lost bitcoin on electrum - wallet closed after transaction went through? i'm noob to bitcoin and lack advanced knowledge of how these wallets work. i followed guides on how to buy bitcoin and seemingly the transaction went fine, until my electrum wallet suddenly closed and when i opened it back up i could not find my transaction in history, my recieving address changed and the address i used to buy  bitcoin can not be found anywhere.
here is a link to the transaction https://blockchain.info/da/address/157gZExbGA27R33AFHmQS41EzFxXoUpBjP

and an image of the receipt after purchase
did i screw this up completely or can i still get my bitcoin into my electrum wallet?

Hmm.. weird. Here is what you can do: Open Electrum, click on on
  wallet, then master public keys. Copy the master public key and paste
  it in blockchain.info/xpub/"your master public key here" without the
  quotes. It will show you all the transactions related to your current
  Electrum seed. Is the 'lost' transaction listed there?

Well, if you are absolutely sure that you saw the transaction in Electrum, and the address has now disappeared even using the same seed. There is only one thing left to do: Submit an issue directly to the Electrum developers. github.com/spesmilo/electrum/issues and mention that you tried with your master public key and didn't find the corresponding transaction.


Blockchain Tools for Voting Among Small Groups? I am considering starting a new co-op based business. Since the business will be member-owned, it would be nice to launch the business with a voting tool. I want to be able to propose items to the co-op members and have them vote through a transparent system. I understand that there are efforts to use the blockchain (or blockchain-esque tools) to handle voting. But all of the ones I can find are for large scale efforts (like BitCongress).

Are there any blockchain tools/approaches that can handle voting for small-ish groups? Ideally it would:

Handle voting from 300-400 people
Be able to be deployed on my own server (not a cloud-based solution)
Be simple to use for people that may or may not have previous BTC/blockchain experience

I should also add that I have the coding skills to develop my own blockchain voting tool. So if there is no OOTB solution for what I need, I'd appreciate links to whitepapers or other documentation that outlines approaches to a blockchain voting scheme.

All help is welcome.

Blockchains are a bad solution for voting, and in my opinion the widespread interest in using them for this purpose is misguided.
One of the important properties of a voting system is making sure that it is impossible for a voter to prove after the fact what vote they cast, in order to avoid vote selling or intimidation. Because of this, systems that do allow voters to prove what they voted for are in fact outlawed for government elections in many jurisdictions.
The property you want is auditability (individual users need to be able to check their vote was counted, and verify that the tally was computed correctly), but that doesn't require publication. A blockchain is however inherently a publication mechanism, and systems that rely on a blockchain to tally votes imply that everyone can see all votes.
In practice, modern cryptographic voting systems (see E2E auditable systems) actually have very good properties, without the need for publication. They rely on a central server which can see the IP addresses of the voters (but can't see the encrypted votes, and Tor can conceal IPs), let a group of trustees jointly decrypt the resulting tally, and let individual users verify after the fact that their vote was included in that tally.
But isn't that centralized? Yes it is. But decentralization is only a means to achieve a goal. In Bitcoin, we need decentralization as it's the only alternative to having a central party with transaction censoring rights. In a voting system, having a central party who can censor encrypted votes is typically preferable to allowing the whole world to see your vote (and still allow a 51% majority to censor and thus influence the outcome).
I also recommend reading Ben Adida's blog post on the matter: https://benlog.com/2017/12/28/blockchain-and-voting/

This is certainly possible with Ethereum. It won't meet the requirement of being "simple to use for people that may or may not have previous BTC/blockchain experience" but if you have programming experience you could hook up it up to a nice app or website.

Alternatives that don't seem to meet your needs:

Bitcoin multisig allows up to 15 people voting on a single standard transaction. This has the most support and tools for people to that are new to the concept of a blockchain. Maybe you can do a delegate type setup?

NXT implemented a voting system that allows up to 100 answers. I'm not sure about the number of tools to make this easy to use for your average person.


What does it mean to have -1 confirmations? I have -1 confirmations for an inbound transaction on my Electrum wallet. What does is it mean to have -1 confirmations?

It is a known bug, just restart the client and/or switch to another server in the Network window (green dot in the bottom right).

If this doesn't fix the 'Unverified -1 confirmation error' try deleting the block_headers folder on your Electrum directory -> https://bitcointalk.org/index.php?topic=330626.msg5292794#msg5292794

It probably means, it did not synchronize properly yet, and does not know how many confirmations there are


Would it be possible to patent Bitcoin? Bitcoin utilizes a proof-of-work mechanism to assure against double-spending, as well as providing an example opensource implementation.  However, some countries allow software patents, which could mean that one person/company has the ability to suddenly prevent the legal use of Satoshi Nakamoto's Bitcoin algorithms.

Are these Bitcoin algorithms complex enough to qualify for being patentable, and if so, in what countries might such patents be granted?  Does this pose a significant legal risk for users of Bitcoin?

To claim a patent you must be able to prove against contest that you invented the device, and have a working example that if built to the specs provided, runs.

As it was this Satoshi who invented bitcoin, and there are prior examples of a digital currency, it would be very hard for any one person to claim a patent so far after the fact. Some one could try, but the patent industry is built to make it hard to write a patent, easy to contest. Admitedly many companies do just that and are good at it, but anyone patenting bitcoin would have a hell of a time proving first invent.

As long as the Bitcoin project is open source it would be very hard to claim a copyright on that code which is freely available for copying.

Now if someone wanted to copyright a derivative work then that is possible.


Is the appreciation in bitcoins taxable? If you have large gains in bitcoin, is there any way that it can be taxed?  If I have $5000, and it appreciates to $10,000 worth of bitcoin, when I sell bitcoin for dollars can it be taxed as a capital gain?  I would think that since there is no documentation to support it that it would be difficult.

My guess is that as long as you have a receipt for the buy, and one for the sell then there is no reason why the government would say no to taking their share if it. I guess it's just classed as currency trading??


Creating my own bootstrap.dat? Since I have been tearing down and setting up bitcoin clients a lot for some experiments lately, I was wondering whether there is a simple way to speed up the synchronization with the network. One method that comes to mind is the bootstrap.dat file distributed by some people. The problem is that the last 40'000 blocks, which are the most expensive to get and verify, are not included.

Now I was wondering how to create such a bootstrap.dat myself, from a good copy I have on another machine. Any idea?

Bitcoin Core contains a tool to do this properly (filtering out any orphan blocks, putting everything in the correct order — which will work a lot better than just concatenating the block files. It's documented in its own README, here: https://github.com/bitcoin/bitcoin/tree/master/contrib/linearize

In short:

Launch Bitcoin with an rpcuser and rpcpassword set in your config file, with the correct location as per https://en.bitcoin.it/wiki/Running_Bitcoin#Bitcoin.conf_Configuration_File
Checkout the Bitcoin source from Github and cd to contrib/linearize.
Copy example-linearize.cfg to linearize.cfg and update it with your rpcuser/rpcpassword values, along with the maximum block height you want to output (max_height), and the path to your data directory (input), as well as the path to your desired output file (output_file).
Run ./linearize-hashes.py linearize.cfg > hashlist.txt followed by ./linearize-data.py linearize.cfg.

It is somewhat intuitive what files need to be copy and where once you have a full node built.  What is not so intuitive is how to bootstrap a full node before you have built your first full node. You first need to know where the files need to be placed for the various 'OSes'. I'm not sure if there are little or big endian issues with copying the raw Blockchain node files between different OSes.

Another approach is to let the protocol handle the problem. Secondary and tertiary nodes build very quickly if they a on your own high bandwidth LAN.  Just point a secondary node (by tweaking its bitcoind.conf file) to the primary node that is already built using the "connect=Your_IPv4_LAN_Address". Such builds move very quickly... You might find it to be faster than writing the ledger to a thumb drive and copying it to another computer.


Mining on Nvidia(i know it's bad, but it's a start) So, I have this nvidia geforce fx5200 d256m gpu in an old box, I want to start it out as a no-cost minig rig(laugh all you want, I'm starting base and hoping to spend zero out of the pocket). I wanted to know what the expected hashrate would be, and what kind of settings I should set it up to use with in cgminer.
Remember people, the question is about the card, not my ideas of what I'm doing. Also this is planing to be done in my basement, which is always cold. So airflow/temp isn't an issue either. It's mining litecoins NOT bitcoins.

Here is a comparison chart.  Your card is not even on there. So I assume its going to be about 5khs if you lucky.

I would suggest you sell that card even for five bucks and invest in AMD card with loads of cuda cores. Its obvious you don't want to spend lots of money but for 50 bucks you can find a decent card on eBay or something. That will give you allot more kh/s.

The problem with GFX mining is that electricity is really expensive. If you dont have to pay for it or you are within a green area (Hydro plants, Solar Power) and its "dirt" cheap then it is still worth it.

Good luck with your experiment.

FYI - I would suggest looking into ASIC Erupter for ultra low power BITCOIN miners.

Or you sell everything and stack the pennies up order one of these 5GHs "Jalapeno" miners  from Butterfly LABS. They can be "jail borken" and even go to 9ghs if you add extra fans.

I am in no way affiliated with any of these companies. I just use their stuff and I know it works and brings me money in. No BS!

Previous poster was correct on Grabbing and AMD  card. But no Cuda on AMD cards. That is Nvidia. As far as your card. You will need to install the cuda tools to get it going and yea, looking at 2-5K


How to recover deposit to incorrect address i need some guidance. I deposited Bitcoin from LUNO to an address in Gatehub. The Bitcoin has not arrived in my Gatehub wallet. I believe it went to an incorrect address. How do i trace it and recover it.

Log into Luno and click on transactions.

This should list the deposit that you did to gatehub. In my example in the screenshot this is a transfer I did to the waves platform

If you click on that transaction in the list it will show the transaction number of this deposit. The transaction number will be hyperlinked so you can click on it and it will launch a new page that allows you to view the transaction in the blockchain explorer. Check your transaction in the blockchain explorer and see how many times it has been confirmed and whether it has been added to a block.


When do I have to backup wallet.dat? Is it obligatory to backup wallet.dat after each outgoing transfer?

I understand it is, but not after each incoming transfer.

Every 100 transactions, counting both sending and receiving. For receiving, you can treat multiple transactions to the same address as a single transaction.

