texts:
When I look at blockchain.info or blockexplorer.com, it shows the latest blocks.

The most recent block, #283653, has time 2014-02-01 22:42:08.
The previous block, #283652, has time 2014-02-01 22:45:57.

So the previous block has a timestamp larger than the most recent block. How is this possible?


texts: To collectively trust what happens online - what does that mean?

texts:
I'm reading an article here. There is a sentence the meaning of which I cannot figure out.

  blockchain is the answer to a question we've been asking since the
  dawn of the internet age: How can we collectively trust what happens
  online?

So, the author is trying to say, with blockchain, we can collectively trust what happens online. But what on earth does "to collectively trust what happens online" mean? Does it mean everyone can trust whatever is recorded on the blockchain as the underlying technology makes whatever that is recorded on the blockchain trustworthy?


texts:
Why in some transactions the public key after R and S is longer 33 bytes and in others is 65 bytes? There's a difference during the signature check?

Thanks


texts: Bitcoin Cash difficulty before first hard fork: Emergency Difficulty Adjustment (EDA)

texts:
What were the network rules regarding the difficulty adjustments of the Bitcoin Cash chain, before the first hard fork was implemented on November 13th, 2017?
There was a rule that was a function of the time taken to find the last 2016 blocks, and one based on the Median Time of the last 11 blocks. What was the effect of these rules?


texts: When mining with 2 computers, do I need to use 2 separate wallets addresses?

texts:
I understand that each miner is working on a different block. Correct me if I'm wrong but this is because the first transaction in a block basically contains my wallet address so I can receive the bonus of solving the block. Obviously everyone wants to receive the bonus so that first transaction will be pointing to everyone's separate wallet addresses.

Assume that I have two computers solo mining with both pointing to my wallet address, wouldn't this mean my computers are solving the same block? Continuing with this train of thought, wouldn't that mean that my slower computer is basically useless because it would be generating the same hashes as my faster computer?

Now how does this apply to pooled mining? In a pooled community, is everyone solving the same block which has the first transaction pointing to the pool owner who then distributes the coins?


texts: Do vanity addresses lower the security of my key? (reduced complexity)

texts: Do vanity addresses somehow decrease the security of my private key?


texts: Is 30,000 rounds really needed for PBKDF2?

texts:
In the browser, I'm using AES-256-CBC with 128bit IV & PBKDF2 to encrypt the mnemonic

"tell file snow green proof evil six squeeze budget various orbit clock"

with a password

"s0mesuperl0ng!password@!"

with 30,000 rounds it's taking roughly 22 seconds. It feels too long, but I don't want to make it insecure.

Can I safely reduce the rounds to make it a bit faster? and if so what would be the minimum?

Could I get away with 10,000?


texts: Safest method while actually logging in and using blockchain.info wallet

texts:
Please help. I have finally set up my cold storage system for but I am too paranoid to login to blockchain.info wallet to send the funds out.

Let's assume the account is safe and protected from most attacks at this very moment (strong passwords + graphical keyboard, 2FA, using secure network, no online backups sitting somewhere). Let's also assume bc itself can be trusted.

So I feel the wallet is relatively safe just "sitting there" but I am still concerned about attacks during the actual login and while I am sending transactions.

- Would the chrome app or firefox extension be safer than logging in and out of their URL?

-Is it a bad idea to use TORBROWSER? Can an exit node still sniff my data if I'm using https? What about the FF extension AND torbrowser together.

-Even if I take advantage of all best security practices on the wallet itself, my physical system, and my personal network... WHAT OTHER REALISTIC VECTORS SHOULD I BE AWARE OF?

Thank you so much. Security is a huge hurdle for all of us…I hope that others can benefit from your answers.


texts: What does bitcoin do that prevents someone from using your coins by just generating a key pair and saying "you" sent those coins?

texts:
I think I'm missing and understanding about the current process of how your wallet works and how the transactions are signed.
For example, if I'm user "A" and there exists a transaction from user "B" where I received 10 BTC that has been written into a block. Then for me to use it I just generate a random public/private key pair and sign the transaction with the private key.
What is stopping user "B" from generating a public/private key pair then creating and signing a transaction saying that I, user "A" sent them 10 BTC?
I've read that some wallet implementations generate a list of public/private key pairs that can somehow be associated with the wallet address? I'm not sure how this would come into play if this is the case or if I'm misunderstanding this bit of information.


texts:
I had the (appearntly wrong) impression that miners as a whole would prefer limiting the block size / scalability / TPS in order to increase fees (basically limiting the supply), and users and companies would prefer to increase capacity to reduce fees.

However, reading some contradicting opinions among miners, and allegations against Bitcoin Core developers of pushing the miners to accept Segwit, I realized my understanding is lacking.

Assuming no agreement on what is the truth, what are the alleged incentives of the different parties, as reported by their opposers?


texts:
I am working on a donation based community website (using PHP) where participants register for an account to participate. Each account carries the participant's bitcoin address. A participant makes a commitment to donate say $10 and is paired with another participant (recipient). The donor confirms payment by pasting his/her Transaction hash id on his dashboard to confirm payments. I currently use Blockchain.info API to read the transaction details and check the inputs and outputs of the transaction to ensure that they contain both donor and recipient BTC addresses and the expected amount.
My problem is that most wallet providers generate new BTC address after each transaction making it difficult for my code to confirm transaction as the address will not match if new ones are generated.

How do I confirm transactions for dynamic BTC addresses using PHP OR how would you handle this use case?

Thanks


texts: Simple cryptsy market price observer HOW?

texts:
I am trying to use the cryptsy's API to get the current price of doge. This is my code.

public class Main {

   static Market [] markets;

   public static void main (String [] args) throws CryptsyException, InterruptedException{

      Cryptsy cryptsy = new Cryptsy();
      cryptsy.setAuthKeys("<authkey>", "<authpass>");

      markets = cryptsy.getMarkets();
      while(true){
         for(Market market : markets) {
            DecimalFormat df = new DecimalFormat("#.########");
            if(market.label.equals("DOGE/BTC"))
               System.out.println(market.label + "   " + df.format(market.last_trade) + "   " + market.current_volume );
         }
      TimeUnit.SECONDS.sleep(5);
      }
   }
}

the problem is that the price get updated too rear (30 mins or something) and only if I restart my program. Anyone to know hot to get the current price?


texts: Is it correct to assume that the price of cloud GH/S will vary proportionally with the difficulty change?

texts:
For example, today on CEX.IO I can buy 1 GH/S for 0.08 BTC. From my understanding, a change in difficulty is imminent and will increase roughly by 20% (http://bitcoinwisdom.com/bitcoin/difficulty).

Will the price for GH/S decline by roughly 18.3% (1/1.2)?


texts: Coin base recently prohibited me from making a bitcoin request with a pop up saying I already made too many requests.  I had maybe 3 requests that day.  Any one else see this?  What is the purpose of limiting requests?


texts: How to get the Input Address from vin where only a txid is given (Insight-Api)


texts: Error in checkout while using Bitcoin Payments by BitcoinWay with WooCommerce, "CurveCurveFp Object"

texts:
I have bit coin installed on a clients wordpress site. Upon checkout, when I check Bitcoin as my payment, and click Place Order, the order does not go through and I get the following error at the top of the checkout page:

CurveCurveFp Object
(
    [a:protected] => 0
    [b:protected] => 7
    [prime:protected] => 115792089237316195423570985008687907853269984665640564039457584007908834671663
)
 does not contain point ( 20139727203196486522876591193063649819462947761513549103823800141681658369 , 369049320460203173903206256216019890340108033867982827520 )

Here is the URL: https://www.goldextradellc.com/checkout/

Any help / suggestions you can give me would be great. Thanks


texts: How often do miners update their block transaction list?

texts:
Assuming an interval where no block is found, do we know how often the typical miner updates his block transaction list with new transactions from the mempool?

I found a reference which suggests that the default update time is 60 seconds, but I'm not sure what software the pools are using to generate their block transaction lists.


texts:
Source: https://steemit.com/bitcoin/@dantheman/who-really-controls-bitcoin

This article suggests that governments and electricity companies have the power to control bitcoin.  Any truth in this article?

I've attempted to post this question twice on reddit bitcoin and reddit btc, but my question keeps disappearing.


texts: In the QBundle Burstcoin Wallet, why is a fee of 1 BURST required to set the account info?

texts:
The QBundle Burstcoin Wallet (v2.0.4, installed to Windows 10) requires a fee of 1 BURST to set the Name, Description, and Passphrase for the wallet.

Admittedly, the fee is very low (worth about 2.5 cents at the moment), but why is a fee required? Who receives it?


texts: Can the Bitcoin network be used for cracking?

texts:
I'm assuming that the Bitcoin economy is rapidly building a computing cluster capable of unprecedented amount of hash searching.

Would it be possible for an attacker to leverage this to crack other systems?

E.g. could an attacker input password hashes into transactions and then deduce useful information from the output of miners with regards to hose hashes?

(I'm not asking about the security of Bitcoin as such, so I don't think it's a duplicate of [1] or [2])

[1] Could mining calculations be used to crack private key?

[2] How long would it take a large computer to crack a private key?


texts: Could BitCoin network be destroyed if blockchain would get corrupted?

texts:
This thought came to me whilst watching mr. Robot where the entire database of a financial corporation has been encrypted.

Would that (in theory) be possible if a virus was spread that would target machines in BitCoin network and encrypt the blockchain stored on these machines?

After that attackers would demand users to pay them in a new cryptocurrency which is not available for purchase yet. This would force all the users to mine their currency and (in theory) this currency would become equally as valuable as BTC since the cost would be the entire blockchain.


texts: Bitcoind doesn't find transactions / synchronize / update until last block from Testnet

texts:
I set up bitcoind as server. It downloads the testnet blockchain but it is inconsistent with public data:

http://blockexplorer.com/testnet/q/getblockcount

182951 (As of 18/02/14)

And

bitcoind getblockcount

53317

My testnet accounts receive bitcoins from public faucets:

http://blockexplorer.com/testnet/address/mjDutNstJpZo929nLdZGKPh75fWKuTQNi1  (form 2 different faucets)

But

bitcoind listreceivedbyaddress 0 true
[
...
{
        "address" : "mjDutNstJpZo929nLdZGKPh75fWKuTQNi1",
        "account" : "3",
        "label" : "3",
        "amount" : 0.00000000,
        "confirmations" : 0
    }
]

Any help?

bitcoind getinfo
{
    "version" : 32400,
    "balance" : 0.00000000,
    "blocks" : 53317,
    "connections" : 2,
    "proxy" : "",
    "generate" : false,
    "genproclimit" : -1,
    "difficulty" : 0.55300531,
    "hashespersec" : 0,
    "testnet" : true,
    "keypoololdest" : 1392632512,
    "paytxfee" : 0.00000000,
    "errors" : ""
}

Solution

Please read the accepted answer.

