texts: How do I get the scriptPubKey type from the raw output script?

texts:
I use zeroMQ to get the transactions from Bitcoin Core.
The output looks like this:

{ value: 200000,
  script: <Buffer 00 20 e3 30 7e 8e 0b 63 0e 53 c2 f1 f8 17 06 7b ce 01 c4 38 92 83 3e 02 2d ad f5 e9 5f 31 be 89 b1 22>
}

The same output looks like this in Bitcoin Core:

{
      "value": 0.00200000,
      "n": 0,
      "scriptPubKey": {
        "asm": "0 e3307e8e0b630e53c2f1f817067bce01c43892833e022dadf5e95f31be89b122",
        "hex": "0020e3307e8e0b630e53c2f1f817067bce01c43892833e022dadf5e95f31be89b122",
        "reqSigs": 1,
        "type": "witness_v0_scripthash",
        "addresses": [
          "tb1quvc8arstvv898sh3lqtsv77wq8zr3y5r8cpzmt04a90nr05fky3qemqr3j"
        ]
      }
    }

Question: How do I get the scriptPubKey type from the script buffer ?


texts: Potential security problem: wallettpassphrase opens up the wallet for everybody!

texts:
I am dabbling with Bitcoin-QT with -server parameter locally, I guess this is not very different from using bitcoind remotely. I use Java and some http client library pluss a json parser to communicate with Bitcoin API via JSON RPC. However, this question is not related to the platform I use in any way, this is a pure Bitcoin API question.

What I have noticed is the following: if I make a call to wallettpassphrase with timeout, say, 5 seconds, the wallet remains open for all other connections for the same amount of time. For example, if connection A issues wallettpassphrase my_phrase 5, another connection, say B, does not have to know passphrase to spend coins. It is sufficient to try many times until some other connection opens up the wallet.

I haven't tried it myself, but I wonder... is this the same with bitcoind? In other word, if 2 different machines, A and B, connect to the same bitcoind server residing on a third machine, say C, and if machine A issues walletpassphrase for 5 seconds, will machine B be able to spend coins without knowing the passphrase within those 5 seconds?

If it will, isn't this a most serious impendiment for using bitcoind with many connections?


texts: Remove Orphan blocks from "personal" blockchain

texts:
Alright, so I've been trying to learn a little more about the blockchain and blockchain-development lately. For every other altcoin, I've noticed that there's such a thing as a bootstrap.dat-file which, as I understood it, essentially is a file containing the "correct" blockchain which simply get imported to the computer in order to speed up the synchronisation of the blockchain of a certain coin. I would like to learn how to create one of these bootstrap.dat-files by myself (or at least learn the theory behind it).

I found this post. I followed the instructions in the second answer, running this cat blk000*.dat > bootstrap.dat code in Terminal which did create a bootstrap-file. I imported this to my second computer, started the client (Fastcoin 0.8.7.2) and while this worked I was unable to restart the client as it almost immediately freezes while it keeps reading data from the disk. I have to force quit the client to get out of this. I emailed the support and while I wait for their answer I figured I'd try to make some research by myself.

According to this thread on Bitcointalk, a valid bootstrap.dat-file does not contain orphan blocks (which I know mine does) and have the blocks in the correct order (which I'm not sure how to check). I read that Bitcoin uses a linearize.py-script to resolve these issues, but as I understood it it doesn't use the data on disk to do this but rather from a server which is not what I'm trying to do.

Since the code in my third paragraph actually did create a bootstrap-file, I figure I might be on to something that way. But how do I avoid the orphan-blocks/sort them out as well as getting the "valid" blocks in the correct order? All help will be greatly appreciated!


texts: What are some of the GitHub alternatives that you consider for Bitcoin Core and other Bitcoin related projects?

texts:
Time for Bitcoin Core and other bitcoin related projects to look for GitHub alternatives?
Some of the issues:
https://techcrunch.com/2019/07/29/github-ban-sanctioned-countries/
https://twitter.com/lrvick/status/1320246266270519297
https://twitter.com/jonatack/status/1315623229747322880


texts: Redeeming a raw transaction step by step example required

texts:
I am looking, specifically, for a step by step example transaction of sending Bitcoin which uses an actual transaction (How To Redeem A Basic Txn, from a few years back, does a great job of outlining most steps of sending a raw txn but does not use a real TxID).

I have played around with both the Python pybitcointools library, the SX library and JSON output from the Bitcoin Core client (Bitcoin-QT, Bitcoin-cli, Bitcoin daemon) but have yet to find an actual step by step guide using raw transaction output (single input / single output Bitcoin txn, ie not multisig).

Hopefully the bounty will bring a step by step example transaction (with private keys for the sending address) will bring an answer showing how it's done and, specifically:

how the ScriptPubKey element fits into the raw txn
how the ScriptSig element fits into the raw txn
how the txn is signed (with DER encoding).

EDIT: I think the best resource is Ken Shirriff's Bitcoins the hard way: Using the raw Bitcoin protocol, but again, there's no single source online that answers my question without skimming past areas like scriptPubKey, signing etc.

When I activate the bounty, if you can answer this refer to this Tx as it can serve as the actual example (ie I'll provide ~$1 in BTC and private keys for 1From/1MBngSqZbMydscpzSoehjP8kznMaHAzh9y if interested)

EDIT 2: The RoyalFork Blog: Deconstructing Txns provides an unbelievably good reference for interactive Txn creation


texts: Pros and Cons between Ripple payment verification and centralized authority's payment verification

texts: I want to know the advantages and disadvantages between Ripple payment verification system and centralized authority's payment verification system.


texts:
How many languages are mnemonic seeds currently offered in other than English?

Does the entropy for different languages depend on the number of words the relevant dictionary has available to draw from?


texts: How to delete my BlockChain.info account?

texts: Is there any way to delete a BlockChain.info account? I am not able to find any such option in settings.


texts: When opening a LN channel using LND, what does 'push-amt' do?

texts:
I set up Lightning node (LND) and wanted to receive a payment. Autopilot for managing the channels always creates channels w/ zero remote balance, thus nobody can route a payment to/through my node.

The command for manual channel opening is lncli openchannel [command options] node-key local-amt push-amt. If I specify nonzero push-amt, the remote balance is then, unsurprisingly, nonzero.

But what I find very confusing is "whose" money that was? Have I just given my peer free bitcoin?

The help command for openchannel push-amt states: the number of satoshis to push to the remote side as part of the initial commitment state (default: 0).


texts: Is bitcoin the only entrance to buying other coins?

texts:
I am totally newbie and looking into buying some other coins such as Megacoin and Quark with my bank account. After some research, I found that the only way to buy those coins seems to be buying them with Bitcoin.

Are there ways for me to directly buy other coins?


texts: Is it possible to handle BCH transactions on Bitcoin Core wallet?

texts:
I've installed Bitcoin Core on a server and it works well for BTC. I would like to know can I use the same server and platform to support BCH too?
I know that the addresses generated in Bitcoin Core are usable for BCH too. But how if I am able to handle BCH transactions in this machine, how can I differ them from BTC ones?

Thank you in advance for your replies.


texts: How many days the verification could take?

texts:
I first time bought a smaller piece of bitcoin and wanted to do some shopping from that, but I still my wallet contains only not confirmed bitcoins.

My questions are:

Why the confirmation takes so long?
I saw a page that shows the total count of unconfirmed transactions, its increasing, not decreasing - could it mean that my transaction will never be confirmed?
How does the confirmation work?

Thanks!


texts: How does a Cryptocurrency Exchange Start

texts:
I understand the basics of an exchange and how they work, but I am confused as to how one initially begins.

For example, in order for an exchange to function, there needs to be both bids and asks simultaneously. If there is no asks, then no one can buy that specific cryptocurrency therefore there is no volume/trades.

Would an exchange have to simply front some money and place ask orders themselves in order to get the volume jump started and then having the market take over?


texts: In Deepbit how do you get the Bitcoins transfered to your wallet?

texts: In Deepbit I've mined a fraction of a Bitcoin. How do I get the money into my wallet? Here it says "Instant payout button is shown when your balance is at least 0.01 BTC and you received less than 3 payments in last 24 hours." does this mean I have to wait until I have mad 0.01BTC?


texts: How does the architecture prevent someone taking over by running a several billion clients?

texts:
I'm new to bitcoin and was wondering: As far as I know, bitcoin relies that the majority of the users is to be trusted.

Why is it not a problem then if someone starts up billions of clients, eg. a data center owner? Seemingly a single entity could take over the whole network. What is the bitcoin feature that is the counter-measure here?


texts: bech32 addresses beginning with "bcrt..." on regtest

texts:
I'm playing around with regtest and wanted to generate a bech32 address. My Bitcoin Core version is 0.18.0.

I ran getnewaddress "" bech32 and got an address that began with bcrt, like this one : bcrt1qs758ursh4q9z627kt3pp5yysm78ddny6txaqgw.

I'm a bit surprised, because I was thinking that testnet bech32 addresses were different, and indeed I checked this page that says it should begin with tb1...

I tried to send some tbtc to this address with Electrum and a faucet, none worked, they indeed both say address is invalid.

So what am I missing here?


texts:
a couple of question before I have my own wallet.

Does having a wallet require personally identifiable information?  Do I need to use my real first and last name or company name, etc?

It seems that individual transactions in your wallet are always public. What about your total balance?  Is it possible to be a bitcoin millionaire without others knowing about it?  If you trade a few bitcoins for real currency every once in a while (i.e. make "withdrawals" for the lack of a better word), will people know that also?


texts: Someone said they would send me bitcoin, they sent me a exe file, called bitcoin.exe, and it is not running

texts: They said they saved bitcoin in that exe file. How do I access this bitcoin? They also created other bitcoin exe files with different names. Thank you


texts: Is there a list of countries that are not likely to persecute bitcoin businesses?

texts:
It seems that at some point countries will start cracking down on Bitcoins.  And Bitcoin is designed to handle that.  However, are there some countries that are openly friendly to bitcoin businesses and/or have a history of permitting additional currencies.

To put this question in another way, are there countries that are to Bitcoins like Switzerland is to banking?


texts: Can a Lightning channel's initial BTC value be updated?

texts: When an LN channel is created, it is funded with an initial BTC amount by at least one one peer. But given that most of the whole idea of LN is the existence of long running channels, I wonder if this means that it's possible for a channel to be "emptied", thus making "long running" a bit of a misnomer. Is it therefore possible for the channel's creator to "top up" the channel?


texts: Recover Old Bitcoin Wallet (Currently getting a Segfault)

texts:
I have a bit of bitcoin lingering in an old bitcoin wallet (circa 2011). I just restored it from a backup but I can't seem to load it into bitcoin-qt.