This ensures that you don't lose any bitcoins if, for example, your hard drive crashes.

The option keypool in Bitcoin-Qt client adjusts this.

You're never obligated to back up your wallet. It is something you do to protect yourself.

You do not need to backup your wallet to prevent from double spending (you spend BTC, loose your wallet, restore from an old wallet and try to spend the same coin). The protocol will stop that from happening because the transfer exists in the block chain.

However, you do need to back up your wallet to know what you have to spend. Without a current wallet the protocol won't know that you own a BTC and that you can spend it.

It is impossible (without a lot of computing power) to double spend BTC. Without your wallet you won't know what you have to spend. You can loose Bitcoins forever just like you can loose cash forever.


Mining pool hashrate effect on a miner's income Newbie miners have many misconceptions about how the hashrate of the pool they mine in will affect their mining income.

If a big miner joins the pool there are some unhappy miners who think that now they will get paid less because big miners take a big share of the mined coins, while others are cheering because they think a big miner will help them pull in more coins.

Some miners believe you should pick a big/medium/small pool depending on whether your own hashrate is high or low.

How does pool hashrate actually affect miner income? Assuming the pool is not PPS (fixed pay).

The size of a pool, its total hashrate and the distribution of hashrate between bigger and smaller miners, have no effect on the rewards you, mining with a specific hashrate, will obtain on average.

The total block rewards collected by the pool are proportional to the number of blocks it finds per time unit, which is proportional on average to its total hashrate. In every fair pool reward method, the rewards you get on average are exactly proportional to your part in the total work done by the pool. If you mine in a pool twice as large, the pool will collect twice as much rewards but your share in them will be cut by half, meaning you get the same on average.

More specifically, all fair reward methods give miners on average (1-f)pB per share they submit, with f being the fee, p the probability that a share will be a block, and B the block reward. This amount does not depend on anything else, in particular not on the pool size.

What does differ according to the size of the pool is the variance in the rewards (how much they vary from the average due to randomness) and the maturity time (how long it takes to obtain the rewards). It is always the case that a bigger pool will have less variance and maturity time, and thus for a miner of any size it is better to mine for a pool as large as possible (however, it is better yet to mine for multiple pools simultaneously).

One point where a miner needs to optimize based on his own size is the share difficulty; smaller miners will want easier shares, so they should make sure their pool offers it. While bigger miners should work on more difficult shares to make sure the pool server isn't overloaded.

I like your pool because it has an easy Java miner that takes the effort out of configuration! But, if it didn't matter, then why does my math NOT add up?:

The world gets one block (25 BTC) every ten minutes. Nothing on earth can change that for this currency as it is set in this specific protocol.

Being hypothetical:

Small pool = 20% and large pool = 80% of all hashing power
Your 1 GHash/s miner pulls in say 10% of the shares on the small server
Your 1 GHash/s miner pulls in 1/5th of that on a large server as it is only 2% of shares

1 block is mined for this shift

A 0.2 small pool is rewarded their 20% of the block == 10% is your work == .02 blocks
A 0.8 large pool is rewarded their 80% of the block == 2% is your work == .016 blocks

I understand that over the course of a shift, the hashing power should cause the bigger pool to mine more shares which is supposed to even out the distribution curve, but I think that this is not exactly true either, because it is a "random" drawing for the correct "hash=greater than difficulty" solution to solve the block and continue the work in sequence.


Can I buy/sell a lot of bitcoins without moving the price? I am curious about how to acquire a lot of bitcoins (or similarly move a lot of bitcoins) without hitting the bid/ask

I don't care about blockexplorer, I am just curious about price discovery

are there any darkpools? could I just use an illiquid exchange and personally contact the counterparty and have them take the trade

options would be good too, this would make acquiring bitcoins at a certain strike easier as this is already a negotiation between the person on the other side of the contract

It won't work, no matter how you do it. If you acquire a lot of Bitcoins, that will mean that a lot of people who wanted to get rid of their Bitcoins no longer want to get rid of their Bitcoins. Thus, they will stop supplying them. The reduction in supply will move the bid/ask prices. It's fundamental economics and you can't change it.

High volume traders can apply for a "dark net" account with Mt. Gox. I believe you qualify for this type of account if you trade over 1,000 BTC per month. (Something like that, I can't find the exact specifications at first glance.) You can also make in-person trades of digital or physical wallets, which would be "off the grid" in the sense you are speaking of.


Attach worker to CEX.IO account I have been able to set up basic mining using minerd, and it is happily mining away on GHash.IO. However, it doesn't seem to be attached to my CEX.IO account, even though I am mining with these arguments:

minerd --url stratum+tcp://uk1.ghash.io:3333 --threads 2 --userpass [myusername].worker1:

Can anyone point me in the right direction?

EDIT: The above was mining with my account after all. A refresh rate of 1/day lead me to believe otherwise. Sorry to waste everyone's time!

this work
./minerd --url=stratum+tcp://uk1.ghash.io:3333 -u username.workername -p xxx


What is the appropriate forum for technical discussions about Ripple? Is there a mailing list where software developers and other interested parties can have technical discussions about the Ripple source code and other aspects of the network?

Bitcoin Stack Exchange is more suitable for Q&A, where questions have definite answers.

There are a number of forums. Ripple Labs has an official forum that the developers read regularly. There's also a Google Ripple Server group.

There is not very active Q&A:

http://www.rippleoverflow.com/

And mostly active ripple chat at freenode:

IRC chat.freenode.net:6667 #ripple


Are there any blockchain explorers that provide raw Tx data and block headers? I've looked at some of the more popular blockchain explorers, but none of them seem to provide the feature I'm looking for. I'd like to find a blockchain explorer that allows you to see raw Tx data and raw block headers. The explorer's I've seen parse the raw data and present it in a more human readable format. Are there any that provide the raw data?

Thank you!

You can get this info from blockchain.info, by simply adding ?format=hexto the end of the relevant URL.

For example, here is a recent block (height 509,244):

https://blockchain.info/block/0000000000000000000635bda771916ca727db53fea5441508f7161386e066be

And here is the raw data for that block, in hex:

https://blockchain.info/block/0000000000000000000635bda771916ca727db53fea5441508f7161386e066be?format=hex

(Note that you will need to parse the block header out of this data, as that URL will dump the raw data for the entire block)

Similarly, here is a transaction from that block:

https://blockchain.info/tx/74d350ca44c324f4643274b98801f9a023b2b8b72e8e895879fd9070a68f7f1f

And here is the raw data from that transaction, in hex

https://blockchain.info/tx/74d350ca44c324f4643274b98801f9a023b2b8b72e8e895879fd9070a68f7f1f?format=hex

Feel free to use Blockchair API to find information about raw transactions. Look up  "raw transactions" headline here: https://blockchair.com/api.


MintChip and Bitcoin - how do they compare? The Royal Canadian Mint announced some time ago a new solution called MintChip, which appears to share some similarities to Bitcoin. How do those two projects differ, and how are they similar?

Note: My information about MintChip is a bit limited and may be incorrect. Corrections are appreciated.

Authority: Bitcoin has no central authority. MintChip is run by a government agency.

Security: Bitcoin is secured by cryptography. MintChip is secured by tamper-resistant hardware. (The Mint says they'll support other models, but I'm quite puzzled how they'll make that work with their framework.)

Anonymity: Bitcoin is pseudonymous. You perform transactions through an account and transactions are public. You can have more than one account. MintChip transactions are only known to the participants and the system operator.

Currency: Bitcoin is a commodity that acts much like a currency. The supply of Bitcoins is fundamentally limited by the mathematics of the system. MintChip is a way to trade fiat currency that can be devalued by inflation and whose supply is limited only by politics.

Mintchip is a payment system, and a wallet for multiple currency.

Bitcoin is a payment system, a currency, and a wallet for Bitcoin.

Mintchip greatest advantage over Bitcoin will come when Mintchip support payment in gold, redeemable for gold stored at the mint.

Bitcoin greatest advantage over Mintchip is being a borderless floating currency with a infinitely-divisible finite supply.

The two nicely complement each other.


Should you protect your Bitcoin address like your credit card number? Today, I recieved this scam email:

  We have reached the biggest milestone in our history – over a million wallets.

  https://[removed] will celebrate with some big prizes.

  In October 2013, the lucky user who created the 500,000th wallet was rewarded with 10 BTC.

  Read more about this: http://[removed]

  We have discovered that you created the wallet with number 1.000.000

  [removed] want to reward you with 50 BTC.

  To prove that you are the rightful owner of the lucky wallet,
     please reply to this email and send us your mnemonic ( the long string of words generated randomly when your account was created)

  After verification, your wallet will be credited instantly with the 50 BTC.

  Thank you that you have chosen https://[removed]

I am guessing this is a scam as (a) it was sent to two separate email addresses I have, (b) the sender's email is in no way affiliated to the websites listed in the email and (c) I don't think anyone is willing to just give away 50 BTC which is close to $42,000 USD. I was wondering if I were to give them my Bitcoin address, what would happen next? Would they be able to use it like a credit card number? Or would they just be asking for more personal information?

A bitcoin address is not like a credit card number. You can safely give your bitcoin address out publicly.

What the email is asking for is something you should never give out publicly: the mnemonic that you use (e.g. if you use Electrum, they have a 12-word mnemonic code), from which you can calculate your private keys. With this, they can easily steal all bitcoins on any address that was generated using that mnemonic.

If they actually wanted to know that you are the owner of an address, they could ask you to sign a message. There's not normally much of a reason to do this, though: I don't see a scenario in which a signed message is needed in order to give you money, instead of just the address.

If they actually just wanted to send you money (as they claim), all they need is your address.

Giving away your public address wouldn't be the same as giving away your credit card. But what I think the sender of this email is might be trying to do is the following:

Collect BTC loaded public addresses.
Run (with brute force) common phrases, or even with common words to crack it
Collect any BTC with addresses which have weak private keys.

If I would have done this, I would have used vanitygen to verify the common passwords (private keys), against the public addresses. Given that you can check 60k-300k private keys per second (with an i5 core), it'll be fairly easy to check all of the submitted addresses.

