texts: Is it possible to use something besides sheer computational power as the limiting factor on block release?

texts:
Why hasn’t anyone tried to create a blockchain that, rather than using computational capacity as the hash scarcity test, just has a direct limit on how many times a particular wallet can make a guess per day? (or something like that..)

I’m just thinking that the whole arms race for processing power means that the system isn’t really as democratic as it initially seems. Like sure, you don’t have a fed that controls inflation, but every new crypto currency from now on will be mostly owned by whoever has the most ASIC farms won’t it?


texts: Blockchain is showing 2 incoming addresses for a transaction?

texts: A transaction into one of my wallets is showing that it came from two addresses? How can I find out which one it came from?


texts: Miniscript or_i, d: - do they always imply a witness input?

texts:
The question: is the following description of the behavior of these fragments correct?
The or_i fragment and d: wrappers all have an IF in their script that does not take the value from the argument(s), but from some external source. This external source cannot be the result of another miniscript fragment, because the fragments are composed as nested expression, not as a sequence of actions. This means that an input to IF in or_i, d: have to come from the witness that is specified at the spending time (that should be 1 or 0 due to MINIMALIF).
EDIT: removed j: wrapper from the question and the description because it does not take the value from external source, it just checks for the size of the data that X consumes


texts: How do you create a planet-specific cryptocurrency that will ignore longer block chains from other planets?

texts: I'm sure that cryptocurrencies will play a huge part of the economy across the solar system, when we have colonized many different planets, moons, and asteroids. But there are problems with using a single coin for the entire solar system. Let's just start with the example of a Mars colony. Long distances mean long delays in communication so it would take a very long time to get confirmations of Bitcoin transactions that originate on Mars. That could be problematic. Additionally, people on Mars could never hope to mine bitcoins because the average communications delay between Earth and Mars is 20 minutes one way, which is twice as long as the ten-minute blocks of Bitcoin. So I believe that a different coin would be best for each planet. But here's the crazy part. Even if Mars had its own coin (let's call it Marscoin), Earth would most likely have more computer processing power, so miners on Earth could download Marscoin's block chain and extend it faster than the miners on Mars. Then the miners on Mars would no longer be able to mine Marscoin. Then we would be back to the same problem of using Bitcoin on Mars. So, I think someone would have to create a coin that can somehow be planet-specific, so that longer block chains from other planets will always be rejected.


texts: How to get access to funds on keys that were derived using public key child derivation? BIP 32

texts:
If I have a key m/0'/0' and I'm using CKDpub to derive m/0'/0'/0 and then CKDPub to get m/0'/0'/0/0. How do I get access to the funds on the addresses generated by CKDPub?

Can m/0'/0' ->  CKDPriv -> CKDPriv => m/0'/0'/0/0 key use those funds?

Another way: if I take a private/public key pair, use CKDPub on the public and CKDPriv on the private, do they yield the same public keys?


texts: How to get all addresses - including the "change" addresses - from bitcoind?

texts:
I want to get all my addresses - including the auto-generated "change" addresses - from a running bitcoind somehow.

I haven't been able to do it in a simple way. "getaddressesbyaccount" and all the other API options are only listing the "public" addresses and sometimes few additional ones, but never the already used change addresses. Can I do that somehow?


texts: How do I accept Bitcoin Cash without using a third-party?

texts:
I'm looking for a way to accept Bitcoin Cash on my e-commerce site without using a third-party payment processor such as Rocketr. Third party services would not be ideal for me because:

I would not hold the private keys to my Bitcoin Cash.
I would pay a fee for each transaction.

Seeing this as the case, I'm only willing to use software on my own servers to accept Bitcoin Cash in a security-minded way.

Here's my current approach:

Have two servers: Server A, which runs Apache; and Server B, which runs a Bitcoin Cash wallet such a Bitcoin Unlimited.
Server A requests addresses from Server B through the JSON-RPC interface.
Server A displays the address to the user and pings Server B at intervals until the payment is confirmed.
The user sees a confirmation page and the order is complete.

Advantages to this approach:

I hold my private keys.
I would not have to "refill" the server with public keys.
Private keys (theoretically) never leave Server B.

Disadvantages:

Both Server A and Server B must be online in order to accept transactions.
Server B must be configured in a way so that the commands dumpprivkey, dumpwallet, createrawtransaction, and send* are disabled. (How?)

So, is my approach the way to go, or is there a superior alternative?


texts: Why are there always some unconfirmed transactions?

texts:
As far as I know, a miner begins creating a new block as soon as it receives a valid block from another miner. It then begins to construct and hash the next block on top of the block it just received by using all the transactions it has in its memory pool.

However, there are still some transactions that are not easily confirmed (or not confirmed at all), in the BitCoin.

Can anyone explain to me why this can happen? Is it because of some transaction selection mechanism that the miners use? or is it because of the unreliability of the connecitivity between the nodes? or something else?


texts: Following SegWit implementation, is BIP-146 signalling and implementation still on the docket?

texts:
Is BIP 146, which defines using the low S value, still on the docket to be signalled and implemented given that SegWit fixed the txid malleability issue by moving the witness outside the transaction? I'm asking because it can fix the wtxid malleability which now requires re-syncing of transaction data when it is changed from what it was originally relayed.

Also, will the implementation be a soft-fork which would treat this transactions as non-standard but miners can still include them in the block, or will it treat the transactions with high S value as invalid?


texts: If you have two chains of same length and you add your block to one chain while n/w selects the other

texts: If you have two block-chains of same length and you add your block to one chain while the network selects the other chain, what happens to the transactions in your block ?


texts: What are segwit extended key prefix bytes for regtest?

texts:
I need the HD version bytes for equivalent of ypub, zpub, Ypub, Zpub but on the regtest network.

I also need Ypub on testnet.

All the rest I can find in slip132, but it is incomplete.

thanks.


texts:
When generating a new block, how is the nbits field in block header calculated? Is nbits calculated for every new block like:

nbits=nbits of last block * (timstamp of lastblock-timestamp of (lastblocknum-2016))/20160

Or, nbits is only updated every 2016 blocks like:

if(currentblocknum%2016==0)
    nbits=nbits of last block * (timstamp of lastblock-timestamp of (lastblocknum-2016))/20160
else
    nbits=nbits of lastblock

And when a node receives a new block, it will calculate the correct nbits itself for the new block (instead of using the nbits in the received block) before verifying the hash result, right?

I have not read the source code of bitcoin, and am confused by the introduction of nbits in some books.


texts: Does anyone get custodial control of your funds when using Lightning Network?

texts: When I open a payment channel on Lightning Network, do I need to subject my funds to custodial control of another party? Is there a counterparty risk in Lightning Network?


texts: Can I verify a sub public key came from it's parent public key in a HD wallet without involving any private keys?

texts:
I know I can sign a piece of text using a bitcoin private key to prove control over a public address but are there any operations I can perform to know if a public key submitted to me was derived from a parent public key if I do not have any private keys at my disposal?

I have looked at:
https://github.com/richardkiss/pycoin and
https://github.com/jmcorgan/bip32utils
but have not yet found a way to do it.

Thank you for any input :)


texts: How many transaction can I broadcast simultaneously?

texts:
Let's say I build two transactions, and in the second one I add an input which refers to an output of the first one. Then I broadcast simultaneously the two transactions.
Now, I know that in Bitcoin exists a Transaction Chaining mechanism, still there is a limit on how many transactions I can chain this way (25 as I remember).
When that limit is reached, do I have to wait for the next block to chain more transactions, or just a couple of seconds so that each node can reconstruct the chain ?
Thank you very much.


texts: The change to the size of blockchain data files

texts: The blkXXXXX.dat files in the new Bitcoin-Qt client (v0.8.1) are about 130MB each in size, while the old ones are about 1.9GB in size each. Does anyone know the motivation behind this change?


texts: Solving a Block with more than one miner connected to same daemon

texts:
Well excuse me in advance if my question sounds funny. But I'm just curious perhaps someone can shed a light.

When in a pool of miners, let's say there are 100 miners connected to a single daemon node, do they solve every block together, concurrently computing, work is divided among miners? Or each miner solves the block individually, parallel?

To further elaborate, for example I got 100 machines, should I connect them all to a single daemon node to mine or it's better to let them mine with their own daemon node each?


texts:
My friend asked me to do a research for him on bitcoin mining, I don't know a lot so I'm asking. He's consider buying either NVIDIA gtx titan or NVIDIA gtc 980. Decent motherboard and internet speed. I stumbled upon a question on this site which says that Gpu and Cpu mining is over, it's all about ASIC now, but we can't afford ASIC.

All in USA, we're living in Lebanon
Overly expensive and we didn't count shipping costs

Now I want you to consider

Internet is free
Electricity is free
Other than buying the hardware, we have no expenses at all

My question now is the following:

In best case scenario, using NVIDIA gtx titan or NVIDIA gtc 980, how
much bitcoin can we expect to mine? (unless it's really dead)
Is it wise to buy NVIDIA gtx titan or NVIDIA gtc 980 to mine bitcoins if you don't pay taxes? Would it pay off?


texts:
Due to bip 44 list

https://github.com/satoshilabs/slips/blob/master/slip-0044.md

HD wallets support multi coins.

does it mean HD wallets support multi networks? like omni for bitcoin, TRc20 for tron?
what is network role in the HD wallets? I think in the derivation of child for multi coin, nothing, yes? but what about in sign a transaction? is there any difference or all networks are same?


texts:
From Electrum's documentation, the following should sweep all private keys to a new address:

electrum listaddresses --funded | electrum getprivatekeys - | jq 'map(.[0])' | electrum sweep - [destination address]

Is there any way to enter a WIF key into the command line to specify it directly?  The address I'm wanting to sweep isn't in my Electrum.

For example, let's say this is the private key (never use this):  L3ei8Zdu3eVRxMifD8XFN14jofv25ME51AhTzJr999dazxrWZMrZ

And this is the address I want the coins swept to: 1KdcMcRXNTBYT5BnHcmFHuYvvdWGsPnnwb

Assume that neither the sending nor receiving address is in my Electrum wallet.

What would I need to enter in Electrum command-line?


texts:
Edit: The answer is that they are unsafe and have been attacked. Please don't use them!

Brain wallets can be created with a (minimum 15 character) pass phrase at https://www.bitaddress.org

There are no warnings given on the site about the safety of this. How secure are brain wallets?

A recent contest provided 5 bitcoin (receiving) addresses generated with a brain wallet pass phrase, with each address holding 1BTC as a prize.

The challenger did give some hints along the way, but within 7 hours, the first prize was taken, and after around 18 days, all of them were taken.