If I launch the app, shut it down, the copy in my old wallet.dat file and re-open, it shows a zero balance.

If, instead, I shut it down, copy over the entirety of my old .bitcoin folder, and then re-open, I get an immediate segfault. How screwed am I?


texts:
Whenever Bitcoins are discussed, one generally reads how "Bitcoins are decentralized. No company nor state controls them". My question is, how is this statement true when you read about how Bitcoin Clients find each other.

Reading from here How do Bitcoin clients find each other? we find out that Bitcoin clients use a number of ways to find other Bitcoin clients. To summarize those methods can be:

List of previous connections
DNS seeds which points to host names
(Abandoned) IRC server

So with that in mind, how are these methods decentralized? I understand how method one is, but method one can not act always act as the default method per new connections.

When you look at method 2 and 3, I question primarily the decentralized nature of a host name, as someone has to pay for the registration of said domain name and the ICANN organization is responsible for such registration. While method 3, someone has to host a server. Someone is paying for or owns the hardware and is therefore not decentralized.

The only methods I can think of that are truly decentralized is

List of previous connections (As currently implemented)
IP/Port scan for other Bitcoin clients. (Attempt to initiate a handshake to identify other clients. I understand this would be incredibly slow but seems purely decentralized to me)

Can anyone shed light how the actual methods do ensure Bitcoin is decentralized? My only other thought is the "spec" of Bitcoin is decentralized and the implementation of the clients themselves happen to not be.


texts: Why check for multiple nonces despite finding a golden nonce?

texts:
I'm still new at trying to understand the entire idea surrounding the mining process.
I read the following:

When mining, you are given a set of data to perform hashes on. As you
noted, this is done by manipulating the nonce and hashing each time
the nonce changes. What you really want to do is check all possible
nonces. Even if you've already found a "golden nonce" (one which gives
you a hash starting with 32 zeros), you need to keep searching for
more. There could be anywhere between 0 and 2^32 solutions to a given
block of work, so it is in your best interest to keep looking for
more. Hence, there are no stop conditions in the sense of when to stop
running your algorithm, other than having exhausted all possible
nonces (at which point, you would get more work).

Source
This confused me, because I thought that once you found a golden nonce, you can broadcast that to the network and move on. Why would you continue to check for more? Is it because if you let's say found 5 golden nonces and broadcasted all of them as you found them, you'd have a higher probability that the next block would be building off the one you found? Adding onto that, if many people find valid nonces to a block, how is the winner of the reward, and which gets included in the main chain, determined?


texts: How do I check if a particular address is 'owned' by a loaded wallet in Bitcoin Core?

texts:
I'm interested in knowing if there is an rpc method to determine whether or not an address was generated, and thus is owned by, a loaded Bitcoin Core wallet.
I have a few addresses that I generated a month or so ago using getnewaddress. These have been stored in a relatively secure encrypted location. In my paranoia, I am reluctant to now use the addresses to receive funds in the wallet, since as far as I know there is no benefit in doing so (besides increasing the gap between used addresses - but I am in no way approaching any gap limit, so this is irrelevant) over simply generating a new address which I can be sure is indeed owned by the loaded wallet. That said, I am curious to know if this is possible (since it may in some cases be useful, if sufficiently trustworthy - which if it were an rpc method for a trusted Bitcoin Corre instance, I'd assume to be the case) and after searching bitcoin.org RPC docs and on here, I have not been able to find an answer to this yet.
Note - I am aware of the validateaddress rpc, but as far as I understand, this only validates whether or not a Bitcoin address is valid, not whether it is associated with the loaded (or any particular) wallet.


texts: Bitcoin multi-sign and the amount of storage it required

texts:
I read the paper "Threshold-optimal DSA/ECDSA signatures and an application to Bitcoin wallet security". The authors said that in the optimal threshold signature that they propose, players require just a constant amount of storage, while the previous threshold schemes were not efficient because the number of rounds increase according to the number of players; therefore, also the amount of storage that each player needs increased accordingly.

Now, I am wondering about the amount of storage that each players needs when they use multi-signature scheme?
Is it constant or does it increase when the number of player increase?


texts: Could an algorithm be made ASIC-resistant by simply adding deterministic permutations depending on the hash of the previous block and the nonce?

texts:
I was thinking of permuting bits in a block before it is hashed, in order to require some adaptability from the mining hardware while retaining the security of SHA-256.

Permutations would depend on the hash of the previous block so that they cannot be anticipated.
They would also depend on the nonce, so that the permutation step would have to be performed once per hash, preventing a single external CPU from efficiently preprocessing the data.

A simple example of algorithm:

Seed a pseudo-random number generator with the hash of the previous block appended to the nonce. Draw 1000 pairs of pseudo-random numbers between 1 and the length of the block in bits. Swap the bits corresponding to these pairs. Hash with SHA-256.

It seems to me these permutations would be particularly troublesome to implement electronically, and I was thinking this might drive up the cost of ASIC implementations.


texts: Can a Trezor accept/use a private key created independently offline?

texts: Can I create a private key using bitaddress.org offline and then use that private key in a trezor wallet? Also will the trezor use that private key to produce a mnemonic phrase?


texts: Should we wait 10 minutes to confirm a transaction

texts:
I have read this proof of work calculation takes about 10 minutes. That mean people who are making the transaction should wait 10 minutes ?

Let's imagine i want to buy a drink with bitcoin. The waiter should wait 10 minutes to be sure the transaction is okay before giving me a beer ?

Thanks


texts: What exactly is a "non-fungible token" and why would anyone care or want one?

texts:
https://en.wikipedia.org/wiki/Non-fungible_token
I've read that many times. It makes zero sense to me. (Just like 99,99% of the nonsensical word salad that's said these days.)
Okay, so it's some kind of garbagecoin where each coin is "unique", and that's somehow... worth money? What?
Isn't the truth that this is just yet another crypto currency-related scam designed purely to make people give them money so that they can buy more Bitcoin, the only crypto-currency which has actual value?


texts: Proving the address belongs to a shared wallet where one can control some deposits and withdrawals

texts:
A bitcoin exchange is using a shared web wallet where its users deposits and withdraw bitcoins. The withdrawal transactions are merged, so that the pending transactions of several users are grouped together to save tx fees. The shared wallet is backed by a normal bitcoind installation.

Let's imagine we want to confirm that particular address X belongs to the shared wallet. The address X has received Bitcoins and then some of those Bitcoins have been withdrew through other unrelated transactions.

Because we are the users of the same shared web wallet, we can send in and out Bitcoins from this shared wallet and we gain knowledge of some receiving and change addresses and transactions related to the shared wallet.

Thus, is it possible to

To prove address X belongs to the shared wallet by analyzing the other transactions we know to belong to this shared wallet
Are there any tools or scripts to do this kind of blockchain analysis yet


texts: First time buyer, questions before I screw up

texts:
I am wanting to buy BTC to buy goods but things are a bit confusing to me.

First off, would I be better off buying from someone or a website, or use an atm? Once I purchase the BTC what is the best place to store it? I don't want to link bank accounts and all that which is why I think using an atm would be best.

If I do use the atm here locally do they just give me a QR code and if so what's the best mobile app to use to get my coins where I can spend them? I've read the FAQs around I'm just still a bit confused.

All help is greatly appreciated


texts:
Just noticed 2 conflicting blocks by the same pool.

One of the blocks was naturally orphaned, but why would the same pool broadcast 2 such blocks? Does it happen often?


texts:
1 - Whats is the limit for sendmany?
2 - Can i batch a large number of payments (several hundreds)?
3 - Does an error in processing any address would interrupt the whole process?


texts: Can you transfer NXT assets directly to another nxt account?

texts: I purchased a few mgwBTC (multigateway bitcoins) and I want to be able to transfer them to my other account. Is this possible? Can someone take a snapshot of how this is done? thanks.


texts: Blockchain validation process is linear?

texts:
I've read at a few places that the nodes validate transactions in a linear fashion, i.e. after node A validates, then node B, etc. (which is also the reason, as claimed by many, why blockchain suffers from a scalability issue)
But if blockchain is decentralized, how would the nodes know in what global order to validate? It must be the case that several nodes validate on the same block in parallel.


texts: What is the chance of someone (randomly) finding the private key for an existing Bitcoin address?

texts:
Say I have created a paper wallet with one bitcoin address in a vault. What are chances that someone else will find the private key for this wallet?

Related: what are the chances of vanitygen address - private key pair collision?


texts: Does the future SIGHASH_ANYPREVOUT capability hurt the privacy of Taproot lightning channels?

texts:
One of the advantages I've heard about Taproot is that all transactions will appear identical to a blockchain observer. This would of course also be true for lightning channel open/close transactions as well which would be a great privacy benefit for lightning users.
For what I understand of the proposed ANYPREVOUT upgrade, it will build on top of Taproot but will need to use a different length pubkey. Would it be possible for an observer to scan the blockchain for this pubkey length in order to determine which transactions are using ANYPREVOUT, and are therefore likely to be lightning related? Or is it possible to somehow hide this inside Taproot in such a way that privacy can still be maintained?


texts: How does blockchain.info resolve adresses?

texts:
I wonder how sites such as blockchain.info resolve the owners of public bitcoin addresses. For example, blockchain.info knows that the xkcd donation address 14FHqYSgA... belongs to xkcd.com. It is available at xkcd.com/bitcoin, but somebody must be crawling all websites searching for that folder, right?

I assume there is a directory where this kind of websites are stored so that blockchain.info can look it up. Where is it and is there a public API available?

Thanks!


texts:
Situation: bitcoin hardforks and I got payment with coins, that were in the blockchain before fork:

what can prevent me for sending the same transaction to the other forked network and get the second forked money, because I have a signed sending transaction and I own the target address private keys.


texts:
I am implementing a payment module for bitcoins.

I have the following case. I need customers to be able to pay in bitcoins. But for some reasons I cannot use existing solutions like Bitpay.

Therefore I have thought and ended up with the following solution.

We have a private key wallet of HD type, so we can generate child addresses from our master key.
When a user tries to pay in Bitcoins we are generating a new address and display it to the user.
We associate an address with an order id
A daemon running in background is checking pending orders requesting information from Blockchain for a concrete address and checking whether this address received amount equal to an order total sum.
In case there are more than X confirmations we are setting a status of an order to PAID

I wonder whether this is acceptable solutions or maybe there are some better ways to implement custom bitcoin payments ?

I would be great for any suggestions and help.

