryptodaemon/.bitcoincash/db.log
2018-09-09 07:48:21 Failed to rename wallet.dat to wallet.dat.1536479301.bak

How can I move the wallet from one server to another?
Could anyone give me pointers in doing this?


texts: I need to get transaction confirmations via command line. But seems there is no such method. onchain_history seems returns information but I don't want to pull a whole history, I need info about one transaction only not all. Is it possible?


texts: Configure Bitcoin full node in my local LAN

texts: It is said that deploying a Bitcoin full node would protect the privacy of my Bitcoin addresses. If I configure a Bitcoin full node to be outbound only, would that be enough to protect me? Do i still need to have a public IP address? (Since no other full node will connect in, do i still need to configure/supply a public IP address?)


texts:
In the process of trying to understand the effects of segwit on Bitcoin I started watching this:

https://www.youtube.com/watch?v=NOYNZB5BCHM

Which are the cases in which the receiver does not need the signatures? (minute 6.20)

Am I right, saying that signatures for segwit outputs will never be relayed to old clients?


texts: lightning to lightning non custodial swaps

texts: Do you know the way to freeze funds in lightning tx to implement atomic swap between two independent lightning networks?


texts: How to refund bitcoin after wallet recovery?

texts: I lost my bitcoin balance after I forgot my wallet password in blockchain. Although I managed to get my wallet (same wallet with the same security phrase) recovered,my balance showed 0. Where did my bitcoin go ? Can I access them again?


texts: Brother died and I am sole survivor..just found out he has a wallet. How do I go about getting his bit coins I have no info

texts:
Brother died I am the sole survivor. I have no info..How do I retreive ..I have death certificate. Thank You
LJF


texts: How do SPV (simple payment verification) wallets learn about incoming transactions?

texts:
I try to understand a SPV implementation.

I read the wiki pages on Protocol Specification and Thin Client Security as well as the white-paper's chapter 8 .

What I don't understand:
Assume user A has Bitcoin address X.
User A can do getheaders and load all block headers and then have all block hashes and timestamps.

So: how does a SPV client then find possible transactions to the user's Bitcoin address X without loading all blocks (and all transactions)?


texts: Bitcoin wallet showing balance, Blockchain receiving address shows 0.00, wallet is from 2009 and hasn't been synced

texts: Old wallet, like from the first client, Has not been synced for at least 7 years. BTC balance shown, 0 pend, 0 available and blockchain address shows 0 balance. Still waiting for entire blockchain to sync but its passed the deposit date by years with no confirmations. 0.00 pending/avail am I boned?


texts: If SHA256 produces an alphanumeric hash, how can a hash be "less than a certain value"?

texts:
I was under the impression that Bitcoin's method for validating a hash involved making sure the hash started with a pre-determined number of zeroes.  However, after reading the docs here, I see the following sentence:

  To prove you did some extra work to create a block, you must create a
  hash of the block header which does not exceed a certain value.  To
  prove you did some extra work to create a block, you must create a
  hash of the block header which does not exceed a certain value. For
  example, if the maximum possible hash value is 2^256 − 1, you can prove
  that you tried up to two combinations by producing a hash value less
  than 2^255.

This is confusing to me, since according to my research the Bitcoin protocol uses the SHA256 hashing algorithm, which produces alphanumeric hashes.  For instance, when I hash an empty file named "foobar.txt", I get "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855".

My question is, how can one alphanumeric hash output be "less than" another?


texts: Mitigating a Double Spend Attack by Punishing the Attacker?

texts:
One of the main reasons it's not safe to accept Bitcoin with 0 confirmations is due to the possibility of a double spend (where Mr. Scammer first sends 1 BTC to Alice and then creates an identical transaction in which he sends the same 1 BTC to Bob or to another address controlled by himself. If the network ends up including the second transaction in the blockchain only Bob (or Mr. Scammer himself) will be viewed as the rightful owner of the coins and Alice will be left with nothing).
However, being that it is impossible to hide a double spend forever, and everyone on the network will eventually discover that Mr. Scammer double spent his coins, why is it not possible to penalize the double spender in order to reduce the economical incentives of doing so in the first place? For example, we could create a special type of transaction in which Mr. Scammer has to lock up an equivalent amount of BTC for a specified amount of time. If the network indeed concludes that a double spend has occurred we "burn" (or destroy) the locked up BTC.
Wouldn't this significantly reduce the likelihood of a double spend occurring in the first place?


texts: What prior work influenced the design of the Bitcoin instruction set?

texts:
The "Script" system used by Bitcoin transactions is commonly described as a Forth-like, stack-based language.
What prior work influenced the design and layout of the Script instruction set?
Based on the locations of OP_RESERVED1 and OP_RESERVED2, it seems that the Bitcoin instruction set may draw on large segments of some earlier work.
There may have been a research paper or essay about a "Security Forth" published in the early 2000s which shared unusual similarities with the Bitcoin instruction set (like OP_2OVER and OP_3DUP operations). Though in recent years, no one has been able to locate a copy of this work.
What was the title of that work? Where was it published? Can anyone find a copy?


texts: Can I access a BCH wallet with a BTC seed phrase?

texts: So I've accidentally given someone a BTC address and she sent BCH to this address. The wallet was created post-fork. Is it possible to go through the same process as accessing BCH immediately after the hard fork, or are these BCH funds lost forever?


texts: How does mining process takes Approximately 10 minutes?

texts:
I don't think that I fully understood the "difficulty" topic in blockchain, and therefore I don't understand how mining process takes close to 10 minutes.

If I have "Target" value (some hash value, which each block's value must be lower or equal to this Target), Why does it take 10 minutes to find hash value for the block? Maybe when the Nonce=2 the value of the block will be <= Target, maybe when the Nonce = 100000000 the value will be <= Target.

But if Nonce = 2 , then the time of the mining is couple of seconds, and if the Nonce = 100000000 , the time of mining is couple of minutes..

So it's a matter of luck or something, but the time of the mining can change.. So what is the principle in the blockchain \ What does miners do, in order to make the mining process in a 10 minutes average?

I'm new to this technology so i would appreciate simple answers
Thanks in advance


texts:
I am using sendtoaddress API call.
The problem is that I need to specify amount that includes fees.
For example, if I withdraw 1 btc, I need bitcoind to deduct fees from that amount and in example to send 0.999 as transaction amount and 0.001 as fee (or any other fee amount that recommended for this transaction)

Please, help and tell if that possible to achieve such result.


texts: How can one generate a vanity Bitcoin address with both a given prefix and suffix?

texts:
I want generate a unique Bitcoin address with vanitygen that has both a given prefix and a given suffix:
  1Bit******************Bit

How would I be able to achieve that?


texts: the guidebook says that "when you open MultiBit, the wallets that were open in the previous use of MultiBit are reopened", but I've stored some money in a wallet that I created in a USB key. Now I am opening again multibit and I can't see this wallet. The .wallet and .info files are in the flash and I know its address so the problem is, how to do in order to see the wallet in multibit again? there is not an explanation of it in this short guidebook. Thanks for your help.


texts: Are people incentivized with BTC to run nodes?

texts:
Bitnodes shows everyone running nodes.

Are these people incentivized to run nodes? If not, why not? If so, do node operators make some BTC from transaction fees, etc.?


texts: Blockchain.info - Forgot My Secondary Password. How to recover it?

texts:
I haven't accessed my blockchain.info account and I completely forgot my secondary password in order to send out bitcoins. I still have my mnemonic, but that's totally useless and MISLEADING as it states I can recover my Bitcoins with it. But it will not recover my secondary password on blockchain.info

How can I reset my secondary password ?


texts:
Now that bitcoin gold launched, I am looking for a way to get my BTG from the BTC paper wallet they were held at the forked block.