Dont do apt-get update and install (at least in Ubuntu 12.04.4 LTS)

Instead:

sudo aptitude install python-software-properties
sudo add-apt-repository ppa:bitcoin/bitcoin
sudo aptitude update
sudo aptitude install bitcoind


texts: Transfer coins to a paper wallet created before the fork

texts: So I have a paper wallet with BTC (and I assume BCH) that I created before the hard fork. I have recently purchased some BTC and would like to transfer them to my paper wallet. Would this cause any problem or should I create a new BTC paper wallet?


texts:
I've created many raw transactions today and after an hour I found out that my bitcoin node is only connected to 3 peers (testnet). Is it possible that my node has been banned due to wrong or double spent transactions?
How long I will be banned?


texts: Is atomic swaps available for someone reasonably techical right now?

texts:
I keep my coins in a trezor and ledger. For the upcoming hard-fork, I would like to keep the coins with private keys.

However, I think there is a big risk in the upcoming bitcoin fork that is not priced in. Therefore I plan to sell my bitcoins for ethereum maybe 24h before the fork. Are there any tools and/or markets for doing this right now with atomic swaps or is it more like a technical prototype?


texts: What options are there to combine mining over multiple computers?

texts: Assuming you have multiple (30+) computers, what options are there available to do a distributed solo-mine?  Can I have them all checking into one bitcoin application over the network, or do I need to create/join a pool?


texts: What parts of SHA-256 hashing an ASIC miner really does, and what remains a CPU job?

texts:
I know that ASIC does not perform transactions ledgering, it is a CPU job.

I also know that SHA256 consists of two logical parts: a digest function, which reduces any big message, like ~1MB block, to 256-bit chunk, and a cryptographic hash, which takes and returns exactly 256-bit per iteration. Does both of these SHA256 parts are performed on ASIC, or only cryptographic one?


texts: Can we measure bitcoin's accumulated work in terms of entropy (in bits) directly rather than expected number of hashes?

texts:
The Background

Bitcoin tracks chain work by counting the (expected) minimum number of hashes it would take to create a chain of the same number of blocks and same difficulty steps[1]. Naturally, accumulated work measured in this fashion (e.g. expected number of hashes) increases with each new block that is added to the chain.

For a given target t, the minimum expected number of hash attempts necessary to find a block which meets the proof of work criteria (hash less than or equal to t) is geometrically distributed[2] with parameter p = t / 2^256.

We can calculate the entropy, w, of such a geometrically distributed random variable[3] by the equation w(p) = (-(1-p)log2(1-p) - plog2(p)) / p, and using p = t / 2^256 we can trivially rewrite this into a function of the target instead, w(t).

Using this method we can calculate the minimum work (e.g. entropy) w(t), denominated in bits, necessary to describe the proof of work signal. Other components of the blockchain (such as what data is in the blocks besides the proof of work signal) are not included in this analysis so that is why it is an estimate of the minimum encoding.

Plugging in some numbers:

for block zero (and any block with the lowest possible difficulty, hence p = 1 / 2^32), we get approximately 33.44 bits of work per block.
for a more recent block, say block #602784 we getapproximately 76.97 bits of work per block.

The Question

Can we complete the above analysis for every difficulty period and sum the entropies to obtain a lower bound on the minimum complexity, in bits, of the (proof of work aspects of the) Bitcoin blockchain? Or is there some assumption (such as being able to sum the entropies in this context?) that is unsafe/wrong?

An Attempted Answer & Some Motivation

Performing such an analysis[4] seems to give a result, as of block 602784, of approximately 36.9 million bits or 4.6 megabytes and growing.

However, one reason why the method seems interesting is that, if it is reasonable, then it seems that all the math which the bitcoin protocol currently does with "time" (in the unix timestamp sense, such as difficulty adjustments, and block timestamp must advance median of last n block's timestamps) could instead be done in "bits." As such, this could be helpful for when/if the protocol is extended into operate across vast distances of spacetime?

Then again, there is probably something terribly wrong with this analysis which is why the question is being asked here.

References

[1] Strongest vs Longest chain and orphaned blocks

[2] How is it that concurrent miners do not subvert each other's work?

[3] https://math.stackexchange.com/questions/490559/entropy-of-geometric-random-variable

[4] https://github.com/philbertw4/mathematicalbitcoin/blob/master/scala/SatsPerBit.sc


texts: how to calculate max spendable from all wallet

texts: Using latest bitoind, any way to calculate max spendable from wallet with some amount of outputs? For example i need to send all wallet amount to 2 outputs and set mining fee enough to get confirmation in first block. How can i calculate max spendable amount?


texts: Why have prices fallen so drastically around October 2011?

texts: Any idea why bitcoin prices have fallen so in September and October of 2011?  It seems like back in August, one bitcoin cost about US$17, whereas in late October, it's just somewhat over US$2.


texts: Do sigops count towards the block weight in SegWit?

texts:
I was just rereading the SegWit benefits page and noticed that the section Moving towards a single combined block limit contains an example in which sigops count towards the blockweight.

Did this become part of the final version of SegWit? If not, what happened to this idea?


texts: Can the service providing the bitcoin wallet know how much value has the user loaded into his wallet?

texts:
Say for example I run an ecommerce website which mandates users to have a minimum balance of 1 bitcoin in their wallets to access the platform. In the event the balance in his wallet falls below 1 bitcoin he should not be able to access the platform and he should see a message on his screen saying "Please load to minimum balance".

So, the question is, can I, or the Bitcoin wallet provider I use, read the bitcoin balance of the users so as to fulfil the above business requirement?


texts: Hash of backed up wallet file not the same as hash of wallet currently in use

texts:
A couple of months ago I had backed up the wallet.dat (I use bitcoin-qt) file and saved it some place else.

Lately I've opened the data folder for the current running node (also bitcoin-qt) and I compared the md5 hashes of both files and they are different.

What caused this? Surely my private keys have not changed so why is the wallet.dat file not exactly the same as the backed up version?

Thank you


texts: How are Electrum addresses connected to my private key?

texts:
I've started using Electrum and created my first wallet. I saved the private key seed on a piece of paper.
I also created a new address by going to the Receive tab and clicking "New Address". I successfully used that address to transfer my coins from my exchange, and they show up in Electrum under the Coins tab. I did this twice successfully with 2 different addresses on the same wallet.
What confuses me is this: how did Electrum create a new address? How is that address related to my private key/seed? When I go to Wallet Information the Master Public Key is completely different from the public keys of the addresses I used in the transactions. If I use a different computer, and I enter my seed phrase into Electrum, will it find my coins? If so, how does it do that based on just my private key?
Thanks.


texts: Do bitcoind and bitcoin-qt resume blockchain downloading from the same place?

texts:
This is a multi-part question.

I downloaded source code of bitcoin core from github and compiled it on my Windows 10. Then I got bitcoind and bitcoin-qt among other commands. I first run bitcoin-qt and choose a directory(D:\bitcoin) for blockchain data storing. However because I need to use bitcoin-cli tool and bitcoin-qt doesn't expose an RPC service by default, I close bitcoin-qt and start bitcoind.

But then I found that bitcoind didn't download blockchain from where bitcoin-qt stopped(by run bitcoin-cli -getinfo). How can I make bitcoind download that way? (I use bitcoind -datadir=D:\bitcoin to do that, is it right?)

Another question is where should I put my configure file. In my home directory(C:\Users\MyName) or just in the same data directory(D:\bitcoin)? Does bitcoind and bitcoin-qt use the same configure file?


texts: Comparison of different active cryptocurrencies

texts:
I haven't realized until recently how many different crypto-currencies have emerged the last years; coinmarketcap.com lists around 60 of them* and it seems that it isn't even a complete list (for example allahcoin that I've read about recently at HN is not listed).

I guess most of them are derived from Bitcoin and are somehow different trying to solve a real problem, eg Litecoin being more efficiently mined to reduce energy costs, but some are simply clones with only minor twists if any at all, or trying to appeal only specific audiences (gaming community, sex shoppers etc).

I think it would be interesting for me and others, a simple comparison list that explains in a few words how the concept of each currency is different to Bitcoin and what problems are they trying to solve, and not other details such as market capitalization, initial reward, who created it etc.

Related lists:

http://en.wikipedia.org/wiki/List_of_cryptocurrencies (interesting but doesn't explain the differences of the concept)
https://en.bitcoin.it/wiki/List_of_alternative_cryptocurrencies
https://bitcointalk.org/index.php?topic=134179.0 (by far the most complete list and quite close to what I'm asking, but doesn't explain clearly IMHO in all items what are the differences from Bitcoin)

* Follows the list of currencies found in coinmarketcap.com that I'm interested in; description of additional active ones are of course welcome: Litecoin, MasterCoin, Peercoin, Nxt, Namecoin, Quark, ProtoShares, WorldCoin, Megacoin, Primecoin, Feathercoin, Infinitecoin, DogeCoin, Novacoin, Zetacoin, Devcoin, Anoncoin, Digitalcoin, Freicoin, Copperlark, Terracoin, Ixcoin, Cryptogenic Bullion, NetCoin, GoldCoin, Tickets, BBQCoin, StableCoin, Sexcoin, Fastcoin, Deutsche eMark, Unobtanium, MemoryCoin, Datacoin, GrandCoin, Yacoin, FlorinCoin, Mincoin, I0Coin, Tigercoin, BetaCoin, Luckycoin, TagCoin, Diamond, GlobalCoin, BitBar, CasinoCoin, EZCoin, Philosopher Stones, Phoenixcoin, Orbitcoin, Bytecoin, GameCoin, Argentum, Franko, HoboNickels, Noirbits, Joulecoin, CraftCoin, Elacoin, Junkcoin, Spots.


texts: Explanation of probability of forks in the Bitcoin blockchain

texts:
I am reading this paper on how information is propagated on the Bitcoin network. The authors present a model to predict the rate at which forks occur in the blockchain which is given as below

Here, F is the number of conflicting blocks in the network, Pb is the probability of the network finding a block b in a given second (ideally, 1/600 since a block is expected every 10 mins = 600 secs) and f(t) represents the ratio of nodes that hear about the block b in t secs. However, what I cannot understand is how this entire expression is derived. I understand that the term in the exponent represents the mean amount of time it takes for the network to learn about a block (and this value can be derived from a graph given in the paper). I assume 1 - Pb represents the probability of the network finding more blocks in the remaining 599 seconds in the 10-minute interval. Why is this probability raised to the mean amount of time it takes for the network to learn about a block?