Thanks


texts: Can I force json_encode in PHP to output 8 digits after dot for RPC?

texts:
after reading bitcoin wiki "Proper money handling" I supposed that there shouldn't be any precision problems.

However, sending/moving for instance 16999999.99999999 sends/moves 17000000.
I figured out where the problem is:
- PHP stores float value with sufficient precision. I can printf it with 8 correct digits after dot.
- json-rpc php library copies that float into "params" array, and again, precision is fine.
- Unfortunately, string produced by json_encode() used in json-rpc library contains "rounded" value, so there is a problem.

So, can I force json_encode() to output 8 digits (or more)? Or do I have to write my own, which isn't very complicated, but will be rather slower than standard function.

Please note those topics about problems with floats in PHP and Python on bitcointalk, so it is not my fault. One of the results of this issue is genjix branch of bitcoin, that sends amounts as strings.

Best wishes


texts: Why do the Bitcoin RPC Calls use decimals for coin amounts?

texts:
The Bitcoin RPC calls all use 8 digit decimals ('reals') to encode amounts of satoshis. For example, if I get a transaction output, it might look like this:

{
  "value" : 0.00050000,
  "n" : 1,
  "scriptPubKey" : {
  "asm" : "OP_HASH160 c6e0b29d2aa23b6436cec99e65dfeed2c64a2cad OP_EQUAL",
  "hex" : "a914c6e0b29d2aa23b6436cec99e65dfeed2c64a2cad87",
  "reqSigs" : 1,
  "type" : "scripthash",
  "addresses" : [
    "3KpatoAjz3H5huJJieSpH4j7qFUeTXMnFC"
  ]
}

Is there a reason the developers decided to work with "0.00050000" instead of just "50000"? A whole number seems like it would be better for computers to work with.

EDIT: I guess the other half of this is that if the RPC calls are being used by a person, then it is easier to use with amounts in decimals (a human can tell the difference between 5.5 and 0.55 a lot easier than 55000000 and 5500000). So I guess the real question is, is the RPC interface meant to be used more for human command line use or for coding applications' use?


texts: Bitcoin cross trading from Bitstamp to Bitfinex

texts:
Bitstamp exchange price for Bitcoin is right now 1056.07 USD

https://bitcoinaverage.com/en/exchanges/bitstamp/btc-to-usd

while Bitfinex is 963.41 USD

https://bitcoinaverage.com/en/exchanges/bitfinex/btc-to-usd

Is it possible to exploit such a big difference to extract value? Probably this is a well known strategy on markets, but my finance knowledge is quite limited.

Is there any bot doing that kind of operations without human intervention? Thx!

Refs.:

Bitcoin trading at bitstamp

How Does One Make Money from Bitcoin Trading?

Need help understanding how to profit from bitcoin trading (like forex?)

Is there a forum-like exchange for trading Bitcoins person-to-person?

http://en.wikipedia.org/wiki/Order_book_%28trading%29


texts:
I really need some help.

So as you know, BTC is out there, and I recall at the beginning of 2015 when it was really not a big deal, I decided to get learn more about btc and somehow I downloaded a type of software in my laptop that allowed me mine BTC now, my laptop ran for days and really I thought it was not a good idea  i decided to cancel the process, but somehow it looks like I mined some btc, now my laptop got really full on space  so i took it to the apple store and they figured out what happened,this happened at the beginning of this year 2017, I had an external hard drive and i put all those codes, blocks, pages however they may be call into the folder and they genius guy told me that i may havce some good money there bc it was a lot.

now, with that story put out there, my question is; how can i transfer those things from my external hard drive to a physical btc wallet? so i can somehow enjoy it.

any advice will highly appreciated it.


texts: where in the source code is the the proof of work checking the blockheader hash and nonce?

texts:
Where in the source code do we check whether

 hash(blockheader*nonce) < Difficulty

In fact, the line I found is as follows:
https://github.com/bitcoin/bitcoin/blob/v0.17.0.1/src/pow.cpp#L87

My problem with this is 3-fold

a) this is not the code that miners use to perform the check; it probably is the validation on node-side ?

b) here the "hash" refers to what exactly ?

c) why is this value tested against nTarget ? rather than Difficulty ?

d) this check is usually advertised in media as "<"less rather than "<=" less than equal. But seeing how this line
is coded , it means
     HASH<= nTarget
is OK.


texts: Bitcoin "scantxoutset" rpc command return response too slow

texts:
For one of our decentralized mobile wallet, We need to fetch balance of imported BTC address quickly.
After lot of research on google then I found Bitcoin deamon rpc command "scantxoutset", which give unspent outputs of imported address.
The only problem with this command is that it takes more than a minute to return the response, which is too slow. User will not wait for 1 minute.
Anyone, could you please suggest me, is there any alternative to fetch the balance of imported BTC address quickly from the BTC node. ( not from any third party api)
Thanks.


texts: Where can I get a list of places I can use my Bitcoins?

texts:
I am new to Bitcoin and I'm trying to understand how it works and how I can make it work for me.

So, let's say I travel often to different Spanish speaking countries in South America and Spain. How can I acquire a list of all the vendors, merchants, services, etc. that use the Bitcoin exchange in all these areas to avoid using the banking system of "money transfer?"


texts: Mining Bitcoin Wallet's Private Keys Instead of Blocks

texts:
Instead of mining Bitcoins directly, couldn't one of these huge processing farms dedicate their processing power to instead discovering the private keys of the largest wallets on the ledger?

I realize randomly guessing private keys is unlikely. However unlikely though, it would seem you'd increase your likelihood for each additional guess and a mining farm could do a lot of guessing with 24 hours a day 365 days a year. And, any particular guess could be the lucky one that cracks the wallet.

I'm asking this question not because I want to do this. I'm asking it because "if I can think of it" someone else is probably already trying it.

Each day, this farm could query the top 10 wallets in the ledger and just do random private key guesses all day long. If these big accounts switched wallets each day, it wouldn't matter, a farm would be guessing on those new wallets constantly (what ever is top 10, at any given time, could be constantly randomly guessed at).

What prevents this?


texts:
I am running Bitcoin-Qt, and it is shutting down my laptop while trying to synchronize. I even tried on a different laptop with the same result of shutting itself down.

This situation happens while synchronizing, the CPU usage and the CPU temperature raises dramatically and the computer doesn't have any other option than shutting itself down before becoming permanently damaged. How can I fix this problem?

Here are some of the system details:

Samsung R730 laptop with

4 GB RAM
Intel Core i3 dual core processor
Arch Linux system


texts: Whats the difference in way you installing full nodes

texts: I'm newbie in blockchain world, so I'm curious what is the difference between installing full node by using libs such as bitcore-lib (using node.js) and installing it through the daemon (mentioned here https://bitcoin.org/en/full-node#ubuntu-1604) (sudo apt-add-repository ppa:bitcoin/bitcoin etc..)


texts:
Is it worth mining Litecoins and then exchange them for Bitcoins (because I am not sure if there will be space for more crypto currencies in the future)?

I can get about 25k hash/sec by CPU mining on my laptop, so this turns in something about 0.1 LTC per day which is 0.06 BTC per month (current exchange rate is 1:50). Does my approach make any sense or is there nowadays even any way to mine with everage/above average hardware?


texts:
I have tried to installed zcash insight ui & api in my local machine (ubuntu OS) and it is completed all the steps but I m facing issue while start services in frontground.

Let me share with you command, config file.

npm install -g zcash-bitcore-node
zcash-bitcore-node create mynode
cd mynode
zcash-bitcore-node install insight-api
zcash-bitcore-node install insight-ui
zcash-bitcore-node start

But getting below error in my terminal:

[2018-01-30T12:33:03.687Z] info: Using config: /home/kiran/zcashnodenew/zcash-bitcore-node.json
[2018-01-30T12:33:03.688Z] info: Using network: testnet
[2018-01-30T12:33:03.688Z] info: Starting bitcoind
[2018-01-30T12:33:03.690Z] info: Using zcash config file: /home/kiran/zcashnodenew/data/zcash.conf
[2018-01-30T12:33:03.691Z] info: Starting zcash process
[2018-01-30T12:33:03.699Z] error: Error: spawn /usr/local/lib/node_modules/zcash-bitcore-node/bin/zcashd ENOENT
at _errnoException (util.js:1003:13)
at Process.ChildProcess._handle.onexit (internal/child_process.js:201:19)
at onErrorNT (internal/child_process.js:389:16)
at process._tickCallback (internal/process/next_tick.js:152:19)

MY Config File  (zcash-bitcore-node.json)

{
  "network": "testnet",
  "port": 3003,
  "services": [
    "bitcoind",
    "insight-api",
    "insight-ui",
    "web"
  ],
  "servicesConfig": {
    "bitcoind": {
      "spawn": {
        "datadir": "./data",
        "exec": "/usr/local/lib/node_modules/zcash-bitcore-node/bin/zcashd"
      }
    }
  }
}

Zcash Config  (zcash.conf)

server=1
whitelist=127.0.0.1
txindex=1
addressindex=1
timestampindex=1
spentindex=1
zmqpubrawtx=tcp://127.0.0.1:28332
zmqpubhashblock=tcp://127.0.0.1:28332
rpcallowip=127.0.0.1
rpcuser=bitcoin2
rpcpassword=local321
uacomment=bitcore

Can you please help me with it? What is wrong in which step?


texts: How Lightning channels will helps with scaling in practice

texts:
I watched the 2015 presentation of LN, and I've read a portion of the paper - so I understand basically how the channels work (I think).  However, I'm not sure I've fully grasped how this will help scalability in practice.

If Bob and Alice want to transact (let's say Alice is a random internet retailer - not Amazon - and Bob wants to buy waaaaaay too many tattoo stickers for his daughters for Christmas, not realizing that each little package has like 40 sheets of the things).  Bob would then have to open a channel with Alice, transfer the balance required to complete the purchase, and then the channel would be closed.

For pretty much all economic relationships except for a few enormous ones (Amazon, eBay, Walmart, etc), you won't (and wouldn't be able to) keep open channels all the time.

From these two observations, I wonder: wouldn't the process of opening / closing a channel actually create two transactions to be processed on the blockchain?  If most transactions are between actors who don't maintain channels between themselves, then how does LN actually help?

If the answer is "you keep open channels with a small number of other actors and then route payments through open channels", doesn't that encourage a very high degree of centralization due to the prohibitively large capital requirements for main hub nodes?


texts: Bitcoin client which doesn't use wallet.dat?

texts:
Is it possible to use Bitcoin client without wallet.dat file, by entering your addresses and being able to see the balance, but without the ability to spend bitcoins? I know that it's possible to backup wallet.dat and use another wallet.dat, but in that way you don't see your transactions and balance and can't label your addresses etc.