I know Coinomi works, but it only has an android app... any other that has a web or desktop app?


texts: We are developing UI for coin trading. We have a plan to use  all the coins present in coinmarketcap. I am greatly confused how to generate coin address for all coins. I knew that from cryptsy.com, it is possible to generate address for all coins from bitcoin but I don't know how to implement it. Is there any easiest way to generate coin address for all coins or can anybody tell how cryptsy do this for all coins? We are doing this in Ruby. Can you please suggest some more ideas to implement this. Any help is appreciated.


texts: What's the advantage of using non-truncated mining targets?

texts:
Bitcoin Wiki (Difficulty):

  The highest possible target (difficulty 1) is defined as 0x1d00ffff,
  which gives us a hex target of

0x00000000FFFF0000000000000000000000000000000000000000000000000000

  It should be noted that pooled mining often uses non-truncated
  targets, which puts "pool difficulty 1" at

0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

From what I know, using non-truncated targets puts the target at a higher number than the network would accept. In other words, we may end up finding a hash accepted by the "pooled mining" (lower than non-truncated), yet rejected by the network (higher than truncated).

Why do people use non-truncated mining targets?

Why not simply use the actual truncated targets so that we can have a more accurate picture of the network and avoid overheads incurred as such?


texts: Please explain how to configure a satellite for btc payments with blockstream via space

texts:
Blockstream has its own satellites in the space orbit, right. So , as I understand, there must be very special requirements met for your satellite to be able to do transactions through space. Not every type of satellit is able to fulfill this...

Which are the exact requirements?  I was told that you need:
- satellite brand / exact type of the satellite
- exact coordinates/communication channel
- receiver box name/type of receiver box

What does one need precisely and how should you configure it?

Is any wallet capable of this sort of tx, or if not, which one is?

Thanks!


texts: How does a new node get all the previous blocks in a blockchain?

texts:
From what I understand, when a new full node is started, it begins by fetching all the previous blocks in the blockchain from it's peers.

I want to know how exactly it does that? Does it ask for a local copy of the blockchain from other peers and save it? In case multiple peers have different chains, how does it resolve?


texts:
I created a channel in lightning network, did the payment and the channel balance of the receiver got updated. But after closing the channel , the wallet balance of the receiver is not getting updated and the sender is also losing the funds. (Even after mining)

Is there anything that needs to be done for the balance to get updated.


texts: Why shouldn't I accept PayPal when trading bitcoin?

texts: I've heard that it's not a good idea to accept PayPal payments in exchange for Bitcoin. Why?


texts:
I'm using GUIMiner. It's not using my CPU. My CPU is at a very low utilization (~10%).

What I can do to use my CPU?

Why isn't CPU mining turned on by default?


texts: help can I recover ltc sent to a btc address

texts: Im super new like a lot of people. I have a nano s ledger and I attetpted to send ltc from coinbase to the ledger only to realize I used the btc address on my ledger. Is this recoverable?


texts: How widespread is OP_RETURN forwarding and mining (as of February 2014)?

texts:
As of now (February 2014), how easy is it to have a transaction which makes use of OP_RETURN data confirmed into a block?

Do standard nodes forward such transactions yet? Have major mining pools committed to support?

Are there specific steps that can improve the chances of such a transaction being mined, like connecting to certain nodes with advertised support, or adding extra transaction fees?


texts: Is it safe to send to my own address from my wallet?

texts:
I have a wallet.dat which has so many addresses in it. Like 1, 2, 3, 4, ....., 1234324234 addresses. (Each number is address)

I backed up original wallet.dat, and I want to use this light wallet.dat from now on.
This light wallet.dat has only 1, 2, 3, .... 100 addresses in it I think.
(keypool size was 100)

Both wallet.dat has same address "1", so is it okay to sending all coins to address "1" and use light wallet.dat after that?

It may cause sending to address "1" from "1". Is it okay?


texts: Where can i buy zcash coins, named as ZEC?

texts: I tried to  buy from https://www.buy-zcash.com/ but the application does not seem to work: the buy button is never activated even if i fill in a valid zcash wallet address


texts: How can one confirm that reported transactions on the exchange actually occur and are not due to wash-trading?

texts: For instance, if I'm subscribed to binance's websocket trade stream.. and it is reporting trades..  how can one be assured that the trades are actually occuring and not just the exchange trading with itself or generating false data to pump up their volume numbers?


texts:
I was trying to learn working of bitcoin and trying to understand the working of bitcoin wallet.

I can see the behavior of how an HD wallet starts with an address and adds additional addresses later for receiving bitcoin.

I read bip-0032, but still am  confused. If I regenerate a wallet from the seed (in another mobile phone), how the system will populate the wallet with all previous addresses containing a balance? Will it try to download the earlier blockchain and search it, or is there another way?

How do we locate a list of all addresses we created with the HD wallet? How can we verify the balance of those addresses?

I know that this question is going to receive down votes, please give me some ideas.

Also it would be helpful if somebody can share some links where I could get some help on clarifying doubts (not programming, general working).


texts: What is the difference between BTC and Bitcoin Core?

texts: To my understanding BTC and bitcoin core are the same, when mentioned against S2X/B2X. Is that the case? (Bitcoin Core is BTC in the post segwit2x world?)


texts: What percentage of newly created bitcoins have never been moved?

texts: As of today, what number of coinbases, what number of coins, and therefore what percentage of the newly created coins have never been moved?


texts: How do I use Blockchain.info's Receive Payments API with node JS / Express?

texts:
Blockchain has great documentation for PHP, but nothing really for node!

Does anyone here have any projects,where they used the blockchain.info Receive Payments API, in their node apps, to receive money / check for confirmations?

I learn a lot better by viewing / recreating example code so any you have would help me out tons!


texts: Transaction Malleability in the blockchain

texts: How does a transaction malleability look like in the blockchain? Are there any examples?


texts: I have lost my blockchain password and recovery phrase, how can I recover my wallet?

texts:
I forgot my blockchain password and recovery phrase because it was saved in my phone— and i have lost my phone.
please help me if there are any chances for recover my funds that was in blockchain


texts: How can I force estimatesmartfee to return estimates on regtest?

texts:
Creating an app that utilizes estimatesmartfee, and it works in production, but I use regtest for automated testing and can't get it to return a value.

Looking at bitcoind tests it is splitting UTXOs in a loop etc.

What is the bare minimum I need to do as far as dummy transactions and mining blocks in order to get estimatesmartfee to work like it does on mainnet.

Thanks.


texts: What pool catters to multiple alternate currency?

texts: I want to mine alternate coins. I am looking for pools that support many of the coins here so I do not have to keep changing pools.


texts:
There has been a new mining pool appearing after the halving called Lubian.com cf https://www.cryptoglobe.com/latest/2020/05/new-bitcoin-mining-pool-comes-out-of-nowhere-already-5th-largest/

How does a miners say to the world who he is, and how can he prove he is the one that has mined a specific block ?


texts: In ListReceivedByAddress, what is the meaning of Confirmations if the address is reused?

texts:
The API ListReceivedByAddress allows me to view a list a sum* of all the transactions that an address has received.   This returns an array listing the sum of what was sent.

If the address is reused for more than one transaction, what is the expected value of "confirmations"?
Is the value of confirmations the Max, Min, or Average?
Should there be an entry listing how many transactions were sent to that address?