-Besir


Finite field mathematics and elliptic curves don't use the "normal operations". For example adding two finite field elements a and b isn't as simple as a + b. its actually
(a+b)%Prime where prime is the size of the finite field, this ensures the CLOSED property is meant. which says that if a is in the set and b is in the set than a + b is also in the set.
Same goes with multiplication which is what we have here.
ab=(ab)%Prime
so for gx and gy you can use this (gy^2) % (2^256 - 2^32 - 977) = ((gx^3) + 7) % (2^256 - 2^32 - 977). These are in fact are equal.


How does the full lifecycle of a cryptocurrency trading look like? I am new into cryptocurrencies and I am wondering how to trade them. By trading cryptocurrencies I mean:

Transfer fiat currency (ie. USD) from my bank account into some account that enables buying cryptocurrency.
Buy a cryptocurrency like BTC or ETH with fiat currency.
Transfer cryptocurrency back to USD.
Transfer USD back into bank account.

Is there one platform where I could accomplish this full lifecycle of a trade?

From my research I was able to create a cryptocurrency wallet with Atomic wallet. This app allows to transfer USD via credit card into the app and then trade USD with multiple crypto currencies. The fee for transferring USD to a crypto is 12% of the amount. Which does not make much sense for serious trading (I need to pay 112 USD for every 100 USD transferred to Atomic wallet). Are there cheaper ways to trade fiat to crypto?

Additionally, it is only half of the story.

Atomic does not allow to transfer crypto to fiat and send back to bank account. To accomplish this I need to create another account in currency exchange like Bitstamp or Coinbase and verify it with some documents. Then I can trade crypto to USD and finally back to bank account. I did not accomplish this step so I don't know what are the costs of transferring back to bank account.

Apart of this, I've found that some trading platforms, like Ledger Live require particular devices to be bought to be able to trade crypto. Making it useless for other wallet owners.

My question
- what are the most convenient (ideally one platform) and cost efficient ways of trading crypto for fiat and back?

I assume that at the moment there is no single platform that does this but at least two accounts are needed to trade. In this case what are best ones according to cost efficiency and market accessibility?

Depending on where you live there are different options. I would suggest, if in the US, to go with one of the larger platforms like Kraken.com, or CoinBase.com. In these systems you can wire funds (Kraken) or attach to a bank account to purchase currency.

In my experience, CoinBase will be your training wheels. It's hard to see what you're buying/selling as the actual transaction occurs automatically when you click the button. What you see is not what you'll get (unless that changed in the last week). However it is very easy to use.

Kraken will require more verification for additional tiers (work with more value). But you can control the trading. You can set buy/sell limits which means you won't get 1 penny less than what you told it. They have tons of additional trading options if you want to get more advanced as well.

Final note, Kraken supports many more crypto currency options and bought cryptowat.ch over a year ago for a nice live feed of prices across multiple platforms.

Hope this helps you get started!

Edit: I'm not here to judge intentions or viability. The question was  "what can i use". Any assumption (including commentary on the current market, political, legal, etc) other than "I'm simply answering the question" would be incorrect.

I honestly don't know what to tell you except:

Don't. You don't know enough about crypto if you're asking this question.
Don't. The market is in a bear market, buying crypto is an extraordinarily stupid thing to do right now.
Don't. Trading takes tonnes of research - you need to know which exchanges are which, what technical analysis is, have a fundamental idea of what a bitcoin is worth to you, and have some tokens/coins you are interested in. If you're asking this question, you don't have any clue what you're doing
Don't. Right now, regulatory bodies that you've never heard of are moving their slow thighs, and slouching towards some dark purpose. Many, many coins are in breach of various legislations, and several exchanges are in breach of various legislations. Do you know which, or what the impact might be of santions?
Don't. You aren't inquisitive enough if you have to ask this question. There are plenty of online resources out there, most of them are run by second-rate snake oil salesmen. If you cannot even find those resources, if you're just going to blindly take what someone gives you, then you're very naive and you're going to lose all your money.
Don't. Trading is much, much harder than engineering. It also requires a different mindset - you shouldn't care about wallets and technical crap, but about what the market thinks is a good idea, business case models, interest rates and pricing strategies.
Don't. It's coming up to Christmas, your money is better spent buying your loved ones nicer presents.
Don't. "I did not accomplish this step so I don't know what are the costs of transferring back to bank account." If you cannot use google enough to search for "withdraw fiat fees EXCHANGE" then you are nowhere near technically capable enough to do trading.
Don't. If you're asking this question on this board, you don't have any friends/acquaintances who are trading crypto. If you don't have anyone to discuss with then you will really struggle to learn the best forums/blogs/sites/tweets to make head or tail of the market.
Don't. Bond yields have inverted. You don't know what that means, why not find out about bond prices and their implications instead?


Why did Bitcoin lose value so fast in early January 2015? What on earth is driving the price of Bitcoin and other alternative currencies down lately? It's one thing for it to go down a bit but losing practically 80% of its value in less than a year? I feel like bitcoin is coming to a complete collapse. A list of the most important factors and a detailed explanation would be great guys.

Adding to my answer on What are some of the proposed ideas to why the Bitcoin dropped to sub $400 in the end of summer 2014?, which I think is still mostly accurate:

Bitstamp loot

There are about 19k bitcoins held by the hacker that raided Bitstamp. While, as far as I know, they haven't found their way back into the market, it is an amount that would impact the markets if it were dumped. It is possible that some speculators were expecting a dump, and tried to position themselves to buy low. Such a dump in itself could have scared the already skittish market into further dumps.

Bitstamp has no trading fee until 19th

While Bitstamp seems to have weathered the hack well-enough, they are not taking any trading fee until the 19th. The fee usually being 0.2% – 0.5%, trades on much smaller movements are currently profitable. As Bitstamp is still the most important Western Exchange, this might have spiked a new dynamic.

The loss in value

Markets amplify the current trend. The loss in value is causing fear, leading to further dumps, creating a catch-22.

Russia banning Bitcoin websites

Bitcoin supposedly was a hip way to withdraw money out of Russia for a while. Although Russia had been rattling with their saber a while towards Bitcoin, they are finally starting to take action by blocking Bitcoin services there now. This might induce a trend of Russians moving out of Bitcoin.

Butterfly Labs has to sell their stash to confirm with financial obligations

Apparently, Butterfly labs has been ordered by court to refund their customers. According to rumors on reddit, they have been selling thousands of Bitcoins and are still sitting on more than 90k.

Mining operations sliding into unprofitable ranges

A bunch of mining operations, as for example CEX.IO, have cited that the current price makes their mining unprofitable. To cover financial obligations, they have to liquidate a larger percentage of their bitcoins than before, perhaps even their saved holding they were hoping to carry over to the next bubble. With the dropping price covering their obligations by liquidating bitcoins only gets more bitcoin-expensive.

Bringing oneself in position to buy takes a few days

When the price quickly lost value, few of those that were interested in catching up the cheap coins were already in position to buy. As it takes a few days for money to be transferred to exchanges, the buy reaction is a bit delayed in comparison to a price drop.

Especially on Bitstamp where deposits were closed for a few days during the slump in the aftermath of the hack, people were probably waiting for the dust to settle. In fact, a lot of the deposits from Bitstamp were immediately withdrawn on reopening.

Once the dust settled, and people started to realize that Bitstamp actually appeared to be in good shape, it still took a few days for potential buyers to transfer money to Bitstamp, which would explain why the price was somewhat shifted lower on Bitstamp in comparison to other exchanges for a while.

As usual: I'm a computer scientist, not knowledgeable in economy beyond what I read here and there. Please do not consider this investment advice; I have been wrong before. Please trade responsibly.

Because bitcoin is a pyramid scheme. And it falls now.


What Do I Do? Unconfirmed Transaction For Almost 7 Hours :( Sorry if I'm acting like a noob. Never had a transaction take this long and it's worrying :/ It's been about 6-7 hours and still no confirmations. Do I just wait it out? Please help! :(

The transaction ID is
c3cfa18f21ab69dce87b269643cc841f0c16b7e69683afaad14a25d4b0740277

EDIT: My wallet will not synchronize now either...

Thanks

You can thank the China government and internet censorship for the recent blockchain issues considering the two largest bitcoin miners are in China.

I have payments from yesterday almost 18 hours that have not finalized so you are not alone.

It is the beginning of the end for bitcoin brotha better start learning Monero!


How did Nakamoto untraceably pay for registering bitcoin.org? Wikipedia says "Nakamoto created a website with the domain name bitcoin.org" and "transferred several related domains", while bitcoin.org says it was "originally registered and owned by Bitcoin's first two developers, Satoshi Nakamoto and Martti Malmi".  A 2014 businessinsider.com article says bitcoin.org was first registered in 2008 via anonymousspeech.com, and that Malmi stated bitcoin.org was "originally created by Satoshi", and Malmi's first contact with Nakamoto was in 2011 when bitcoin.org was transferred to Malmi.
The article also says anonymousspeech.com accepted cash and E-gold.  Did Nakamoto pay for the original bitcoin.org registration, and used cash or E-gold (paid for with cash) to do that and keep his origins untraceable?  Or is it possible that somewhere in history is a non-anonymous payment of some kind that would finger Nakamoto?  For example, archive.org shows bitcoin.org was an actual hosted site at least by January 31, 2009.  Where was it hosted, and how and to whom was that hosting paid for?

How did Nakamoto untraceably pay for registering bitcoin.org?

Nobody knows for certain apart from Nakamoto and the businesses involved.
Nakamoto was (and remains) notably secretive and their true identity is not reliably known† and they no longer communicate with the world using that name in any verifiable manner.
All the businesses involved in the alleged registration process protect the identity and other confidential information associated with their customers. As they should. Therefore the details sought are not public knowledge.

first registered in 2008 ...

That certainly appears to be the case.
The domain registry information currently includes the following information:
Domain Name: BITCOIN.ORG
Registry Domain ID: D153621148-LROR
Registrar WHOIS Server: whois.namecheap.com
Registrar URL: http://www.namecheap.com
Creation Date: 2008-08-18T13:19:55Z
Registrar: NameCheap, Inc.

...via anonymousspeech.com,

The website of AnonymousSpeech.org says

Any inquiries  regarding the identity of our subscribers are ignored. We do not respond to any of them.

We are committed to the privacy of our users, and will absolutely not release any kind of data to any foreign governments.

archive.org shows bitcoin.org was an actual hosted site at least by January 31, 2009. Where was it hosted, and how and to whom was that hosting paid for?