The author of the blog summarises that brain wallets are generally safe, but is this really the case?

With a well indexed database of the existing Bitcoin addresses that hold a positive balance and a well-tuned script for trying out likely pass phrases, surely there's some quite long phrases that would still be easy to guess?


texts: Can the Antminer S3 mine Bitcoin using Scrypt algorithm?

texts: Because I can use my PC to mine Bitcoin using the Scrypt algorithm. I use NiceHash. They have an option to select which algorithm we want to use. So I was wondering, once I get my Antminer S3, is it possible to point it to NiceHash's Scrypt stratum and mine using the Scrypt algorithm?


texts: Is there a list of news articles related to bitcoin?

texts: What articles if any have been in the mainstream media about bitcoin?


texts: How do I verify an address with GPG and Sign a bitcoin txid with a sending key as proof I sent bitcoin?

texts:
I was looking at donating Bitcoin to the Free Software Foundation and took a look at their PGP signed message here.
However, I have three questions regarding the signed message.

1.) While I was reading the message I saw the text below saying to "verify each address, line and signature." How would one go about verifying these?

The following lines containing each address, owner and date are signed
by their respective private keys, suggesting that they are valid,
controlled by the FSF and this GPG message signer attests that they
are to be used for donations. Please use each client software to
verify each address, line and signature.

1PC9aZC4hNX2rmmrt7uHTfYAS3hRbph4UN donate@fsf.org 20130802
pG+OoJaENOBvY2rPqB8s8Vssmb+/aw7SgE/2TLtZVmtVO8be5eYBXt4CTqbQo0YzcN97eGz8Fv8GpaqhdV2NgrfI=

2.) If I were to send some bitcoins to the Free Software Foundation and would like for them to know they came from me, I would have to provide some sort of proof. The following excerpt from the message says how to do this; however, I still do not quite understand how to execute this:

Request Receipt of Donation
===========================

If you would like for us to know who the contribution came from, and
to be able to acknowledge receipt of your donation, then please email
<donate@fsf.org> with your name, mailing address, and contribution
info including your txid. Signing your txid with one of the sending
keys as visible in the block explorer is optional but it can serve as
proof that your contribution really came from you.

We are a 501(c)(3) charity.

I know that the txid is a unique id of the transaction and hash, but how what would a "sending key" be? How would I then proceed to sign the txid with the sending key?

3.) I used Gpg4win to verify the whole message by importing John Sullivan's GPG public key from here and clicking the "Verify" button. But how does this work and what purpose does the PGP signature at the bottom of the message serve?


texts:
My wallet hasn't synchronized, can I make a transfer?

I'm assuming that the transaction will not come up on my wallet but im guessing it would come up on the person I send too?


texts: walletNotify on every Bitcoin Network transaction

texts:
Is there any way by which I can receive each and every Bitcoin transaction that takes place on the Bitcoin network(not only my own wallet's transactions)? Just the way Blockchain.info provides a transaction stream no matter who made them and to whom they are going?

Can txindex=1 helps in this regard too?


texts: BIP9: What happens if I make a segwit transaction after lock in but before activation?

texts:
Will it be treated a anyone-can-spend or do the nodes enforce the new rules?

Along the same lines, what exactly happens when we say a soft fork is activated?

Are the enforced at the time SF becomes activated?
Or they are always enforced from the moment you download the client, but we consider it safe to use after activation?


texts:
What was the thought behind a banscore threshold of 100?  Why is that default, why not lower or higher?

In what legitimate circumstances would a node operator change the banscore for their node?


texts: What is the bitcoind command to see how much btc a specific address has?

texts: I was wondering if I can make a query via the console on how much btc a specific address has without having to go into blockchain.info. What is this command?


texts: Sending Bitcoin from LocalBitcoin to another wallet to secure my funds, does it work?

texts:
I have an account with LocalBitcoin, that I use to ONLY fund my backpage account. However, this account is on the clearnet, is linked to my email address and bank account, and has been used without any privacy/protection layer whatsoever. I live in a place that do not seems to have any option for cash payment to get bitcoins, that's why I used my bank account to fund it and didn't consider protecting it when I first used it.

Well, now I would like to purchase something with bitcoins, but I do not want this transaction to be linked in any way to my LocalBitcoin account (and all personal information).

My questions are:

If I cannot fund an account by cash payment, can I create another account from a different website, to which I would be safely sending bitcoins from my LocalBitcoin account?
Does this allow me a certain layer of security/privacy considering that this new account would be created with a different identity, and dedicated only to usage with TOR browser?
Does Bitcoin transfer the bitcoins from normal web to TOR Network securely in any way?

Thanks a lot

(I'm really sorry if I do not use the right terms, im not a pro in these languages)


texts: How is it possible, that nobody can track anyone on the bitcoin network?

texts: Is it possible that a person on the bitcoin network cannot be tracked?


texts: With so many confirms on any one bitcoin trade, how do the multiple miners make any money. do they split the fee between them until it's so minuscule it's ridiculous?


texts: How can I combine all the tiny amounts I've received to minimise transaction fees, and do I need to?

texts:
Important parts in bold, for those who don't want to read the detail!

I've received lots of tiny transactions, in amounts sometimes as low as 0.000003BTC.
Even though I've also received (relatively) larger amounts, I'm worried that when I want to spend my bitcoins the transaction fees may be very high thanks to the large number of "input" transactions needed to make up the output transaction.

As I understand it, the network has an algorithm for determining minimum transaction fees, and the relationship between number of inputs and required transaction fee is non-linear. This means there is likely some optimum way to combine my inputs. This has already been discussed here and here, but neither question asks how it can be done, and how bad the consequences can be.

It might be best to somehow include as many tiny inputs with a larger input each time I spend a moderate amount, or perhaps it would be better to somehow combine all the tiny inputs in individual batches of some optimum size and send them to myself to prevent future problems.

If I were to combine the tiny amounts, I'd be happy to wait for the newly combined bitcoins to age, so additional fees which would be required by spending young bitcoins won't be a problem.

In most, but not all, cases, my tiny amounts have been received to a dedicated tony-amount address.

For the sake of the question, let's assume I've received 1000 tiny transactions of 0.001BTC each, and another 100 transactions of 0.1BTC each, all in the same wallet. This would give a total balance of 11BTC. Assume all amounts were received 6 months ago.

If I wanted to spend the entire 11BTC at once (with 1100 transaction inputs), how high might the fee be?

If I only spent 1BTC at a time, how high might the fee be?

How can I actually combine the tiny amounts without affecting the larger ones?

I'm running the standard (Satoshi) client, but other clients could be an option.


texts: Warning Newbie: How does a Ledger hold multiple currencies?

texts:
So you startup your ledger, copy down your 24 words, and you now have a public and private key. (I think). Now you add the BitCoin App to your Ledger and you can add BTC to your "hardware wallet" using those keys. (Though phrasing it that way is a bit of a misnomer since the only thing your Ledger ever really stores is your private/public keys.)

So far so good for one currency. However, a Ledger will hold multiple currencies. That I can find there is no asking for another 24 words. You just add the second app and you now have a wallet in that new currency. So I assume that means that if you purchase Ethereum coins it is going to use the same public/private keys that you used on BitCoin?

That would also imply that you cannot have two BitCoin wallets on the same Ledger because attempting to do so wouldn't make sense without a second set of keys which the Ledger doesn't have.

Is what I am saying correct?

Frank


texts: Can we find an algorithm to compute the average price (as energy consumption) of 1 BTC being generated if we know: hash rate, difficulty, energy price?


texts: How to get senders address with bitcoinj (no duplicate)?

texts:
I am using bitcoinj (java implementation). I have read many answers here but none of them answers my question.
How to get senders address using bitcoinj?

I have transaction variable tx. I can get it's hash, I have used this as well: https://blockchain.info/tx/myTXhash and it showed me the transactions. The problem is not even that web is showing me the sender.

BUT: if I use that generated .wallet file and open it with multibit (bitcoin wallet) I can see there, under transactions, from who were the money sent. That means there is a way how to get senders address, but HOW?

EDIT: I was mistaken, multibit does not know from who the money came from, I was just confused because it showed me it was sent to the right address (but that was set up by me in args).

But is there any possibility to get the message somehow from client to know if it is him who sent the money?


texts: Information to recipient of the transaction

texts:
I have some questions of the transactions bitcoin,

In a transaction bitcoin, there is not information on the recipient, right?

How do services such as blockchain.com track information about a transaction, from which wallets have they started and to which wallets have they arrived?


texts:
Is anybody familiar with this problem using btc qt debug console?

Would like to dump wallet and sweep into electrum.


texts:
I understand bitcoin addresses are randomly selected from such a large pool that the statistical chances of someone discovering your address is very low.

In light of the above is it still not possible?

i.e. if I have a large holding of bitcoin in an address the someone "could" by chance generate the same private key and access my fund.

Is this correct?


texts:
I have an offline wallet and I wanted to send some bitcoins to myself on an account I have on one of the exchanges. I sent a small amount 6 days ago and it still hasn’t gone through. I’m not sure why it’s taking so long and was wondering if anyone had any tips. I made a mistake of not adding a fee to it so I resent another small amount to my exchange based wallet with a fee of .0005 and that one hasn’t gone through either even though its been 5 days. Is there a way to reset the transactions or something so I can try again?

My transaction ID is: 2e0e6fcc39596707e6566b22c2806d68ca9d57117f43f1eeb31514c059b1e962


texts: Can one send bitcoind transactions that will only be valid after a certain amount of time?

texts: The standard client only allows one to spend coins from a transaction after getting 6 confirmations (120 in case of mining rewards). Can one send bitcoind a JSON-RPC command telling it to send those unconfirmed coins before they gather enough confirmations, so the transactions would be executed once those confirmations appear (essentially telling it "once you get enough confirmations, send my coins to X")?


texts: How do I verify the GPG sig for Litecoin Core?

texts:
Usually I am able to verify signatures using the verify option in GPG, but this doesn't work when attempting to verify the Litecoin Core client DMG.

For example:

$ gpg --verify litecoin-0.14.2-osx.dmg.asc litecoin-0.14.2-osx.dmg
gpg: Signature made Mon Jul 31 14:44:45 2017 PDT
gpg:                using RSA key FE3348877809386C
gpg: Can't check signature: No public key

I am using the GPG 2.2.3 install from Homebrew.


texts: I am just wondering what are the methods which can hide all the transactions and also able to validate transactions in an block chain?

texts:
I am new to block chain and was looking at how block chain work mainly proof of stake based . They check validity by going through all the transactions which is something concerning as everyone can see the transactions. So what are ways to hide all transactions and also make everyone able to check validity of new block.
This question is not only for block chain relm but also for cryptography.


texts:
In my %APPDATA%\Bitcoin folder (in Windows 7) I have a file called wallet.dat.rewrite

It was apparently last modified on 12th May 2011.