*Footnote I'm not entirely sure that the ListReceivedByAddress actually returns a sum of all transactions to that address.  I assume it's possible that the value could be the first, last,or sum of all transactions to an address.


texts:
If I have a bulk wallet with, say 100000 key pairs (address/private key) and I have received payments on any, say 1000 of them, how can I sweep all the coins to a new address? It would be even better if I can do it from the command line, for example > sweep keypairs.txt 1Q7nrZ7PGWTtKVkQk1mLZovbJKEfLubXtv and all the available coins are transacted to the destination address. The format is for example:

1,"1E4MuBWjv2qZeJH5ti9ig5XMoJHQF63cdX","5JmLyBtdFEaKefsFXPd9E9PmbvT8JogG1V6Yer5jmZ9MX6bXP88"
2,"1BhJsijfGxwbzKgkQj5hRLDnBkmX2Y1RNN","5K5BBepZgaq8n9sJrsoM5inEWCX7W8bh7U8fr2wSP1PAkseasdQ"
3,"1ATP4LHYxqCZhDva661SLWJoN3vdNE2u1J","5JchXy3Y97F3TjaHsMJmyaaik1Gd4DpLP15PegbcvcZ5u2HBJg7"
...
100000,"17GX2ZFSpDip3BR6jMYP5He53tPMZqpSSG","5JyZsU9K2kokXzJQjg5F7mormCcwiPBcBjD3UZXHNwMSPuDGCNK"


texts: How to get the list of transactions that has gone into an address with the amount and date?

texts:
How to get the list of transactions that has deposited funds in an address, including information about the amount that has been deposited (sent towards my address not sent away from it), and the date when the transaction occurred.

For example here is address A (my address) :

TX 1)  from address B , 2   bitcoins , 2014 1 january 12:12 pm
TX 2)  from address C , 1   bitcoins , 2014 2 january 7:51 am
TX 3)  from address D , 4   bitcoins , 2014 5 january 3:22 am
TX 4)  from address E , 0.5 bitcoins , 2014 6 january 1:42 pm

Also, I want it to use an API that is online, so that I don't need to download the whole block chain.

Preferably blockchain.info API or blockexporer.com API would be nice.

A link to a tutorial would also be helpful. I have an specific application in mind that needs this info for an address.


texts: How can i set up CPU mining on bfgminer?

texts: I just downloaded Bitcoin Core and BFGminer on linux and I would like to start CPU mining just to see how it works, maybe later I'll buy ASIC. So, how can I configure CPU mining on BFGminer?


texts: Are there any math contests paid in Bitcoin?

texts: Are there any hard math problems or math contests that have rewards paid in Bitcoin?


texts:
I am attempting to run  bitcoind on a computer in my local area network (LAN) and then have bitcoin-cli access/communicate with that computer in lieu of running Bitcoin-QT on the same machine alongside bitcoind.

Is that possible?

Thus far I've tried to modify the bitcoin.conf but without success.


texts: Is it feasible to use the Blockchain technology without the Bitcoin?

texts:
Every once and a while, I step into some article like this one: Forget Bitcoin -- What Is the Blockchain and Why Should You Care?.

I've been hearing a lot of blabbering about companies to begin using the Blockchain technology for book keeping, for example, but making no use of Bitcoin at all.

I wonder: how is it possible to separate both things?

I mean, the aim of Satoshi Nakamoto was to create a decentralized coin that would supress the need of a trustworthy third part, which operates over the Blockchain.

The main aspect of the Blockchain is that it's a decentralized network, working on a peer-to-peer basis, no servers, no clients, only peers. The only reason someone would contribute to the building of the Blockchain is the monetary reward in form of mined bitcoins.

How could a company make use of the Blockchain? How would it pay someone to do its book keeping (or whatever) without payments in crypto-currency?

I see that this might be a rather wide question, but I'd be satisfied with only one example of how could it be possible to use the Blockchain technology without Bitcoin (or similar crypto-currencies).


texts: Determining xprv from xpub and child private key

texts:
I'm confused by the wording in BIP0032:

  One weakness that may not be immediately obvious, is that knowledge of
  a parent extended public key plus any non-hardened private key
  descending from it is equivalent to knowing the parent extended
  private key (and thus every private and public key descending from
  it). This means that extended public keys must be treated more
  carefully than regular public keys. It is also the reason for the
  existence of hardened keys, and why they are used for the account
  level in the tree. This way, a leak of account-specific (or below)
  private key never risks compromising the master or other accounts.

The default recommended wallet layout is m/0'/0/i.

So if I leak the xpub of m/0'/0 (which, in theory, my auditor has) and a private key in m/0'/0/14, then wouldn't all keys in m/0'/0/i be compromised? I understand that m/1' and m are safe but now you've lost an entire account when all that needed to be done was harden the index. What is the cause for this recommendation?


texts: What is the scriptCode in a P2WSH transaction?

texts:
Let's say I am spending from a 2-of-2 multisig with this script:

522103c2f21de0f430251d8e3987fbe89ff51f3d6f3a48b234b84b60ddb9f24d587cf52103e0948a03f50377290847d27c93d383b8ab7e2d0bc065e96e0e1136b315388b5452ae

OP_2 <len(pubkey1)> <pubkey1> <len(pubkey2)> <pubkey2> OP_2 OP_CHECKMULTISIG

What would go in the scriptCode according to BIP143? Is it just the script listed above? Here is the relevant part from BIP143.

  For P2WSH witness program,
  - if the witnessScript does not contain any OP_CODESEPARATOR, the scriptCode is the witnessScript serialized as scripts inside CTxOut.
  - if the witnessScript contains any OP_CODESEPARATOR, the scriptCode is the witnessScript but removing everything up to and including the last executed OP_CODESEPARATOR before the signature checking opcode being executed, serialized as scripts inside CTxOut. (The exact semantics is demonstrated in the examples below)


texts:
I have bitcoin daemon and I want to use the walletnotify option with a json-rpc call. Some of the examples use a "transaction.sh" file for walletnotify. What is it for?

What do I have to write in that sh file, to make walletnotify work for more than 6 confirmations.


texts: Is my Tor bitcoind node seen by new normal nodes?

texts:
I've finished the setup of a bitcoind node behind Tor like in method 1 of this guide
I'd like to be as helpful as possible to the network and especially new nodes trying to sync.
Are new nodes able to see me right from the bat even if my 8333 port is only open using a .onion ip address?
Unfortunately I can't open port 8333 because I'm behind a firewall and my ISP charges for a public IP address.
If I want to set up an electrum server (electrumx) using .onion address will it be easy for normal electrum wallets to connect to my machine?
Thanks


texts: What are the advantages of using my own blockchain versus the Bitcoin blockchain?

texts: Let's say I have a project that takes advantage of blockchain technology. Now I see a number of banks dropping the Bitcoin blockchain for their own. I'm sure that has something to do with secrecy, but, assuming I'm just a normal entrepreneur and not some massive financial institution, what would be the reasons for me to create my own blockchain vs. the Bitcoin blockchain? What are their respective (dis)advantages?


texts: How to get Master Private key in electrum wallet

texts:
I have a wallet in electrum. I would like to get my wallet master private key. I don't know how to get that. Please, anyone, suggest me steps to get my key

Thanks in Advance


texts: bitcoind jsonrpc bumpfee not returning hash of newly created transaction

texts:
I'm trying to implement replace by fee functionality with bictoind (v18) and bumpfee rpc call described here

It works by mean that new transaction is created with higher fee, but result should be:

{
  "txid":    "value",   (string)  The id of the new transaction
  "origfee":  n,         (numeric) Fee of the replaced transaction
  "fee":      n,         (numeric) Fee of the new transaction
  "errors":  [ str... ] (json array of strings) Errors encountered during processing (may be empty)
}

but I'm getting basically all null response

{
  "id": "BumpFeeRequest 1561247020661",
  "error": null,
  "txid": null,
  "origfee": null,
  "fee": null,
  "errors": null
}

Which makes it hard to identify the new transaction in down-steam system.

How can I get the txid, except querying for last tx


texts: How do I set up my machine to process transactions and earn the transaction fees?

texts:
I am unable to earn money from solving blocks, but I think I could make money from transaction fees. The issue is that pools hide the transaction fees from the miners. The miners earn the solved blocks. How would I go about processing transactions on my own?