Any explanation would be appreciated.


texts:
I just tried downloading Bitcoin Core to my PC today for the first time and am getting an error. I am a noob to this, but was hoping someone could point me in the right direction in getting this fixed as I'm trying to get smarter on this stuff. Google led me to try re-indexing, but unfortunately that crashed as well after a few hours of running.
The below is the error message and the debug file. It appears it crashed due to a corrupt block found and potential hardware error. It could certainly be a hardware error as I only currently have the storage space for a full node on an old HDD, but haven't had any issues with this HDD previously.
Appreciate any help here. Thanks!

New Error When downloading on new SSD


texts: Password not working in Bitcoin core wallet

texts: I am trying to transfer my BTC to another wallet and it is saying my passphrase is incorrect when I know it is not and use this password for a few things. Any ideas to get around this?


texts: How are the transactions chosen from the Mempool if every node has its Mempool?

texts:
I have this scenario:

So whenever a wallet user is initiating a transaction, this goes as far as I understood into a Mempool. And that each node has its own Mempool.

I have some questions though: Do every node get all the transactions in their mempool, meaning it's like a syncronisez place where everybody can see the same transactions? If so, how does the rest of the network of miners know that the transactions they have chosen from the mining pool isn't already being mine by another miner?

Or each and every node get different transactions in their Mempools? If so, how is the transaction broadcasted? Does it go randomly to some miner's mempool?

Thank you for your patience!


texts: Security implications of regular saving into cold storage

texts:
I am thinking about following this plan:

Regularly buy bitcoins in an online exchange, 100€/month at market prices.
Once the balance in the exchange exceeds a certain limit (500€), move those bitcoins to cold storage, as long-term savings.

(the reason why I want to do 2 is that I do not feel I really own bitcoins until they are in a wallet under my control)

With this scheme I would be transferring to my cold wallet a couple of times per year. I have read that reusing a bitcoin address is not recommended. I am worried about these two facts:

Will reusing my cold-storage address decrease the security of my cold-storage wallet?
The balance of the offline wallet will be visible on the blockchain. I have read about privacy implications of having several parties transfer to a single bitcoin address (employer being able to see my rent, for example), but since the only one transferring to this account will be myself, from the account in the online exchange, there is no danger of private information becoming public, correct? That is, from these regular transfers no spending habits can be inferred. Furthermore, the receiving address will not be linked to any real persona. The only one knowing the identity of the sender is the exchange, and the identity of the receiver (the cold wallet) is completely hidden since he is not engaging in other transactions with any other party. Is this correct?

Note: I am not planning to spend from the offline wallet at the moment, and I know that spending changes the security and privacy implications. I am planning to only save into the offline wallet.


texts: Can i still use the old address to recieve Bitcoin with Bitcoin.com Wallet

texts:
I tried Cloud Minning recently And I use Bitcoin.com Wallet to register bitcoinonlinepool.com, today I accidentally press the change address button, will my account still able to recieve Bitcoin?
Btw, is bitcoinonlinepool.com a legit or spam


texts: How to free up the space taken by bitcoind?

texts:
I am trying to create a wallet on my computer with bitcoind following this guide. I installed it, ran it, and monitored the process with bitcoin-cli. It went on for about 15 hours, at which it failed with an error message: "Error: Error: Disk space is low!". bitcoind had taken up the whole 160 Gb available in my home disk.

How can I safely free up the space taken by bitcoind? Should it be uninstalled? Or delete files (which?) will suffice?


texts:
I'm confused about how exactly I should compute a change for transactions.
Say, for a given address I have 4 unspent outputs containing 2 BTC each and I want to send 5 BTC to other address.

Here's what I do:

Find 3 outputs needed so the total is 6 BTC
Now, what should the change be? 6-5=1 or 8-5=3?


texts: Can I send/receive payments but prevent forwarding payments in Lightning Network?

texts:
Say I am using a very computationally constrained device (eg. a sensor) and it uses Lightning Network to send/receive payments. However, being computationally constrained it doesn't want to forward incoming payments that are actually meant for other nodes. The reasons could be that forwarding a payment will require it to forward the htlc, fulfill it as well as compute the onion for routing to the next node which might be computationally draining. However, sending an error would be just one operation after parsing the onion.

Every time the sensor node parses the onion and sees that the payment is not meant for it, it will send a temporary_node_failure or temporary_channel_failure error message. In situations where the lightning software uses some data analysis tools like autopilot, other nodes might completely eschew this sensor node out from forwarding the payments due to its high failure rate.

Is this something that can be implemented with a slight tweak to the current lightning implementations (like LND or c-lightning)? If the failure rate is too high, is there something like a banscore that is being kept by other nodes that might prevent this sensor node from receiving/sending payments in the future?


texts: Where does the litecoin wallet store coins?

texts:
I recently installed the official LiteCoin wallet on Ubuntu. I accidentally deleted it about 80% of the way through the synch, and reinstalled it, expecting it to resynch. It resumed. My address didn't change either.

So it seems that the wallet data is stored somewhere in the system. Is this safe? I reasonably expect my system to eventually implode, so I will need to backup/export my data somehow.

Where is the data stored, and how do I back it up?


texts: When walletnotify and blocknotify notifications are sent out?

texts: Do the notifications from walletnotify and blocknotify are sent during the wallet synchronization or at the end? Say the wallet was offline for 100 blocks and when started: will it send the notifications after the each block it downloads and verifies and so all the relevant transactions in them or will it send them at the end? I would assume it sends them as it gets them, so then how would I resolve these properly if all the incoming request at that time are blocked?


texts:
How are bitcoins reassigned, that is, what about a transaction makes a "coin" no longer usable by the sender, and makes it usable by the recipient?

Alice wants to send bitcoins to Bob. Alice's wallet gathers transactions originally sent to Alice so that the monetary amount of said transactions is at least the amount that Alice wants to send Bob. The transaction is basically a message, so a little bit of ECDSA on top of that and boom, there's a transaction: only Alice could have created that particular transaction (message), and anyone can verify Alice's signature for that transaction.

Now Bob "receives" the money. Why can he use it? (Indeed, why could Alice use the money above...) Digital signatures of themselves don't solve this problem, i.e. the transaction/message along with its signature doesn't "transfer" anything, there's gotta be some other ingredient involved, but what is it? I can't see, or at least not understand, the answer in the various sources I've read.

It has to be something about Bob's private key, but I can't see how it's used to "unlock" the money he received from Alice. I don't know what transactions look like exactly, but suppose they're basically of the form tx_1 = (Alice's public key)+amount+(Bob's public key) - would Bob's wallet basically be saying "reproduce Bob's public key and you can access tx_1"? I guess that would do the trick, but then again Bob was already "logged on" to his wallet so he's already proven the ability to reproduce Bob's public key.

Ok I think I'm getting ahead of myself. Anyway, received transactions, how are they "unlocked"? Thanks.

(Yes, I have tried finding an answer on BSE and elsewhere already.)


texts: Testvectors for dedicated hardware miner

texts:
I have written my own hardware implementation for hash computation. I am participating in a pool, that is I get sent the midstate and some data which should then be hashed.

I wonder, whether there are any testvectors out there, that is I need input the midstate plus data, and see then whether my implementation finds the appropriate nonce that is also supplied with the testvectors.

Many thanks for your help,
Patrick


texts: Are there wallets that provide access to different HD wallets from the same masterseed using different passphrases?

texts:
I have a well-protected masterseed that I have not memorized, and memorizing it won't help since it could already be compromised.  My solution is to use a clever passphrase on top of that masterseed.  I've been looking around in Mycelium because I read somewhere that you can appear to access your bitcoin wallet and show any bad guys that it's empty by using an incorrect passphrase.  This makes so much sense that I want to do it, at least just for fun.

As I understand it, the masterseed encodes an integer which is the private key for a bitcoin address, and also a chunk of entropy that is used to generate the paths in the resulting HD wallet.  When a passphrase is used, the effect is to change the masterseed so that an entirely different HD wallet is the result.  So with one masterseed, you can have as many (invisible!) HD wallets as you want.  The feature required is the ability to restore from the masterseed plus passphrase.  Indeed, if the wallet is locked with the passphrase, then entering the wrong passphrase gives you a new wallet (and you'd have to realize on your own that you entered the wrong passphrase).

That is my dream: to be able to run Mycelium in front of a bad guy, enter my passphrase, and show that I have zero-balance.  An additional feature would be the option for old transactions to show up so that it still looks real, but like everything has been spent.

I have an Android with Mycelium, and I've looked at the cold storage and backup features (and the "Advanced" add-a-key feature) and I can't find a place where I can enter my 12 masterseed words PLUS passphrase and get a new wallet.  The only place I found like that is for cold-storage spending, and then it says "no funds found" (as expected).  It could at least give me a btc address so I could send some funds to my special secret passphrase address.


texts: what do red and green bars at bitcoinity.org mean?

texts:
The changebars graph at http://bitcoinity.org has red and green bars. Some of them below and some above zero.

What is their meaning?

If they are above zero

and are green
and are red

if they are below zero

and are green
and are red?

Is there a wikipedia article about that kind of graph? What would the search term be?

The rest of the graph is explained here http://i.imgur.com/516v5Nz.jpg but not the red and green bars.

Thank you.


texts: Is bitcoin node and bitcoin client the same thing?

texts:
What is the difference between btc node and btc client?