I don't think it's a file I created manually, so what is it?


texts: My Bitcoin Transfer is unconfirmed and its 2 days

texts:
Can anyone help me please? I tried withdrawal money via yobit to another wallet but I see no issue on Yobit's side. Can anyone tell me how to get it done right away? My withdrawal BTC is really lesser like $200 so I can't pay $150 for the transaction to accelerate :/

This is not duplicate since I have paid much fee $0.0008 already for transaction.


texts:
I am trying to track inventory as it flows through the supply chain.  This inventory requires chain of custody.

The original transaction would be from the manufacturer for a number of Satoshi equal to the quantity of units in the block.  It must be verifiable that the wallet that created the transaction was from the manufacturer.

Subsequent holders of inventory should be allowed to be anonymous or public on a per transaction basis.

How can I accomplish this?


texts: "Lost" password to BIP38 encrypted private key, encrypter may be faulty (Bippy)

texts:
Few years ago I encrypted my Bitcoin private key for cold storage with an offline app called Bippy. Recently I tried to access my wallet by decrypting the private key, but my password was rejected.

I've checked out this Bippy program again, and I'm beginning to suspect it's faulty somehow. It seems that private keys beginning with a '5' - encrypted with Bippy - won't decrypt with the same password. Other prefixes seem to work OK.

Now, this Bippy app is open-source and written in Python, and I got it from here. I've tried, as a test, to encrypt the private key 5Ka1Bv4RpKayZygPhZbBcREejqeYwq2iSRzWPKsg49SPgVRTnpW with password testingOneTwo (it's a fresh pk, no bitcoins there ;)). In Bippy this encrypts to 6PYMN8WT4CW7xLYczLvYfXZCtQWND7XEesk32QbXujMgKhf2v5A2ZQANpL, however, using the above password fails to decrypt it to its original... I've tried several other '5'-private keys and passwords, and the same happens every time.

Luckily the program is open-source; sadly, the project seems abandoned a few years back and my knowledge of Python and encryption is not at a level good enough to pinpoint the bug at play here, and hoping for some help here :)


texts: Understanding Bitcoin protocol (through practice)

texts:
OK, firstly, Ken Sheriff (the guy who mined Bitcoin using pencil and paper) has posted some fantastic Bitcoin articles on his blog.

In "Using Bitcoins the Hard Way" he writes (emphasis added):

  It turns out that actually using the Bitcoin protocol is harder than I
  expected. As you will see, the protocol is a bit of a jumble: it uses
  big-endian numbers, little-endian numbers, fixed-length numbers,
  variable-length numbers, custom encodings, DER encoding, and a variety
  of cryptographic algorithms, seemingly arbitrarily. As a result,
  there's a lot of annoying manipulation to get data into the right
  format.

  The second complication with using the protocol directly is that being
  cryptographic, it is very unforgiving. If you get one byte wrong, the
  transaction is rejected with no clue as to where the problem is.

  The final difficulty I encountered is that the process of signing a
  transaction is much more difficult than necessary, with a lot of
  details that need to be correct. In particular, the version of a
  transaction that gets signed is very different from the version that
  actually gets used.

Obviously working through Ken's Python files helps to understand the varying instances of appending bytes, changing endianness and the various other complicated procedures used for sending a transaction in raw hex. Likewise, the following are useful:

Protocol Specification @ Bitcoin Wiki
Graphical Address Generator @ RoyalFork
Ken Sheriff's Python code used in association with this post

My question: how does one go about learning the Bitcoin protocol by practising with the Testnet? (What resources are recommended to help formulate a raw transaction to send over the Bitcoin (Testnet) network?)


texts: I study bitcoin and found a simple open source miner on githab. It runs on the CPU, and uses the outdated GetWork protocol, but it's enough to study. Is there now a bitcoin pool that still supports the GetWork?


texts: Was Bitcoin originally designed to be easy to mine?

texts: I’ve read that back around early 2009, Bitcoin was so easy to mine that an old laptop could mine hundreds of coins in a day by simply using a CPU. Was this Satoshi’s original idea for how people should mine Bitcoin, or did he try to design the system so that it could eventually be manipulated by GPU and ASIC farms, causing the difficulty to increase significantly?


texts: Trouble running bitcoin unit tests with test_bitcoin on Ubuntu

texts:
From Bitcoin Core's test directory (bitcoin/src/test), the executable test_bitcoin is supposed to run the unit tests. When I run test_bitcoin, however, I get:

replication requires locking support
Test setup error: std::runtime_error: CDBEnv::MakeMock : Error 22 opening database environment.

How can I run test_bitcoin? I installed Bitcoin from source.

Also:

I ran configure using the --with-incompatible-bdb flag.


texts: Bitcoind server spontaneously shutting down

texts:
I'm running the latest version of the headless bitcoind server on an Ubuntu micro instance on AWS and every hour or so it spontaneously shuts down. It's hard to get any meaningful data from the debug log because it seems to happen completely randomly. This is a brand new install on a brand new AWS box. I'm also running the testnet, by the way.

If you can think of meaningful data I can provide, please tell me, but I'm at a loss here! Does anybody know what could be going on?

Edit:

After some more research, I think it's because of the limited memory in a micro EC2 instance:

https://bitcointalk.org/index.php?topic=21451.0


texts: Is there any way to store personal data in a blockchain?

texts:
Generally everyone can see all data stored in a blockchain.
Is there any way to handle private personal data like personal medical records which only right person can see?


texts: Is there any pool that rewards shares submitted during lower difficulty more than shares submitted during high difficulty?

texts:
I want to rent miner and buy hash and send them to pool.

The thing is I want to do so only when difficulty is lower. Difficulty fluctuates and in general, the market take care of things well eliminating arbitrage opportunity.

However, once in a while I can buy hash at a lower price when an alt coin difficulty drops before "market correct itself"

The problem is most pool do not directly value share proportional to difficulty. Shares submitted during low difficulty tend to worth the same with shares submitted before.

I want pools that recoqnize okay difficulty is low, so your share worths more. Alternatively I want pools that make it easier to get a share when difficulty of the network is indeed lower.

Is there such pool?

It has to be PPLNS or something that is pool hoping proof.

Is there such pool?

I am looking for altcoins algorithm. Miningpoolhub is fine but I don't know whether it qualifies or not.


texts: What happens to price when the block reward is gone completely?

texts:
What will happen, specifically to the price of Bitcoin and transaction fees when the block reward drops to a negligible amount?

Today, each block reward is approximately worth 25 * $300 = $7,500. To generate a tantamount reward as today, with (an assumed) 4000 transactions per block at today's exchange rate, the average transaction fee would have to be $1.87.
Under these assumptions that would put Bitcoin out of business in terms of being an affordable way to make everyday transactions, especially micropayments.

Now I know that block size is mutable so does this mean it's inevitable? Or does it mean that the price of BTC will have to rise to at least the cost to mine a block divided by the transactions per block multiplied by the exchange rate to be worthwhile? Doesn't this then mean that the value of Bitcoin outside it's functional value, is then ultimately determined by the block size which markets don't have control of?

Does BTC fiat price increase to meet the collective cost of actually hashing the transaction block or does the total block transaction fee value determine it?

My point is, when transaction fees are the ONLY incentive to mine (and that will happen eventually as a certainty) the total sum of the transaction fees must match the cost of mining the block they were included in. If the block costs more to mine than the value of the transaction fees in a block, miners (most) will shut down. At least so many will shut down that the network becomes insecure and Bitcoin will die.


texts: Digital signature why it can't be used by other public key

texts: Digital signature is made from private key of sender A.if only public key of B can use it then public key is available to everybody then why can anyone catch that digital signature and use it to his own public key ? Sorry for my bad english my native language is not english


texts: Do I need to pay taxes if I sit on (do not use) bitcoins?

texts:
I've done some reading on the IRS bitcoin guidelines and I'm a bit confused how the capital gains taxes works. If I buy some bitcoins in Jan, the value of the bitcoins double by the of the year but I still keep them, do I need to pay a tax on those? Or do I only need to pay tax if I buy something with them/convert them to fiat?

I'm in the USA by the way.


texts: Are there any instruments that I can use to trade bitcoin volatility?

texts: In the stock market, there are several financial products that allow an individual investor to trade/hedge daily volatility? As an example, there is the VIIX. Are there any such financial products available in the bitcoin community? IF one wanted bitcoin exposure for a day or two, due to a major event, is the only way to buy bitcoins themselves?


texts: How can I use raw litecoin protocol to connect to nodes?

texts: I am trying to connect to litecoin nodes using raw protocol. I follow Ken Shirriff instructions from this article . My code works perfect with bitcoin, so I just replaced bitcoin nodes connection parameters with litecoin ones: port for connection and magic number for messages (as I know their protocols are the same), but It doesn't work. Have no idea what's wrong. Here is my code.


texts: Is there a Wiki comparing different wallets?

texts:
I am new here so please go easy on me if my question is not written to your standards. If you ask me to make changes, I will make them so that my question is more suitable for this SE.

If you look at Wikipedia's Comparison of numerical analysis software or Comparison of smartphones, you quickly see information (such as whether the software supports GPUs or only CPUs, or what year the software was first released), that is by no means not available elsewhere, but is probably unmatched in how well it's organized.

I wonder if there is such a Wiki (website where users can make their own edits, not necessarily on Wikipedia) for comparing different cryptocurrency wallets. For example the table could include information such as the year that wallet first became available, whether they currently charge a fee for transactions, etc.

Wikipedia does have a List of cryptocurrencies but doesn't seem to have a list of wallets.

There is a bitcoin-specific Wiki site which has a page on "wallets", but it only lists wallet formats, so none of the top wallets listed for example here, such as Coinbase and RobinHood are listed there.

I have done some research before coming here.

1) Is there a comparison between different blockchain.info's wallets? - is specific to blockchain.info
2) Is there a website that compares the features of different cryptocoins? - is asking about cryptocoins, not wallets (and also doesn't have any answers).
3) Comparison of different active cryptocurrencies - asks about different coins, not wallets.

Question (1) did not end up getting closed, but in the comments it says "Questions seeking product or service recommendations are off-topic because they tend to become obsolete quickly. Instead, describe your situation and the specific problem you're trying to solve."