This will satisfy two goals:

earn transaction fees
any transactions I perform, I can process myself


texts: Are HD wallets private keys any different than regular private keys

texts:
Aside from the fact that HD wallets derive them deterministically, is it correct to state that keys driven at any path or index under BIP32 isn't any different from a private key that's derived randomly in a non-HD wallet?

In other words, its theoretically possible for someone to derive a private key that's at a particular node under your master key in HD wallets, irrespective of how small the probability is, and actually the same probability that there is for generating a private key (non-deterministically) that's already in use by someone else?

Essentially, private key being just a number in a specific range, you can either guess it randomly every single time or have a mechanism of generating random numbers, it essentially means the same thing and is possible to arrive at the same number from either of the ways.

Correct?


texts: Is the transaction size relevant if fee per byte is the same?

texts:
Is the size of the transaction some factor when the miner chooses one transaction over the other, provided that they both have the same fee per byte?
In other words, will the miner prefer larger or smaller transactions if they all have the same fee per byte?


texts: Why is wif prefix 0x80 more than pubKeyHash prefix

texts:
I forked a coin and found that whatever I put in pubKeyHash prefix, I need to add 0x80 to it, to calculate wif prefix and hence generate an address keypair, i.e address and private key corresponding to that address. If I add anything apart from 0x80, to calculate wif prefix,the private key generated doesn't correspond to that address.
Would anyone tell me the reason for the same.


texts:
In case I'm a selfish miner and have successfully forked the blockchain, I'd like to know the state of progress of my honest nodes at any given time - how can I achieve this?

Do peers on separate blockchains exchange information about their progress through data messages?

Let's look at this scenario for a better understanding:
selfish node=s;    honest node=h

s: mine a block#1 (child of genesis block), don't report
h: mine block#2, block#3 publicly
s: mine block#4, block#5 secretly (don't report)
h: mine block#4 publicly
s: get information what block height the honest network is at!?

NOTE:

pindexLastCommonBlock doesn't seem to be helpful since calling its
height would say that last common block is 3, but does not say what
height honest nodes are at.
setInventoryKnown in case of a fork stores all blocks ever mined.


texts: Improve uniqueness of block for nonce creation

texts:
I am going through online Blockchain course and in the course, they have mentioned that uniqueness of a block is defined using hashes with leading zeros as well as timestamp. Since, in the training, they have assumed 18 leading zeros in hashes, the valid hash count is 4 billion. So, with the unique combination, every node has 4 billion valid hashes per second to get the golden nonce. But since all the miners are trying at the same time to generate the nonce, this range gets covered quickly within a second. So for this, the solution is to change block configuration.

My question is -
If per second, all the 4 billion hashes are getting covered without finding golden nonce, why cannot we have 1 more field in the block like node id?

So, the uniqueness of the block can be defined using 3 variables - node id, timestamp and hash. Since node id of the node is unique to the node, every node gets free chance to use up to 4 billion hashes per timestamp.

I am sure this must been thought of by designers or probably I am not thinking properly.


texts: Does one of these exchanges have a sandbox to test?

texts: I want to test some trading. Does Binance, Bittrex, Poloniex, Kraken or Gemini have a sandbox to trade fake crypto to test systems?


texts: BTC/hashes/second rates for various pools

texts:
Do all pools have the same average BTC/hashes/second rates (for individual members of the pool)?

For example, this profitability calculator says 4 Th/s hash rates will produce 0.04 BTC per day, yet I've seen pools awarding 0.1 BTC every few days for 4 Th/s mining rates.


texts: Migration from Bitcoin wallet (Schildbach) to bitcoin core

texts:
Is there a standard way of migrating from Bitcoin Wallet (Schildbach) to Bitcoin Core?

I understand that backups are not compatible.


texts:
Can someone please help to confirm my understanding of SegWit ?

My understanding:

Originally, signatures are included in each block alongside each transaction, these signatures can be read by nodes to prove validity of each transactions.
With SegWit, signatures are omitted from the blocks, but instead recorded in a side-chain called Witness blockchain.
Whoever wants to verify a transaction can refer to the corresponding signature from the Witness side-chain
The total amount of data remains the same, but since we now have two separate chains running in parallel, the size of each block is effectively doubled.

Questions:

Is my understanding correct please?
Does it mean that for old-fashioned Nodes who don’t look at Witness side-chain, they can only verify transactions up to the Segwit implementation, and will have to reject new blocks because they won't find a valid signature within the new blocks?
In that case, how is it a soft-fork? Since all nodes will be forced to upgrade in order to operate. (by here I am sure I am wrong somewhere..)
Finally, do miners and nodes now keep both chains and when they broadcast the new block, they also broadcast the new Witness block?

Thank you very much.


texts: Is it possible to create a Bitcoin URI with multiple outputs?

texts:
The Bitcoin URI scheme allows for the creation of single-click payment request, using the format

bitcoin:<address>&amount=<amount>

such as

bitcoin:1AzGoMQfrQ7fYaE12dAvEVkke8111rxwCm&amount=0.01

Does the URI scheme also allow multiple payments to multiple destination addresses?


texts: coin seems to have gone to a duplicate address

texts:
in attempting to answer Bitcoin-qt multiple wallets and transferring between?, and teach myself in the process, I created a new wallet.dat file and saved it to group_wallet.dat after generating an address. I then restored my_wallet.dat to be wallet.dat, and sent an AmericanCoin to that address. almost a full day later, the funds don't show up. the transaction is in the blockchain, but they never made it to the wallet. I've switched wallets back and forth a few times since then; the one from which I sent the money is fine, and shows the -1.0 transaction.

jcomeau@aspire:~/.americancoin$ americancoind getaddressesbyaccount ''
[
    "AzpvNNAUFYjW79uCS1Q9ALNSVhABqrUC1U",
    "Argr7YW2enzC7TkFp4cJiVDJ1wSYPkh5ox"
]
jcomeau@aspire:~/.americancoin$ americancoind getreceivedbyaddress AzpvNNAUFYjW79uCS1Q9ALNSVhABqrUC1U
0.00000000
jcomeau@aspire:~/.americancoin$ americancoind decoderawtransaction $(americancoind getrawtransaction 9982de4dc77eab126d2ad4837db477577bbeee733ef381c1889576cfbd328473)
{
    "txid" : "9982de4dc77eab126d2ad4837db477577bbeee733ef381c1889576cfbd328473",
    "version" : 1,
    "locktime" : 0,
    "vin" : [
        {
            "txid" : "45614d6a67973f9d4728a2724547f3b7e9274218df28599d63f50f112cfa1d8b",
            "vout" : 1,
            "scriptSig" : {
                "asm" : "304602210088aacfccfe71532a5bbfc3145bbff8c1f3470e228b35e879146b30ec4b3526b8022100f566b0aa825ee6786af3619f1e73d89d2b3902468c4a15082af0e15324fc37c201 02047541ccbfea550183dcd9cc21b11af6975339f61c5908f13b8f8d6d2c42fbdb",
                "hex" : "49304602210088aacfccfe71532a5bbfc3145bbff8c1f3470e228b35e879146b30ec4b3526b8022100f566b0aa825ee6786af3619f1e73d89d2b3902468c4a15082af0e15324fc37c2012102047541ccbfea550183dcd9cc21b11af6975339f61c5908f13b8f8d6d2c42fbdb"
            },
            "sequence" : 4294967295
        }
    ],
    "vout" : [
        {
            "value" : 25.74101000,
            "n" : 0,
            "scriptPubKey" : {
                "asm" : "OP_DUP OP_HASH160 a1ddfc061b9f000cb647f3cd1c08e6fdeacf72ec OP_EQUALVERIFY OP_CHECKSIG",
                "hex" : "76a914a1ddfc061b9f000cb647f3cd1c08e6fdeacf72ec88ac",
                "reqSigs" : 1,
                "type" : "pubkeyhash",
                "addresses" : [
                    "AusMMF3ETMkzvhfTUp61NoWBcCDoHcn9rQ"
                ]
            }
        },
        {
            "value" : 1.00000000,
            "n" : 1,
            "scriptPubKey" : {
                "asm" : "OP_DUP OP_HASH160 d840edbda2020b44b9fa4ad8ff912e79eb3cc000 OP_EQUALVERIFY OP_CHECKSIG",
                "hex" : "76a914d840edbda2020b44b9fa4ad8ff912e79eb3cc00088ac",
                "reqSigs" : 1,
                "type" : "pubkeyhash",
                "addresses" : [
                    "AzpvNNAUFYjW79uCS1Q9ALNSVhABqrUC1U"
                ]
            }
        }
    ]
}