Which one is bitcoin-core and which bitcoind?


texts:
I have been thinking for a while and can't really figure this out..

From my understanding, in Bitcoin network, 'bitcoins' are created when a miner successfully mines a transaction. So this means in order for the network to create a bitcoin, there has to be something to be mined and that something is transaction.

But what I also read, the first transaction was from Satoshi to Hal where Satoshi transferred 10 BTC to Hal. How is the possible since to create 10 BTC, they had to do mining previously which can only be done on previous transaction which makes this transaction not first.. Circular.

Or is it the genesis bitcoin was created without mining? Could be the case, but I am not able to find a reference to that.


texts:
We are building an online game and planning to enable our players to play for bitcoins.  Therefore, we need to enable players to deposit and withdraw bitcoins.

Which way is the easiest to start accepting bitcoins from users?  Use the bitcoin API call list (https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list) or use Blockchain.info's "receive payment API" (http://blockchain.info/api/api_receive)?

On Blockchain.info's page for "receive payment API", it gives a PHP example near the bottom of the page.  The example enables your website to prompt the user to send bitcoins to us, via Blockchain.info.  I like to test this out.  Which way is the best way to test it out?  Send real bitcoins or send testnet bitcoins?

If the best way to test is to use real bitcoins, I'm assuming that we should send one Satoshi (0.00000001 BTC) each time?  But how much transaction or network fee will I have to pay (since it is likely that I'll need to send BTC many times)?

If the best way to test is to use Testnet coins, then how does one use them?  I cannot find good information on how to use them to answer questions such as:  Can we use testnet coins to test out the bitcoin API call list or Blockchain.info's "receive payment API" and their PHP example?


texts: Recovering 2 of 2 multisig HD Wallet with bip38 encrypted private key

texts:
I have been trying to figure out if it is possible to restore my wallet with the current information I have.

The wallet is a 2 of 2 multisignature HD wallet
The first key is Bip38 and requires a password to decrypt private key
The second key has a 24 word seed

I currently have both xpub's, and the 24 word seed of the second key. Unfortunately I do not have the password for the bip38 encrypted private key. I created the wallet a while ago and cannot remember the password but I have some ideas of what the password might have been. Given this information, I believe it might be worthwhile to try to brute force the password.
I am unsure the best method of brute forcing a multisig wallet. If it was a non-multisig wallet, I could just do something like this:
const decryptedKey = bip38.decrypt(encryptedPrivateKey, password);
const privateKeyWif = wif.encode(
      0x80,
      decryptedKey.privateKey,
      decryptedKey.compressed
    );
const coinkey = CoinKey.fromWif(privateKeyWif);
console.log('address with btc im trying to recover' === coinkey.publicAddress, password) // Found password

The address I am trying to recover starts with a 3 as it is a P2SH address (multisig). When I run the code above I get an address that starts with a 1 (not multisig). With all this being said, what is the best way (if there is any) to validate the "correctness" of a password during brute forcing one key of a multisig wallet?


texts: Balance not going up in deepbit after mining

texts:
I've been mining with a deepbit account and noticed the balance hasn't been increasing. I use the following bat file to run cgminer version 3.5.0

cgminer.exe -o http://pit.deepbit.net:8332 -u emailme@gmail.com_one -p 123abc -I 10 -g 1 --auto-fan --queue 1 --temp-target 70 --gpu-engine 945 --gpu-memclock 275 --temp-overheat 80 --gpu-fan 75-85  -k diablo -v 2 -w 256

After upgrading to 3.5 when I press q to quit Windows gives me the error "Display driver stopped responding and has recovered".

Here's a screen shot of it working

What should I do to find out why it's not working?


texts:
I am being invited to invest small amount of BTC. I am being asked to create second wallet. Is this legitimate?  I am trying to understand the mining process,  I did not think one needed to use bitcoin to mine more bitcoin.

I am trying to understand how this works, excuse my slow learning.

Thank you,
Andrea


texts:
I have a question about how the bitcoin core wallet works with descriptors.
I am creating a wallet using the createwallet method and passing in a name (all other args are default).
I then import addresses into Bitcoin Core using importmulti and wsh(sortedmulti(2,[abc123ef/48h/0h/0h/2h]xpubyadayada.../0/*, [abc345ef/48h/0h/0h/2h]xpubyadaya1da.../0/*, [abc567ef/48h/0h/0h/2h]xpubyadaya2da.../0/*))#checksum
When I run deriveaddresses with wsh(sortedmulti(2,[abc123ef/48h/0h/0h/2h]xpubyadayada.../0/*, [abc345ef/48h/0h/0h/2h]xpubyadaya1da.../0/*, [abc567ef/48h/0h/0h/2h]xpubyadaya2da.../0/*))#checksum I get the expected addresses as an output but when I run the getnewaddress command after running importmulti, I get an address but not any of the addresses that were output from deriveaddresses.
I then noticed there is a disable_private_keys option when creating the wallet, so I've setup a new wallet using that flag.
I go through the setup process again with keypool=true when importing multi but when I run getnewaddress I get "Error: This wallet has no available keys". The importmulti call returns success: true, and I get Already have script 522103b403e66... in my logs when I try running the command twice.
Does getnewaddress not work with descriptors? Or am I setting up the wallet incorrectly? I see there is an argument blank to pass in when creating a wallet but when I try that and import I get Error: This wallet has no available keys too.
I would expect getnewaddress to output the first address returned from deriveaddresses on a fresh wallet. Have I overlooked something in the documentation?
I looked at these docs too and I think I've followed them exactly:
https://gist.github.com/achow101/a9cf757d45df56753fae9d65db4d6e1d
Using importmulti with internal set to true does not add any change keys. What am I doing wrong?
Import multisig change addresses into Bitcoin Core using "importmulti" + descriptor
What is the best way to create a wallet with a blank keypool then add keys to it?
Thanks!


texts:
One of the arguments made in favor of relying on ASIC mining hardware to secure the Bitcoin blockchain is that commodity hardware is more prone to a 51% attack since an attacker could easily infect millions of computers through a malware attack and use the computer's resources to execute a 51% attack against the network.

It's very hard to.. hack into someone's SHA256d ASICs

Are ASICs really resistant to malware attacks? If so, why?


texts: Can an unconfirmed transaction that only Blockchain.info shows be manually re-broadcast?

texts:
Blockchain.info shows a transaction that was created by Blockchain.info/wallet but for whatever reason the transaction didn't confirm right away and appears to not be getting re-broadcast (perhaps because the transaction is more than a day old now).

Is there a way to recreate the transaction (reconstruct as an identical copy, resulting in the same transaction hash) using just the data shown from the blockchain.info website (the Input scripts and Output scripts from the transaction's view on the site) to construct a raw transaction that I can manually re-broadcast using http://Blockchain.info/pushtx or http://brainwallet.org/#tx ?


texts: Where can I find well-written criticism about Bitcoin?

texts: I couldn't find an article about criticism in the wiki. Is there some other place that contains well-constructed criticism for Bitcoin?


texts: Is this thing on? (How to tell if my cpuminer is working?)

texts:
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.


texts:
I'm registering with a few different bitcoin sites.  I notice that, at least according to older questions, paypal isn't generally accepted.

Is there a simple way to buy a few US dollars worth of bitcoins?  The purpose is to register a domain with gandi who have a $10 min for paypal.  Some domains are quite inexpensive:  .pw is less than one dollar.

Or, would I simply end up paying more in transaction fees and time than its worth?  For security and volatility, alone, I don't want to hold on to bitcoin.


texts: Will the Liquid sidechain be open to any user?

texts:
With the recent start of the private beta of Liquid, the first sidechain is now in production on the Bitcoin network.

One of the features advertised is:

  User Control – Users can hold their Liquid funds off of exchanges and in a wallet they control, enabling them to rapidly transfer funds to and from any participating exchange in the network.

It was my understanding that Liquid was primarily to facilitate payments betweent larger users in the Bitcoin network such as exchanges and payment processors.

The above feature seems contradictory with the company focus. Will everybody be able to have a wallet on Liquid?


texts:
I can send a signed message using the standard client, but if I see a signed message in, say, a forum, how can I verify it?

I understand this hasn't yet been implemented in the GUI for the standard client.


texts:
What is the absolute bare minimum RAM required for a full node.  So for example a pi zero with 512MB RAM, could that act as a full node?

If not what components are causing the RAM usage, my own theory is that the txleveldb is fully loaded to RAM?  If so as the chain gets longer, RAM usage will need to increase?


texts: Bitcoin Insight API - How to create new address?

texts:
I need to create new public address with private key. but there is no way to create new address using insight rest api. If you guys are aware about insight api then please share with me code snippet so, i can update my insight api library and i can create new public address using that.

Currently I have used: https://github.com/bitpay/insight-api


texts: Getwork - can the miner increment timestamp?

texts: When requesting getwork from bitcoind or a pool, the miner is expected to be incrementing the nonce value of the block, but can it also increment the timestamp value, or would such tempering cause a submitted work to be rejected by bitcoind or a given pool?


texts:
I just started running a full node and was wondering how to use these commands to verify my node: https://getaddr.bitnodes.io/api/

Specifically, what command line or IDE do I need to type these commands into? Very new at this, sorry


texts: What would happen to the Bitcoin network if all ISP's collectively block port 8333 at once?

texts: Will nodes still be able to find each other using today's official Bitcoin client?


texts: Who pays the fees for transactions initiated by a smart contract in Ethereum?

texts:
I am wondering who pays the fees for transactions initiated by a smart contract in Ethereum?

For example, if I have a contract that simply forwards any payment made into it to someone else, does the contract have to pay its own transaction fees for payments moving out, or does the transaction that initiate the contract have to pay the fees for both its transaction and the resulting transaction coming from the contract?


texts: I am naively under the impression that just about anything can be a soft fork nowadays, and that this is one of the benefits of Segwit.  Also, it seems that many claim in order for Bitcoin Core to implement replay protection, a hard fork is required.  This seems contradictory.  Perhaps someone could correct any of these assumptions?


texts: What happens with the transactions a miner didn't include in a block?

texts:
Let's say a miner pulls from the node the available transactions to be included in the next block. He receives transactions A, B and C. For whatever reason he discards transaction B and so he mines a block that includes only A and C. Meantime, before the miner pushes the new block, the node has received a new transaction D.