If it's not possible in official client (I believe it isn't), are there alternate clients that allow this? The point is to be able to backup wallet.dat and plug it in only when spending bitcoins, but not lose the ability to see your transactions in the meantime.


texts: Can I use my Electrum seed without Electrum?

texts:
Assumptions:

I've memorized my electrum seed and will never forget it
In the future, I'm robbed of everything but mind and body
In the future, Electrum software is not easily accessible or I can
only access thin clients

Question:

Is there another way to use my 12 word seed?

HTML port of Electrum hosted somewhere?  iOS wallet that's electrum compatible? Etc.

Is there a reason it's local software and not just HTML? (other than someone dedicating the time)

Is there a reason 12 word seeds aren't universal across wallets that use 12 word seeds?


texts: How does the 'queryroutes' function in lightning's LND calculate the route fees?

texts:
I am testing my own routing implementation and for some weird reason a handful of channels reject my payment stating InsufficientFee.

The scenario is A -c1-> B -c2-> C whereby Node A is sending a payment to C via B where the channels used are denoted as c1 and c2.

For c1 the node fee policies are

    "node1_policy": {
        "time_lock_delta": 40,
        "min_htlc": "1",
        "fee_base_msat": "1000",
        "fee_rate_milli_msat": "1",
        "max_htlc_msat": "16777215000",
    },
    "node2_policy": {
        "time_lock_delta": 144,
        "min_htlc": "1000",
        "fee_base_msat": "1000",
        "fee_rate_milli_msat": "100",
        "max_htlc_msat": "16777215000",
    },

For c2 the node fee policies are

    "node1_policy": null,
    "node2_policy": {
        "time_lock_delta": 144,
        "min_htlc": "1000",
        "fee_base_msat": "10000",
        "fee_rate_milli_msat": "100",
        "max_htlc_msat": "10000000000",

    }

For an amount of 4999000 mSat queryroutes uses this route and calculates the fees as

{'amt_to_forward': '4999',
                       'amt_to_forward_msat': '4999000',
                       'chan_capacity': '16777215',
                       'chan_id': 'c1',
                       'fee': '10',
                       'fee_msat': '10499',},
                      {'amt_to_forward': '4999',
                       'amt_to_forward_msat': '4999000',
                       'chan_capacity': '10000000',
                       'chan_id': 'c2',
                       'fee': '0',
                       'fee_msat': '0',}
             'total_amt': '5009',
             'total_amt_msat': '5009499',
             'total_fees': '10',
             'total_fees_msat': '10499',}

Could someone please explain in step-by-step detail how the lnd client gets to this value?


texts: how does node remove conflicting transactions from memory pool?

texts:
Sorry for the long text. This is just my observation and was wondering if you could let me know if I am correct or not.
Case 1)
Let's say minerA and minerB both have the same transaction in their mempool since my transaction got propagated to the network before including it in the block.
Now, Let's say minerA was trying to mine a block and before it did, minerB solved it and broadcasted it to minerA.
Now, it's time that minerA has to remove the conflicting transactions that already happened on minerB's block. How will it remove those transactions from memory pool ? will minerA take a look at the minerB's block, get txId's from the transactions, and check if transactions with those txId is in its mempool and if it is, it removes them from it.
Case 2)
Let's say I have 1 BTC only. I send this 1BTC to address B on minerA, and I send this same BTC at the same time to minerB. minerB will include the transaction to its mempool and then move it to block and start mining on it. minerA will also include the transaction to its mempool, then move it to block and start mining on it.
let's say minerB solved its block quicker and broadcasted it. Now, what's gonna happen is minerA stops mining its block, since minerB was quicker. Now, minerA will look minerB's block, and seems legit. So now it will add it to its chain.
Right now, because minerB block got solved, minerA now needs to validate mempool again (it has to remove conflicting transactions as explained in case 1 and also has to check if after including minerB's block, if minerA's pool still has the valid transactions(balance is valid), in this case, since I only had 1BTC, it will check the transaction that i sent to address b and see that i don't have any BTC anymore. so it will remove it .
NOTE: miner will start validating mempool again before that miner includes transactions in a block and starts mining on it.  right ?
I guess , miners remove transactions from mempool if

transaction is conflicting as explained in Case 1

transaction can't be included anymore because it's already invalid due to blocks mined at the same time as explained in Case 2.

What do you think I missed, do you agree to my observations ?


texts: Do miners have to start over whenever a block is found?

texts:
If I understand correctly, each miner selects a set of pending transactions, puts them in a block, and then tries to sign that block. Pooled miners do the same, but the specific set of transactions is selected by the pool server.

Since each block must link to the previous one, does it mean that whenever a new block is found (by another miner) the whole process must start over?


texts: Is the time a transaction was done recorded in the block chain?

texts: Is there something like a timestamp of each transaction recorded in the block chain, or only the mere fact that the transaction was done?


texts: Is it possible that one knows how much BTC is in wallet.dat without knowing password?

texts:
Someone says that he or she wants to sell his or her wallet.dat which seems to contain a lot of BTC.
He shows screenshot of wallet software containing many BTCs.
He says that when I place wallet.dat in the wallet software location I can see how much BTC in contains, but it needs password to transact.
Is it possible?
Otherwise, is he trying to cheat me out of money?


texts: Several Q's about consensus about the longest chain and when this chain be confirmed?

texts:
According to:

How Does the Blockchain Work?

Each node will adopt the longest chain as the only option.

But what will happen if 2 (or more) nodes will solve the next block at the same time,and they will start to build their own chain ?

Which longest chain (if their chains has the same size) will be adopted ?
When (and who) decide to confirm the longest chain ?


texts: What exactly happens when a new wallet is created?

texts:
I am asking for what is being created when there is a new wallet created.

And the second part of my question is considering public key. Is the public key the same thing as the address? I read that there is for every private key a large pool of 100 adresses. Every adress is used when sending any single transaction and "creating" new adress.


texts: JSON RPC library unable to connect to bitcoind?

texts:
I'm able to connect to bitcoind using my command line and the process is running with the appropriate port but when I try to run it through XAMPP after using the JSON-RPC library (I used the PHP developer intro for the code) it's giving me the following error, and I don't know why:

Warning:  fopen(): Failed to enable crypto in /opt/lampp/htdocs/bitcoins/jsonRPCClient.php on line 132

Warning:  fopen(https://...@127.0.0.1:8332/): failed to open stream: operation failed in /opt/lampp/htdocs/bitcoins/jsonRPCClient.php on line 132
Fatal error:  Uncaught exception 'Exception' with message 'Unable to connect to https://user:password
@127.0.0.1:8332/' in /opt/lampp/htdocs/bitcoins/jsonRPCClient.php:140
Stack trace:
#0 /opt/lampp/htdocs/bitcoins/testServer.php(7): jsonRPCClient->__call('getinfo', Array)
#1 /opt/lampp/htdocs/bitcoins/testServer.php(7): jsonRPCClient->getinfo()
#2 {main}
  thrown in /opt/lampp/htdocs/bitcoins/jsonRPCClient.php on line 140

The code is the following: (we tried toggling between http and https and it's still not working)

require_once 'jsonRPCClient.php';

$bitcoin = new jsonRPCClient('https://user:password@127.0.0.1:8332/');

echo "<pre>\n";
print_r($bitcoin->getinfo());
echo "</pre>";


texts: What will happen on November 15th 2017, when the Segwit proposal expires?

texts:
The time duration for the BIP-148 UASF is from August 1st to November 15th. During this time, the BIP-148 nodes will reject blocks that do not signal for Segwit.

Now, after Nov. 15th, even the BIP-148 nodes would start accepting all the blocks, whether they signal for Segwit or not. So, just after Nov. 15th, what would happen:

Case I: If the BIP-148 block chain is longer than the Legacy block chain?
(My understanding is, this won't even happen. Because if the BIP-148 network hash rate gets higher than that of the Legacy network, the Legacy block chain will always be "in sync" with the BIP-148 block chain, and the two block chains will be exactly the same. Am I correct?)

Case II: If the Legacy block chain is longer than the BIP-148 block chain?
(Now, after Nov 15th, the BIP-148 nodes start accepting all the blocks. The next solved block will most probably be a Legacy block. So, will the BIP-148 nodes switch to the "longer chain" [which is the Legacy chain], and discard all the blocks since the fork happened?)


texts: Moved Bitcoin-Qt wallet to blockchain - can see my funds but can't send them?

texts:
It all started the other day when I sent some coins to Bitcoin-Qt, a 'safer' wallet ... was so slow to sync and was crashing et cetera.

Anyway, I imported the wallet.dat to blockchain.info opening up a mywallet(blockchain) there. I can see the coins in the wallet now, but I can't send them (no access to send option), which is what I have to do.

How to resolve this?


texts: How can I use bitcoin testnet in coinbase php

texts:
I'm using coinbase wallet for bitcoin transactions. Is there any option to use testnet for transactions testing purpose in coinbase?

Any suggestions will helpful.


texts: Where's my Bitcoin Cash? We followed Coinbase's advice and moved our BTC into a Jaxx wallet- No Bitcoin Cash anywhere to be found

texts:
We followed Coinbase's advice and moved our BTC into a Jaxx wallet-until the fork happened, then moved it back into Coinbase, then Gdax.
We never saw any evidence of Bitcoin Cash on either our Jaxx wallet or on Coinbase/Gdax. How do we find it?  And retrieve it?


texts:
I study bitcoin and don't exactly understand that how new wallet generate?
The documentation write below sentence:
"For generate new wallet, first search that there is no such wallet"
How we can found that the new wallet didn't generate before?
What is complexity of search?


texts: Is there an open source bot I can get for BTC-E?

texts: I'm interested in automatic trading but I don't know how to get started.


texts: I heard that china gonna block bitcoin signal and shut down all the miners. Is it possible? if possible is there any way to bypass it？Will Core release new update to prevent this?


texts: Where to find the blockchain on Bitcoin ABC?

texts:
So if I'm running a full node on Bitcoin ABC, where can I find the file or files which contain the blockchain when it is being downloaded?
The folder in Program Files is too small, I think, to contain the blockchain.


texts: I'm exploring the topic of selfish mining attacks and how to detect and stop them. I do not really understand any of given solutions. Can someone please explain in plain English, how selfish mining gets detected, how to stop it from happening and how to react to it when the attack happens? Were there any selfish mining attacks so far? Were there any mitigations of the selfish mining attack added to the Bitcoin protocol since it was described?


texts: Getting the wrong txid for coinbase transactions

texts:
I'm trying to hash transactions to get the txid. I get the hex values from blockchain.info. I get the correct hash for all transactions except for the coinbase when I hash it twice. Is there something different about how the coinbase transaction is supposed to be hashed?