there may be multiple ways to find out what block it's in, but I stumbled upon one yesterday by attempting to resend the raw transaction:

jcomeau@aspire:~/.americancoin$ americancoind sendrawtransaction $(americancoind getrawtransaction 9982de4dc77eab126d2ad4837db477577bbeee733ef381c1889576cfbd328473)
error: {"code":-5,"message":"transaction already in block 29ddf391af012069f02a6e120348d5206548d50f818cad4d5182f28540d842fd"}
jcomeau@aspire:~/.americancoin$ americancoind getblock 29ddf391af012069f02a6e120348d5206548d50f818cad4d5182f28540d842fd | grep confirm
    "confirmations" : 167,

I'm well aware that one needs to get 120 confirmations on a block to get the block reward, but transactions, as I understand, are considered valid after 6. but this has surpassed even the 120. so where is the coin? I'm assuming someone else generated the same address with a different private key. if they instead stole my wallet (by cracking my netbook) it should still show up in the transaction list.

but is that the most likely possibility? there almost has to be something I'm overlooking.


texts: How big is the input of a P2PKH transaction?

texts:
How many bytes does a P2PKH input have? I'm finding a few different numbers:

Why does the default miner implementation use pay-to-pubkey? states:

  push + sig + push + key = 1 + 72 + 1 + 61 = 139

Princeton Bitcoin Book states [p.123]:

  The approximate size of a transaction is 148 bytes for each input[…]

A knowledgeable Bitcoin developer calculated from the top of the mind for me over coffee:

  PREVOUT + SCRIPTSIG = 36 + (1 + 1 + 33 + 1 + (71 or 72)) = 143 or 144

I couldn't find further information in the Bitcoin Developer Guide or the wiki.

Bonus-question: How come there are different numbers? Did the size change over time?


texts: Multiple transactions for a single payment in bitpay

texts:
Let's say we are 4 people and we want to purchase something that is currently worth 10 coins. When we click the purchase button, we are presented with an address to transfer the coins within 15 minutes.

The question: Should we send the necessary coins in a single transaction? Or is it possible to make (for example) 4 different transactions of (for example) 2.5 btc each, summing in 10 btc? If so, what if one of us cannot make the transfer on time?

Any information/experience is appreciated.


texts:
I understand that electrum offer the amazing ability to use the 12 words seed to fully restore a wallet, but that is really dangerous because it doesn't require any password.

Is there a good way to digitally store a backup that enable to regain access to my wallets by entering a password?

P.S. I can export public keys to have a safe read-only wallet backup, but if I export also the private keys will these be password-less and enable anyone who posses them to gain full control of my wallet or do they need to enter the password I provided during the creation phase?


texts: Where are contracts used in the real world

texts:
I'd be interested to see some examples of Bitcoin contracts used right now.

Websites that provide escrow services.
Smart properties.
Trading of contracts.
Oracles.

Or are they not really in use right now?


texts: How does schnorr signature construct multisig functionality?

texts:
How does the multiparty schnorr signature work and enable multisig
functionality in Bitcoin?
What are its limitations? Can we construct any m of n signature?
Is there anyway to hide the signers among the participants?

*I specifically would like to see the elliptic curve math in details.


texts: Wouldn't the expected return of a mining pool be no more than solo mining?

texts: I don't understand the advantages of pool mining if you want to maximize your return.  It seems like all it does is even out your return to make it more predictable by paying you smaller amounts more often rather than nothing for long periods punctuated by an occasional 25 BTC.  But in the end won't you end up making the same amount, if not less (considering the pool operator's profit) by joining a pool?


texts: Sending Bitcoins with Armory doesn't work

texts:
I have a few Bitcoins that I manage with Armory. It shows the correct amount of money in my wallet under the correct address.

I now want to send the Bitcoins to somebody else. When I open my wallet and select the address with the Bitcoins and click on "Send Bitcoins," all that happens is my that my wallet window closes and I am back in Armory's main menu.

Is that a common problem? What should I do?


texts: How to check the balance of a person when his public keys are different on different input transactions?

texts: A person can use a different public key/private key generated from his eWallet for each transaction. How the miner check the balance of that person from his multi-input transactions with different public keys?


texts:
The tor network relies on volunteers providing bandwidth. This is a limiting factor of that system, since there is currently no direct benefit by operating a tor relay.

As I understood, TorCoins are altcoins that can be mined by providing bandwidth to the system. But how would a Proof-of-Work mechanism work for such a system?


texts: Data about number of block mined + stale blocks per day in Bitcoin?

texts:
I am wondering if there is any easy way to get number of mined blocks per day + number of stale blocks per day for the last three month e.g.,?
I could not find such data on Blockchain.info

In Ethereum, however, Etherscan provides these, see: https://etherscan.io/chart/blocks and https://etherscan.io/chart/uncles

Any help about getting such data for Bitcoin?


texts: How can I benefit by running a full Bitcoin node?

texts:
I noticed that I can run a node with Bitcoin Core.

If I open my computer always and make the full node run on my device, what benefits can I get? Is there any reward for serving this?


texts: Import of BTC BIP38 Paper Walet into Electrum 3.3.4 not working

texts:
Trying to finalize importing BTC from a BIP38 Paper Wallet into Electrum wallet

About an hour ago I opened Electum 3.3.4, created a new wallet, set a password, saved a copy of the new wallet to a USB stick.

Then I clicked Electum's menu options for WALLET, PRIVATE KEYS, IMPORT, and pasted the decrypted private key for the BIP38 Paper Wallet into the box that opened, and clicked NEXT.

Nothing has happened: The blockexplorer shows the BTC balance is still in the Paper Wallet and not in the Electrum wallet. I closed and restarted Electrum, but same.

When I decrypted the BIP38 Paper Wallet to obtain its private key I used bitaddress.org offline, which provided me with a table containing a number of options re the decryted private key.

The specific key I chose, copied and pasted into Electrum was the one under the heading "WIF compressed format 52 character base 58 starting with 'K' or 'L' "

Would that be what needs to be corrected?

A second thing is that I see, when I click the Electrum server big green button (no idea what its called ha) that the Overview shows "Status" as connected to 10 nodes. Server is noveltybobble.coinjoined.com and Blockchain is 565750. When I initially checked this on importing the BIP38 Paper Wallet it was set to automatic not a specific server

I have read that Electrum servers can be an issue to processing transactions, and am thinking maybe that could be a problem here?