What happens with the transactions B and D? I suppose the node verifies which transactions were not included in the mined block and keeps them available for the next block, is that correct?


texts: What is the fastest possible way to download the blockchain?

texts:
How to download the blockchain with full bandwidth?

How to download the blockchain fast?


texts: Restore Wallet From Jaxx to Coinomi: ETH missing (but BTC and LTC are fine)

texts:
I have some BTC, ETH and LTC in a wallet created with Jaxx, but I want to use Coinomi instead. I downloaded Coinomi and chose Restore Wallet and entered my 12 words. My BTC and my LTC popped right up, but the ETH is nowhere to be seen (even after several hours).

I've tried adding some additional ETH wallets as suggested in this thread: https://www.reddit.com/r/COINOMI/comments/7b8wxb/help_lost_ltc_when_restoring_my_old_wallet/

I can still access all currencies in my Jaxx wallet, so I could just transfer the ETH to my wallet in Coinomi, but I'd quite like to keep my transaction history.

Should my ETH be showing in Coinomi? Or am I wrong in my assumption that I can use my 12 words to restore in another wallet?


texts: What is the simplest python program that would query the bitcoin core client for a raw tx?

texts:
I put this one together that claims "no JSON object could be decoded".

  from bitcoinrpc.authproxy import AuthServiceProxy

  access =
  AuthServiceProxy("http://user:password@127.0.0.1:8332")

  printme=access.getrawtransaction("6359f0868171b1d194cbee1af2f16ea598ae8fad666d9b012c8ed2b79a236ec4")

  print printme

My bitcoin core wallet is set to "server=1" and "listen=1", but it is currently downloading the blockchain (idk if that would have an impact).


texts: Majority attack no drawbacks (unlike bitcoin wiki suggests)

texts:
In the bitcoin wiki article on Majority attack (https://en.bitcoin.it/wiki/Majority_attack) it says:
"No amount of confirmations can prevent this attack; however, waiting for confirmations does increase the aggregate resource cost of performing the attack, which could make it unprofitable [...]"

Taking into account that the attacker miner will impose his block-chain branch (he has over 50% of hashrate) eventually, won't the bitcoin reward for mining these blocks make up for this aggregate resource cost, thus making the wiki statement false? Am I missing anything (I probably do)?


texts: Why should BIP157 compact filters be processed in-order?

texts:
In BIP157, under "Client Operation", we have the following paragraph:

Starting from the first block in the desired range, the client now MAY download the filters. The client SHOULD test that each filter links to its corresponding filter header and ban peers that send incorrect filters. The client MAY download multiple filters at once to increase throughput, though it SHOULD test the filters sequentially. [...]

I'm wondering about the bolded part: why should the client test the filters in sequence? Why can't it test them as it receives them? I'm having a hard time coming up with a good reason to test them sequentially. Anyone knows?


texts: Converting raw scriptPubKey to readable format

texts:
I am debugging Bitcoin cpp code. I wanted to see what exactly come for scriptPubKey property of output. Theoretically, I know this but I want to see in the code how does it looks like.

Now while debugging I see  scriptPubKey object which is of type CScript and hence the format is different which is unreadable (see the screen shot below, it looks like char[]). How to read this value?

It looks like this :

\200\002\0\0à\210¼XUU\0\0\220»ÿÿÿ\177\0\0à¡·XUU\0


texts: Generate private key from a bip-39 seed phrase?

texts:
I'm able to generate a new private key and associated public addresses using bitcoin-core, but what I really want to do is generate a new private key from a 24 word seed phrase. I'm not sure how to go about this and I have not been able to find any examples.

BIP-39 Word list:

https://github.com/bitcoin/bips/blob/master/bip-0039/english.txt

Current code:

var bitcore=require("bitcore-lib");
var buffer=bitcore.crypto.Random.getRandomBuffer(256);
var hash=bitcore.crypto.Hash.sha256(buffer);
var bn=bitcore.crypto.BN.fromBuffer(hash);
var pk=new bitcore.PrivateKey(bn).toWIF();
var address=new bitcore.PrivateKey(bn).toAddress()+'';

If I understand correctly I will generate a hash from 24 randomly selected words (from the BIP-39 word list) then use that to generate a private key. What are the steps and format for hashing the seed phrase?


texts: Circular rebalance through 1 of 7 channels always times out

texts:
I have the following 8 channels open

I am able to do a circular rebalance through the first 6 as expected
The bottom 2 channels are to the same node
Every time I try to do a circular rebalance (tried all paths through the other channels) through either of the bottom 2 channels, the payment times out

Has 1ml.com done something to prevent me from using these channels?
If so, leaving these channels open could lead to unnecessary failures through those routes when someone attempts to use my node for routing?


texts: Why does P2SH-P2WPKH use DER encoded signatures?

texts: If we simply assumed 32 bytes of r and s each, then signatures can be 64 bytes. Now they are on average 71 bytes in DER plus an additional byte to declare their size, effectively making them use 72 bytes of space. Similarly, if we assume public key is always compressed then we can simply keep 2 stack items of 64+32 bytes. I guess it is to do with the way OP_CheckSig is implemented.


texts: Is it possible/feasible to send out large amounts of small transactions without paying fees?

texts:
How long would it take to process 1000 transactions from the same wallet, with outputs ranging from 100 bits to 1000 bits and no transaction fees for any of them?

How about if 1000 of these transactions were sent out every hour? Would Bitcoin be able to handle this?


texts: Where do you get the transaction data & where do you submit your work?

texts:
The concept of bitcoin mining (hash functions & the goal) are well elaborated on many sites. There are also lots of examples.
However, when going into real production I guess you need data like the latest hash, info about the block and transactions and so forth.
In addition, once you make your guess, you have to submit the work somewhere.
I can however not find any resources that explain where to do this? Is there an API to which you submit your work, to which you attach also your bitcoin address of your wallet, and once you make the right guess the btc is transferred to this account?
What are the bitcoin endpoints in my case?


texts: Is blockchain protected from history spaming?

texts:
As I understand, full nodes accept block even if it is not mined on top of most recent block and store it as alternative chain as long as it fullfills protocol rules.

What would happen If one start mining millions (or more) of new versions of block height 10 (based on block 9) and keep sending them to the network? Could this cause full nodes to fill their hard drives and make them inoperational?

In other words - is there a limit for side chains enforced somehow by Bitcoin Core or protocol rules?


texts: Traditional currencies have anti-counterfeiting features designed to make them hard to copy, but despite this attempt counterfeit money is a real threat.  Since bitcoins are digital, it's trivial to copy them.  Does this mean that bitcoins can be counterfeited?


texts: I don't know how to export a private key from blockchain.info

texts: I am trying to make a raw transaction which requires a private key but i can't seem to find a way to get it from blockchain.info.


texts: How to fix "Failed to resolve (?wrong URL) cgminer.exe --bmsc-options"

texts:
I downloaded CGMiner and have my pool with slushs pool. So below I believe is the correct setup for CGMiner.

cgminer.exe --bmsc-options 115200:20 -o stratum.bitcoin.cz:3333 -u Starfleet.worker3 -p ***** --bmsc-freq 0781

However, every time I try and connect, it says exactly this:....

Failed to resolve (?wrong URL) cgminer.exe --bmsc-options
Pool 0 slow/down or URL or credentials invalid
Pool setup failed

Can anyone please help me, I am not sure what I am doing wrong. And I do not really know how to write script.


texts: Exception CompactSize when I parsing the blk file >= 976

texts:
I wrote a bitcoin core parser, for my personal project and because it helped me to start understanding the bitcoin protocol as a data structure.

This project mainly parsers every blk file and creates the corresponding json with the deserialized information.

I launched the alpha version of the project and actually parserizes the information and converts it into a json file, my application worked fine until the blk file number 976, where I get an exception from the blockchain library and precisely in the ReadCompactSize operation, the exception is of the type

unknown file: Failure
C++ exception with description "ReadCompactSize(): size too large: iostream error" thrown in the test body

I used the bitcoin core libraries for example serialize.h

I don't understand why this error only comes up to me after blk00976 blochi and for all the subsequent ones I tried also with the file blk00977 blk01124

I have some posts I have consulted and others where I asked about this problem, now I was opening an issue on github for bitcoins but there it is written that for general questions you have to refer here.

The questions I have read but do not solve the problem
How to handle incomplete blocks when reading blk*.dat files?

My question
https://bitcointalk.org/index.php?topic=5134784.msg50723554#msg50723554

My source code
https://github.com/vincenzopalazzo/SpyCblock

Two words about the source code

I am a java programmer dealing with the bitcoin protocol and I decided to carry out the C ++ project to study the language too, so to those who linked the code I apologize if it looks like an offense because it is badly written but I am studying to refact and improve the performance of the parser but also the quality of the source code.


texts: Recovered wallet does not contain imported address. How can I recover my funds?

texts:
I had a few transactions sitting in my imported address and not in my actual wallet (at that time I didn’t know I had to move the funds from the imported address to the main wallet).  I only found out recently when I changed phones  and forgot my login since I didn’t use the blockchain app for a while. I used the 12 word phrase to recover the account and when I regained access, the balance was zero. Now I know that the 12 word phrase does not back up the imported addresses.
What can I do to recover the funds?


texts:
I wrote my own ECDSA signature algorithm just for the purpose of creating unit tests.

With it I created two signatures which went into transaction 56ec7ca7df..., sending from 1GXFXm3es.... These signatures used the same k values, although k values must never be reused.

Later on, someone was able to steal 0.0016 btc from 1GXFXm3es.... and send them to 17WRjamox6VhTUaHsTWfFnMNDYHvwCtWio.

So someone must be monitoring the blockchain for mistakes like this and stealing funds if they encounter them.