That information is not available.
We know a couple of important things about Nakamoto:

They were extremely protective of the secrecy of their identity.
Though their work was not without flaws, they were competent in the field of online privacy and encryption.

We should therefore not expect to easily find any information they specifically sought to hide from the public.
Nakamoto's main aim was to create a cash system that did not rely on trusting third parties - their aim was not to teach us how to anonymously register DNS domains. This should shape our expectations of available information.

Footnotes
† So far as I know, the people claiming to be Nakamoto have failed to provide proof or have provided evidence subsequently shown to be false. We cannot ask Nakamoto and if we could, they would not an answer if their behaviour is consistent with their past behaviour.

The answer to this is the way domain names are purchased and secured at registrars such as godaddy.com and namecheap.com plus multiple registrar payment methods. For a fee the registrar will hide the true owner and all details of a site and put in a proxy name. You can go to www.internic.net to find out about a domain such as:

Domain Name: BITCOIN.ORG
Registry Domain ID: D153621148-LROR
Registrar WHOIS Server: whois.namecheap.com
Registrar URL: http://www.namecheap.com
Updated Date: 2019-11-24T13:58:35Z
Creation Date: 2008-08-18T13:19:55Z
Registry Expiry Date: 2029-08-18T13:19:55Z
Registrar Registration Expiration Date:
Registrar: NameCheap, Inc.
Registrar IANA ID: 1068
Registrar Abuse Contact Email: abuse@namecheap.com
Registrar Abuse Contact Phone: +1.6613102107
Reseller:
Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited
Registrant Organization: WhoisGuard, Inc.
Registrant State/Province: Panama
Registrant Country: PA
Name Server: DNS1.REGISTRAR-SERVERS.COM
Name Server: DNS2.REGISTRAR-SERVERS.COM
DNSSEC: unsigned

Domain names  can be moved from owner to owner of registrar to registrar around in a highly secure fashion and decentralized fashion. Now that I think about it, a little like coin transfers.


is bfgminer running correctly? As a complete newbie I purchased USB ASIC mining device, installed bfgminer on raspberry pi and tried to run it. As the reward is not changing, I am wondering whether bfgminer is running correctly.

This is the snapshot of bfgminer:

And this is the snapshot of workers status in Slush's pool:

I would be very thankful if anyone could tell whether this is working correctly or how to check in general if everything is OK.

When i look at the snapshot it seems like your device isn't hashing. Did you have your device hashing? and did you get the USB TO UART DRIVER BY SILICONE LABS? respond when you have the answers.


How do I buy bitcoins with South African Rands? I have South African Rands that I would like to purchase bitcoins with. No Websites I know of accept Rands (ZAR). How do I get around this?

https://www.luno.com (previously known as BitX) trades BTC for ZAR via EFT to South African banks. They have accounts at FNB and Standard Bank. If you have an account at one of those, it will clear faster.

You need a wealth translator who would take a fee due to the illiquidity of Rands/Bitcoins transactions.  Or do it yourself realizing there is a bid/ask on every translation.


How to withdraw all funds from a Ripple account? I'm trying to close my account by withdrawing all my XRP into a new account. But the Ripple client insists on keeping a minimum balance of 50 XRP. How can I properly close this account?

You can't withdraw the deposit, just leave it as it is.

Remove all trust and all offers to lower the minimum deposit.

totally a scam. Using the word “reserve” for mandatory contribution . The consumer has all the rights for there money. ITS A SCAM!!


GPU mining slows down my ubuntu I'm trying to mine using my CPU and GPU. When the CPU is set to use all its cores, I have no problems, but when I use my GPU, my desktop gets way too slow because unity uses it too I think, so I need to find a way to be able to use my GPU for mining while using Intel graphics for unity and the rest, can anyone help? I have a Nvidia GTX 850M and Ubuntu 16.04, and I don't know where to begin.

Mining on a cpu at all is a bad idea, it can and will wear the cpu down, and is ridiculously slow compared to a gpu. Also mining with an Nvidia card isn't the smartest thing either as they are much slower than AMD cards. Regardless you will make next to no money mining with this kind of hardware given that there are thousands of people with ASIC miners that pump out 2TH/s +. My advice would be save up some money and purchase a high-end ASIC miner and refrain from mining with your current computer.

After a lot of research and tries and fails, i found the solution in here, and it works great
https://askubuntu.com/questions/758972/does-ubuntu-16-04-support-hybrid-grafics-cards-bumblebee


Does it make sense to design a mutable blockchain? I work in a large consulting firm which is marketing a mutable blockchain solution to its clients. But I personally fail to grasp any advantage of using a blockchain design if you are discarding immutability. Am I missing something here?

I agree more context is needed to provide a more directly meaningful answer.

But in general: a blockchain allows users to interact without trusting a central authority, instead they verify the system’s state on their own. As a user, I can verify that I own some amount of bitcoin by running a node, and seeing the transactions that paid me as confirmed in the blockchain record. I know that the network’s rules do not allow those coins to be moved unless a transaction is signed by the valid keys (which I control). If the system allows mutability, then how confident can I be that the transaction which paid me will not be changed in the future? With an immutable blockchain, the energy spent on POW mining helps guarantee this, but if mutability is allowed... ??? How can I be sure?

If some form of mutability can be added while preserving this factor of trustlessness, then maybe a ‘mutable blockchain’ is reasonable. But I am yet to see such a proposal. If the user must trust a central authority to not change the system, then using blockchain architecture is superfluous.

In reality, I suspect in most cases a ‘mutable blockchain’ would be an inefficient way to implement a database, albeit one that can be dressed up in marketing buzzwords and sold to customers more easily due to the ‘blockchain hype’.

  But I personally fail to grasp any advantage of using a blockchain design if you are discarding immutability. Am I missing something here?

Advantage: customers love blockchain hype, so they’ll be more willing to buy what you’re selling.

I’m sorry to say, but I think your intuition is correct. Frankly, such projects seem either misguided, or scammy to me.

EDIT: perhaps worth mentioning as well: allowing a central authority to alter the blockchain record creates a monstrous security risk. No matter how well intentioned or benevolent the authority is, an attacker targeting their system of control represents a huge existential risk to the network. There is no such thing as a secure backdoor that only ‘the good guys’ can access.

I can see a potential mutable blockchain being valuable for a number of reasons:

If only 'trusted nodes' are allowed to change the blockchain, and there is significant reputation and financial resources at stake at making a false claim and
The mutability is limited to 'fraud protection'/reversing transactions, so that if someone is genuinely a victim of fraud (or they lose their coins...) the blockchain can be modified to release these funds, rather than permanent loss as is the case with bitcoin/immutable blockchains.


How does Satoshi Dice's 'zero confirmations' transaction system work technically? The popular bitcoin betting game Satoshi Dice sends back payments very fast, they don't wait for confirmations. The user sends money to Satoshi Dice and gets back winnings a couple of seconds later. Here's a quote from their site:

  The SatoshiDice Bitcoin game operates with zero confirmations [...] This is safe because it always builds the answering transaction with the output of your bet transaction. This means a blockchain that does not contain your bet cannot contain the site's answer.

I think I understand the theory behind this: Satoshi Dice always sends back coins from your own bet. So if your bet doesn't get confirmed then your winnings also won't get confirmed.

What I don't understand is how I could technically create these kind of transactions. Using bitcoind, how could one build these transactions?

Thanks for your suggestions.

A transaction claims some outputs from previous transactions and then creates new outputs whose summed value is equal to (or less than, in the case of fees) the sum of the claimed outputs values.

For a transaction to be valid it must be the only one that claims the outputs (no double spend) and the transaction that created the claimed outputs must be valid. Satoshi Dice can immediately send back a transaction containing the winnings because the transaction claims the output of the incoming transaction, chaining the two transactions together.

The result is that either both transactions are valid, in which case the player gets his winnings, or the first transaction is not valid, immediately invalidating the second one, and Satoshi Dice is not tricked into sending coins back without receiving the wager.

simply put its like a paradox if i send 100 Satoshi to the site and only have 99 in my wallet the transaction fails i will have spent no Satoshis they will have received none trying to send Satoshi that does not exist would invalidate the second transaction

so unlike money you can not do the following walk into a store take a dollar item and leave 90 cents on the counter walk out and then try to return that item later on for store credit the act of saying i have a dollar when i only have 90 cents will invalidate the entire transaction i will have given zero then sending me some of the bitcoins i never really sent everytime a bit coin is sent the new owner becomes part of that bitcoin their address gets imprinted on it so if SatoshiDice never got your bitcoin officially then they can not send it back you as that would be a bitcoin that does not exist in a sense this is why the debate over resseting the blockchain to reduce the storage broaden is a big issue well it could be done another story for another day in short that would make a bitcoin bank Holiday of sorts  likely a few hours as the network would have to shutdown as in stop accepting payments then verify all payments accepted then reduce each bitcoin to a base hash minis all of its history and then have the wallets shorten this down using a standardized algorithm  for those who do not spend most of what they have no problem a typical computer would straiten out a typical wallet in less then 5 min an older smartphone might take a day even an iphone might take a half an hour for the most part most people would be ready for bussines before the block chain was back up the wait would be the transactions to be verified by the miners as a non static network could never get back into sync off topic but bottom line is SatoshiDice is secure due to the nature of how the transactions are verified if a block chain reset were to take place say once a month then SatoshiDice would likely cancel all betting for that day and resoume an hour after the network was confirmed to be up and running then you still have the trust of a central server for all past transactions i would like to see a torrent like system to split up the block chain for faster access and secure storage


How can I use bitcoins on deposit? I had received bitcoins before my wallet was fully synchronized and it took several days for it to finish the process, so I decided to deposit the bitcoins in another wallet. Now I can see they are "on deposit", but they do not show up in my other wallet. How can I move them to my wallet or use them?
Thank you!

If you want to send newly received Bitcoins from a wallet that is not yet synchronized you have two choices:

Wait until your incoming Bitcoin transaction has synced. Your wallet cannot send Bitcoins that it cannot yet determine it has received (because it has not yet synced to the block height were you received the BTC)
Import the keys of your receiving address or HD wallet into a wallet that has fully synced the blockchain or a light/SPV wallet

Please understand that you own any Bitcoin for which you control the private keys and that Bitcoin can be used with any wallet. However just because you own Bitcoin does not mean that you can spend it from a wallet that is not yet synchronized. When a wallet is not synchronized at least up to the point where an address you control has received the Bitcoin you are looking for, your wallet has no way to verify your ownership of that BTC.