Any suggestions or help would be appreciated

ty


texts: What does "Reindexing blocks on disk" mean?

texts: When I upgraded to 0.8.1, it said Reindexing blocks on disk and it took about four days (Grr).  But later, it said something about a corrupted database and it had to do it again! What is it doing?


texts: Why is the SHA256 regularly applied twice?

texts:
I have come across at least two times in bitcoin computations that the sha256 algorithm is applied twice - merkle root computation and address computation. Why is this?
Not sure of an appropriate tag - please edit.


texts: Segwit (BIP141) is active since block 481824 in 24th August. I wonder if it was the BIP91 that made the segwit happen? I mean lets say BIP91 never existed, would segwit be activated in 24th August anyhow.


texts: Why guiminer is using different amount of GPU each time I restart my copmuter?

texts:
Why guiminer is using different amount of GPU each time I restart my computer?
I'm running guiminer-20121203, NVIDIA GeForce GTX 670M, poclbm.exe with flags  -s 0.005 -f 60
What I noticed was, it was 35Mgash/s with 75% GPU usage. And after I restart my computer, it became  50Mgash/s with 100% GPU usage with the same flag settings.

Also, before when I tried only with flag -s 0.010 it utilized 100% GPU, but without restarting computer, using flag -s 0.011 reduced GPU usage to 60%.

What's going on??


texts: Why won't my bitcoin miner detect any of my hardware?

texts:
I recently set up a bitcoin miner on my gaming pc just to test it out and I can't seem to get it working. I am using bfgminer on Ubuntu and when I start it up it says this:

NO DEVICES FOUND: Press 'M' and '+' to add

I have tried pressing M and + and then selecting auto but it still gives me that message, I have also tried selecting all and the same thing happens.

my computer:

Processor: 8x AMD FX(tm)-8320 Eight-Core Processor

Memory: 8074MB (1255MB used)

Graphics: Sapphire HD, ATi radeon 4800

Operating System: Ubuntu 14.04.1 LTS


texts: How Do I Fix: "Safe mode: Warning: Displayed transactions may not be correct!"

texts:
While trying to retrieve the private key from satoshi bitcoin client i'm getting this error code:

Safe mode: Warning: Displayed transactions may not be correct! You may need to upgrade, or other nodes may need to upgrade. (code -2)

Does anyone know how to fix this?

It is QT VERSION 4.8.2 & v0.7.2-beta in the lower right hand corner it says it is catching up but has not added any blocks for a really, really, really, long time, it sitting on 90.13% . What else do you need to know?

I am Technically inept so I need to be clear so I dont screw up. I NEED THE PRIVATE KEYS for 2 ADDRESSES generated by this bitcoin-qt, when I type in dumpprivkey address I get the above error message. Will upgrading cause a conflict?  What is the proper way to upgrade as I dont see that as an option?


texts: Byte array to hexadecimal and back again in JavaScript

texts:
I can generate a byte array with

var myByteArray = window.crypto.getRandomValues(new Uint8Array(16))

and I get

181,143,16,173,231,56,63,149,181,185,224,124,84,230,123,36

I can then turn this into a string with

cryptoHelpers.convertByteArrayToString(myByteArray);

and i get

µç8?µ¹à|Tæ{$

But what I really want is a 128 bit hexadecimal like...

6a3e52297b2e593f4d506f7164

And I want to be able to go back from hexadecimal to a byte array.

Is there a copy and paste function or library to make this magic happen?


texts: Is multi-PPS the correct solution to the mining centralization problem?

texts:
See this post. Meni believes that this could be the correct solution to the mining pool centralization problem, and that are no known drawbacks. There is some work that needs to be done to write, test and integrate the code of course (perhaps money could be raised for this via Lighthouse).

Is multi-PPS indeed the right solution?


texts: How can I use Bitcoin Core with the anonymous network protocol I2P?

texts: How can I use Bitcoin Core with the I2P anonymous network protocol?


texts: How to resolve Minera cgminer "no devices found" error after installing additional GekkoScience USB-Antsticks?

texts:
I successfully completed my first attempt to configure my Raspberry Pi for Bitcoin mining with a GekkoScience USB Antstick and Minera; however, after installing additional Antsticks, my env somehow became corrupted which ultimately lead me to wipe my Raspberry Pi and install a fresh copy of Raspian and reinstalling Minera- my question is this: should I have re-compiled Minera after installing additional Antsticks, as detailed within screenshot below captured from the Minera manual-install page?

I've detailed my Minera install-process within the following Gist if that helps clarify- basically, I'd like to avoid any future complications after installing additional Antsticks or miners because more are on the way!  Thank you.


texts: Calculating average number of hashes tried before hitting a valid block

texts: I'm toying with the idea of starting to mine, and was wondering how to calculate how many hashes on average must be tried before one will "hit" a valid block?  I'm talking about a single user (not a pool) using one rig.


texts:
In BIP 174/PSBT, there is a PSBT Input key-value pair called "PSBT_IN_WITNESS_SCRIPT" (0x05) and another called "PSBT_IN_FINAL_SCRIPTWITNESS" (0x08). What is the difference between a WitnessScript and a scriptWitness?
From what I understood, a witness script is the witness data for a single input (the signatures and scripts that unlock it). Is the scriptWitness something different?


texts: Normal hashrate but no accepted shares in

texts:
For the moment I'm trying to mine altcoins using an AMD HD6850.
The version of cgminer is 3.7.2. The pool I'm using is prohashing.com.
It's a scrypt-mining pool which mines the most profitable coins at the moment. When I'm connecting to the pool, I get decent hashrates for my GPU (200Mh/s), but I get no accepted shares... When I look on the prohashing profile page I see that next to my worker there's following message:

"This miner is not responding to work restart testing, so a suboptimal default value was chosen. Use the r= password argument to manually set a default value."

My main screen is looking like this:

My configuration file is as following:

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer.exe -o stratum+tcp://prohashing.com:3333 -u CoinHunter -p "" -I 13 -w 256 --thread-concurrency 6144

Changing the difficulty or mining a specific coin didn't do the job...
Someone who has an idea?


texts: How to get the time when a block is received at a node?

texts:
Is there any variable in the bitcoind code that records the timestamp when a block is received for the first time by a particular node? To be more precise, for transactions, transaction information returned by Bitcoind JSON RPC API contains timereceived. Is there similar field for blocks in the API?

There happens to be similar existing questions in stackexchange but none of them has been appropriately answered.


texts: What does the SegWit2MB proposal agreed upon at Consensus 2017 entail for the bitcoin network?

texts: From what I've read, I know this proposal is the combination of a hardfork to 2MB blocks with the activation of SegWit, but I haven't actually seen the code for this proposal to understand what the activation conditions are and what exactly happens and when. If this proposal were activated, what exactly would happen to the bitcoin network?


texts: what are the actual requirements for a bitcoin transaction? Not the simple inputs, outputs, verification or amounts, but in the technical sense. what does your wallet do? every thing I read says you need a client but what does it do? people used paper wallets before how were they able to do so? did they still need a client? and if so for what reason? does it just connect them to the network or is there more to it?


texts: What happens if a miner receives a block but not its previous?

texts:
Suppose the following:

A miner has stored the current blockchain A-B-C.
It stops listening for blocks during some time.
During that time, blocks D and E are mined and broadcasted.
The miner reconnects and immediately listens to the block E, before even knowing about D.

Will the miner simply ignore that block? And, how will the miner update to A-B-C-D-E (step by step)?


texts:
What can be changed in signed bitcoin transaction?
I mean how is possible to modify transaction to change its hash, but keep transaction valid, without need to have sign private keys?


texts: Which price need to be taken for bitcoin analysis

texts:
I'm doing a bitcoin statistical analysis using Python. The bitcoin prices consist of close,open, low, high prices per an hour. For statistical analysis, which price do I need to take to consider. Is it close price? Or the mean prices.