How do you derive the private key from two signatures that share the same k value?


texts: can blocks remain capped to 1MB forever?

texts:
this is perhaps more of an economics question than a bitcoin question, but i'm wondering if it would be viable to leave the block size capped at 1MB for all time and simply let a series of rules govern which transactions get included into a mined block, eg:

paying a higher fee gives higher priority
older coins get higher priority
bigger spend gets higher priority
etc

this would incentivize people to rely more on off-chain transactions (eg gyft cards), or sidechains, to accumulate many payments into a single transaction, and perhaps to delay transactions if they do not wish to pay high fees. and one benefit would be that the blockchain would not grow beyond a size which would fit on a single user's hard disk. this would keep bitcoin decentralized without any need for a hardfork.

are there any fatal flaws to this notion?


texts:
this sounds like an old topic but i have not found a satisfying answer yet; in history there lived two blocks with identical coinbase transactions:

https://www.blockchain.com/btc/block-index/106662
https://www.blockchain.com/btc/block-index/106692
https://www.blockchain.com/btc/block-index/106572
https://www.blockchain.com/btc/block-index/106730

but if you check the receiver address (1, 2)you would find they both get rewarded only once not twice; even though the same transaction was being used repeatedly, the two blocks have different nonces, which proved two shares of work in mining; then, which rule regards this as invalid and why is it designed like that?


texts: Migrate from Bitcoin Core Wallet to somewhere else before sync completed

texts:
I created a Bitcoin wallet yesterday using Bitcoin Core Wallet application and bought some bitcoin via buy.bitcoin.com to the address mentioned in File>Recieving Address in my Bitcoin Core Wallet. They sent the money but I can't see if I received it or not because I did it before synchronization complete and it seems it takes at least 2 weeks for my bitcoin core wallet to finish synchronization (I think the number is increasing):

Is there anyway I can move my wallet to some other bitcoin client and start using it instantly? I paid a lot of money to but bitcoins and it seems I can't use it until this app finish its synchronization.

If so, then which client and how?

Any help/guide will be appreciated.


texts: I have a worker on slush's pool, I have my BFGminer running (Pool 0 is hiding block contents unsure if that's important) and my Antminer S7, but I can't  seem to get it to see it as a device. It ask for a target which is a serial port to probe for mining devices but I'm unsure what it's asking.


texts: Possible to buy bitcoin at MtGox at $259 and sell for $635 at BitStamp at 18th February 2014?

texts: So would it really be possible to buy bitcoin at MtGox at $259 and sell for $635 at BitStamp at 18th February 2014? Because those are the bitcoin exchange prices at that moment?


texts: Bitcoind randomly stops downloading the blockchain

texts:
I have bitcoind running from a 2 GB CentOS 6 box in order to check balances of addresses. The problem is that it just randomly stops downloading the blockchain sometimes, and I have to use ./bitcoind stop and ./bitcoind to start it back up again.

./bitcoind getinfo gives me:

{
    "version" : 90201,
    "protocolversion" : 70002,
    "walletversion" : 60000,
    "balance" : 0.00000000,
    "blocks" : 213322,
    "timeoffset" : 0,
    "connections" : 14,
    "proxy" : "",
    "difficulty" : 3370181.79927784,
    "testnet" : false,
    "keypoololdest" : 1410016320,
    "keypoolsize" : 101,
    "paytxfee" : 0.00000000,
    "relayfee" : 0.00001000,
    "errors" : ""
}


texts: How to use bitcoin from the command line in Windows?

texts: Do there exist any stable and audited bitcoin wallets that can be used from the cli on Windows? I have looked but have been unable to find any that I can use for automated tasks.


texts:
I am very new to Bitcoin development so forgive me...
I'm using NBitcoin in a .Net console app to generate a master key using a mnemonic and then derive hierarchical keys. Here is the code I am using:
Mnemonic mnemo = new Mnemonic(Wordlist.English, WordCount.Twelve);
ExtKey hdroot = mnemo.DeriveExtKey();
var wif = hdroot.GetWif(Network.Main);
var defaultAddress = hdroot.Derive(new KeyPath("m/0/0"));

Here is the Mnemonic I get as a result, as wells as a public address derived from the master key using the "m/0/0" path:

Mnemonic: dry brown drive parade drastic shine embrace hard report loan fold iron
Path: m/0/0/: 1GcchMaHAN1XRQsoi8gPg8TShqzN4sNGvu

I tested recreating my keys using the mnemonic and was always able to derive the same exact keys as expected within my console app.
Being curious I wanted to see if I could import this mnemonic into existing wallet software and get the same keys as well. Since the Exodus wallet uses a standard twelve word mnemonic I fired it up and generated my wallet using the same mnemonic. However none of the keys match up! I exported my public key and made sure it was the same path of "m/0/0" from the master. As you can see it is NOT a match:
Exported public key from Exodus using the same mnemonic:

Mnemonic: dry brown drive parade drastic shine embrace hard report loan fold iron
Address: 1DMDJ266gxMCJiTcWk5MZFbfxxx4Ss3URN
Path: m/0/0

I also tested the mnemonic on Jaxx as well as the the Coinomi wallet on Android and it derived the same keys as Exodus does.
So I am completly confused. The only thing I can think of is that there is a standard entropy that these wallets use that is missing from my implementation?
My question is, how can I use NBitcoin to create the same mnemonic standrad that wallets like Exodus, Coinomi and Jaxx use?


texts: Compressed or uncompressed for brainwallet?

texts:
When creating a brain wallet, should I choose the compressed or uncompressed version? Why?
What happens if I choose the uncompressed version (which is what the official client uses, right?), and someone sends coins to the compressed address? Will I see the coins? Would I be able to spend them if I saw them sitting in the other address?
Will I have to remember which option I chose, or the pass phrase is enough? Will other options keep popping up? (eg: super compressed)


texts: Where can i find instructions on how to install a NXT wallet app on my Ubuntu server so I can access it via the web?

texts: I want to install a NXT wallet client/server on my ubuntu server so i can access it from my website. Where can i find instructions for this? And is there a way to change the port # for nxt? currently it 7876.


texts: What are the parts of a Bitcoin Transaction "Input" script?

texts:
All the terminologies I find seem rather confusing about what explains what and they usually miss a few steps.

Example: Transaction 82d62d5f4e69ae8338c39b7ae2e1d33db59bdf62c869ded7344adc936bab8653

Found at https://blockchain.info/tx/82d62d5f4e69ae8338c39b7ae2e1d33db59bdf62c869ded7344adc936bab8653

Shows an "Input Script" of:

3045022100d52330113ccd033ccb1aaa3b759e9696c216e802922e5f1902cd5ada69c612e5022057880205319dccb05eebbe34323a852ee82653f09f81253ddccd08a810e9d42d01
03e5b9f0bb669b289efb8d2826487a24ef5f3985624c8bc3a3e34f6bd54e080b27

So, what parts of that are what, and how can I tell which parts are what in this transaction's "input script" as well as others?


texts: Is it possible to add a proxy to an Antmner S3? I want to place the Antminer at work, but there is a proxy I have to go through. I can see where to put the DNS information, but not where to put a proxy name. Any help would be great.


texts: Do I have to pay tax if I buy bitcoins with my USD?

texts:
Theoretical question:

If I make $1000, which gets deposited into my bank account, and then I deposit that $1000 into a bitcoin wallet the next day, and just sit on it for one tax year, do I have to pay income tax on that $1000? Can the gov't track me down and get me to pay tax?

Thanks.


texts: Bitcoin Core Wallet - Invalid Transaction

texts:
A few months ago I tried to transfer my bitcoin but the transaction fee was too low which resulted in an Invalid Transaction. After eading about similar problems in this forum it is clear to me that the bitcoins are not lost but I need to convince my wallet to "ignore" the transaction. How can I do it with Bitcoin Core Wallet?
Thanks for a hint! Jozef


texts: Bitcoin inflation in 9/12 doesn't seem to have been corrected. Why not and will it be fixed?

texts:
I'm looking at the Total Bitcoins in Circulation graph and don't understand why there is a spike of coins being generated in Sept '12.  What caused this to happen?

Also, since there is a fixed number of Bitcoins that will be created, then I would expect this deviation would be corrected and fall in-line with the previous rate of growth.  It doesn't appear that a correction has occurred.  Which of the following will happen:

The final end date of new bitcoin mining will be earlier than planned
At some arbitrary date in the future there will be fewer Bitcoin being mined

Sure, the longer we wait the impact of that occurrence of inflation on 9/12 will decrease over time, but what happens the next time a Bitcoin mining spike occurs?


texts: I was using Ninki as my wallet, however, the service got discontinued therefore I cant access it how would I go to recover my bitcoin or is it completely lost? Please help id really appreciate it


texts: When running a bitcoin node on an enterprise level: a lot of addresses will be generated with getaddress RPC for users to send their funds to. As far as I understand, these addresses, as well as the private keys for them, are all stored somewhere in the datadir. The whole key tree, as well as the seed key, can be dumped through rpc. Are there any rules of thumb to secure these keys from being dumped by unauthorized people? Are there any scalability problems with having too many keys stored in bitcoin core? Any other rules according to private keys and business set up?


texts: What is the benefit of upgrading the wallet file?

texts:
bitcoind -help

displays

-upgradewallet         Upgrade wallet to latest format

I have noticed that my wallet format is a few behind bitcoind's version number. Does this mean it is an old format? If so, why should I upgrade it?


texts:
I know that HODL means you hold your crypto for the long run, whether the price goes up or down, but where does the term come from?

I have heard people say it means "Hold On for Dear Life" and other that it was a typo.


texts: problem when start using cpuminer / cudaminer

texts:
I got this in the CMD :

cgminer.exe is not recognized as an internal or external command, operable program or batch file

I have downloaded cpuminer and cudaminer to mine LTC with my labtop (core i7, Nvidia GT 525 M)

using www.wemineltc.com  pool

but when I double click the .bat  file (cmd flash for a sec)  then nothing happen

can someone  help me please ?

i  have used this tutorial : https://teksyndicate.com/forum/litecoin/guide-mining-nvidia-now-guide-mining-feathercoin/137688


texts:
I sent two transactions to the same place. I think they both show in blockchain, but they aren't at the intended address. After 48 hours, I got concerned and changed from Electrum to Bitcoin-Qt, sending my remaining coins to Bitcoin-Qt. That doesn't show in the blockchain as far as I can see. I included the default transaction fee each time.