I have noticed myself that does take some time for everything to synchronize but once it does it'll be there for you


How to recover corrupted Electrum wallet.dat I invested in bitcoins at the beginning of 2015. At the same time back in 2015, i installed Electrum wallet and somehow an offline version which meant that I stored the bitcoins on the computer's hard drive, this offline version was not something I wanted, it just happened by a mistake. Once the bitcoins were sent to my Wallet, it took about 3 days until the hard drive crashed.
A good friend managed to get into the hard drive via the wrong safe mode, and ran a backup of all important files, including the files to Electrum, including my wallet.dat file, which I have understood is a relatively important file.
I bought a new computer and downloaded the files from my backup and tried to restore my wallet, but I could not solve this.
An error message appeared when I tried to access / restore Electrum. When I tried to open the wallet file in a program called something with HEX, (which people had written about in diffrent forums), it stod ”the file is corrupt” according to the program.
I let it all go and more or less forgot this until now. I have read and i was thinking, could the reason why the file apears to be "corrupt" , just because its  encrypted? I know the password for the encryption and I have just finally finished syncing the Bitcoin core. But i dont now how to decrypt it, and is my idea about the file issue, possible?
What is my next step to recover my bitcoins?

If the file is corrupt, it will require manual editing to be able to open it with electrum.
Depending on how corrupt the file is, it might be possible to recover and and it also might not.
Say, for example, a single bit is flipped. Then a brute-force approach might work where every bit is flipped in the file and then check which result can be opened and decrypted with electrum..
Check with electrum developers who are most familiar with how a non-corrupt file should look.
If I were in this situation myself, what I would also do is generate a few new wallet.dat files using the same electrum version you used in 2015, open them in hex viewers / text editors next to each other, and try to see the patterns. Compare to your corrupt file.
Good luck.

The fact you might be ill or not is irrelevant, as is your family story.
The fact remains you're quoting a remuneration of $20,000 for a job we don't know how much effort entails.  And I don't think you're paying $20,000 "for effort", you're paying only if the job's done.
So maybe if someone could 'crack' this in a month or even a year, it'd be worth the effort, but what if it takes their whole lifetime, and they still haven't finished?  Since the effort they need to put into this is undecidable, how will they know it will ever end?
So I would not take the job, even if it'd pay a thousand times as much.  Too much risk involved (the risk of wasting my time and earn nothing).
Secondarily, if your request is genuine, and the puzzle you're presenting can be solved, what assures you that the person who solves it won't keep the digital coins to him or herself?  If as soon as he takes the coins he disappears, and won't communicate any more with you, or make contact only to make fun of you, how could you enforce the terms (for him to give you the money)?  As even if you promise $20,000, the coins themselves could be worth more.  In these circumstances and if stealing them from you (safely) is easy, they might as well do that.  You might end up being the deceived one.
Either way I think the safest bet is to forget about the whole thing - forget you can get paid collaborators.  Either try and do the job alone yourself (though I'd say if you do this you will almost certainly fail), or ask for free collaborators (in which case most people will ignore you and move on as if your request wasn't genuine - and as I will myself do as soon as I'm done writing this answer).
You're trying to put a price on something you don't know the price for.  Time to face up to that.  You don't know how much your own life or that of your family is valued either, or your collaborators' or even people who steal from you for that matter.  Stop dreaming or playing the numbers' game.  Salvation comes from inside, or it doesn't exist at all.  Salvation grows inside or it will never be there.  Stop the chase, and make the peace.


Claiming my BTG from my BTC private key I have a BTC private key, how do I get my BTG? I have tried a few methods and tutorials but none seem to be working.
And beside that, is there any working BTG explorer? All the ones I found seem to be buggy (including btgexp.com) and wont recognize my address.

EDIT: yes I had BTC on this address at the time of the split

EDIT 2: found a working explorer with https://bitinfocharts.com/bitcoin%20gold

EDIT 3: yes I have transferred all my BTC to another address, and I just want to get rid of my BTG now

AFAIK there's one good wallet other than the reference client that can import the private key and make a transaction.

That's Coinomi, it can import the private key and does support BTG.

(When I wanted to dump and sell my BTG, Coinomi was great, although I needed to use the Android emulator Genymotion [because I don't have an android device])

Solution:

First, confirm your BTG balance on https://bitinfocharts.com/bitcoin%20gold/address/

go to https://www.bitaddress.org "Wallet Details"
(optional) Download the site to use it locally offline, check the github code to confirm it does not do anything harmful
put your BTC private key and press View Details
Install Coinomi
Create a new wallet and add BTG, then choose Sweep Wallet
Swipe the QR Code "Private Key WIF 51 characters base58, starts with
a '5'

DONE!!!

Always try first with a low value address, dont trust anyone when playing with private keys

EDIT 1: added step BTG explorer
EDIT 2: changed step 2 (optional)


What is the optimal way to increment extranonce? I'm trying to learn how to block headers are created and an efficient way of doing so. Given a list .of transactions, can I change the extranonce without having to rehash the entire list?
EDIT: To clarify, I am not asking about what the extranonce is but whether there are algorithms to recompute the merkletree better than others.

The Merkle root of the transactions is calculated by building a binary tree from the transactions as leaves where each parent node is the hash of its two children. As the coinbase transaction is the first transaction in the block, you can store the hashing partners on the coinbase transaction's Merkle branch and only repeat all the hashes to which the coinbase transaction contributes. This reduces the required number of hashes to calculate the new Merkle root for n transactions from O(n) to O(log(n)) given that no other transactions in the block were changed.
There is no way around repeating the whole left flank of hashes in the binary tree, since changing the extranonce in the coinbase transaction changes the outcome of the bottom left hash combining coinbase transaction and first regular transaction.

The extranonce is a part of the coinbase transaction, inside the coinbase transaction there is an arbitrary data, and when you change this data, your merkle will change too


How do I create a shopping cart that accepts Bitcoin? I need to start a website to sell and buy goods with Bitcoin. Then I need to know how to add an shopping cart system for it. Are there any CMS plugins or modules for Joomla, Drupal, or another? Or can you tell me how to add a shopping cart system for a PHP based website without any modules?

I have same needs, and i found Stripe that accepts bitcoins payment similar like paypal do, then i planned too to use CMSs and i found a solid plugin for opencart on GitHub.
Simply googling i found alot of results, the bitcoin shopping cart plugins are around .. :D
I Also Found interesting bitcoinpay.com,
I can use Api to accept Bitcoin and send to a bitcoin address
...
 even if i not understood if i can operate as Anonymous or i have to link a bank account.
(Obviously i wannot)

The most for all is to find a way to collect bitcoins without to be forced to link a  Bank account.
Tms


What piece of code would allow me to check if a block has been found then run an operation? I am relatively new to C++ and I was wondering if anybody could help me out. I am looking piece of code that will loop until a block is found by a node and then when one is found print a simple output like "Block found".

Thanks!

You could simply record the value of bitcoind getblockcount somewhere and see when that changes by calling getblockcount repeatedly.

#include <string>
#include <iostream>
#include <stdio.h>

std::string exec(char* cmd) {
    FILE* pipe = popen(cmd, "r");
    if (!pipe) return "ERROR";
    char buffer[128];
    std::string result = "";
    while(!feof(pipe)) {
        if(fgets(buffer, 128, pipe) != NULL)
            result += buffer;
    }
    pclose(pipe);
    return result;
}

int main(){
    int count;
    count = stoi(exec("bitcoind getblockcount"));
    for(;;){
        int new_count = stoi(exec("bitcoind getblockcount"));
        while(count < new_count){
            std::cout << "Block found." << std::endl;
            count++;
        }
        system("sleep 1"); // There are other ways of sleeping. This is the quick and dirty way.
    }
    return 0;
}

To be fair, this is a rip off of Luca's idea and https://stackoverflow.com/questions/478898/how-to-execute-a-command-and-get-output-of-command-within-c.


where can I buy a whole bitcoin? I want to buy a full bitcoin at the current price. But coinbase only allows me to buy in $250 increments. Where can I go to purchase an entire bitcoin?

I would go to Localbitcoins.com but their fees are usually too high.

So what I need is a low fee way of buying an entire bitcoin.

Thanks

If you are in the US, you can buy it on coinbase.com or https://exchange.gemini.com/

You need to buy some Bitcoins on coinbase, they will automatically increase your limit. I can buy $5000 worth of Bitcoins on Coinbase, and would if I had the money.

Fees of Gemini are low, ie .05 cents for $20 in BTC, or 50 cents for a $200 order.

Or localbitcoins, if you care about anonymity, but they charge a high markup.

Try http://localbitcoins.com.

From the website:

  Buy and sell bitcoins near you
  Instant. Secure. Private.
  Trade bitcoins in 14431 cities and 248 countries including United States.

It does appear to require an account to be made, but it appears to be free.


Is it worthy to use "bitcoin usb block erupter" I was searching for Mining hardware on internet and found that a new technology is available known as "bitcoin usb block erupter" for mining bitcoins as 300MH/S

I just want to know if it is useful to use these hardware instead of GPU mining and how to calculate breakeven point for them.

P.S. : I've searched google for many things but there were mixed responses that's why I asked this question here

A typical USB block erupter will get 333MH/s under realistic conditions. Today, a share is worth about 1/156 of a penny and 333MH/s will get you a share every 13 seconds. That comes out to 43 cents per day per erupter, not counting the cost of electricity. Difficulty is going up, and thus profitability going down, around 25% per month. So you can figure maybe $11 your first month, $8 your next, $6 the next, then $5, and so on. You might get about $50 before it becomes more trouble than it's worth.

I would have to say substatiantly it will become the revenue of the future making money obselete. It will make everyone able to live a possibly better life if it is controled bitcoin mining then it will boost our economy not endanger it. Actually soon their might be a transition from money to bitcoin and the profit margrine will go up which means everyone on the planet will be rich wich is better for everyone.


Can coin wallets create their own network/blockchain? In other words, I want a coin with NO premine and NO mining.  Can the wallet, alone, generate the coin(s) and the blockchain, based solely on inter-wallet communication (establishing a wallet "communication" network (kinda like the game Marco Polo in the pool) and chatting between users would generate a certain number/percentage of coins, per user, every day) and direct coin transfers between wallets?