Many of the analysis had used the closing price as shown below. What is the base for that? What if we consider the mean of them?

https://medium.com/spreadstreet/bitcoin-madness-how-to-simulate-bitcoin-prices-in-google-sheets-c61cb42f26ed

Sorry if this is not the write place to post this question


texts:
In 2013 I installed a BITCOIN CORE (V0.10.2) wallet in my netbook computer and purchased 1 bitcoin. Recently I have wanted to sell but found the wallet out of sync and needing to download the entire Blockchain because the computer crashed years ago due to dud battery. when I get past the date when I purchased my bitcoine it appears in my wallet OK but trying to complete the block chain download takes so long that the netbook Locks up before it is complete - why i don't know, but anyway....................
Is there a way to transfer my wallet or its contents to a new BITCOIN CORE wallet (v0.15) that I have in a much newer computer without completing the blockchain in my old netbook? Put another way - what constitutes the identity of my old wallet? - and can that identity be transfered to my new wallet so my bitcoin appears there?


texts: Is there a service that automatically "sweeps" funds to another address whenever they are sent?

texts:
There's the sweepprivkey proposal from 2011 which was not accepted, that would have allowed one to instruct her bitcoind client to listen to transactions and sweep funds whenever they are transferred from one address to another.

There is also this question, "Is there a way to automatically send bitcoins from one wallet to another?", but it does not specifically ask about a service that would do that.

I was wondering whether someone developed, or is considering the development, of such a service.
There would be security implications, as the service would have to know the private key of the address to sweep - is there any secure way to implement this otherwise?


texts: Bitcoin client communication time constraints

texts: How long does the standard Bitcoin client wait between sending a message to another client and deciding that the client is not responding? That is, if someone makes a client that takes a couple seconds to write a response to a request, will it still work with the Bitcoin network?


texts:
These are steps to run the network quoted from the Bitcoin white paper (https://bitcoin.org/bitcoin.pdf):

New transactions are broadcast to all nodes.
Each node collects new transactions into a block.
Each node works on finding a difficult proof-of-work for its block.
When a node finds a proof-of-work, it broadcasts the block to all nodes.
Nodes accept the block only if all transactions in it are valid and not already spent.
Nodes express their acceptance of the block by working on creating the
next block in the chain, using the hash of the accepted block as the
previous hash.

I am wondering weather there will be a scenario where the miners do not accept a valid block or accept a malicious block. Can anyone explain how steps 5 and 6 are executed?


texts: Is it possible to trigger a contract with a not prunable public trigger message?

texts:
In the current state pruning is not implemented. Therefore an attached public trigger message should stay in the blockchain until pruning is enabled. When this is the case, will it be possible to make the trigger message unprunable? This could be useful for contract params validation. For example:

If I trigger a contract with the following attached message: {"contract":"ExampleContract","params":{"veryImportantParameter":"42"}}

I would like to make this message public (so everybody can validate that I've triggered the contract ExampleContract with the parameter veryImportantParameter and it's value 42) and not prunable (so that everybody can validate the message at any time in the future).

Is this going to be possible?


texts: Colluding miners attack: Is the Bitcoin protocol compromised?

texts:
A very interesting academic paper has been recently published by two researches from the Cornell University (abstract, full PDF):

  Abstract

  The Bitcoin cryptocurrency records its transactions in a public log
  called the blockchain. Its security rests critically on the
  distributed protocol that maintains the blockchain, run by
  participants called miners.  Conventional wisdom asserts that the
  protocol is incentive-compatible and secure against colluding minority
  groups, i.e., it incentivizes miners to follow the protocol as
  prescribed.

  We show that the Bitcoin protocol is not incentive-compatible. We
  present an attack with which colluding miners obtain a revenue larger
  than their fair share.  This attack can have significant consequences
  for Bitcoin: Rational miners will prefer to join the selfish miners,
  and the colluding group will increase in size until it becomes a
  majority. At this point, the Bitcoin system ceases to be a
  decentralized currency.

  Selfish mining is feasible for any group size of colluding miners. We
  propose a practical modification to the Bitcoin protocol that protects
  against selfish mining pools that command less than 1/4 of the
  resources.  This threshold is lower than the wrongly assumed 1/2
  bound, but better than the current reality where a group of any size
  can compromise the system.

The article suggests that miners who group together can earn more than their fair share, which means rational miners will eventually group together into a pool whose size is larger than half the network's computation power and control the currency. The method was termed "selfish mining" by the media.

This seems to be the first serious cryptographic exploit of the Bitcoin protocol.

Do you think this poses a real threat to the stability of the currency?


texts: Are people still fighting about this or have they come to a consensus? Also, as of today (Sep 2015), what is the main advantage of Ripple over Bitcoin?


texts: How do you push a transaction to the Bitcoin Cash Network?

texts:
There are plenty of APIs for pushing to the Bitcoin network, like Smartbit's:

https://www.smartbit.com.au/api

However, the only API I found for Bitcoin Cash was Blocktrail's:

https://www.blocktrail.com/api/docs/lang/nodejs#payments_overview

And they do not seem to have a basic push endpoint.


texts: How to solve error: Incorrect or no genesis block found. Wrong datadir for network?

texts:
I am making my own alt-coin, and I have mined the first genesis block hash(after some time), Merkle hash, nnonce and time. I am running on Ubuntu14.04.

But when I run ./bitcoind I get this error

  Error: Incorrect or no genesis block found. Wrong datadir for network?

What does it mean? how do I fix it?

Here is debug.log shows:

2018-04-02 18:33:04 Booducoin version v0.8.7.4-gc1e46ab3a90b-beta ()
2018-04-02 18:33:04 Using OpenSSL version OpenSSL 1.0.1f 6 Jan 2014
2018-04-02 18:33:04 Default data directory /home/boodu/.booducoin
2018-04-02 18:33:04 Using data directory /home/boodu/.booducoin
2018-04-02 18:33:04 Using at most 125 connections (1024 file descriptors available)
2018-04-02 18:33:04 init message: Verifying wallet...
2018-04-02 18:33:04 dbenv.open LogDir=/home/boodu/.booducoin/database ErrorFile=/home/boodu/.booducoin/db.log
2018-04-02 18:33:04 Bound to [::]:9333
2018-04-02 18:33:04 Bound to 0.0.0.0:9333
2018-04-02 18:33:04 init message: Loading block index...
2018-04-02 18:33:04 Opening LevelDB in /home/boodu/.booducoin/blocks/index
2018-04-02 18:33:04 Opened LevelDB successfully
2018-04-02 18:33:04 Opening LevelDB in /home/boodu/.booducoin/chainstate
2018-04-02 18:33:04 Opened LevelDB successfully
2018-04-02 18:33:04 LoadBlockIndexDB(): last block file = 0
2018-04-02 18:33:04 LoadBlockIndexDB(): last block file info: CBlockFileInfo(blocks=1, size=241, heights=0...0, time=2018-04-01...2018-04-01)
2018-04-02 18:33:04 LoadBlockIndexDB(): transaction index disabled
2018-04-02 18:33:04 LoadBlockIndexDB(): hashBestChain=5e55391ddfe7258c5d1dc5ebf2c8ce9bdec72edf482f171a6cb04416c53be9b8  height=0 date=2018-04-0$
2018-04-02 18:33:04 Error: Incorrect or no genesis block found. Wrong datadir for network?
2018-04-02 18:33:04 Shutdown : In progress...
2018-04-02 18:33:04 StopNode()
2018-04-02 18:33:04 Flushed 0 addresses to peers.dat  3ms
2018-04-02 18:33:04 Committing 0 changed transactions to coin database...
2018-04-02 18:33:04 Shutdown : done


texts: I'm interested in doing some research on the ripple system. Is there a whitepaper which explains the underlying fundamentals and how they are realised? I know about the Wiki, but that is not citeable in research publications.


texts: Building Signed Bitcoin Transaction in Java

texts:
I have been attempting to build my own raw transaction generator in Java which I can then broadcast on the testnet network. The problem is when I attempt to broadcast the transaction it says there is an error in the redemption script, which I do not understand.