The block I have tried is: https://blockchain.info/no/block/0000000000000000000870497004514bd3807cdc98b9f3a57038faf5df04144f.

The txid of the coinbase is supposed to be:
44763fed906f1a0e8b82e7497ac83856baa4b1c5621affdce04108a212018c4e

But I get:
6e129e567970540b2812ec58388d131c3b8fdbf4e4c992d140e255895df2992e


texts:
How can I send Shared Coins using BlockChain new wallet?!

I can't find that option in the new wallet!


texts:
I've just started toying around with the bitcoind Python wrapper (bitcoin-python) and have run into some issues when trying to move funds around.

On the client side, I have generated a new address, via

new_addr = conn.getnewaddress(ACCT)

Upon calling

conn.getaddressesbyaccount(ACCT)

I see new_addr within the addresses listed.

I now send a test transaction (~1mBTC) on blockchain.info to new_addr, and have waited for some period of time, so that there is at least one confirmation in the chain.

However, upon calling

amount_received = btc_conn.getreceivedbyaddress(new_addr)

I have not received any coins at that address.

Furthermore, when attempting to find out more information about the transaction via

btc_conn.gettransaction(tx_id)

where tx_id is given in blockchain.info/tx/tx_id, I'm getting an InvalidAddressOrKey error.

Is there there anything I'm doing wrong?


texts: What happens if I don't "pick up" bitcoins with a Bitcoin client?

texts: Say I want to save ten bitcoins could I send them to myself and just not 'pick them up' with my client? In a way would I be storing the bitcoins in the blockchain and when I want them just start up the client? Or would it be possible for someone else to 'pick them up'? Or are the private keys already in the wallet file as soon as the payment is 'sent'?


texts: Is there any RPC Java library using which I can call lite coin methods?

texts: In case of bitcoin there is bitcoinj. but in Litecoin what will I use?


texts: Will old accepted blocks ever be removed?

texts: Or are they kept forever such that the chain from the Generation Block will always remain verifiable?


texts: Why Bitcoin Core does not support importing extended public keys directly?

texts:
I'm trying to create a watch-only wallet importing the extended public key from a Ledger Nano (as an example) but is not to easy to do directly to my Node, I should do it through electrum personal server or something like that.
I was trying to find a clear (like 5 years old) explanation of what is the reason for that.
I was trying to do that in the mainnet and from the regtest following the next command in order to get the checksum but all the time a message said that the key is not valid.

bitcoin-cli --regtest getdescriptorinfo "wpkh(vpub5UwuWtLWaprMvQBpnZeufhRAqYsgrYf7ZMxr6Kf7N41aa9M7UzZJ1e7HMwzdxGnfer5g2PaFgcvmNU7iRZAasNXz6EdDW6FGdcKf8m4oF7b/*)"

And there are plans to allow this import function?, I think so it's a very convenience feature.


texts: clustering addresses, what's the most effective way?

texts:
The Fistful of Bitcoins paper by Meiklejohn et al has some nice heuristics. i.e.

HEURISTIC 1. If two (or more) addresses are inputs to the same transaction, they are controlled by the same user; i.e., for any transaction t, all pk ∈ inputs(t) are controlled by the same user.

HEURISTIC 2. The one-time change address is controlled by
the same user as the input addresses; i.e., for any transaction t, the
controller of inputs(t) also controls the one-time change address
pk ∈ outputs(t) (if such an address exists).

Are there any others that are particularly effective?

Is it possible to bootstrap my clustering, for instance, maybe if some people have already associated a certain cluster with Kraken or Satoshi Dice, is this information available?


texts: Does Lightning Network has concept of continuous stream of value?

texts:
Examples:

Car insurance: $1000 per year.
Legal consultation: $500 per hour.
Visiting a website: $100 per hour.

Assuming 1 BTC = $8000

1 hour = $100 = 0.0125 BTC = 1,250,000 sat

1 second = 1,250,000 sat / 3600 = 347.22 sat

I could generate a new invoice and pay it every second.

Continous stream of value?

I was thinking about something else:

  until further notice, please charge me 3472.22 sat per second

To avoid me going offline, there could 10 second heartbeat.

Is it overcomplicated?

Because of speed of light limit and network propagation, 1s resolution is good enough, no need for a continous stream of value.

Issuing a new invoice every second is a simple workaround and no need to overcomplicate.

Or maybe it exists natively?

EDIT / UPDATE: https://github.com/lightningnetwork/lightning-rfc/wiki/Brainstorming#streaming-payments


texts: Is there a Drupal shopping cart interface for Bitcoin?

texts: Is there any Drupal SCI for Bitcoin available? Either tied into Ubercart or, more preferably,  Drupal Commerce.


texts: How do Bitcoin transactions work, and what does one need in order to send or receive one?

texts:
I am trying to understand how Bitcoin works and whether it is possible to manage a bitcoin transaction anonymously.

If someone transfers a bitcoin, what do I need to sign it with?

Can it be signed using another bitcoin? What is the id that is used to sign the bitcoin over to me? Is that not an identifier?

How many identifiers can one have and how to do you get such an identifier/wallet?

Problem is that if you have one wallet then all related transactions can be found, so to stay anonymous you actually need many wallets. How do you get a wallet?

Can you create a wallet per bitcoin transaction?


texts: Will -addnode option help keeping same condition of mempool between my bitcoind servers?

texts:
I have multiple bitcoind servers and they are load balancing. Using IP sticky feature of the load balancer, client app connects to same bitcoind server. However, the stickness is not perfect.

I'm having many broadcast error which are Missing inputs or txn-mempool-conflict errors due to seeing different bitcoin servers between at creating a transaction and at broadcast.

[Environment]

My app -----> Load balancer -----> bitcoind-A
                              |--> bitcoind-B

What I want to do is that syncing between bitcoind-A and bitcoind-B as soon as possible. Are there any ways?

[This is what I want]

(1)broadcast the signed transacton to bitcoind-A (my app calls sendrawtransaction via rpc)

My app -----> Load balancer -----> bitcoind-A

(2)bitcoind-B will notice by somehow that bitcoind-A received a new broadcast and update mempool of bitcoind-B.

Update 1

I'm not sure but seems -addnode= may by helpful.

How do I configure Bitcoin Core to connect always to a particular node?

  -addnode= Add a node to connect to and attempt to keep the connection open

Update 2

My bitcoind is version 0.13.2

Update 3

I added the following configs and looking at the sync status between two nodes. I will let you know the findings later.

bitcoin.conf

addnode=10.x.x.x
debug=mempool
debug=rpc

getaddednodeinfo

$bitcoin-cli getaddednodeinfo true

[
  {
    "addednode": "10.x.x.x",
    "connected": true,
    "addresses": [
      {
        "address": "10.x.x.x:xxxx",
        "connected": "outbound"
      }
    ]
  }
]

Does anyone know the difference outbound and inbound? I'm looking into it. My two servers has addnode setting each other but both result of getaddednodeinfo are "outbound". It is OK to me if it could help syncing mempool quickly regardless outbound or inbound.


texts: Can you explain some of the dynamics that drive the variations in mempool depth?

texts:
I often see mempool graphs such as Jochen Hoenicke's that show significant fluctuations in mempool depth and hence the fee needed to get into upcoming blocks. Can you explain some of the dynamics that are driving these variations?
Should I be monitoring and understanding these graphs before making a transaction if I want to choose an opportune time to broadcast a lower fee transaction?
I have heard it is generally better to broadcast transactions at the weekend as there is less activity on the network. Is this a good rule of thumb such that I don't need to monitor these graphs?


texts: NBitcoin, how to implement wallet restoration? How does it work?

texts:
at first sorry for my ignorance, I have little experience at bitcoin programming.

Im trying to implement a very simple wallet using NBitcoin library. I have done some work, but now Im stucked with wallet restoration function.

Lets say I have mnemonic private key, then I calculate its public key.

With public key am I able to track all transactions associated with this key? Even if I used multiple adresses? How its done(NBitcoin)? Any advice? Do I have to iterate throught whole blockchain and chceck signatures?

Thank you.


texts: Bitcoin built with a newer Berkeley Database incompatible with a older wallet?

texts:
Is a Bitcoin client built with a newer Berkeley Database incompatible with a wallet file from a older client? Or is it that a wallet made from a newer Berkeley Database not compatible with an older client?

EDIT: What I'm trying to figure out... If I have a wallet from years ago and I import it into a newer client that was built with a different Berkeley database unknowingly would I have any issues?


texts: How to exploit the possibilites of blockchain for proof of authorship?

texts:
I want to to create some kind of Proof-of-Authorship mechanism, that's something that many artists had asked before: How can I prove authorship of my work

To accomplish my objective I need to deal with 2 problems:

first, how to precisely and uniquely define a work, and
second, use something like a public ledger to store and validate that information.

I will think about first later; it's a very complex problem; I want to know if I could use the blockchain for the second one. (If you can give me some suggestions for the first problem they will be appreciated too.)


texts: How to trade BCC with Blockchain app and private key

texts:
There is something I do not understand.

I have handled a few bitcoin transactions using Android Blockchain app and imported private key. That worked and could buy/sell with btcdirect.eu (start transaction with btcdirect.eu and exchange bitcoin with Blockchain app)

Now after the hard fork I want to see my BCC and buy more of it, but how can I do that with my private key? If possible I want to use the Blockchain app.


texts: How does the Clearing & Settlement process work in Open Transaction

texts:
From what I have read and understood. As open transaction platform uses coloured coins. The issuer of the coloured coin can associate it with a particular asset: like a ticket to a concert, or gold or real estate etc.
Now the issuer can trade these coloured coins on the open transaction platform.

Now the question I have is:
Who manages the settlement and clearance process? That is who insures that the physical ownership of the asset that was represented by the coloured coin and transacted on the platform is transferred to its new owner?

As an example. The coloured coin represented gold. I as an end user purchased the coloured coin paid the owner the desired price. The open transaction records that I am now the Owner of this gold (courtesy of the coloured coin). However how does the physical settlement and clearance take place? What if the seller refuses to handover physical ownership of the gold?


texts: Why some blocks didn't use full potential of their size?

texts:
Currently there is 73600 Unconfirmed Transactions. But some blocks has only 749 kB or 0,21 kB or two block in row has 33 and 173 kB.