After about a week, I'm still in the same state. I'll add transaction ID's when I get back to my mac. More info to follow. I checked answers to other questions but couldn't find a resolve or anything that seemed to fit my attempted exchanges.


texts:
I am relatively new to cryptocurrencies and would like your feedback on how to safely generate paper wallets for BTC, ETH, LTC and XMR tokens. I intended to follow these steps:

Download and install Tails on a USB flash drive using the Tor
browser.
Boot Tails (without activating any persistent volume) and
download an offline copy of the following paper wallet generators:
BTC, ETH, LTC and XMR.
Disable any internet connection.
Generate the adresses and private keys using the paper walletsg enerators.
Hand write each of these adresses and private keys on a paper.
As a digital backup, save pdf files containing the adresses and private
keys on a new USB flash drive.
Restart the computer in order to clear any trace of the private keys from the Tails USB flash drive.

Also, is there a safe way to verify that the recently generated private keys and adresses work properly (i.e. no bugs/mistyping)?

Please let me know if you spot a flaw or if you have any advice. Thank you for your inputs!


texts: What does this elaborate output script mean?

texts:
Bitcoin transaction a214a2daf91691afdd491fd00d894eb3301e35bc18b5554b14e12843037e954c has an interesting output script:

  PUSHDATA(33)[02085c6600657566acc2d6382a47bc3f324008d2aa10940dd7705a48aa2a5a5e33] CHECKSIG SWAP PUSHDATA(33)[03f5d0fb955f95dd6be6115ce85661db412ec6a08abcbfce7da0ba8297c6cc0ec4] CHECKSIG SWAP 3 PICK SHA256 PUSHDATA(32)[d68df9e32a147cffa36193c6f7c43a1c8c69cda530e1c6db354bfabdcfefaf3c] EQUAL 3 PICK SHA256 PUSHDATA(32)[f531f3041d3136701ea09067c53e7159c8f9b2746a56c3d82966c54bbc553226] EQUAL BOOLAND 4 PICK SIZE NIP PUSHDATA(1)[20] PUSHDATA(1)[22] WITHIN BOOLAND 3 PICK SIZE NIP PUSHDATA(1)[20] PUSHDATA(1)[22] WITHIN BOOLAND IF 3 PICK SIZE NIP 3 PICK SIZE NIP EQUAL PICK ELSE BOOLAND ENDIF

I'm very curious what this means. It is not a standard transaction type and therefore it does not have an address.

This output is redeemed using two signatures:

  ScriptSig: 0[] 0[] PUSHDATA(72)[30450221009a29101094b283ae62a6fed68603c554ca3a624b9a78d83e8065edcf97ae231b02202cbed6e796ee6f4caf30edef8f5597a08a6be265d6601ad92283990b55c038fa01] PUSHDATA(71)[3044022045d08719828fbd93e49c9223e63f4d2dab2de6c568e1faa2cccb33adf2575d2c02200c00126cb0105275040a963d91e45460147e40451b590485cf438606d3c784cf01]

What does this output script mean?


texts: Can some one explain how the block validation is done in blockchain based system with suitable example.


texts:
Bitcoins are spent via transaction scripts that can be quite complicated. How do miners understand what a transaction does?

A miner has to decide whether to include a transaction in their block, but this could be quite a difficult decision, because scripts can be complicated. How could you even know, for example, that a transaction has a fee in it, without decoding the transaction? A person could create a transaction with a big fee, but it could be hard to determine that due to the script complexity.


texts:
Has the fundamental problem in cryptovoting, one person, one vote, in a completely decentralized or blockchain centric manner been solved?

In other words, how can votes be allocated in a decentralized manner?

The intent of this question presupposes that vote allocation is not delivered by a state, that a blockchain itself can at the very least implement a completely basic, pure democracy: truly one person, one vote.

How can this intent be implemented?


texts: I installed a bitcoin-qt  and received a transaction. Few minutes later, the pc crashed,after restoration of the pc,I only saw  an automatic saved wallet.dat file  I tried to recover fund but no avail. Please help me to restore my fund


texts: Why is target stored in the block at all?

texts:
Currently, target is stored in each block. Why is that? Why it is not simply computed by each client based on the previous timestamps from previous blocks? Why it has to be stored within the block?

In other words, doesn't allowing miner to choose the target remove that it is exponentially harder to create a new block? Other miners might have to mine 256 consequent blocks, but I have only to be lucky once and get one block with 8 more zeroes to replace those 256 blocks. While it is less probable, it grows linearly (256x less probable) and not exponentially.


texts: Sending coins when the priv/public keys are not in wallet (bitcoind)

texts: I've created the hex for a raw transaction but do not have the wallet priv/keys in the wallet. Can I still send the transaction using sendrawtransaction? I've checked the message using signrawtransaction and this returns complete.


texts: Malicious full nodes causing denial of service attacks

texts: To control >51% of the mining power in bitcoin is impractical due to the immense investment that will be required. Also, The Bitcoin Core client has DoS protection against malicious nodes forwarding a flood of transactions. But what would happen if an attacker who has placed several full nodes across the world, does not forward the transactions to the other honest nodes? There are over 10K full nodes on the bitcoin network. An attacker can place 10x the amount of these nodes spread very efficiently in terms of geographic dispersion so that they are one of the first to see the transactions broadcasted. In order to prevent the malicious node from getting dropped by the honest node, it can relay transaction once in a while so as to keep the connection active. Given, that there are 10x more malicious nodes than honest ones, it might highly likely be the case that miners do not see the broadcasted transactions and they do not include them in the block. Has any research been done to prevent such scenario?


texts: Probability that a block will be confirmed in x minutes

texts:
I know that a block usually takes 10 minutes on average to get confirmed. But what is the probability that this will happen?

I mean is there any formula that we can use to calculate the probability that a block will be confirmed in the bitcoin network within x minutes? (assuming that the resources are fixed in the whole network)


texts: What is the User Activated Softfork (UASF) proposal? How do its risks compare to hardforks?

texts:
The Bitcoin community is abuzz with discussion about shaolinfry's proposal of a UASF to activate SegWit as an alternative to the Version Bits activation. I've seen frequent and extensive discussion of the proposal and especially questions about the risks and advantages of it compared to other methods of softfork activation and hardforks.

What does the UASF proposal entail?
How do its risks compare to other methods of upgrading the protocol?


texts: Is there a way to a get a list of all address tags from Blockchain.com? (either by scrapping or API)

texts:
I am looking to get the most complete list of address association with entity names.
I am thinking blockchain.com must have a good one but here https://www.blockchain.com/btc/tags?filter=8&offset=500 you can only search by address or name and not get a complete list.
Is there a way to get it?
Does another website give access to a good list?
Thank you


texts: How to get a readable format of curl with a transaction?


texts: How Bitcoin dose find and verify UTXO ? is this efficient?

texts:
If Bitcoin sees all blocks, it will be very slow based on chain length and block size but, it can certainly verify incoming transactions.

I know that blockchain is never modified any previous block. so if user consumes own transaction, Bitcoin dose just create new TXO which is reference to UTXO. so it is two penalty. one is that our disk is quickly filled and lastly it must check all the blocks to see whether TXO(reference to UTXO) is existed or not.

I have a good idea. that is we should mark something in the UTXO. so it gives two good points. one is that we don't need to create TXO to figure out whether UTXO was used or not. and lastly we don't need to fill our disk with TXO.
But my idea has strange point that information of transaction already written on block should be modified.

How think about it? I would like to discuss about my point.

Sorry for my English.


texts: Is transaction malleability the only consensus issue that needs fix to allow lightning network?

texts:
Is transaction malleability the only thing needs fix in the bitcoin consensus code to enable lightning network to be implemented?

Of course, lightning network itself would need to be implemented, but I'm wondering if after fixing transaction malleability, any changes to bitcoin itself is required.

In particular, if BIP 62 is implemented, would that be enough?


texts: What are the chances that a nonce for one block is a nonce for another?

texts: Just to put a cap, let’s say in 1 million blocks, what is the chance that 2 blocks will share the same nonce value? Has it happened before?


texts: In what circumstances would a block appear in the Leveldb .ldb index but have no data in a .dat file?

texts: I've observed this behavior with Bitcoin Core v0.15 while parsing the LevelDB index in .bitcoin/blocks/index. It is also a situation that is obviously accounted for in the Bitcoin Core source code here (See BLOCK_HAVE_DATA and BLOCK_HAVE_UNDO). I am just looking to understand what would cause this to happen? Can a peer receive the block header before receiving the block itself? I'm finding that only the top few blocks in the chain seem to be missing data; They appear in the index but not the .dat files.


texts: Papers/Books on how bitcoin works from a mathematical perspective?

texts: I'm a math student interested in Cryptography. Is there any paper or book which explains, in mathematics and cryptography terms, how bitcoin (more general, a digital cryptocurrency system) works? In my course book there is only about 4 pages on how cryptocurrencies work, but I'm hungry for more.


texts: Is it possible to "break" the traceability of the blockchain by sending ZEC between z-addr and t-addr?


texts: If you have a mobile wallet, do you lose your coins when you lose your phone?

texts:
I'm new to this Bitcoin stuff and discussing it with friends. Somebody said, if you "have bitcoins on your phone" and you lose your phone, you also lose your bitcoins.

Is this true?


texts:
I would like to know if it's possible to change private key of bitcoin wallet via rpc call to bitcoind.

Thank you for your answers


texts: Number of transactions and transaction history don't match in XenCoinQt

texts:
I am solo mining XenCoin using XenCoin QT v0.6.3.3-g069d718-beta.

The number of transactions shown on the overview tab is 9, yet there are 7 transactions listed in the transaction history.

Also, recently I my cgminer 3.7.2 reported that it had found a block. The number of transactions increased on the XenCoinQT overview tab, but the mining reward didn't get credited to my account.

Can anyone explain what's happening? Is someone stealing my coins?