I am therefore not seeking a product recommendation, but rather I'm asking whether or not there exists a page where I can go and study the different products myself easily. Such a page would not go "obsolete quickly" because on a Wiki, people can constantly update it to include new wallets or remove features no longer offered. I did start this research because I wanted to find something like RobinHood but not requiring for me to have an SSN card from the USA, or like Coinbase but without requiring me to be able to receive text messages (I only have a land-line phone) but still allows free transactions, but some link to a Wiki page would suffice if I can't ask directly whether or not the type of wallet I want exists.


texts: Why Bitcoin Mining requires "Hash Guessing" problems, even though Consensus algorithm exists to tackle BFTP?

texts:
This post on CoinText explains Purpose of Hashing in Bitcoin Mining:

  The purpose of all the extra work is to prevent the traitors from sending false messages but serves no other purpose.

The idea seems to make the false/rogue attempts of Byzantinian nodes more difficult.

Since I am researching on this, would like the community's view(s) on:

We have Consensus algorithm in place to deal with false/rogue messages, then why is there a need to make the process more difficult by adding hash guessing work?
If we skip hash guessing work, how will it impact the resiliency or reliability of Blockchain?
Since hash guessing tries to make further rogue attempts costly and there is no value-add from the computation, can we route some other difficult problems to Miners to keep the message attempt difficult and still utilize resources to compute something of value?


texts: Did Bitcoin Core relay blocks sequentially or in parallel to peers before Compact Blocks?

texts: As I can see in the Bitcoin code, currently a node sends a block in parallel to all its peers. This makes sense as the block sending time is relatively small compared to the P2P latency. However, my question is how this mechanism worked before BIP152 when a peer had to send 1MB block? In that case, it makes more sense to send the block first to 1 peer before start sending to the others. This is because if we finish sending the block to the first peer, we will utilize his upload bandwidth faster.


texts: How to return Bitcoins to sender through Bitcoin API?

texts: I want to get information about the creator of a given transaction through Bitcoin API. More specifically, any or all addresses they sent their Bitcoins from, so I can return some of the money back. Is it possible to do using just the JSON RPC, or do I have to rely on external sources (such as the Block Explorer)?


texts:
What is the query param to specify the decimal precision in Bitfinex API v2?
Seemly the default precision is ####.0, but i want a "precision more precise" than only one decimal place


texts: Why do bitcoin mining companies sell hardware if the hardware they are selling makes them money?

texts:
Why do bitcoin mining companies sell hardware and make ASICS if the hardware they are selling makes them money? Surely they would hold onto the profitable hardware and sell it when it's less profitable?

Does this actually happen?


texts: C# code for Bitcoin Cash address conversion between legacy and new format

texts:
I need to convert legacy Bitcoin Cash addresses to new format and back. I am aware of similar question, but it asks about PRC and has solution using python, JS. I need it done in C# with no dependencies.

Does anyone know a library? Or have working sample?


texts: What Bitcoin exchange is the real bitcoin value?

texts: I have seen a lot of Bitcoin exchanges, BTC-e, Coinbase, Bitstamp,  LocalBitcoins and Bitfinex. (I saw those on blockchain.info)  But which one of them is the real bitcoin value?


texts: How can I buy Bitcoins in the UK now that Blockchain.info has suspended its deposits?

texts:
After blockchain.info suspended Pingit, there is no convenient way to buy a small quantity of bitcoins. Any other alternatives to acquire bitcoins (mining or working are out of the questions.)

I've heard a SEPA transfer will allow UK bank accounts holders to utilize European exchanges, unfortunately I am concerned about the legality of these exchanges (ie: who owns/runs the exchange, for example.) As such I would like the company to be based in the UK, where I have more protection if the transaction goes awry.


texts: how to get Received Time of Transaction in validation.cpp bitcoin core

texts: for research purpose i needed Transaction hash,size, fee and received time. i have already managed to get hash, size and fee but unable to get time. what to do?


texts: signmessage and verifymessage CLI commands not accepting Address from getnewaddress?

texts:
I am trying the following commands on my v0.19.0.1 Core implementation:
CLI signmessage $(CLI getnewaddress) <message>
and the identical
CLI signmessagewithprivkey $(bitcoin-cli dumpprivkey $(CLI getnewaddress)) <message>
Both times I get Error code: -3 "Address does not refer to key"
All my addresses are wrapped-Segwit (3...). Does this mean since its P2SH there is no way to find the privkey from the address?
Thank you


texts: Clarification of Tx Fees settings in Bitcoincore 0.10

texts: I'm looking for clarification of the new Tx priority and Tx Fees settings (eg fee per kB in the 0.10 version of Bitcoincore. Is the 0.0001 BTC fee deprecated? Why the move towards variable Tx fees?


texts: Bitcoin address generation and UTXO scanning

texts:
I'm developing bitcoin payment processing application.

I've two question to ask:

In each bip32 address, How much UTXO each address should have to consider generating new address to avoid address re-using? for example If address A used twice should I generate a new address or does it have specified number for address re-use before generating new one?
When new address generated, from my understanding , I've to scan following address for each address derivation path to see if each index have fund or not:

Legacy
Segwit
Change address for Legacy
Change address for Segwit

What's best way to scan addresses without submitting so much request (for each index) to blockchain explorer to scan funds?

Thanks in advance.


texts: Where is sum(vin) > sum(vout) check in Bitcoin Core?

texts:
I'm searching the function that validates a transaction according to Protocol rules - "tx" messages especially step 14 sum(vin) > sum(vout).

I found this interesting function CheckTransaction(const CTransaction& tx, CValidationState &state) but it does not validate step 14, right?

Where is this check for step 14?


texts: bitcoin public key vs public key hash vs. pub key

texts:
I am not talking about the privacy related concerns just the security aspect and the ability for someone to 'break my private key'.

The addresses that my wallet generates are p2pkh addresses. If i use the bitcoin core and do 'validateaddress' i get a json blob back which includes 'pubkey'.

If i had a database that had a bunch of public keys, not p2pkh but the "pubkey" from validateaddress, and that database were to be breached, would all of the utxos at the original wallet be at risk? (Let's assume the wallet is in cold storage and not connected to the internet). The only thing in that database would be the pubkey(s).

If this is the case... why do we even go through the process of creating p2pkh addresses in the first place? Is it just for aesthetics, less bytes in the transaction, just for privacy, or is there an actual security reason?

Finally is this "pubkey" that validates an address, why would we even need a p2pk in the first place (unless it is literally for the equivalent reason of "improving" to a p2pkh from p2pk).

Thanks

THis is different from the question posted in the first comment as i am talking purely about security ramifications. IE.. there is nothing more inherent secure by using SHA256 +RipeMD to hash a public key then just using the public key itself.


texts: Can you please point me to a tutorial for an explanation of the specific "Critical section" implementation that is used in main.cpp. I would like to understand a bit better how does it work. I studied concurrency before so I have some background to be able to understand it.


texts: 0 active connection to bitcoin network (testnet)

texts: I am working with the testnet. I downloaded the bitcoin-core application on Linux and I am running the version Bitcoin Core version v0.12.1.0-g9779e1e (64-bit) I was able to download the bitcoin block, recently its no longer syncing with the bitcoin network. Its showing 3 days behind and 0 active connection to the bitcoin network. How can I fix the issue. I want to connect to the testnet. I tried to change the network settings in the application. Still its not working.


texts: How to best structure Internal bitcoin payments within a webapp?

texts:
I'm building out a pet project webapp called CollaboTree, a big part of it is allowing users to set bounties for completing/collaborating on little bits of work. I'd like these micro payments to be as cheap/free as possible, and fast (instant?) would be good.

Would it make sense to:

Make a wallet for every user on signup, and make all internal payments go onto the blockchain between real wallets
allow users to load/unload bitcoin onto their accounts to some kind of shared wallet which only the app has access to, then maintain a balance for each user in database letting them transfer among themselves instantly outside of the blockchain, then letting them get their coins back 'live' when needed
Have one big wallet for the entire app, with each user having their own address which is the only one they can spend from or something?


texts:
I am getting an error {"code"=>-5, "message"=>"No information available about transaction"} when issuing getrawtransaction.

I am aware that

  since bitcoind/Bitcoin-qt 0.8, no transaction index is kept anymore by
  default, as it is not necessary for validation in the new database
  model.

( Discussed here: getrawtransaction error? [Code -5] )

I have followed the answers and rebuilt my index with --reindex. I also have txindex=1 specified in my Bitcoin.conf file.

I am still getting the same error every time. What could be the issue? How do I make sure the client keeps an updated index along with synchronising for new blocks?

UPDATE: I tried working with a random hash: "d3ad39fa52a89997ac7381c95eeffeaf40b66af7a57e9eba144be0a175a12b11" and it works. Not for all though. Is transaction data specific only to some blocks?


texts: Is the a library for generating signatures and transactions for scrypt coins?

texts: I'm looking for a library similar to this bitcoin one but that works with scrypt based coins.


texts: Can I install custom software on an Antminer S5?

texts: It is possible to install custom software (another than cgminer) on Antminer hardware? For example on antminer s5?


texts: Killerstorm mentioned "non-final transactions" as something Satoshi talked envisioned. Can anyone elaborate what this means?


texts: Do we have an estimate of how many people are using Bitcoin?

texts:
I found this map: http://bitnodes.io/

But I'm not sure what can be inferred from it.

Can the network grow much more than this?


texts:
I need to automatically send funds from my hotwallet to users on my website at various times when they do something on the site.

Later I will also need to be able to see total balance for an address receive data about address totals and funds etc. (for this I have ABR block explorer and API setup to read the blockchain for addresses)

I know there are all the commands that can be executed from the terminal or CMD when running bitcoind, but how to trigger these from my website? Do I need to write a webAPI to handle such requests direct against the network? or is it more common to make a call to run these commands via scripts direct against the bitcoind?

Any help appreciated


texts: Can a channel be closed while the funding tx is still stuck in the mempool?

texts: I have attempted to open a channel recently, but accidentally set the fee for the funding transaction too low. Now the funding tx has been stuck in the mempool for over a week. Is there some way to close the channel even though it was never actually opened?


texts:
If I understand it right, a stale block is a block for which an earlier confirmation has been found and was accepted by majority of people. This block is considered invalid and is later never used.