Why this blocks does not have 99x.xx kB? I mean there is a space for other transaction, why it is not include to this blocks?

Blocks:

440216 - 33 kB

440217 - 173 kB


texts: Bitcoin full clients checks all the blockchain every time they receive bloom filter?

texts:
I assume that an spv client like bitcoinJ requested transactions related to the client one week before and the client has been offline for a week. When the spv client come online, does it just request new transactions which has been created while it was offline?

Also, does a full client which receives a bloom filter from the spv client check only the new transactions, or all the blockchain from the genesis block?


texts: Did the new nodes accept the old blocks in hard fork?

texts:
i had knew that the old nodes will reject the new blocks.how about the new nodes treating the old blocks?
i got the definition of the hard fork in the Hard Fork.but it didn't explain how did the new nodes treat the old blocks.


texts: What is off-by one error in updating target? How is it fixed?

texts: Can some one explain completely what off by one error is? how is it fixed?


texts:
I have a:

Wallet public/private key pair with X BTC
Wallet Address I want to sent Y BTC to

I'm developing an app in NodeJS and trying to initiate payments automatically. I'm very confused how I'm supposed to do this.

From my research it seems like I have to generate some "raw" transaction hash, then encrypt that again with my private key, then I'm supposed to broadcast that encrypted data.

Is there some library/some simple API that can help me do this? I don't want to have to run a bitcoin server if I don't have to...


texts: How do you make a coin resistant to soft forking?

texts:
Soft forks are probably worse than hard forks, since it is hard for a client to reject a soft fork (indeed, that is the point of soft forks). The only way to do so is either to gain 51% of the hash power, or to do a hard fork rejecting it.

How can you make an altcoin resilient to soft forking (or only allow certain types of soft forks)? I think doing this is in general might be impossible, but making it harder would be good. Having no soft fork policy built into the coins philosophy would help, but probably isn't good enough.


texts: QT wallet never syncronizes; often crashes; is locked and not showing attempt to send BTC

texts:
Running Windows 7;
I'm not really sure what is going on. The wallet has stolen my BTC.

The wallet never synchronizes, it never finishes. If I leave it on all day -I will come home to see it crashed.

The application is also not visible from anywhere except possibly from Task Manager. When I try to start it.. it says:

cannot obtain a lock on data directory ... Bitcoin is probably already running.

My goal here is to get the bitcoins that I have and move them back to the account I have with the vendor. Then I will purge my system of this so called "program" and never use it again.

Additional information: Bitcoin Wallet version 0.5.0.1

This is old -can I upgrade without losing my secure key? WHERE IS MY WALLET.DAT FILE? I CAN'T FIND IT.

http://img19.imageshack.us/img19/2080/qk0m.jpg

ANY HELP IS GOOD.


texts: First bitcoin payment, sent X BTC, but transaction amount on blockchain.info shows as more than 2X?

texts:
I sent 0.01047 BTC through coinpayments.net using electrum.

First I selected minimum fee option, then I went back and selected one level higher as the fee tier.

My electrum wallet and blockexplorer.com show different wallet balances after the transaction. This is how the transaction and wallet look like in electrum:

However online blockchain explorers tell otherwise:

Wallet: https://blockexplorer.com/address/1HNN4AZkeupaTT5675k8s7XT4YCLUDpybK
Transaction: https://blockexplorer.com/tx/3437ff74196c8f5b4b348c636a88f84773577c47979a6941ef378b79044abe76

I also recognized at the above transaction link that one of the outputs is "unspent" and the other one "spent".

Also under blockchain.info link (https://blockchain.info/tx/3437ff74196c8f5b4b348c636a88f84773577c47979a6941ef378b79044abe76) it says "Estimated BTC Transacted     0.01047 BTC" although a few lines above the transaction amount shows as: 0.02217459 BTC

Can someone explain to me what this is? Have I lost some of my bitcoins?


texts:
I am interested in starting to mine alt coins.
I have little in funds to invest in hardware, besides a laptop that I got from bestbuy.
are there any coins that would be able to be mined from such a basic setup?

my goal is to get coins and then trade them in for bitcoins and then onto fiat.

im not looking for a big return in profits at first just something to get me started and then to work my way up?

if there us anything you would like clarified please let me know


texts:
Ledger wallets have a single static address where to send BTC to, but when looking at the details of the transactions, it is always recorded as different receiving addresses. Looking up the static address on blockchain.info (the address you send BTC to) will always show a total of 0 BTC.

Is there a way to know the total balance of a Ledger wallet from the
static address?
Is there another way to know the total balance
without actually plugging in the Ledger device?


texts: Unconfirmed transaction, cannot see money in receiving account

texts:
I sent 0.6 bitcoin from my coinbase account to my blockchain account. The money doesn't show up in my blockchain account and shows as pending on my coinbase account with 0 confirmations. It has been about 2.5 hours. I'm a little worried because blockchain changes the wallet id for each transaction, and I never requested the money but just scanned the QR code from my iphone. Am I just being paranoid?

Miners fee was 0.00115, or about $5

What happens if it never gets confirmed or that address is no longer valid?


texts: How is RonPaulCoin different from Bitcoin/Litecoin?

texts: Is RonPaulCoin a clone of Bitcoin/Litecoin or are there differences beyond the specifications such as coin limit and difficulty algorithm?


texts: Is there a website that allows one to trade multiple different cryptocoins (Bitcoins, Namecoins, SolidCoins, RuCoins, LiteCoins, etc) all in one place?


texts: Does `importprivkey` need a rescan even in a txindex=1 node?

texts:
Documentation for importprivkey RPC command has an optional boolean argument called "rescan" which hints that the user may want to rescan the blockchain to be able to see previous deposits to this address.

Is the rescan needed if the node is configured as txindex=1?


texts:
I have a bitcoin core full node with a wallet on VPS.

I use my own script to connect to the RPC. The script works on another VPS.

Sometimes bitcoin VPS goes offline. Once the recovery took a long time because the blockchain broke down. I'd like to avoid this situation in future. I've bought another VPS and installed second full node. If main node goes offiline, scriptwill check it and will connect to second node.

Now I'm finding a way for syncing wallets between nodes. I know, hot copying wallet.dat file is not allowed. I tried to use cron for dumpwallet on master and restorewallet on slave. But restorewallet took a lot of time. And I lost some newest addresses.

What is right way to build bitcoin core wallet replication?


texts: Buy BTC without linking PAN card and aadhar card

texts: How can we buy bitcoins in India without linking our pan card and aadhar card?


texts: Should a node follow the longest chain, or the chain with most work while syncing?

texts:
I'm reading mixed things online - some saying to follow the longest chain, and some say to follow the chain with the most work. But I'm not convinced of the former.
If the node follows the longest chain, what is to stop the scenario of a bad actor sending a completely false chain to my node with a really easy target of 1? The chain could be longer than the main chain, and I can't see any consensus mechanisms preventing that chain from technically being invalid.
If following the chain with the most work is the way to go, then how can we verify most work? Is it just a case of following the chain with the lowest integer value for its hash (as my understanding is that the hash needs to be below an ever-increasing target, and shrinks in size as more miners join the chain)?
Any guidance would be much appreciated.


texts: During Bitcoin Script execution, what is the significance of the signature verification in the stack?

texts: During execution of the script i.e. ScriptSig + ScriptPub , the last step is the verification of the Signature against the public key provided by the recipient. How does this work and what is the significance of verifying two entities which belong to the same user?


texts: Will mining significantly increase the power consumption of my PC?

texts:
I have a PC that is always on 24/7. I use it as an SSH and backup server, and it has a modest, not-too-great GPU that sits idle most of the time.

I hear a lot of talk about mining not being cost-effective for most people because electricity isn't free. However I'm already paying the electricity bill for my PC. I might as well let it sit and mine all day while it's on, right? Maybe help pay the electric bill?

Or will mining increase my PC's power consumption so much that it's still not worth it?


texts: Is there a service that let's me "send" bitcoins via email and doesn't require any account creation/login?

texts:
I'm familiar with the Coinbase and Blockchain.info approaches to this, but both these require registration/login (correct me if I'm wrong). I heard about something called Coinapult, but on visiting their website I don't see much about sending coins, and it says "not available in your country", and I'm in the U.S. I'm pretty sure I saw something for Dogecoin that does this, but not bitcoin.

Wouldn't there be some demand for a simple service that:

Lets you visit it on desktop/mobile web
Has no login or account needed to send or receive coins
Lets you specify a timeout and return to address if the recipient doesn't retrieve the coins in time
Generates and displays a recipient bitcoin address, QR, hyperlink for you to copy/paste, scan or click so that your bitcoin wallet gets the address or payment request.
Saves the private keys for the generated addresses in their own system, but with the idea that recipients of coins will be prompted to transfer funds to their own wallet.
Sends an email to the recipient with a hyperlink to gain access to a web form that lets them transfer the coins to any bitcoin address they choose.
Does not charge fees (maybe ad supported or maybe offers opportunity to download a wallet application) or maybe charges a very minimal transaction fee.

Anyway, does this exist for Bitcoin yet? Or what features above are missing or should get changed?


texts: If I have made a BTC transaction after the fork and haven't claimed my BCH before, have I lost them?

texts:
The title sums it up pretty well, I made a transaction with bitcoin core wallet after the fork, but I hadn't claimed those bitcoin cash, can I claim them, or have I lost them?

Thanks!


texts: What is the benchmark that mining ASICs are measured with to determine the hash rates?

texts: When a mining ASIC claims to run at 1 MH/s or 10/MH/s or even 1000 GH/s, at what difficulty and with what algorithm is that measured against?


texts: How many channels of Lightning Network can I open in one transaction?

texts: To open channel I should create a transaction with a special script and at least one output to P2WSH address. Is it possible to open more than one channel in one transaction if I created transaction with two or more outputs to different P2WSH addresses and relevant scripts?


texts: Transaction to "dynamic" wallet doesn't arrive?

texts:
about one week ago I tried to make a deposit to a service called "escrowbitcommunidad" (some of you might know it). They are using some kind of "dynamic" wallet addresses, meaning each time one reloads the payment page, the BTC address they display changes (please excuse my lack of professional terms).
Now, I sent the bitcoins to the address they displayed using the etherum BTC client, the transaction ID is:

1968cc2b31b396c3ef0677c69ed68a588f6bdec1ed9e60fcb8500fddda46b068

From this, it seems like the transaction is completed already, however the BTC did not arrive to my account so far and from what I've heard from other users, this is a common problem caused by some delay in the blockchain (?) system.
As you will have noticed, my understanding of how bitcoin transactions work is very rudimentary. Can someone briefly explain me where the problem could be?


texts: Transactions are not guaranted to be validated

texts:
I have read some posts about transactions never to be confirmed, but those post implied small transfers with no fees.