Here is an example testnet transaction:

  0100000001e468833270cf713f3bbccc62b7b5b0fc0b0a4570608718530816795a6589f322000000008a473044022051646b77924f6bb7c411c5aa890110ab55db8812b8998fe24c8bdce39795ebd602200bc4de18fd5524ad8b946ee57604424e2b943ef2a14fc7199a7853dda0743cbe014104b97c679207532e0f4ee2515aedaba5f87700bbe0138f7457baa58e89a53153823ab29632e6c3c804ecaab5913656512339792479a1b898b7e5dc31f075ff8660ffffffff0176df1710000000001976a91448ddfd3891f3f422d5c3c9c25e35b382667fc6e688ac00000000

The script I am attempting to unlock:

  76a91448ddfd3891f3f422d5c3c9c25e35b382667fc6e688ac

With the redemption script being:

  473044022051646b77924f6bb7c411c5aa890110ab55db8812b8998fe24c8bdce39795ebd602200bc4de18fd5524ad8b946ee57604424e2b943ef2a14fc7199a7853dda0743cbe014104b97c679207532e0f4ee2515aedaba5f87700bbe0138f7457baa58e89a53153823ab29632e6c3c804ecaab5913656512339792479a1b898b7e5dc31f075ff8660

This is the Java code to sign the reverse double sha256 hash:

  public static byte[] sign(byte[] hash, BigInteger priv){

        ECDSASigner signer = new ECDSASigner(new HMacDSAKCalculator(new SHA256Digest()));
        signer.init(true, new ECPrivateKeyParameters(priv, domain));

        BigInteger[] signature = signer.generateSignature(hash);
        ByteArrayOutputStream s = new ByteArrayOutputStream();

        try {
            DERSequenceGenerator seq = new DERSequenceGenerator(s);
            seq.addObject(new ASN1Integer(signature[0]));
            seq.addObject(new ASN1Integer(signature[1]));
            seq.close();
            return s.toByteArray();
        }
        catch(IOException e){
            return null;
        }
    }

What is wrong?


texts: Ironically, encryption is not an important part of bitcoin (?)

texts:
The above statement is taken out of a book which I've been reading: Mastering Bitcoin 2nd Edition.

  ...as its communications and transaction data are not encrypted and do
  not need to be encrypted to protect the funds...

Just started about bitcoin, going through the third chapter and when I come across the above lines, I merely struck by one question, and that is, if the communication happens between (peers' / wallet to bitcoin network) is not encrypted...then I am just thinking a scenario

X is sending BTC to Z (obviously by mentioning Z's address in txn)

Y (bad guy) cuts in the communication which is not encrypted (as per the above reading) and tampers the transaction that X has been sent ( by Just putting his address in beneficiary )

I mean, honestly, it is a very naive scenario that anyone could think of and I know there would be something in bitcoin (which I am not aware of) could prevent this from happening, so, giving clarification on how this kind of attacks being handled or mitigated in Bitcoin would be much helpful for this post.


texts: What's the advantage to requesting a higher difficulty when mining?

texts: I've seen pools recommend higher difficulties for higher-speed hardware - what's the benefit (for either the pool or the miner) in doing so?


texts: Is there any difference in hashrate if I mine from mainboard with pci-e v1 v2 or v3. Also is there difference if I use x1 slot with extension to x16?


texts: Can you inherit bitcoins without the private key?

texts:
Since the private key is needed to validate ownership, how does it work when you cannot access the private key?

Say X owned bitcoins and willed it to Y, but Y does not have X's private key. Say X's estate does not want to to give access to the private key or the location of the private key is untraceable.


texts: What restrictions are there to the application of opt-in RBF?

texts:
It is a common meme in some parts of the Bitcoin sphere that RBF erodes the option of accepting zero confirmation transactions. It would be beneficial if the following questions were answered:

What restrictions are placed on RBF in the deployed "opt-in RBF" variant?
How does opt-in RBF interact with unconfirmed transactions?
What influence does this have on zero confirmation payment processing?


texts: Set bitcoin fee lower than minimum estimatesmartfee value

texts:
Currently when I broadcast transactions, I seem to be unable to do so with a fee below ~10^-4 bitcoin (~$2 at current exchange rate). Any 'conftarget' value between approximately 100 - 1000 yields the same ~10^-4 estimate. I would prefer to send some less urgent transactions with lower fees but it's not clear how to do so if when I set conftarget=1008 (which I believe is the bitcoin core max) for the transaction, I cannot access fees lower than described. Is this expected behaviour for Bitcoin Core?
On a related note, it is not completely clear to me how the estimatesmartfee 'estimate_mode' parameter functions. From the help, I can see that the options are 'ECONOMICAL' and 'CONSERVATIVE', which seem quite self-explanatory on a high level (former estimates lower fees than latter for same conftarget), but in practice - how does the estimation differ? So far I have used the default 'UNSET', which I understand defaults to 'CONSERVATIVE' - would this affect the value of the apparent minimum possible network fee described above?


texts: Who was the owner of the first crypto exchange bitcoinmarket.com (aka dwdollar)?

texts:
I am researching the early history of Bitcoin. We know that bitcoinmarket.com (the first exchange) was created by 'dwdollar'. Did we ever find out the real name of the owner or owners? or are these people still anonymous?
Edit: It seems his first name is Dustin. Not sure about last name.


texts: Do I need to open the client(I use multiBit) while transaction is being confirmed?

texts: Do I need to keep the client(I use multiBit) running while transaction is being confirmed? I have started a transaction at 1:00 nignight, when I get up at 6:00, it still didn't finish! they say a transaction need 6 confirm witch cost about 1,5 hours.


texts: I have more than 20 paper wallets with very little bitcoin in them. How can I combine all of them together?

texts: I have a bunch of paper wallets with different small amounts of Bitcoin in them. How can I combine them all into one address without having to pay a fee for sending each paper wallet to my own account? How to do a bulk send and pay a one time fee that would be cheap?


texts: Raspberry Pi cpuminer error: -bash: ./minerd: No such file or directory

texts:
I created a cpuminer instance for my Raspberry Pi derived from this tutorial.  Apparently, I've correctly configured the implementation because I can run the example provided in the README:

./cpuminer -u alexanderjsingleton.Pericles -p pass -o stratum+tcp://stratum.slushpool.com:3333 -t cputhreads

Apparently, that command is indeed the example because I'm not seeing any feedback displayed within my slushpool-account dashboard for that worker.
 However, according to this StackExchange:Bitcoin post, the appropriate cpuminer-syntax should be:

./minerd -u alexanderjsingleton.Pericles -p pass -o stratum+tcp://stratum.slushpool.com:3333 -t cputhreads

but that command returns the following error:

   ./minerd -h --algo scrypt --scantime 33  --url stratum+tcp://stratum.slushpool.com:3333 --userpass [alexanderjsingleton.Pericles]:[password] --threads 1 --retries -1 -P
-bash: ./minerd: No such file or directory

In any case, this is my first experiment with actual Bitcoin-mining, so I'd appreciate any guidance whatsoever to start mining on my first block- thank you!


texts: HD wallet getting every time diffrent derivedPrivatekey from same derivation path

texts:
every time i am getting diffrent orderPrivateKey and address for same derivation path. but it should be same as i am not changing derivation path.

var bitcore = require('bitcore-lib');
var DerivationPath = "m/44'/145'/0'/0"
var hdPrivateKey = new bitcore.HDPrivateKey('testnet','xprv8ZgxMBicQKsPdsKyyKSwTJtBXWB1rbDwEAxW3xV6xwNeCHs3n9kvFsCZim8KKMgc3wVGRJR4kJ82t9mRRr8TZ3Ybpxqp8brRA7aMVDJgCt2');
var orderPrivateKey  = hdPrivateKey.derive(DerivationPath).privateKey;
var Address = orderPrivateKey.toAddress().toString();

can anyone explain it??