But what is a orphaned block. How is it created? How is it verified that it is orphaned and what is done to the orphaned block?


texts: How to get a VanityGenerated public address for a hardware wallet? (Ledger Nano S)

texts: I recently bought a Nano Ledger S and have not opened or set it up yet. I read that you can use a VanityGen to create a Vanity public address. How would I do this for my Nano Ledger, if I want to make sure that I keep my keys 100% safe?


texts: What made the core developers choose C++ as the main programming language for implementing bitcoin? Was this because of their personal preference? Or another reason?


texts: I'm looking for a way to generate private keys in Java. I'd like to make this a standalone program, so I'd rather not use a library like bitcoinj. From my research I've only seen people recommend using bitcoinj. Has anyone created anything like this? Thanks.


texts: When importing the mempool, my debug log mentions failed and expired imports

texts:
I read in my debug file:

Imported mempool transactions from disk:
143751 successes, 235 failed, 1 expired

What does failed and expired mean in this context? How can I fix that?


texts: I've understood that address reuse undermines privacy and potentially also security in the future. Recently though, I accidentally reused the same public address when receiving funds from an exchange. Is there a way to fix this and future proof the security of my funds? Would it perhaps be sufficient to send all the funds to a new public address under the same private key or would I need to generate a totally new wallet?


texts: Why does Wikipedia's Bitcoin entry imply Satoshi's whitepaper is from May 2009?

texts:
The first citation in Wikipedia's Bitcoin article is of Satoshi's original whitepaper. It is worded:

  Nakamoto, Satoshi (24 May 2009). "Bitcoin: A Peer-to-Peer Electronic Cash System". Retrieved 20 December 2012.

Satoshi's whitepaper was released on 1 Nov 2008, not on 2009.

What am I missing here? Did anything relevant happen at 24 May 2009? Is this a factual error in the Wikipedia entry? (It's there for a long time, so it's not any recent vandalism).


texts: Can the fees in a coinbase be used to launder Bitcoins?

texts:
Generally Bitcoins coming from a coinbase are considered clean as they are newly generated. However while answering this question I realized that mining pools could offer to launder Bitcoins in the following (in its edge case even extrem) way:

Let's say I want to launder 1 Btc

I create a chain of btc transactions with a relatively high fee (1000 Satoshi per byte). In the extreme case  I could even make an extremely large transaction by including a couple of outputs with large scripts producing 1 tx which has basically the entire amount as a fee.
I send this (those) tx only to the mining pool that helps me to launder the Bitcoin.
The mining pool then sends me an output from the coinbase to a new Address of a value less then the 1 btc (taking their share of the laundering operation) also since I wanted to launder I could receive several smaller payouts to various addresses.

Let's say this is impossible due to KYC requirements of miners. Such an endeavor could also be achieved by solomining such a block by renting out hash power.

Of course such an extreme tx would already look suspecious but I could create a similar situation by spammimg tx during a high fee market (or even producing such a fee market by spamming.)

Somehow this picture makes me worry as it seems to me that criminals would not only be incentivised to do so it would also interfere with the entire ecosystem.

Am I missing some point here? Why has that not been done yet? In case of stolen coins (for example quadrica exchange, it seems to me that it would even be worthwhile to just create a mining operation for such an endeavor)


texts: Final Balance -Balance showing different then Coinspot BTC wallet

texts:
Bit of a beginner question
I have been using crypto wallets for a few months and have basically learned through trial and error.
The question is my BTC wallet on Coinspot has a $0 and 0.0 BTC balance.
However when I check my BTC wallet address on btc.com or blockchain explorer etc it shows a Final Balance/balance of a small amount of BTC.
https://btc.com/19xJAVY3XHnKr24XjbMX3ZRhiTL1DRDpMi
https://www.blockchain.com/btc/address/19xJAVY3XHnKr24XjbMX3ZRhiTL1DRDpMi
I'm not sure why it's different (guessing it's transaction fees or some error)  if the final balance is correct and my coinspot wallet balance is wrong/showing 0.0 what/how do I get access to it...


texts: Transactions not showing up in bitcoind log?

texts:
I have a bitcoind running on a server behind the www box which I poll every minute for new transactions and save new data into a table.

Something strange is happening sometimes. If i send 1 btc from my wallet to an address on the bitcoind server, it gets through just fine and shows up right away in the log when downloading transactions via RPC.

If however I send from an exchange, it does not show up (at least not for a day or two). I've noticed that these exchanges add another address and amount to the same txid, could that be the cause?

Is there a workaround for this?

TIA


texts: When running bitcoind under OSX/Linux, how can we add a watch-only wallet using the JSON RPC? Do we need the public key or is the bitcoin address sufficient?


texts:
When running bitcoind from a systemd service, as in https://github.com/bitcoin/bitcoin/blob/master/contrib/init/bitcoind.service, what is the role of the -daemon flag?

Basically I'm asking what does -daemon do in a situation where bitcoind is run as service, and not as a wallet. And what happens if -daemon is not used -> in a systemd service file.

If one sets daemon=1 in bitcoin.conf, is it redundant to also use the -daemon flag when starting


texts: Is it possible to create a system for 'shared wallets' on top of bitcoin?

texts:
Is it possible to build a system on top of bitcoin, where:

Random people will deposit money in a wallet X.
Nobody has access to that wallet.
After a few months, those users will vote in other wallets for the money in wallet X to go.
The money in wallet X is distributed between those wallets.

Is it possible on top of bitcoin, or would it need the design of a new system?


texts: "bitcoinrpc.authproxy.JSONRPCException: -342: non-JSON HTTP response with '401 Unauthorized' from server"

texts:
I used the following code to connect to the bitcoin core client and encountered this error:
bitcoinrpc.authproxy.JSONRPCException: -342: non-JSON HTTP response with '401 Unauthorized' from server

My configuration file: bitcoin.conf is written as follows:
Expose the RPC/JSON API
server=1
rpcbind="127.0.0.1"
rpcport=8332
rpcuser="bitcoin"
rpcpassword="J9JkYnPiXWqgRzg3vAA"

May I ask what caused my code to report an error, and how should I solve this problem?


texts: Is using a new address for each transaction pointless when applied to a donation button on a private website?

texts:
I'm just looking at how to implement donations on my site and also read that I should use a new address for each transaction to increase anonymity.

Is this an ultimately pointless practice when tied to a single private website?


texts: What is the source of the price info shown in the Ledger Live app?

texts:
How is the pricing info in the Ledger Live Desktop app dashboard populated?
From the 6/10/20 blog post, Coinify powers the buy/sell functionality, and Changelly powers the currency swapping. Is either of these APIs the source of the price info?

Thank you!
Adam


texts:
When I studied the stratum on here,I found that there were little difference between the stratum and solo mining for building block header.

The stratum tell us that we needed to pad the header to uint512.

'000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000'

The bits is different to the algorithm of sha256's padding.

But when I practiced the example which solved testnet3 block,I couldn't use the information to calculate the hash until I discarded the padding.

In real-work,whether I need to pad or not?

By the way,the previous hash provided from  notification is not correct,you need to find it on there.


texts: How to calculate the checksum of an extended public key?

texts:
Very difficult to find definitive info on this.

From what I can find on google and looking at BIP32 it seems like the process to calculate a checksum for an extended key is to decode the base58 string to data, then perform a double sha256 on the data and the first 4 bytes from the double hash are the checksum.

I am trying to take in a non xpub (vpubs, upub ypub etc) and convert it to an xpub/tpub programmatically. Currently I have it working but the last 6 digits of the xpub are always incorrect, I am assuming this is the checksum?

In order to correctly calculate the checksum do I remove the prefix first, then remove the existing checksum then do the double sha256 on the stripped down extended key or do I keep the new xpub prefix and then perform the double sha256? Or am I completely wrong in my assumptions here?

Thanks in advanced!


texts:
I recently took my BTC off my QT Core Client on my computer and got the coins onto my Ledger Nano S wallet fine.

My question is if the Wallet.Dat file on my computer (from the QT client install) were ever compromised, could that be used to steal my BTC from the blockchain?

In other words, do I still need to be concerned about security of my Wallet.Dat file given it could reveal my private keys?


texts: How do satoshidice's draws work? (HMAC hashes)

texts:
I am trying to understand how does a satoshidice draw work.

As far as i have understood satoshidice generates daily two public hashes:

HMAC hash (H from here on)
Position hash (P grom here on)

You can check here all the H and Ps until 31.10.2014. As you can see they include hash for the next two weeks too?why?

Getting an example of a H they provide (b8dd879f66b36f0b0705c00eb56d91a82c927f6c5d25b0d470d4f17615702bed) i can see they are 64bytes Hexadecimal long so that's a SHA256 Hash.

But how do they calculate this hashes? I mean they are the product of using a SHA256 hash calculation, without secret key (HMAC)? And the next day they release the original data that originated H and P, so that people can check what? I don't understand it very well..

If the resulting string used in the draw is calculated as:

Resulting String = hmac_sha512(daily_secret, "tx_id:out_index")

I suppose daily secret is our H. What's "tx_id:out_index"? Trasaction id concatenated by index?

How could i verify my draw was totally fair with all these hashes? This is a mess..

They say:

"That is, the daily 'HMAC' Secret String is used as the key to an HMAC_SHA512(key, message) function. The message portion of this function is a string formed from the transaction ID, a colon, and the output index number of the bet payment within the transaction. In order to calculate the lucky number, 4 Hexadecimal Digits are being chosen from the above HMAC Output. The position of these 4 Digits, is being taken from the First bytes of the 'Positions' Secret Key. Finally,having the output of the HMAC Function,and the daily Positions,we have the Lucky Number as an unsigned Integer in the range 0-65535."

If i now H and P ahead of time, if could get "tx_id:out_index" too wouldn't i be able to predict the drawing result?

Regards,


texts: How does one create another transaction when all funds are tied up in an unconfirmed previous transaction?

texts:
If I have only one UTXO and I spend from it that's fine, I send myself back the change and that works how I expect it to. However if I want to create a new transaction in the time that the first transaction hasn't confirmed yet then what do wallets do?

Do they use CPFP/RBF? What's the most reliable way to send a new transaction that depends on the first transaction getting confirmed.


texts: Someon offered me btc mine trough his mining device

texts:
Someone from the social network offered me a btc mine through his mining device. He asked me for an email address so he could create a mining wallet address for me. I gave it to him. I don't know what he did, but very soon after that I received an email from Blockchain informing me that my wallet address had been created and that I could connect it directly to the mining stream.
After this I should deposit a certain amount of btc to this wallet address, which is now, supposedly connected to this gentleman’s mining device.
is this a scam attack or ..


texts: FutureBlock offer and example seems to violate No Arbitrage Rule

texts:
If you look at, e.g. the best offers at the 420 BTCUSD strike price (this was as-of 4:15 pm EST on November 14, 2013), or at the "How It Works" page for Future Block, it seems like there is a violation of the No Arbitrage Rule.

For example, from the "How It Works" example. Suppose I sell one BTC's worth of "up" contract (I get 1 BTC) at 80% payout (I pay back 1.8 BTC if price is above strike at expiry).