In my case my two transactions have something like 0.000428 BTC of fee.

I don't know if the fee is too small. I have not chosen, it was my wallet Coinmoni that did it for me.

Anyway after almost 3 days without the 2 transactions being confirmed... my first impression is that there is a flaw in the Bitcoin system. What is the guarantee the transaction ever happens ?

No guarantee. Am I wrong ? It's up to miners to choose the block they will compute.

What's the community thinking about transfers not being validated ? Isn't it a problem if Bitcoin really wants to become a public payment method, if transfer/transactions are not guaranted to be validated ?


texts: Is the news story about the missing hard drive containing £4 million GBP of Bitcoins technically feasable?

texts:
I'll admit to being a complete newbie to Bitcoins.

The whole thing has up until now passed me by, until my interest was peaked by this news story about a gentleman in the UK who supposedly threw away a hard drive containing £4 million GBP of Bitcoins, and is now apparently searching through his local landfill.

I'm a little skeptical to say the least, and have a few questions:

Is this technically feasable? I have seen comments about the place suggesting that one individual wouldn't have had access to the computing power needed to mine this many bitcoins in 2009
Is there any way to verify this guys story? Surely there is a record somewhere of which bitcoins are registered to who
Doesn't Bitcoin have a 'Forgot my password' feature or something similar? Surely something like this exists, or there is some administrative body who could be contacted in this scenario.

Thanks


texts: Is there a way to make a crypto-currency stable by design? How?

texts:
I'm just wondering if there's any way of creating a crypto-currency that is stable by-design.

How would one do so? Can there be something like a "central bank" built in into the currency client?

I know it defeats the purpose of a decentralized currency to have a "central bank". I believe bitcoin can be manipulated by someone with a large enough wallet (very large if you ask me) and it is possible for a single entity to act as a "central bank" of sorts if it has the required funds. Or if the government banned and seized all mining equipment to themselves, which would be very impractical manipulation scenario.

Neither can we think of it as a "currency", since it is currently too volatile to think of it as a viable store of value. However it is great for transactional users, which I think gives it the upper hand over current money transmission methods.

Edit 1:
My focus is on an built-in algorithmical solution. I've read about the difficulties of pegging the currency, or what a country would have to reinvent if Bitcoin were the official currency. This is not about having a P2P wallet loadable with fiat (as other questions would imply).

Edit 2:
The idea is something more akin "A Third Endgame For Bitcoin or, Creating a Truly Free Coin" by Owen Gunden. He proposes unbounding the coin quantity limit, and giving more coins to miners when the price goes up, increasing the amount and therefore lowering its value.

Can a crypto-currency be designed from the ground-up to be a stable and solid store of value? Zero inflation.


texts:
Is it possible to write a script that would allow withdrawal of money only to a specific address?
Is it possible to write a script that would allow withdrawal only specific amount?

Any examples ? Thanks!


texts: Bitcoin public keys from uncompressed to compressed version with code sample

texts:
Hi there I was looking for some code sample on compressing a bitcoin public keys  from the curve secp256k1. Just for me to get a good grasp, I have seen code going from compressed to uncompressed, I'd like to see also code from uncompressed to compressed.
Any language is fine, preferably Java/Js.


texts: Who and How are Bitcoin Mining Puzzles Orgiinated

texts: For "miners", who makes up the "complex mathematical puzzles" that have to be solved?


texts: If hackers convert stolen money into bitcoin and then deposit the money into a regular commercial bank assuming that they stole like 100 million dollars or more, would it be possible for them little by little to wire the clean money into a regular commercial bank in the United States or for that matter into some other rich developed first world nation like Canada, Australia or New Zealand??? Thank you.


texts: How long do miner collect transactions to include in a block?

texts:
I don't really understand which transactions a miner includes in a block. Since the transactions are hashed, any newly included transaction in a block should cause a restart of finding the correct nounce, shouldn't it? So a miner has to collect the whole set of transactions he wants to include in the block he is calculating for before beginning to find the nounce?

I presume it works the following way:
A Miner collects all transactions reaching him while the network still calculates the nounce for the block before. If he receices a newly found block from another miner, the includes all transactions that reached him up to this time and begins trying to finde the node. Is this correct?


texts: Can I mine with both AMD gpu and AMD integrated graphics at the same time

texts: Right off the bat I'm not planning to mine bitcoins but i would like to have this knowledge for some other cryptocurrency. I have an old pc with AMD A8 cpu that has integrated graphics and AMD Radeon HD 7890. I want to know is it possible for me two mine with both integrated and dedicated card at the same time.


texts: What do I need to consider, when I chose media to store a cold/offline wallet?

texts:
I'd like to stash away at least part of my Bitcoins in an offline wallet which I will put in a bank deposit box.

Which media is recommended to use for that? Should I burn a CD/DVD or put it on an USB stick? Which one has the longest expiration date? Are there other alternatives?


texts: Exactly how to add bitcoind params (e.g. "verbose") on command line?

texts:
Some bitcoind commands have optional params. For example, when doing "bitcoind help", it says the getrawmempool has a "verbose" param.

But no matter what I try, I can't seem to set this param on the command line. I've tried this:

bitcoind -verbose getrawmempool
bitcoind getrawmempool verbose
bitcoind getrawmempool -verbose
bitcoind getrawmempool verbose=1
bitcoind getrawmempool -verbose=1
bitcoind getrawmempool {"verbose":"1"}
bitcoind getrawmempool {"verbose":"true"}
bitcoind getrawmempool {\"verbose\":\"1\"}
bitcoind getrawmempool {\"verbose\":\"true\"}

Especially notice how the last few result in "error: value type is obj, expected bool" whereas the others give "error parsing JSON".

What should I type on the command line exactly in order to execute the 'getrawmempool' with the 'verbose' parameter?


texts: Two out of Four transaction with excluding some key pairs

texts:
Is it in theory possible to set up a 2 out of 4 multi-sig transaction, but only allow a subset of all possible combinations?

More concrete: I want to have the keys A, B, C, D.

Alice controls A
Bob controls B
Charlie controls C
Dennis controls D

There are six ways to select 2 items from 4 items. However, the only valid combinations should be:

A, B
C, D
A, D


texts: How can one Bitcoin address be associated with mulitple IP addresses?

texts:
I'm new to Bitcoin and I'm having trouble understanding the concept of "address". I understand that an address is created when you want to send or receive bitcoins from someone. You create a bitcoin address and you give that address to someone so that he or she can send bitcoin to that address and you'll receive the payment.

However, how can a bitcoin address be associated with multiple IPs? For example: https://blockchain.info/address-relayed-ips/15VjRaDX9zpbA8LVnbrCAFzrVzN7ixHNsC

This bitcoin address is connected with multiple IPs. I know that many bitcoin users advocate that we shouldn't reuse addresses. There is no way that someone else can just "pick up" the address that we just abandoned, since addresses are generated randomly. Then how is it possible that an address can be used in different IPs? Is it because the associated IPs include the IPs from which it has received payments?


texts: Can Bitcoin Help with a devalued currency?

texts:
I worked in Canada, in the Oil industry, CAD took a big hit in the exchange versus USD, can anybody advice me if transferring my money to Bitcoin can help me increase the value of my savings again?

Since I do not live in Canada anymore and I need USD.


texts: How do i configure two (or more) Antminer S9s on one bitcoin.com account?

texts: I just added a second Antminer S9 to my pool. I've been mining with one S9 and bitcoin.com for about a year. in Antminer-1 configuration I have my bitcoin username in the  "Worker" Field / password "123". (works fine). If I enter the same username in my Antminer-2 configuration bitcoin does not seem to see my second Antminer. If I change the Workername in the Worker field, the S9 has no way to access my bitcoin account because the username has changed. It seems the Worker Field entry is functioning as both a Workername and a bitcoin username. The only was I have been able to get both S9s mining is to create a completely separate bitcoin.com account for the second S9 (with a different username). How can I get both S9s mining on the same bitcoin.com account, with different workernames.


texts: Can bitcoin transaction be signed offline without access to blockchain

texts:
To make an offline transaction signing we do the following:

[Online PC]:  Create unsigned transaction
[Offline PC]: Select and sign the transaction
[Online PC]:  Broadcast to network

Is it possible to do the following:

[offline PC]:  Create transaction
[Offline PC]: Select and sign the transaction
[Online PC]:  Broadcast to network


texts: How much more energy efficient is PoS (proof of stake) than PoW (proof of work)? Are there any figures on this?

texts:
I've been trying to look for some evidence showing that PoS is more energy-efficient than PoW. In theory, it's true, but if there are any figures or stats you can share on this, I'd be very grateful.

Thanks!


texts: Differences between addresses with the same 20B hash (Hash 160)

texts:
Why the same Hash 160 has different balance in Bitcoin network?

Hash 160 is B0D5D1FB94B76B39EE82771027BEFD17131042FA.

In the one way it is the address 1H825FgspbkznbiGAnAjFjan7dmYFjpsFe that has zero balance.

By the second way, it is the another address 3Hp2zoBKNW5NsmQhHsqKgMwiGA4FoUj9Q4 that has non-zero balance.

I try to track it on blockchain.info site.

Why there are that differences?


texts: I'm looking into signing up for a year contract on one of the cloud mining sites. However, I'm concerned about the increasing difficulty over time at the locked Gh/s. In what ways can I calculate the loss I would face over time as the difficulty increases?


texts: How to generate a private key to create wallet through api in Block chain

texts:
I need to pass private key while creating a wallet in blockchain.info through api call which is defined here https://blockchain.info/api/create_wallet

I'm using php for creating wallets.

Please suggest me any custom php function to create a private key (Wallet import format preferred) and pass in the create wallet api call.

Thanks in advance!


texts:
I was wondering if anyone ever came across a situation where a wallet.dat file was encoded into an image like a .jpg?
I have this wacky idea of taking a wallet.dat file and somehow encoding it into an image. For example, you would like at a painting, but in the lower right corner, there would be a bunch of encoded jibberish out of which one could reconstruct the wallet.dat file?
Did anyone come across something like this before? How would one do this?
I'm wondering how to translate a wallet.dat into some kind of an image.


texts:
I tried the following RPC call via the debug window:

addmultisigaddress 2 '["0304a7aadeb1ae96482a10fa634825d86d80dbad8d43cd9177664eaf6f0ff7d890", "022426f087fd017db9f29759efb9d7ff6101a075e46fb591466208a6a6beb321c7"]'

The output was:

3MGYcBNapbmYkvfj9CD4hBykzWxukEE61w

This is a P2SH address, right?