I know very little about blockchain technology, so maybe what I'm describing is already done, to one degree or another.  But one person I spoke to thought what I was describing was crazy, so I figure my idea must be a pretty radical departure from traditional implementation, if even possible.

I'll gladly describe it in further detail, if interested, or it's even feasible.

Mining solves two problems: double spending and initial distribution of funds.
Double Spending
You need some way of addressing double-spending; otherwise people can just copy money over and over. Besides Bitcoin's system, there are two secure, distributed ways of addressing double-spending: Ripple's solution and Proof of Stake with broadcast checkpoints.
Ripple's solution is to have a handful of semi-trusted nodes called validators, which are picked by humans. They come to a consensus, and then they all sign the consensus. A client will refuse to trust the state of the network unless all of its validators have signed off on it.
Proof of Stake is a system where nodes generate blocks like normal, but instead of trying to repeatedly hash them, they use their funds as proof that they're a real node. You also need to have checkpoints regularly broadcast by a central node, because otherwise the system is susceptible to an attack where someone rewrites the entire history at once.
This is the harder of the two problems.
Initial Distribution of Funds
You also need some way to issue funds in the first place. There's a bunch of ways that you can issue initial funds: per email address, per IP address, per phone number, et cetera. The problem with this there's generally no way of implementing them in a distributed fashion.
For example, suppose you make a rule saying that a person must prove that they own a Twitter account, and then they get 100 coins. But when other nodes are checking this, half of them get a response saying that the account doesn't exist. (This has happened a couple of times in the past with Twitter.)
A good compromise solution is to have a key held by the developer that has the power to mint X coins every Y hours. Then, have a central server that issues coins according to whatever policy you want.

Simply put, no.

Mining is required to ensure double spending doesn't occur. Your "wallet" would be analogous to emailing people with serial numbers of dollar bills.

I really can't go into all the problems with this, as it's really not suited for SE IMO. I'd recommend checking out Mastering Bitcoin or Bitcoin Wikipedia/Bitcoin Wiki.


Who are creating all the alternate cryptocurrencies? Everyone knows Bitcoin and Litecoins goes hand in hand and they are the most popular cryptocurrencies out there. But who is creating all these alternative cryptocurrencies such as Feathercoin, Peercoin, Quarkcoin, Craftcoin, etc. And why are they created?

I see no potential why they would be something people would want to pay with in the future. I can not think that a café (for example) wants to add any other payments besides BTC and LTC and some FIAT money.

Why would they ever struggle with adding Peercoin, Quarkcoin, Craftcoin etc etc etc?

Once again, who are creating these coins and why? Do they have potential to grow high? If so, why?

Many people have an interest in cryptocurrencies - some of them are interested enough that they would investigate and work on creating a new cryptocurrency.  Some people are in it for a quick profit, i.e. the scam coins, but others are genuinely interested.  Sometimes it is good to be associated with a currency, but often they prefer to be anonymous (to some extent) and watch and help from the sidelines.

A cryptocurrency is not just a once-off effort.  There is work needed to maintain it, especially when a problem occurs, or a security issue affects it.  It is necessary to update clients, maybe even fix a blockchain.

Another reason for the increase in alternate cryptocurrencies is due to the hardware investment in the coin mining community.  For most miners like myself, it is now almost infeasible to mine BTC unless you have or are prepared to buy into the latest ASIC miners, but even then, the timeframe for making a reasonable profit is very short.  What do we do with this hardware - we use it to mine alternate coins that suit the hardware.  USB ASIC miners for SHA-256 based coins.  GPU mining for Scrypt based coins.  Hence the alternate coins are actually filling a need by the mining community to have something to mine and have the chance to make a profit or get a return on their investment.

Many people are creating alternative currencies.

The Litecoin has been created by Charles Lee, a former Google employee. This guy's the only cryptocurrency creator that is publicly known. In fact you can find pictures of him and videos of him.

Most cyrptocurrency creators wish to stay anonymous. Some because their coins are scams, some because they have many coins because they were some of the first "miners" and if the value of their coins rises they'll be rich.

Bitcoin right now is under the control of very few people. An article about a month ago was written about the owners of Bitcoin and we know that 47 people owned about 1/4 of the Bitcoins and 927 owned over 50%.

LESS THAN 1000 PEOPLE OWN MOST OF THE BITCOINS. This was supposed to be for the little guy...you know, like me and you. Well, it's not. This is why other cryptocurrnecies are created. Bitcoin won't help the repressed escape persecution and help them move their wealth in other countries so they can escape. Bitcoin is going to be used to hide fortunes. Bitcoin might be used by the CIA, NSA, US Defense Intelligence for money transfers. Litecoin might soon follow the same trend. Yes, some cryptocurrenceis are scams but many aren't.

It's all about having an option.


which cryptocurrency using Slasher algorithm for Proof of Stake mining process? Ethash algorithm for PoW mining process on my own cryptocurrency. I need to use Slasher algorithm instead of Ethash algorithm for Proof of Stake process.

My question is Which cryptocurrency using Slasher algorithm for Proof of Stake mining process?.
This answer is more helpful for my further process.

etherieum, use the slasher
you can see here:
https://blog.ethereum.org/2014/01/15/slasher-a-punitive-proof-of-stake-algorithm/


What are bitcoin miners really solving? As with mining, what are the bitcoin miners really solving? I read they are solving hashes, but what does that really mean. Can we see what they are solving? Can someone give an example of what a bitcoin mining machine sees to solve?

Here is an extremely simplified sketch of the problem, but it should give a pretty good idea of what the problem is.

The data:

This is the hash of the lastest block (shortened to 30 characters):

00000000000001adf44c7d69767585

These are the hashes of a few valid transactions waiting for inclusion (shortened).

5572eca4dd4
db7d0c0b845

And this the hash of one special transaction that you just crafted, which gives 25BTC (the current reward) to yourself:

916d849af76

Building the next block:

Now, let's use a gross approximation of what a new block might look like (the real one uses binary format). It contains the hash of the previous block and the hashes of those 3 transactions:

00000000000001adf44c7d69767585--5572eca4dd4-db7d0c0b845-916d849af76--

Now let's do mining by hand! Our goal is to complete this block with a nonce (a piece of garbage) such that the hash of the new block starts with 13 zeros (considering the previous hash, it seems that 13 zeroes is the current difficulty!).

Mining (trying to finalize this block):

Let's try with nonce=1, and compute the hash of the block (I'm using the md5 hash algorithm, but Bitcoin uses double sha256):

> echo "00000000000001adf44c7d69767585--5572eca4dd4-db7d0c0b845-916d849af76--1" | md5sum
8b9b994dcf57f8f90194d82e234b72ac

No luck, the hash does not start with a 0… Let's try with nonce=2

> echo "00000000000001adf44c7d69767585--5572eca4dd4-db7d0c0b845-916d849af76--2" | md5sum
5b7ce5bcc07a2822f227fcae7792fd90

No luck…

…

If we pursue until nonce=16, we get our first leading zero.

> echo "00000000000001adf44c7d69767585--5572eca4dd4-db7d0c0b845-916d849af76--16" | md5sum
03b80c7a34b060b33dd8fbbece79cee3

For nonce=208, we get two leading zeroes!

> echo "00000000000001adf44c7d69767585--5572eca4dd4-db7d0c0b845-916d849af76--208" | md5sum
0055e55df5758517c9bed0981b52ce4a

Continue like this… If you finally find a hash that has 13 leading zeroes… you're a winner! Other miners will now build upon your block, you've just got 25BTC.

But you'll have to be fast!

Back to step 1…

If someone manages to build a block before you do, you'll have to start again from the beginning with the new block's hash (the one of the winner).

Mining provides a way to reach consensus on what the transaction ledger should look like and know that nobody is cheating.

That's the non-technical definition of mining.

What exactly is Mining?

The "authority" for double spending is the blockchain.  The blockchain consists of the history of all blocks in the blockchain plus the next block of transactions.  The reward subsidy currently is 25 BTC to the party that submits the next block.  But hey ...you would like that 25 BTC (worth currently about $825) as would I as would everyone else.  So how do you make it so that I can't cheat and claim the block myself?

Well, you put in a system that you and I have to compete.  That's what the proof of work does -- it makes it so that when I claim the reward it is easy to prove that I really did the work involved.  So for me to have a 2% chance of solving a block I need to put in 2% of of the mining work.  There's no way for me to put in less than 2% of all the work and still solve blocks at least 2% of the time (on average).

Thus as a result, when a transaction block is submitted, all the peers verify that there were no double spends, that the right amount of subsidy was claimed, and that the submitter truly expended the work necessary for that solution.  With those three rules, then there doesn't not need to be a central authority managing the process or able to control the outcome.


What is the chance of someone (randomly) finding the private key for an existing Bitcoin address? Say I have created a paper wallet with one bitcoin address in a vault. What are chances that someone else will find the private key for this wallet?

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

Essentially zero. They would have to find a private key whose public key hash matched yours. The public key hash is 160 bits long. If they had a billion computers, each of which could try a billion keys a second, and they tried for a billion years, they'd have much, much less than a one in a billion chance of getting it.

The only true way to defend against this is to avoid large balances with each private key.  But if people do that then it will be much easier to find something if adoption happens and active addresses continued to double every 5 years.

Assuming btc is eventually $ 2 million  per bitcoin and average person saves say 200k in bitcoin. They would need 2000 keys with 0.00005 to avoid losing more than $100 though a random collision attack.

I guess there should be some kind of insurance against this happening but it goes against this idea consolidating uxtos to save fees is a good idea. It’s another reason why low fees are required for btc to work.


Future risk of computer farms generating addresses for previous balance? I understand how difficult it would be to brute force a specific bitcoin address' private key.

I'm wondering out of curiosity though, with bitcoin being adopted so rapidly, will there ever be computer farms where it is more profitable to continuously and rapidly create addresses and checking their balance in hopes of someone out there sharing it?

Or will the amount of power usage generated from such an idea be more profitable simply going to mining?

I think the way to reason about this is to think about the incentives and rewards of such actions.

Yes, I can potentially throw a lot of computational work into generating private keys and checking their balance... But is it really worth it knowing that I can throw the same amount of energy into Mining, and get a guaranteed and constant return on my computational work?