Next, I sell one BTC's worth of "down" contract at the same strike price (I receive another 1 BTC), at 50% payout (I pay back 1.5 BTC if price is below strike at expiry).

If the price is above the strike, the "up" contract clears and I received 2 BTC but pay back 1.8 BTC (netting a gain of 0.2 BTC for me). If the price is below, the "down" contract clears and I receive 2 BTC minus the 1.5 I pay back (netting a gain of 0.5 BTC for me).

Obviously, these example offers may not be close enough to the best offer to attract buyers, but apart from that I can't see any specifications for transaction costs to the seller, fees, etc. Even if there were fees, wouldn't they need to adjust according to the payout rates a seller could command selling on both sides of a strike price?

I think I am probably missing an obvious detail; any help correcting my mistake would be great!

Added:

To clarify, the puzzle here is that at about 4:15 yesterday, the best offer for up and down contracts roughly matched the example I give above, using numbers from the "How It Works" page to illustrate a Dutch book offer selling on both sides of the strike price. That this can happen is not a mystery per se, but that the live best offers reflected that it was a viable live strategy even when there was resonable volume in the market is a puzzle. Either there was simply no volume at all on one side of the strike price (which should have immediately led to better offers on that side) or else there was actually not much participation and the volume data was incorrect / misleading, or both. (Assuming that early adopters of BTC options can't be that irrational... after all, they'd have to know a lot about bitcoin and that particular options platform even to participate. So it seems implausible that buyers were so irrational as to be buying at such prices on both sides of a strike price).


texts: How to do refunds and internal transfers on bitcoind?

texts:
I would like to ask regarding refunds and internal transfers. It wouldn't be difficult if not for the network fee.

How can one do internal transfers without network fees and another is refunds in bitcoind or bitcoindxt?

:)


texts:
Bitcoin can be run on a public testnet (by using a different port than the real Bitcoin network). This is very useful for development, because you can test software handling Bitcoin without handling actual value.

What is the situation for Bitcoin alternatives? Is there a testnet for most (or all) altcoins? Which altcoins have such a testnet feature?


texts:
I'm thinking about a way to split the bip39 words (by hand) and I would like to have some opinions on it.
The aim is to store the word list in several locations, I came with something inspired by one-time-pads.
Example with a 6 words list: wrist orient foil naive shock predict
Step 1: convert the words with their numeric index
Words (W):
1: wrist   -> 2035
2: orient  -> 1252
3: foil    -> 723
4: naive   -> 1173
5: shock   -> 1586
6: predict -> 1357

Step 2: Prepare two sets, each half filled with random numbers between [0; 2047]
Set 1 (S1):
1:
2:
3:
4: random -> 1050
5: random -> 1779
6: random -> 556

Set 2 (S1):
1: random -> 1889
2: random -> 1074
3: random -> 914
4:
5:
6:

Step 3: fill the missing values of each set in order that S1[i] + S2[i] = W[i]
Set 1 (S1):
1: (2048 + W[1] - S2[1]) % 2048 -> (2048 + (wrist=2035) - 1889) % 2048 -> 146
2: (2048 + W[2] - S2[2]) % 2048 -> (2048 + (orient=1252) - 1074) % 2048 -> 178
3: (2048 + W[3] - S2[3]) % 2048 -> (2048 + (foil=723) - 914) % 2048 -> 1857
4: random -> 1050
5: random -> 1779
6: random -> 556

Set 2 (S2):
1: random -> 1889
2: random -> 1074
3: random -> 914
4: (2048 + W[4] - S1[4]) % 2048 -> (2048 + (naive=1173) - 1050) % 2048 -> 123
5: (2048 + W[5] - S1[5]) % 2048 -> (2048 + (shock=1586) - 1779) % 2048 -> 1855
6: (2048 + W[6] - S1[6]) % 2048 -> (2048 + (predict=1357) - 556) % 2048 -> 801

Step 4: write words of the sets with the values as word index
Set 1 (S1):
1: 146 -> banana
2: 178 -> bike
3: 1857 -> trend
4: random -> 1050 -> lobster
5: random -> 1779 -> tattoo
6: random -> 556 -> earth

Set 2 (S2):
1: random -> 1889 -> ugly
2: random -> 1074 -> mail
3: random -> 914 -> impulse
4: 123 -> aunt
5: 1855 -> treat
6: 801 -> goat

Advantages:

You ends up with two sets that looks like valid bip39 words (except for checksums).
You can do this with 2 or more sets.
One (ore more) leaking set does not compromise the private key at all (as long as at least one is kept secret, words are safe).
In case someone asks (if you are physically threatened) you can give the robber your 1/n part of the key, or plausibly says that you misswritten your words (bad checksum), you cannot find back the key at the moment anyway (other parts are located elsewhere).

To find back the words, you simply have to sum each set:
Words (W):
1: S1[1] + S2[1] -> (146 + 1889) % 2048 -> 2035 -> wrist
2: S1[2] + S2[2] -> (178 + 1074) % 2048  -> 1252 -> orient
3: S1[3] + S2[3] -> (1857 + 914) % 2048  -> 723 -> foil
4: S1[4] + S2[4] -> (1050 + 123) % 2048  -> 1173 -> naive
5: S1[5] + S2[5] -> (1779 + 1855) % 2048  -> 1586 -> shock
6: S1[6] + S2[6] -> (556 + 801) % 2048  -> 1357 -> predict

I'd like to know if someone sees any problem or a better solution for this case.


texts: I want a litecoin wallet to store the litecoins that I am going to buy with my bank account. I wanted to use ltc-wallet.com but when I try to go the site, it doesn't load. Also, when I went to sign up for btc-e I find many, many, MANY sites that say that Btc-e is a scam. Finally I found coinbase.com ...which also came with a plethora of horror stories. Is there a LEGITIMATE site that I could use in order to store my litecoins?


texts: how to run bitcoind server on a ubuntu 13.04 server

texts: I am trying to host a bitcoind on my server so I can connect to it on my website, how do I install it, run it, update the conf file? this is on a server not a desktop


texts: Bitcoin ECDSA signature in the compact format

texts:
I would like to understand how to get Bitcoin ECDSA signature in a compact format, when it's exactly 65 bytes.

In the bitcoin-core repository, secp256k1_ecdsa_recoverable_signature_load is responsible for this. As far as I understand, in it r and s are separately reduced to a 32 byte representation using secp256k1_scalar_set_b32, but I don't understand how it function works. What is a EXHAUSTIVE_TEST_ORDER? Why does the resulting representation of 32b scalar remain valid after it? I would be very grateful if someone could explain it to me.


texts:
I have an old paper wallet with Private Keys of 58 characters (all starting with a 6). These can be imported e.g. on blockchain.com, but since I still have BSV on this key, I have to import/sweep it in ElectronCash or ElectrumSV, which doesn't take this format.
So, does anyone know, how to convert this key into WIF (without coding if possible)? Thanks in advance!


texts: What "Identity Verification" features will be part of the QT client?

texts:
When Patrick Murck testified today at the Homeland Security Digital Currency committee, he mentioned that an identity verification feature will be added to the QT client.

What is this identity verification feature, and how does it work?


texts: I am eager to know details about distribution of bitcoin

texts: Bitcoin only has 21 million possible coins so far I know. Who hold these coins? I just want rough estimation.


texts: Why are certain transaction not visible on blockchain.info?

texts:
For example this transaction is visible here but not on blockchain.info

https://blockchair.com/bitcoin/transaction/4c26a54af671b4b86cebe648134fd3e4f05634cf3b86523c17882d416b28ebb0

Why is that?


texts: Creating a raw transaction using Bitcoin Core v0.10.0 bitcoin-tx / createrawtransaction

texts:
I'm trying to create a raw transaction using Bitcoin Core v0.10.0 (on Windows 7 x64, and with txindex=1 optioned).

Bitcoin Core v0.10.0 comes with a new Bitcoin-tx executable utility. The help menu is as follows (under Windows 7 x64):

Bitcoin Core bitcoin-tx utility version v0.10.0

Usage:
  bitcoin-tx [options] <hex-tx> [commands]  Update hex-encoded bitcoin transaction
  bitcoin-tx [options] -create [commands]   Create hex-encoded bitcoin transaction

Options:
  -?                      This help message
  -create                 Create new, empty TX.
  -json                   Select JSON output
  -txid                   Output only the hex-encoded transaction id of the resultant transaction.
  -regtest                Enter regression test mode, which uses a special chain in which blocks can be solved instantly.
  -testnet                Use the test network

Commands:
  delin=N                Delete input N from TX
  delout=N               Delete output N from TX
  in=TXID:VOUT           Add input to TX
  locktime=N             Set TX lock time to N
  nversion=N             Set TX version to N
  outaddr=VALUE:ADDRESS  Add address-based output to TX
  outscript=VALUE:SCRIPT Add raw script output to TX
  sign=SIGHASH-FLAGS     Add zero or more signatures to transaction
      This command requires JSON registers:
      prevtxs=JSON object
      privatekeys=JSON object
      See signrawtransaction docs for format of sighash flags, JSON objects.

Register Commands:
  load=NAME:FILENAME     Load JSON file FILENAME into register NAME
  set=NAME:JSON-STRING   Set register NAME to given JSON-STRING

Using Windows CLI, I'm running into issues with createrawtransaction as it's not parsing the command the same as it does in the Bitcoin-QT console window.

bitcoin-cli createrawtransaction [{"txid":"dbdc2e2c7f143af70c5e7e8725f55d226b3c058d7bf34a303091b3c6a514848c","vout":1}] {"1BCi1L25GC9hUSvtSyGjmEvSyywoYubk4P":0.00011}

Gives error: Error parsing JSON:[{txid:dbdc2e2c7f143af70c5e7e8725f55d226b3c058d7bf34a303091b3c6a514848c,vout:1}]

Likewise, the bitcoin-tx utility won't work with this:

bitcoin-tx.exe -create in=dbdc2e2c7f143af70c5e7e8725f55d226b3c058d7bf34a303091b3c6a514848c:1 locktime=0 nversion=1 outaddr=2000:1BCi1L25GC9hUSvtSyGjmEvSyywoYubk4P outscript=0:687474703a2f2f676f6f2e676c2f7869556243555

How can I create a raw transaction using Bitcoin-cli and bitcoin-tx?


texts: USB hub busy when mining Peercoin with Red Fury ASIC running Minepeon

texts:
I have a RasPI running minepeon 0.2.5, a DLINK USB Hub and a Red Fury USB ASIC Bitcoin Miner 2.2-2.7GH/Sec By BITFURY

I've added my pool https://ppcoin.d7.lt/ and things looked good except nothing is mining.