The RPC call just gave the public keys, though, so my wallet won't actually be able to spend any funds sent to that address, correct?

Why even have an RPC call here that let's the user make an address they won't be able to spend from? Is this method just a utility if the private keys aren't known, and the result won't be used in the actual wallet at all?

I guess just an explanation of 'addmultisigaddress' that is more descriptive than the help via the console would be helpful.


texts: What happens if Gavin and the other developers get hit by a truck?

texts: I know this is an open-source project, but what happens if the core contributors are gone? How will the community decide the future of the client?


texts:
What is a "share rate" one can find in a mining pool dashboard?

I understand what a hash-rate is, and how that applies to myself (miner), as well as to the pool or the network. I also understand to some degree what shares of a block being mined are. But what is then the shown share rate (shown as a value between 0 and 1, as well as in shares/s).


texts: I can see ARK is the only coin in top 20 list (except USDT) of coinmarketcap which is positive. How can I buy this coin?


texts: Getting transaction id from raw transaction of a multisig address

texts:
I am able to get the tx id (or transaction hash) of almost any transaction but the one where the script starts with an "OP_O" (which is, I think, the null dummy introduced here https://github.com/bitcoin/bitcoin/pull/3843)

For example:

https://www.blockchain.com/btc/tx/97d1b00fcef1f19531a19bb1722635341a9f2ad261ecf6eed89eca2cbd3bb3ee

How am I suppose to get the txid of this transaction? And how is it different from a regular (without multisig) one?


texts: Blockchain receive payments API Network propagation

texts:
I'm using the Blockchain API to generate an address to receive payments. I received a payment to a generated address, then Blockchain sends the received amount to the address I defined but that transaction is never confirmed and has Very Poor network propagation 1% - 7 Nodes.

There is no problem if I'm using Blockchain to manage my wallet but my bitcoin client running on my machine never sees that transaction so my blockchain wallet has 0.86964083 Bitcoins and my local wallet (with the same priv keys) has 0.84787744 Bitcoins due to the poor propagation.

What can I do to propagate the transaction to my bitcoin client?


texts:
Is any possible way to set fee to specific value in bitcoinj wallet? Right now I have something like this and I don't know when to set fee:

    Address address = Address.fromBase58(params, destAddress);
    SendRequest req = SendRequest.to(address, Coin.valueOf(value));

    b_wallet.completeTx(req);
    peers.broadcastTransaction(req.tx);


texts: Why is there so much uncertainty with SegWit2x when it has 85%+ mining support?

texts:
I'm confused about the uncertainty and pessimism about the Bitcoin scaling debate. I see coindance https://coin.dance/blocks is signalling a 85% support for SegWit2x. As far as I know SegWit kills 2 birds with one stone i.e. SegWit gets implemented in Bitcoin August 1 and then there is a 2mb hard fork a couple of months later which also has its benefits (and is not as extreme as the 8mb or unlimited proposal).

At 85-90% mining support it looks like the hard fork will have a clear and dominant coin even if other miners do choose to continue mining another chain (+-10%, BU).

So it may be finally possible to buy that coffee with bitcoin at the end of the year while Bitcoin still keeps all of its current benefits to society. Is there something I'm missing?


texts: Question Regarding Send_to_many function of blockchain wallet api

texts:
I am using send to many function of blockchain wallet api and i am facing issue.

when upto 20 transaction done then after i get error in terminal that

1538652825520 - error: ERR_PUSHTX

1538652826930 - error: ERR_PUSHTX

and until that upto 20 transactions get 1 confirmation on block i am unable to send any other transaction from that wallet and it's specific address.

i want to use sent to many function for sending unlimited transaction from one wallet to my site users bitcoin addresses when they submit payment request from their account.

kindly help me regarding this.

Thanks


texts: Which alternative currencies might experience a sharp rise in popularity like bitcoin recently did?

texts:
Simple question for newbies. Which other alternative currencies (crypto and others) are possible candidates for a surge in popularity?

Is there any reason that bitcoin will always dominate the alt currencies or is it just one of many contenders waiting to be discovered by the masses any day now?


texts: How/when are transactions removed from the not-confirmed pool?

texts:
I am not clear as to how the removal of transactions from the non-confirmed pool happens.  I have not found any descriptions explaining how the process works.

Here are the scenarios as I see them:

A) When a node selects a set of transactions to be included in a possible block it removes them from the non-confirmed pool.  So if/when the node solves the block there is no clean up necessary of the not-confirmed pool.

B) Transactions may be included in multiple potential blocks and remain in the not-confirmed pool while blocks are being solved, then when a block is solved the transactions included in the block are removed from the not-confirmed pool.  This sounds to me as the most likely scenario but it is not clear at all who/when removes the transactions from the not-confirmed pool.


texts: Is it useful to have miners work on the same block instead of parallel solo mining?

texts:
While mining with multiple devices GPU, FPGA, etc. at home/work/school, does each device work on its own block or can you combine the resources of each mining device into 1? Say if each device can mine at 1GHash/s, 5 devices for an overall 5GHash/s between all devices. Can you set it up to where that 5GH/s is used on 1 block instead of 5 blocks? As it would reduce the block validation time?

If you can combine the resources of the solo mining operation, I assume setting up a private/solo btc pool is inorder. Would you use long polling in this instance or not?


texts: Does bitcoin mining need a lot of internet bandwidth

texts:
I'm going to be a bitcoin miner and my question is

does it require a lot of internet bandwidth to mine with a pool ??

I'm gonna use guiminer with slush's pool

I have 1MB dsl is it enough ???


texts: Reject all other Blocks and allow only my own mined blocks

texts: I am looking at the source code and I want to know how a person can reject all blocks except the ones mined by himself? I want to be still able to add transaction to my blocks but reject all other mined blocks except mine, where do I need to look in the source code?


texts:
I thought it was the same.

Block maturity - number of blocks created after.
Transaction maturity - maturity of block that contain transaction

Now I see that people use this terms as different. What is the difference?


texts: Is an Xcode project for the Mac Bitcoin client available?

texts: If someone wants to mod the Mac Bitcoin client for their own purposes (e.g. reskinning or development of a client with extra features), is there somewhere they could download the existing Xcode project for the software to get started quickly? If not, why is it not available?


texts: Is there a documentation of the first altcoins timeline?

texts:
Meaning, which altcoin was created one, in a chronological order.

It's interesting, from a historical perspective, to collect such an archive.


texts: Programmatically, How does Bitcoin core differentiate transactions category?

texts:
How does Bitcoin core differentiate transactions category?

for instance, when we are calling listtrnasctions in the response body we have category, how bitcoin core assigns category type for a transaction?
Programmatically, How it decides that some transaction should have send or receive string.

The answer is in here:

// Sent
if ((!listSent.empty() || nFee != 0) && (fAllAccounts || strAccount == strSentAccount))
{

}

// Received
if (listReceived.size() > 0 && wtx.GetDepthInMainChain() >= nMinDepth)
{

}

Can someone read and explain the code? I see that receive transactions have zero fees, and Bitcoin core considers transactions with fees as sent.


texts:
The bitcoin message magic, "Bitcoin Signed Message:\n", is defined: https://github.com/bitcoin/bitcoin/blob/203632d20b3107009f45fae56cc3f7d828b16660/src/main.cpp#L80

I know it is used as a part of signing messages to prove they were sent from owners of specific private keys, as detailed here: What are the safety guidelines for using the Sign Message feature?.

What I don't know, though, is what good is this message magic? Does it make sure the same key can't be used in two coins? Is there some cryptographic reason?


texts: If in order to verify a block your hash just has to be lower than the hash in the block, then why won't 00000000000000000000000000001 work every time?

texts: So if in order to verify a block you just need a hash lower than the block in the hash, then why do you need to do a bunch of calculations rather than just using 0000000000000000000000000000000000000000000000000000000000000000000000000000001 every time?


texts: Does BIP44 key derivation path protects private keys derived within same account?

texts:
I understand that with

Un-hardened parent extended public key
child private key

This will leads to compromise of parent private key and so all the private keys of siblings

BIP44 suggests the path

m / purpose' / coin_type' / account' / change / address_index

Let's say I use the path m/44'/0'/0'/0 to derive  public keys for account 0

Since The change and address_index is not hardened. And in my application I will have the extended public key at level m/44'/0'/0'/0 revealed (to derive addresses), does it means that if any of the private keys derived at the address_index level is compromised, all the private keys within the same account may also be compromised?

So with this path only avoid further compromise up to

Other accounts and
Further up to the master key?

Am I correct?


texts:
Currently, trading on centralized exchanges requires one to keep their funds on the exchange, with the private key controlled by the exchange's server.

Wouldn't it be possible to give people multisig addresses, perhaps in a 2 or 2 configuration or 2 of 3 configuration, where the exchange has one key and the user has the other keys, and giving people the capability of maintaining a known balance and placing orders on the order book with that balance.

Buy example:
When Alice buys Bob's bitcoin or cryptoasset, the exchange places the transfer with Bob's key (notifying Bob) and extends credit to Alice in the GUI, so Alice has "unsettled funds" but may be able to keep trading to an extent. Bob has to authorize the actual trade with his remaining keys, and may be limited in doing anything else on that site until he does authorize it.

The risk here is that Bob never authorizes the transaction, or too many users never authorize, bring the exchange's margin capabilities to a halt.

The benefit is that an exchange being hacked wouldn't result in massive amounts of cryptocurrency being stolen, and I think the risk parts can be mitigated.

Is this a practical possibility?


texts: If you were to get multiple miners that do 7.3TH/s do they add up. for example if i had 3 of them would it give me 21.9TH/s? Also What is the coversion rate for TH like how much is 1TH worth in usd?


texts: How do I withdraw my bitcoins and spend them?

texts: I run a small business online.  I am interested in using Bitcoin to accept monies from my customers but to be honest the whole thing has me a bit confused.  I am in the UK how would I be able to exchange my Bitcoins for £ sterling and then subsequently spend it?


texts: How does bitcoin prevent tampering of blockchain?

texts: Suppose C is starting bitcoin full node for the first time. C would have to download blockchain from some place. Could not this leave bitcoin susceptible for tampering? If blockchain stored in decentralized way or if blockchain full node constantly check their blockchain, wouldn't this still leave bitcoin susceptible to tempering? For example, if people downloaded blockchain more from a particular group of nodes intending to tamper blockchain, would not blockchain be  compromised? If resolution is done based on bitcoin wealth, this also seems to leave serious issues..