Somebody was discussing something similar in 2012 on BitcoinTalk, here's the link https://bitcointalk.org/index.php?topic=107172.0. Note that the author of the post says that "you probably have much better odds finding extraterrestrial life or winning the Powerball 5 times in a row" than randomly finding a generated BTC address with a balance in it.

EDIT: Reason for the downvotes? Why did a couple of people damage my account reputation without explaining exactly what is wrong with my answer? So sad this community is not as nice and newbie-friendly as it should be.


Is there a limit to the number of Bitcoin addresses? Is there a limit to the number of Bitcoin addresses?
And if so, what stops someone from making all these addresses and holding the private keys for them so no one else can make a new public key?

Is there a limit to the number of Bitcoin addresses?

If I understand it correctly, there can never be more than 1461501637330902918203684832716283019655932542976 of the current type of addresses. 2160.

  what stops someone from making all these addresses and holding the private keys for them ...

Probably:

There aren't enough atoms in the universe to make a big enough computer.

There isn't enough time left in the universe before those atoms cease to exist.

  ..so no one else can make a new public key?

Other than the improbability of it occurring, there's nothing in the Bitcoin protocols or concensus rules that would prevent two or more people independently generating the same addresses. Any of those people could then spend any money sent to that address.

Which is to say, your bad-actor can't prevent anyone from generating an private-key a public-key or an address.

One would have to flip a coin 160 times. Get the same 1 or zero 160 times IN ORDER to succeed. To get the same address. Is this close?


Will deflation destroy Bitcoin? With the limited total quantity of bitcoins, and people losing their wallets constantly decreasing that number, won't rampant deflation destroy Bitcoin?

There are two potential ways in which monetary deflation can impact a currency:

1.  Usability

Most modern currencies have a minimum unit, such as the penny in the United States, or the yen in Japan.  If these currencies existed in only finite quantities, then as the economy grew and/or physical money was lost, there might eventually be too few of these units in circulation to allow normal commerce.  Imagine if, for example, the U.S. dollar became so rare that you could buy a car with a single U.S. penny.  How would you buy a loaf of bread?

Bitcoin, however, does not have this problem because unlike the physical currencies of most countries, bitcoins are infinitely divisible.  Even if only one bitcoin remained, it would be sufficient to run a substantial economy on, based on the ability to use tiny fractions of it like the Satoshi.  If even the Satoshi were to become too highly valued/unavailable for commerce, the Bitcoin protocol could be updated to allow even smaller denominations.  So the usability of bitcoins is safe from the effects of deflation.

2. Broader economic consequences from deflation

Many economists believe that deflation is bad for an economy because people will be less likely to invest their money if they can "earn" increased value simply by holding on to it.  Why buy something today, the argument goes, if you could buy it for half as much in a few months time?  Also, taking out loans becomes very difficult, because to be practical they have to have negative interest rates and then why would anyone loan out money in the first place?

However, there is good reason to believe that deflation might not have such a negative effect on Bitcoin.  For one, Bitcoin is unlikely to become the only currency in the world economy, so investments, loans, etc. can simply be denominated in another currency.  But even more importantly there are several concrete examples from history of strictly deflationary currencies.

For example, the Iraqi "Swiss" dinar was a currency that ceased being printed after the first Gulf War, and was left in use only by the Kurdish regions of the country.  With a finite number of "Swiss" dinars in existence, and some being lost or damaged over time, this left the currency in precisely the same state as Bitcoin.  Since it was no longer backed by a government, many economists expected the currency and its economy to collapse.  Instead, the Kurdish economy continued largely as normal for 13 years, and the "Swiss" dinar even appreciated against the "Saddam" dinar that was meant to replace it.

Rick Falkvinge also raises another excellent point regarding deflationary economies.  If, as economists expect, people would decline to buy something today as opposed to next year for half price, then it should be the case that no one ever buys computers, right?  But in fact, the computer industry thrives despite this continued trend of "whatever something costs today, it will cost a fraction of that within a few years".

Ultimately, this is a question for economists to duke out, and you can find more information about how different economic schools approach the problem here.  Suffice it to say, this cannot be considered a crippling fault in Bitcoin as a technology.

People here saying that deflation is only a problem with debt based currencies are wrong.
Inflation is needed not just because of debt, but because of the growing population. With more people, come more goods being produced and consumed. If we elected to create a 1:1 economy, eventually the dollar would start deflating. This would be unavoidable unless the economy and the population never grew. We know that's not going to happen, so we need more currency to compensate for those extra bodies.
We also need it for debt, yes, but debt is just the lubricant, not the engine.
And even if you disagree with that, and you think that debt is the only reason for inflation, what makes you think that if bitcoin were to become a pervasively used currency, that people would not create debt instruments with it? They've already created a multitude of other typical financial instruments based on its value. The only reason why it's not a debt based currency is because we have not yet chosen to use it to create debt instruments. But if/when humans decide to establish bitcoin as an acceptable form of transaction, they will use it for debt, sure as the sun will rise tomorrow. And it is at that point, that people will see this inherent flaw and it will come crashing to the ground.
This does not apply to all cryptocurrencies, and it is reasonable to suspect that others will succeed where bitcoin fails because they will allow for an infinitely increasing creation of units.


Can it be exchanged. Can I send  bitcoins to my main bank account ,and the output is like normal cash in the bank. Rather than selling it online .

No.
Maybe one day some exchange partners with a bank to allow such deposits. But that is very far in time...


When will my no fee transaction come back? i've sent bitcoin with 0 fee 2 weeks ago.
but it doesn't come back.

i saw unconfirmed transactions coming back in 72 hours.

Is there a way to solve it other than double spend?

https://blockchain.info/ja/tx/0e846d7d4ea858cee2e6ba5915caffaa9628f60c120b4a5e6a493dc74f7ec58a

It generally "comes back" in a week or two. Actually the transaction gets discarded by the mining nodes from their memory pools. Until then, your transaction is stuck.
However it depends on the wallet software as well if they let you spend it.
I had complete control over the addresses I was using so it was easier for me to retrieve the funds.


Litecoin query re Wemineltc Wondering if you can help me out with question..

I was mining litecoin with WemineLTC some years ago...  I am aware that they have now disappeared from the market.. I have or had 10 coins which were transferred into my wallet on my PC and have sat there for the last few years doing nothing..  Have these been lost or can they still be redeemed.

Thank you in anticipation

Find the seed phrase you used for your wallet, or open your wallet and transfer them to an exchange.

The actual coins are still on your computer - they are just some strings.
So you need to open your local wallet or restore it using the seed phrase.
Sell the LTC to convert to something else. LTC just isn't worth it.


What are the differences between Bitcoin and other crypto-currencies? What is it that makes Bitcoin unique amongst crypto-currencies?  Is it just the most popular one or does it have better design aspects too?

Until a careful analysis is performed, I think most crypto currencies are very similar in all properties except one - adoption.

Bitcoin has the largest hash rate, participating nodes, accepting sites, and people going over the code and protocol.

While alternative currencies can gain more hash rate, especially if effective forms of merged mining are developed and adopted, it remains to be seen if they gain the same adoption (sites accepting them), and developer base (strong developer community).

(See this post about merged Namecoin/Bitcoin mining)

Edit - One notable exception to this is Namecoin, which does offer unique features making it suitable to use as a DNS or general name registrar.

I was in the bitcoin community in 2011. It seems pretty secure and has a lot of people looking into it. I think one of the main growing pains of a crypto is that it has to run through the growing stages. With the many crashes and hacks that Bitcoin has gotten through, it seems it's here to stay.


INPUT Script with no ScriptSig? Anyone knows what does it mean when there is no ScriptSig under INPUT SCRIPT for a TX?

See here:

https://i.imgur.com/TCHFUfV.jpg

Thanks!

It seems to be a witness transaction according to your screenshot (you can see the same missing scriptSig followed by witness here).

Segwit encodes the signature information slightly differently from the regular script sig, so it will not show up under that heading. A segwit transaction would still contain the information you would traditionally see in the scriptSig, but in the witness section instead.

If it's a P2SH output and the redeem script is OP_TRUE then it's an anyone-can-spend and you don't have to provide anything in the scriptSig


Lightning mainnet peer list? I just set up c-lightning on mainnet and I'd like to open a channel but I can't find a list of node ids and ip addresses. Does anyone know where I can find this?

Here's a site with all the nodes on mainnet
https://1ml.com


Can miners reject transactions from an address? It is alleged that the stolen Bitstamp coins are in this address. In theory, could miners agree to reject all transactions from this address? And if so, would all miners need to agree or just more than half?

Technically it is possible to blacklist addresses, and it needs just the majority of the mining power to agree.

The problem is arriving at the agreement: Nobody stands to gain from witch-hunts, so a consensus to block an address would have to be carefully built on solid proof, which is hard when there is no central organs with jurisdiction, nor a way to get a statement from the culprit.

Also, blacklisting addresses, just like tracking tainted coins, has a strong implication on what we view Bitcoin to be: One of the sources of Bitcoin's value is that bitcoins are considered fungible – that each individual does not need to care about the history of a bitcoin, because a bitcoin is a bitcoin. If we start treating bitcoins differently in accordance to their transaction history, it will make the bitcoin economy more complicated and less useful.

I think miners can't refuse any transactions once they're in a block, except those which are invalid right now.

If everyone agreed, there could be a centralized service that would broadcast alert messages to miners, alerting them that the transaction shouldn't be confirmed. But I am not sure this is a good idea. It would definitely go against the decentralization of bitcoin.


Is this thing on? (How to tell if my cpuminer is working?) I have pretty much no idea what I'm doing. But I've had cpuminer running on my laptop for a half hour or so, just playing around. I know it's not near worth the time or electricity, I'm just having some fun.