The miner states it's running but the device id is 0 and hashrate is 0.

I've tried to start the miner manually in accordance to https://ppcoin.d7.lt/getting-started

cgminer -o stratum+tcp://stratum.d7.lt:3333 -u miner.1 -p 99999

It starts up but states that the USB hub is busy, I see it testing the Red Fury but after that it still is not mining.

Am I missing something?

Related Posts:

http://www.peercointalk.org/index.php?topic=499.msg17709#msg17709
https://bitcointalk.org/index.php?topic=251675.msg4841184#msg4841184


texts: How would the Bitcoin protocol be impacted if nodes only stored the blocks they cared about?

texts:
Right now, full clients of the Bitcoin network store every block ever generated (while "thin" clients instead rely on a node which does so).  This greatly increases first-time initialisation for the client, and also has significant implications for network overhead, amongst other things.  How would the network be impacted if nodes instead stored only the headers of most blocks in the blockchain until or unless they "needed" the actual block?

These situations are fairly common, such as:

verifying the validity of each new block as it is found and transmitted to the network
any time the client is sending or receiving bitcoins
etc.

so that in general clients would still download all blocks broadcast when they were online.  However they would be able to:

purge blocks they "don't care about" if storage space is limited
in the typical case, start sending and receiving bitcoins after downloading only the few most relevant blocks (and all the headers of course)
etc.

Note that there are usually several entities "invested in" the continued availability of a given block, such as the original miner, who wants their 50 btc earned to remain valid, and anyone who received bitcoins from transactions in that block.  However, one intriguing consequence of this scenario would be that miners are incentivised to include as many transactions in their blocks as possible (currently one can mine without including any transactions if one so desires).  What would the other impacts on functionality and security be?

Edit:
I'm looking for a better answer than "I think it would destabilize the network" here--I want to see some estimated impacts on block availability, network overhead up or down once the lower amount of downloading is contrasted with re-downloading later, etc.  Some statistics on how inter-dependent blocks are alone would go a long way towards a solid answer.

Edit 2:
Right now this bounty's going to Shadders in a couple of hours.  But if anyone had more detailed info on the information I asked for in my first edit, they could definitely snipe it.  Any takers?


texts: Can we use fee rate less than 1 sat/vbyte?

texts: Is it possible to create, sign and broadcast a transaction with fee rate less than 1 sat/vbyte?


texts: Is there any rational economic reason to purchase XRP early?

texts: Deflation is a main economic reason to buy bitcoins earlier. However, is there any rational economic reason to purchase XRP early? As far as I know OpenCoin is not clear on distribution policy. The might be giving away billions of XRP at some point.


texts: What happens if you receive a block with an unknown previous hash in the header

texts:
I searched this question and couldn't find an answer to the following scenario.

Block 4440 gets mined at 10:00 AM
Block 4441 gets mined  at 10:01 AM

Lets assume I receive Block 4441 first and 4440 later. What happens? When I received 4441 I didnt know the block with the previous hash and I wasn't able to add 4441 to my chain.

Do I store these kinds of blocks with an unknown previous header in a pool and check periodically if I received the previous block?

Assuming we do this, do you ever remove old blocks from this pool?

If we save "invalid" blocks, how do we prevent people from submitting thousands of invalid blocks and filling up our pool? I assume we check if the difficulty was met but what happens if block 4440 lowered the required difficulty?


texts: Which altcoin would be the easiest to fork a cryptocurrency from for educational purposes?

texts:
Which codebase would you recommend for a novice who wants to create and run an altcoin in order to understand the technology - like a student compiling their own version of MINIX in order to understand operating systems?

If you want an objective criterion for difficulty, that would be how many lines of code are in the repository, not counting common libraries. Personally, I'm not interested in implementations in languages like Python that are considered easy to learn.

Litecoin is a popular choice, but SegWit won't make it easier.
I know Cryptonote is a more complicated protocol than Bitcoin. But what about Nxt, or other cryptocurrencies developed from scratch rather than copying Bitcoin?
Would Ethereum be relatively comprehensible if you removed the smart contract/EVM code?
I know there are tools to generate your own altcoin, but that would defeat the educational purpose, wouldn't it?


texts:
I have been scammed from the platform Perfect Option.
Does anyone else have any dealings with them?
I am interested to find out further information


texts:
I want to know what's the difference between "sidechain" and "layer 2".
Is it the same thing ?
Thanks


texts: How does Bitcoin verify each transaction?

texts:
So I realize that the Bitcoin transaction I make has information such as my wallet number, the amount of BTC being sent, and the recipient wallet number, and this whole message is encrypted using my own private key. And that this message can be decrypted with a public key.

Now, how do all the other nodes who need to verify my message
1) Know that this message is actually from me? When did I ever send them my public key?

2)J Know that I actually have enough funds to cover the transaction?


texts: What is the official website for Bitcoin?

texts:
What is the official website for bitcoin? bitcoin.com or bitcoin.org
Are other websites linked to bitcoin? What about bitcoin.info, bitcoin.help, crypto.com, blockchain.com?


texts:
If the BTC network can only only handle on average 2,759 transactions per block.
During a period where whales attempt a mass dump, could they essentially perform a DoS attack where they make a large number of transactions with higher miner fees than normal, to block unsuspecting network peers from also dumping their coins.
This would allow them to have higher potential gains if they are the only ones who can make a transaction in a 10 minute period.


texts: How to import a private key in bitcoin-qt?

texts: I've a paper wallet with privatekey which is created using coinbase.com. I want to import it in bitcoin-qt but I don't see an option in bitcoin-qt UI.


texts: Is bitcoin.org or bitcoincore.org the one to trust?

texts:
"Download Bitcoin Core": https://bitcoin.org/en/download
"Download Bitcoin Core": https://bitcoincore.org/en/download/
I've been alternating between the two sites for years. I have no clue who to trust the most.
Why are there two? I mean, I get it, it's "decentralized", but we all know that in practice, we must trust some kind of central source to get the actual "reference implementation", which most of us do consider the official "and only" (for us) Bitcoin client.
There's something which psychologically prevents me from ever trusting one of the other Bitcoin wallets/clients. It seems to me that Bitcoin is so absurdly complicated that only one team can really get it right. I've spent endless hours over so many years just trying to understand it on a "user" level, but it's just an Enigma still in so many ways. I'm even nervous for the main Bitcoin Core team to make a mistake, by accident or through evil intentions.


texts: ways to improve bitcoin tx finalization time

texts:
On GDAX website, they claim that 3 confirmations is needed to finalize your tx in. I assume they've done thorough research on this and might've come up with some logic to protect themselves from temporary branches.

In a few other posts, I often found people say at least 6 is needed. I mean obviously it's trade-off between efficiency and robustness, but just wondering what are some of the possible ways to push this number to the lower end while keeping the system as robust as possible.


texts: Bitcoin Wallet: Will 2 payments within 10 minutes cause double spending

texts: I'm using a bitcoin wallet for managing all my transactions. For example, If I have bitcoin 2, 3 and 5. Firstly, I buy a product with price 5. Bitcoin wallet will create a transaction from 2 and 3. When my first payment haven't verified yet, I make second payment by a product with same price is 5. This time will bitcoin wallet choose 2 and 3 or bitcoin 5 for my second payment ? I ask this because first payment haven't confirmed yet.


texts: Can someone explain or point to some documents with pseudo code that would show me how to verify bitcoin address based on a signature and message. I know how to do this in clients I want to know how to programmatically do it.


texts: Knowing if a public address is spendable by an HD seed?

texts:
I want to know if an address is spendable by an HD seed and for that purpose I am using the following command:

> bitcoin-cli getaddressinfo 3LFc64RRd96ejjYvm14KaogBF9fmeNmePW | jq '.solvable'
false

However as mentioned here and here it's impossible to know with 100% certainty that an HD seed can't spend from a certain address as one would need to generate infinite addresses. To counterbalance that I discovered a command that increases the 'search space':

> bitcoin-cli keypoolrefill 1000

However, I am not sure getaddressinfo is sentitive to this keypoolinfo parameter or is just checking the addresses so far generated (the ones that can be obtained via bitcoin-cli listreceivedbyaddress 0 true). I could test this with a second node but my other node might be using another seed to generate new addresses. Even though I used sethdseed, I see a different xpriv when dumping the wallet.


texts: Why does decoded block data not match coinbase transaction input?

texts:
I am looking at the specific block at height 680175.
Via bitcoin-cli getblock 00000000000000000004dbd66fa71fdcd62658bf8c8e2e153521257ad5858c71 0 I obtained the serialized, hex-encoded block data. According to the section Serialized Blocks the txn_count starts at Byte #81. Following the description of CompactSize Unsigned Integers I get:
In [115]: int.from_bytes(byte_arr[80:81], "little", signed=False)
Out[115]: 253

In [116]: tnx_count = byte_arr[81:83]
     ...: tnx_count = int.from_bytes(tnx_count, "little", signed=False)

In [117]: tnx_count
Out[117]: 1702

There are indeed 1702 transactions which can be verified via ./bitcoin-cli getblock 00000000000000000004dbd66fa71fdcd62658bf8c8e2e153521257ad5858c71 2 in the attribute nTx.
Now I know that the rest of the block data is the transactions' part. According to the section Raw Transaction Format the first 4 bytes are the version:
In [118]: tnx_part = byte_arr[83:]

In [119]: version = tnx_part[:4]

In [120]: int.from_bytes(version, "little", signed=False)
Out[120]: 1

This seems to be correct, too. So, the next bytes determine the number of tx_in count, but there I get 0 which is false. And the input of the coinbase transaction does not start with a 32-byte null:
In [121]: int.from_bytes(data[4:5], "little", signed=False)
Out[121]: 0

In [122]: data[4:10]
Out[122]: bytearray(b'\x00\x01\x01\x00\x00\x00')

Am I missing something? The input of the coinbase transaction seems not to match the description.


texts: Does Sovryn really not allow you to use it if you use Bitcoin Core?

texts:
https://live.sovryn.app/
This is apparently what Sovryn consists of. Not a downloadable application, but a website. It's very confusing, and so is its FAQ.
When I click the "Engage Wallet" button, it pops up a choice between:

"Browser Wallet".
"Mobile Wallet".
"Hardware Wallet" (disabled/greyed out).

Where is the "desktop wallet"? How do I use Bitcoin Core with this thing? Why would it support only "browser wallets"? I didn't even know that such a thing existed.
I keep hearing all these fantastic claims, but then when I try to actually use it, it's just... vapor? Fluff? Or am I once again missing something that you all understand?


texts: What happens if a TX was a double spend?

texts: What happens if the 'High' risk option (one confirmation) was chosen and then the TX turns out to be a double spend in the end? Would the value deposited be revoked? Would the user be notified somehow?


texts: Can a live feed of blockchain transactions be obtained from using bitcoin core wallet?

texts: I am interested in both obtaining the entire blockchain transaction history data (for bitcoin) and a live feed of transactions for a data science project. BlockChain.com has a very useful websocket API for the latter and I have been downloading Bitcoin core to obtain the former. Given that bitcoin core clearly receives new transactions in real time - is there a way I could get a live feed of transactions directly from bitcoin core (cutting out the need for the BlockChain.com websocket API). Thanks.


texts: Is the purpose of proof-of-work the immutability of the blockchain?

texts:
I have a disagreement with a person: I believe that the primary and most important goal of including proof-of-work (and therefore the nonce) in a block is to make it hard for an attacker to change that block (and since we are talking about a chain the next ones) without committing enough resources to recalculate not only the current but also all the blocks after that. Without it the attacker could simply create forks of the blockchain without any problems (free).

He claims that it is a mechanism is there to solve the problem of determining representation in majority decision making. If the majority were based on one-IP-address-one-vote, it could be subverted by anyone able to allocate many IPs. Proof-of-work is essentially one-CPU-one-vote.

Who is more right?


texts: I want to use another wallet.dat file with bitcoin-qt. Is this possible?

texts:
my situation is the following: I have a laptop with not much space on disk and therefore using bitcoin on a stick (I start bitcoin-qt with the argument "-datadir=location/to/stick). Now I wanted to transfer some bitcoins from my mobile phone to that account. Accidentaly I typed in a wrong directory (which doesnt exist) and bitcoin-qt lead me to the standard bitcoin directory (which is ~/.bitcoin). I didn't realize this and transferred the bitcoins to that address.

Now I would like to change the wallet.dat file from the ~/.bitcoin/ directory with the wallet.dat file from the directory on my stick, because my stick has all the blockchain already loaded. Is this possible?

What I have tried so far:

simply changing the wallet.dat files: when I now start bitcoin-qt it goes in a very very long loop (probably even an endless-loop). It just says "Dursuche erneut..." (german), what means translated: "Researching..."
doing the above, but with the additional argument "-rescan" ("bitcoin-qt -rescan -datadir=/location/of/stick"): it happens the same as above
trying to backup the relevant wallet.dat file inside the console of bitcoin-qt: when trying to back it up i get the error: "Error: Wallet backup failed! (code: -4)"

Can someone help me with this problem? Thanks in advance!

Edit: I wanted to rewrite my problem in another (probably easier understandable) way: I would like to overwrite the wallet.dat file inside the ~/.bitcoin/ folder. But doing so, bitcoin-qt doesnt stop loading (it just says "Researching...". Is there another way to do what I want?


texts: Who controls the features added to the bitcoin network?

texts: I read an article on cryptocoinsnews about sidechains and they said bitcoin can implement new features but any bugs would be dangerous to the whole bitcoin network. What I don't understand is who would be adding new features? Are there some people that continue to update bitcoin and can add code to the network bitcoin runs on?


texts: How are Namecoins managed by the system?

texts:
First of all, sorry for a potentially silly question, but I flicked through seven pages of questions here and I couldn't find a specific answer for that:

How does Namecoin basically work? I understand the basic principles of Bitcoin and heard these are the same in Namecoin - you mine coins, get a reward, which gradually decreases. But in Namecoin, the coins are also deleted, aren't they? Doesn't it mean that we will eventually run out of the supply of Namecoins?


texts: Closed a wallet in Multibit mac and cant find it from application support

texts: First time installed Multibit for mac and had my bitcoins transfered there. I had the software and wallet open for 2-3 days and decided to close the wallet. After closing i couldnt find the wallet in the application support folder. There was nothing related to multibit in that folder. Ive been trying to search .wallet files from the Finder but it comes up empty. Are my bitcoins gone for good?


texts: Lightning Network: what happens if parties lose their txs?

texts:
Let's take the classical example of Alice and Bob with 0.5BTC each. Commitment Txs are exchanged for a new balance sheet: Alice has 0.6BTC, and Bob 0.4BTC.

If Alice loses Bob's Breach Remedy Tx, she can still publish a Commitment Tx and get her 0.6BTC, but if Bob acts maliciously, she is not able to defraud him. Is that correct?


texts: How to send portion of funds from a private key programmatically?

texts:
I'm building an app and one of my features is being able to scan a bitcoin private key and then send a portion of its funds to another address. How can I do something like this in javascript or php? Do I need to run my own Bitcoin server?

Is there an example script I can use where I can just plug in a private key?


texts: Custom validation logic for transactions/ custom script extensions

texts:
Is it possible to add a hook for custom validation of transactions with a special script "tag" in them? If so, How? In essence, I want to add something similar in  functionality to bitcoin script, but far more complex that what that supports. It doesn't matter if most clients/servers will not recognize the extended bitcoin script , provided they will ignore it.

The idea is that a node, when seeing a transaction with a special script payload, would call some external validation routine and only if that succeeded would it then run the standard integrity checks.

Are there supported hooks for this in the JSON-RPC API, any of the various clients, or would it require extensive modification of the source ?


texts: Does the economics behind exchanges allow to profit from crypto exchange rates?

texts:
Say we have TheBestCryptoMarketSiteEver.com

I have $1000.
I buy BTC with those
I buy ETH with the BTC
I buy LTC with the ETH
I buy USD With the LTC

There's a fee for each of those transaction 0.1% - 0.5% depending.

Would an exchange site's rates ever vary enough to allow for profit from the above gymnastics?
Would it be possible to ever end up with more USD than I started with ?


texts: Is the contest period really necessary for cross-chain transactions in 2-way-peg sidechains?

texts:
According to the first sidechain article (Link), the cross chain transaction process can be briefly describe as follows:

Alice has a wallet on sidechain S1. She wants to send some coins to sidechain S2. So she makes a transaction containing some coins, send it to a certain locked-output on S1.
Wait for confirmation period to end.
After the transaction is confirmed, she submits a SPV proof to S2.
Again, she has to wait for a contest period.
After the contest period ends, an equivalent amount of coins is created and sent to her wallet on S2.

I assume that both the sidechains are secure, otherwise there is not much left to discuss. If they are secure,  then after the confirmation period in step 2 above, the sidechain S2 already knows that the transaction is confirmed on sidechain S1. For example, if Alice purchases something using Bitcoins, step 3 is where she can get the product she purchased from a normal store.

In my opinion, after the confirmation period, the transaction is already in a stable part of S1. Thus, there cannot be any valid SPV proof that contradicts the SPV proof Alice sent, unless S1 does not satisfy the persistence property.

Therfore, I would like to ask, why is the contest period necessary? Is there something I am missing in my argument? Thank you.


texts: Is there a reliable and accurate profitability calculator?

texts: I've looked at the various profitably calculator sites and honestly I'm not sure how up to date they are. They don't seem very accurate. Is there one that's better than the others?


texts: Are there any privacy benefits in using a separate wallet in Bitcoin Core to "separate" myself from my service?

texts:
I currently run Bitcoin Core with the following wallets loaded in:

hot.dat. Contains the smallest possible sum of Bitcoin. Unencrypted and used by myself for various personal Bitcoin purchases, and I intend to have it double as the wallet for my Bitcoin-based website. (Unless you tell me a good reason not to.)
lukewarm.dat. Contains more than the "hot" wallet, but still not much compared to cold.dat. Encrypted with a long passphrase, but which is located on the same computer in a text document. I recon that it will stop at least automated malware which simply checks for wallet.dats and merely "sends them home". It of course won't stop somebody from manually finding the text document on my machine and figuring out that it's the passphrase to use.
cold.dat. Contains the vast majority of my satoshis. Encrypted with a long passphrase (partially stored on the same computer) with a bunch of additional parts with "hints" to myself rather than explicitly spelled out. This passphrase has never been entered to unlock the wallet outside of the dedicated Linux computer where it was created. (Not this machine.)

I'm aware that many would not consider my cold.dat to be a "cold wallet", but I thought the naming scheme fit well enough. The reason I don't use a truly "cold" wallet (where it's not stored on a "live" computer even encrypted) has to do with me fearing losing the file or having a fire or getting it seized more than I fear somebody first hacking into my machine and then somehow figuring out my complicated passphrase scheme. I consider that so unlikely that it is far more likely that I would lose access to it in other ways.
Now I wonder if I should be having a separate "service.dat" wallet dedicated to my new service, or if I can just generate new receive addresses for my existing hot.dat and use those. Is there any privacy benefit in me doing that? Or would I just be wasting yet another transaction fee to send over some satoshis from my hot.dat to my potential "service.dat"?
What if somebody who I do private business with knows who I am (because I have to give them my home address) and when I've paid them using hot.dat, those "inputs"/"outputs" are reused for my service, and suddenly they can associate me, the individual, with my service? And would that change at all if I used a separate "service.dat" wallet for the service? Won't it be the same "track" either way?
PS: No, it's not something illegal or immoral. I'm simply trying to avoid any association between myself and the service, plus I'm also curious about this on an academic level.


texts:
I am running bitcoin-qt v0.8.5 on Linux/amd64 and I encounter a strange behaviour for account commands when using JSON-RPC.

My initial wallet looks like this:

Test-Account | 1PNU1vZbruMCZpVBFk3eKmKrfGKDugBsjB

After issuing the command

setaccount '1PNU1vZbruMCZpVBFk3eKmKrfGKDugBsjB' 'Renamed Account'

I just expected the old account to be renamed, but the wallet changes to:

Renamed Account | 1PNU1vZbruMCZpVBFk3eKmKrfGKDugBsjB
Test-Account    | 16jfcbLM9tGrkvXqGKnuC46j2jqKVMAe46

It created a new address for the old account (it is always the same new address for the same old address !?). Is that behaviour intended? The documentation I could find is unconclusive about that.

After this I issued the command

getaccountaddress 'Renamed Account'

and I expected to get the address "1PNU1vZbruMCZpVBFk3eKmKrfGKDugBsjB" as a result. But instead I got the single address "176uhGVRT8KxScvQqdA7Yh87qQ8F5LMMM6" - and the wallet now looks like:

Renamed Account | 1PNU1vZbruMCZpVBFk3eKmKrfGKDugBsjB
Renamed Account | 176uhGVRT8KxScvQqdA7Yh87qQ8F5LMMM6
Test-Account    | 16jfcbLM9tGrkvXqGKnuC46j2jqKVMAe46

What is happening here? What am I doing wrong?