I'm using Slush's pool, and ran the program:

./minerd --url http://api.bitcoin.cz:8332 --user <me> --pass <pass> --threads 8

And I seem to be generating normal output:

[2013-11-27 13:28:05] thread 7: 291732 hashes, 5.18 khash/s
[2013-11-27 13:28:05] accepted: 0/151 (0.00%), 41.48 khash/s (booooo)
[2013-11-27 13:28:08] Stratum detected new block
[2013-11-27 13:28:08] thread 3: 183216 hashes, 5.18 khash/s
[2013-11-27 13:28:08] thread 7: 17988 hashes, 5.28 khash/s
[2013-11-27 13:28:08] thread 1: 38664 hashes, 5.26 khash/s
[2013-11-27 13:28:08] thread 6: 151224 hashes, 5.16 khash/s
[2013-11-27 13:28:08] thread 4: 161664 hashes, 5.18 khash/s
[2013-11-27 13:28:08] thread 2: 79848 hashes, 5.16 khash/s
[2013-11-27 13:28:08] thread 5: 60576 hashes, 5.21 khash/s
[2013-11-27 13:28:08] thread 0: 164808 hashes, 5.17 khash/s
[2013-11-27 13:28:09] thread 3: 5484 hashes, 5.33 khash/s
[2013-11-27 13:28:10] accepted: 0/152 (0.00%), 41.74 khash/s (booooo)

But I don't know how long it normally takes for my account to begin displaying any kind of progress:

My CPU usage is pegged at around 750%, which makes sense - but I'm not sure how I'll know if/when they're contributing to anything.

You're using the wrong hash algorithm for Bitcoin mining. Bitcoin uses SHA256d (d = double), but cpuminer (at least the version 2.3.2 on my system) defaults to scrypt (for Litecoin) instead:

-a, --algo=ALGO       specify the algorithm to use
                      scrypt    scrypt(1024, 1, 1) (default)
                      sha256d   SHA-256d

Slush's pool is Bitcoin, so you should add -a sha256d to your command line. You'll see a much higher hash rate (scrypt is intentionally much slower to compute than SHA256) and you'll get yay!!! instead of booooo after some time in your log:

[2013-12-09 21:51:25] thread 0: 49985792 hashes, 832.61 khash/s
[2013-12-09 21:51:29] thread 1: 51072988 hashes, 841.16 khash/s
[2013-12-09 21:52:23] thread 0: 49956628 hashes, 864.18 khash/s
[2013-12-09 21:52:32] thread 1: 50469540 hashes, 808.16 khash/s
[2013-12-09 21:53:26] thread 0: 51850904 hashes, 833.58 khash/s
[2013-12-09 21:53:29] thread 1: 48489516 hashes, 855.40 khash/s
[2013-12-09 21:54:25] thread 1: 46821320 hashes, 834.33 khash/s
[2013-12-09 21:54:25] accepted: 1/1 (100.00%), 1668 khash/s (yay!!!)
[2013-12-09 21:54:25] thread 0: 50014552 hashes, 838.40 khash/s
[2013-12-09 21:54:41] thread 1: 13586032 hashes, 850.75 khash/s
[2013-12-09 21:54:41] accepted: 2/2 (100.00%), 1689 khash/s (yay!!!)

For best results, you should also use the above mentioned stratum+tcp protocol and adjust --threads to the number of cores in the system.

EDIT: Looks like you're using minerd (which to my understanding doesn't have stratum support.)  Slush's pool requires it (the FAQ seems to mention this briefly).

Suggestion: Try using one of the miners listed in the FAQ.

Old post: It looks like new blocks are being generated faster than your machine can complete a single unit of work.

Perhaps you could provide us with a more complete log file?


Launch bitcoind at startup on Ubuntu I have bitcoind installed on my VPS runing Ubuntu 18.04, and I want to configure it to launch bitcoind on startup.
What the best way to do so with my configuration ?

To start bitcoind at startup on a system using systemd, use the service configuration provided in contrib/init/ from the root of the bitcoin-core repository.
You can then manage bitcoind as any other systemd service (and possibly have some other rely on it, such as a Lightning Network implementation's service).
systemctl start bitcoind
systemctl stop bitcoind
# This enables launching the service at startup
systemctl enable bitcoind

You could add a cron program that runs on startup, creates a temp file to say it has already ran, and then execute. This makes it so that every time cron tries to run the program, it turns out empty.

Example:

touch /tmp/btc.true
[ ! -f /tmp/btc.true ] && sudo -u $USER sh -c 'HOME=~$USER; bitcoind -daemon'
exit 0


Is pruning transaction history implemented in Satoshi's bitcoin client? The original bitcoin paper suggests a method to discard old transactions. One should compute the Merkle Tree of the entire transaction history, and store only part of the tree.

However, I didn't notice this method implemented. BuildMerkleTree stores it in memory only, and seems to assume you're holding all transaction history, and the serialization method stores the actual transactions and does not store the Merkle Tree.

Is that implemented? Can you give me a reference to where is it in the code?

If not, is it planned for a specific future release?

Since Bitcoin Core v0.8.0, the validation database ("chainstate" or "UTXO set", or "account balance sheet") is separated from the blockchain. When a new block comes in, its effects (removing spent inputs, and adding outputs) are applied to the database. This means blocks are still downloaded and verified like before, but they aren't used for validation anymore afterwards. Blocks are still stored on disk in order to send them to other nodes that are synchronizing, or to rescan for old transactions.

Since Bitcoin Core v0.11.0, it is also possible to run in a true pruned mode, where the blocks on disk are actually deleted after a while. Since v0.12 it is possible to use the wallet while running in pruning mode. Since v0.14 it is possible to manually prune (by issuing an RPC command rather than have the application decide).

Note that neither of these mechanisms rely on the mechanism described in the Bitcoin whitepaper.

No, it requires the entire history to verify new transactions (due to how the security of a new block in the chain requires the security of all previous blocks).

Some future client may not require the whole chain and not fully verify transactions, however I would not consider these secure for large transactions because I have no clue if the "skinny client" I'm on is not stuck on a malicious fork in the chain designed to allow double spends and someone has not ran off to Mexico with my Bitcoins.


Desktop Client Recomendation can you recommend me any desktop clients ? So far I have tried bitcoin-core, Electrum and MultiBit. I liked Bitcoin Core, but as the blocks increase, it becomes extremely heavy. In my computer, it takes more than 10 minutes just to start, and while it is syncing I can't do anything else without freezing my computer, MultiBit uses the file from a server, so it syncs very fast, but the wallet seems to be incompatible with the wallet.dat and it doesn't seem to allow importing the private key, it only allows importing wallets generated by itself. Electrum is fast, doesn't freeze anything, it allows to import private keys, but it is taking way too long to sync, so i think it is downloading the blockchain...

So, I would like a wallet with these characteristics:

Allows to import/export wallet.dat file (or private key) (like Electrum and Bitcoin Core)
Don't need to download the whole block (Like MultiBit)
Runs on Linux

thank you all :)

Electrum does not download the whole blockchain. I would recommend giving it another try as it should be pretty much as fast as any other app. One thing you could try is switching the validation server. This would possibly increase the speed at which you are able to sync up.

About electrum validation:
"This wallet uses SPV and random servers from a list. This means little trust in third parties is required when verifying payments. However, it is not as secure as a full node like Bitcoin Core."

Information above taken from: https://bitcoin.org/en/choose-your-wallet

The above resource should help you pick another wallet besides electrum if you choose to do so.

Recommend Bither Wallet

User Manual：https://github.com/bither/bither-doc/blob/gh-pages/manual-English.md

Bither Wallet can

Allows to import/export private key(QR code or plaintext)
Don't need to download the whole block
Runs on Linux/Windows/OS X/Android/iOS


Why is syncroning taking forever on BitcoinCore It has been synchronizing for months and i want my money now. I have tried re-downloading , clearing cache

i downloading from their website. It is the lastes.t version of Bitcoin Core.Windows 10 ,4.00GB  64 Bit

It depends of your internet speed as the QT has to download the data. I would suggest using electrum if you dont want to download everything.


0/unconfirmed and now no transactions anymore So recently (2days ago) I made this transaction:

Status: 0/unconfirmed, in memory pool
Date: 20.12.2017 23:30
To: N**** 1LecRzTpKXh9kCgqXbUXtdXfQjE145BR87
Debit: -0.00447735 BTC
Transaction fee: -0.00003840 BTC
Net amount: -0.00451575 BTC
Transaction ID: 850a72da35784c22c7fe1e39ac51cdc639923b26ab8bf7322f3cb7af4ffed263
Transaction total size: 191 bytes
Output index: 0

As you can see, the Bitcoins weren't sent and according to the Transaction ID the transaction wasn't done, as you can see here:
https://live.blockcypher.com/btc/tx/850a72da35784c22c7fe1e39ac51cdc639923b26ab8bf7322f3cb7af4ffed263/

So now I started to look around in different posts to get my coins back.
I found a post with the same problem... it told me to start Bitcoin Core like this:

E:\Programme\Bitcoin\bitcoin-qt.exe -zapwallettxes

but now i dont see my transactions anymore and i have 0 BTC in my balance.

I have no clue what to do now and how I can get my BTCs again.

I have observed from other experts that if you 'abandon transaction' your data will eventually be forgotten by other nodes and return to your account. You can 'abandon transaction' from the GUI console in 'transactions' by right clicking on it and selecting 'abandon'. This might take some time as even one outdated node might re-broadcast it again and it will get picked up by other nodes. Patience is what I have read. From there delete mempool and restart.


New Blockchain.info wallet but where are my bitcoins? How to access them? I have/had a wallet with Blockchain.info containing 2 bitcoin addresses. One address contained 0.33 BTC.

Yesterday when I wanted to access my wallet, for whatever reason, I couldn't remember my password, so I thought, no issue, I just can re-enter my wallet using my 12 words, so I did. I tried to recover my wallet with these 12 words and I was given another wallet (another wallet ID I mean).

The problem here is that I cannot see my funds and my known bitcoin address! I can import the bitcoin address (as I can for any address but then it is 'read only').

Can someone explain me / help me how I can recover my funds? These funds have always been in my old wallet (former wallet-ID).

This method will only work if you didn't imported any addresses to your account. (Reason? "Please note that imported addresses are not backed up by the wallet recovery phrase. We strongly recommend you sweep funds from imported addresses." Source)

First go to Electrum and download the wallet from there.

Then install & open that wallet.

While opening, select "standard wallet"

Then select "I have a seed"

After that you will get a screen like this where you need to import your 12 word seed:

Then click on "options"

After that click on "BIP39 Seed"

Then the wallet will have your BTC with the same address.

Hope this helps you in some way.

Check in your sent and received transactions if you have the transactions in there.Check the chain if your wallet has any outgoing transactions. Else i think you can recover with your mail id as they ask it while creating the wallet