Additionally, is it possible to track all the blocks that are mined by me (solo mining)?


texts:
This is example callback verification code in Ruby (https://developers.coinbase.com/docs/wallet/notifications):

CALLBACK_DIGEST = OpenSSL::Digest.new("SHA256")

def self.verify_callback(body, signature)
  return false unless callback_signing_public_key
  callback_signing_public_key.verify(CALLBACK_DIGEST, signature.unpack("m0")[0], body)
  rescue OpenSSL::PKey::RSAError, ArgumentError
  false
end

def self.callback_signing_public_key
  @@callback_signing_public_key ||= nil
  return @@callback_signing_public_key if @@callback_signing_public_key
  path = File.expand_path(File.join(File.dirname(__FILE__), 'coinbase-callback.pub'))
  @@callback_signing_public_key = OpenSSL::PKey::RSA.new(File.read(path))
end

How can I do this in PHP ?


texts: Developers, programmers new to bitcoin engineering ecosystem

texts:
Any sites, forums dedicated  to developers new to bitcoin.
Any recommended git repo, site that shows how to interact with a node, do .i.e. p2sh,p2pkh on testnet.


texts: Why is it safer to keep your bitcoins offline than online on Coinbase?

texts:
I'm trying to think of a good way to store my bitcoins somewhere but I can't really think of a way to do it without

1) having something physical (eg. USB key) that can get lost or destroyed
2) having some sort of password (that I can forget)

The problems with either of those things is I'm planning on leaving my bitcoins to sit for a long time so by the time I need to sell them, I may not be able to remember all the details.

I was thinking maybe I should just leave my coins on Coinbase. At first that sounds more risky giving my coins for somebody else to manage, especially given what happened to Mt Gox.

However, whilst cryptocurrency is kind of like the wild west, Coinbase is a legitimate company. They're also fully insured so if they do get hacked, it doesn't sound like I would be on the hook for any loss. In addition, accessing the coins requires two factor authentication and furthermore, they have my identification details. So these features protect me against me losing access to my own coins.

So please explain why it is safer to keep my own coins offline where I would have to manage and implement my own security instead of just keeping it on CoinBase where they have professionally implemented security, contingencies for if I lose my credentials and where my coins are fully insured?


texts: How small can a payment be while still adding value to your wallet?

texts:
If you receive 1 satoshi (0.00000001 bitcoin) in a transaction then adding it as an input to a larger transaction would add more than 1 satoshi to the transaction fee. This means the 1 satoshi shows in the total balance for your wallet, but in reality it is not worth anything to you because it would cost more than 1 satoshi to spend. In fact if you need to empty the wallet completely then the 1 satoshi is causing a loss.
So how small can a payment be while still adding value to your wallet?


texts: How can I specify transaction fee size when creating a raw transaction?

texts:
Question: Am I able to specify the transaction size in a raw transaction without having to send "change" back to myself?

I get some unspent bitcoins

listunspent()

I grab the txid, vout, and scriptPubKey for each
Then I get the list of all the addresses and quantities that I want to send to

createrawtransaction(source, destination)

Let's say my total unspent is 1.00000000 BTC, the total I want to send out to all the addresses is 0.50000000, and it'll be about a 3100 byte transfer that I need to pay 0.00040000 fees for.
The way I currently build the destination addresses is to place the address it's coming from (myself) as unspent - tx fees - outgoing, so that would be 0.49600000, the destinations would all be specified, and the fee remains unspecified but deduced by the remainder.

So, this is working for my purposes, but is a little inconvenient. The amount that I'm not sending to anyone sends back to myself and has to be reconfirmed so the funds aren't available until then.

If I had a single unspent address with 100 BTC and needed to send 1 BTC to 15 people, it doesn't seem to make sense to temporarily lock up 85 BTC in the process. If I were to use a client and manually send 1 BTC at a time, the unused funds would remain available, so I feel pretty confident what I'm asking for is possible.
Any assistance would be most appreciated.

NOTE: I'm using bitcoind now.


texts: How does Electrum wallet list my transaction record?

texts:
I'm a beginner of Bitcoin and blockchain. I use Electrum as my BitCoin wallet, and install it on both home PC and office PC.

I can see all transaction records on Electrum wallet of both home PC and office PC.

You know a new receiving address will be generated when I require a new  receiving bitcoin every time. I think that the new receiving address is generated  randomly.

I think that Electrum wallet will not record all receiving address I used.

so I'm very stranger that how Electrum wallet find my transaction records from  blockchain quickly, could you tell me?

A bad way is to calculate all private key based seed, and calculate all public key and my receiving bitcoin address based private key, then find all transaction based all my receiving bitcoin address from blockchain. it's a huge work!


texts: The effects of a 'buy wall' on the market?

texts:
I'm learning a lot about coin markets. Now i'm wondering
What are the effects of a buy wall? or a sell wall? Do they affect the market in any way?
Thanks!


texts: How does block propagation delay not cause accidental forks?

texts:
Block propagation delay, it looks like, is about 122 seconds in some cases. If another block is formed before the first block is completed, wouldn't this accidentally create a fork? How would this fork be resolved? Someone's transactions are bound to get lost.
Example:
Let's start with a block A. Say block B was just completed, and is now being propagated.
If, during that delay, someone made a transaction and a new block C was created before block B reached them, wouldn't their blockchain become forked, with A->C and A->B? How does bitcoin prevent accidental forks like this?


texts:
I am trying to catch up/synchronize the blocks in my blockchain with bitcoin-qt. However, the last block time is stuck for hours at Feb 15 04:29:18 2017 since I started bitcoin-qt the last time.

What is the reason?

The debug.log doesn't show anything supsicios.

When I start bitcoin-qt with -testnet, it does catch up.

Appendix, as per Pieter Wuille's comment, the output of getchaintips is

[
  {
    "height": 473710,
    "hash": "0000000000000000007eaaf0899877f5317cd2a480477bde88d9e0a9b57a93c8",
    "branchlen": 20592,
    "status": "headers-only"
  },
  {
    "height": 473064,
    "hash": "00000000000000000006cdfe729e4aa498a0c03f1e9810fb002e7a36a780f4d1",
    "branchlen": 19946,
    "status": "headers-only"
  },
  {
    "height": 472975,
    "hash": "00000000000000000067a24962827bc94d347066a2acec324625da67a0b10168",
    "branchlen": 19857,
    "status": "headers-only"
  },
  {
    "height": 453118,
    "hash": "000000000000000000e1823cc186c494caaced15c7761844010362e8bd280bd3",
    "branchlen": 0,
    "status": "active"
  },
  {
    "height": 229636,
    "hash": "00000000000000c42b95e4714032ca09b245830b8299d8cf5dda46f75c3755ff",
    "branchlen": 1,
    "status": "valid-fork"
  }
]


texts:
I recently updated my bitcoin docker image to bitcoing v0.18.0 version and can't allow external rpc connections to it now. It binds to localhost if I set rpcallowip=X.X.X.X, then I tried to used rpcbind parameter also, but couldn't set my docker container to allow external rpc connetions.

This is what I get:

bitcoin_1       | 2019-05-23T13:39:34Z Bitcoin Core version v0.18.0 (release build)
bitcoin_1       | 2019-05-23T13:39:34Z Assuming ancestors of block 0000000000000000000f1c54590ee18d15ec70e68c8cd4cfbadb1b4f11697eee have valid signatures.
bitcoin_1       | 2019-05-23T13:39:34Z Setting nMinimumChainWork=0000000000000000000000000000000000000000051dc8b82f450202ecb3d471
bitcoin_1       | 2019-05-23T13:39:34Z Using the 'sse4(1way),sse41(4way),avx2(8way)' SHA256 implementation
bitcoin_1       | 2019-05-23T13:39:34Z Using RdSeed as additional entropy source
bitcoin_1       | 2019-05-23T13:39:34Z Using RdRand as an additional entropy source
bitcoin_1       | 2019-05-23T13:39:34Z Default data directory /root/.bitcoin
bitcoin_1       | 2019-05-23T13:39:34Z Using data directory /home/BTC
bitcoin_1       | 2019-05-23T13:39:34Z Config file: /home/BTC/bitcoin.conf
bitcoin_1       | 2019-05-23T13:39:34Z Using at most 125 automatic connections (1048576 file descriptors available)
bitcoin_1       | 2019-05-23T13:39:34Z Using 16 MiB out of 32/2 requested for signature cache, able to store 524288 elements
bitcoin_1       | 2019-05-23T13:39:34Z Using 16 MiB out of 32/2 requested for script execution cache, able to store 524288 elements
bitcoin_1       | 2019-05-23T13:39:34Z Using 0 threads for script verification
bitcoin_1       | 2019-05-23T13:39:34Z Binding RPC on address X.X.X.X port XXXX failed.
bitcoin_1       | 2019-05-23T13:39:34Z Unable to bind any endpoint for RPC server
bitcoin_1       | 2019-05-23T13:39:34Z Error: Unable to start HTTP server. See debug log for details.
bitcoin_1       | Error: Unable to start HTTP server. See debug log for details.
bitcoin_1       | 2019-05-23T13:39:34Z Shutdown: In progress...
bitcoin_1       | 2019-05-23T13:39:34Z scheduler thread start
bitcoin_1       | 2019-05-23T13:39:34Z scheduler thread interrupt
bitcoin_1       | 2019-05-23T13:39:34Z Shutdown: done

My bitcoin.conf file looks like this:

server=1
rpcbind=X.X.X.X
rpcallowip=0.0.0.0/0
rpcport=XXXX
port=XXXX
rpcuser=user
rpcpassword=password


texts: What is an uninitialized read? Can you point out some examples found in Bitcoin Core? How do you detect them?


texts: Depends: libgcc-s1 (>=3.0) but it is not installable (Bitcoind wallet dependency problem on Debian)

texts:
On Debian I successfully compiled .bitcoind without a wallet, but now I need the wallet.
./configure tells me I need Berkeley CXX headers. Searching for how to do this on Debian brings up a bunch of Ubuntu answers saying to do either
sudo apt-get install libdb4.8-dev libdb4.8++ libdb4.8++-dev

after having added a PPA, or
wget http://download.oracle.com/berkeley-db/db-4.8.30.zip
unzip db-4.8.30.zip
cd db-4.8.30
cd build_unix/
../dist/configure --prefix=/usr/local --enable-cxx
make
make install

Both solutions throw errors. I'm focusing on the 1st solution.
The first solution throws this error:

The following packages have unmet dependencies:
 libdb4.8++ : Depends: libgcc-s1 (>= 3.0) but it is not installable

I'm not sure, but I assume this may be an Ubuntu vs. Debian issue? How can I bypass it?


texts: Bitcoin Core GUI gettransaction implementation

texts:
The cli users have the option to "getrawtransaction txid true" in order to find valuable information about a transaction that could be theirs. This is a very powerful api call that effectively eliminates the need of an electrum server if someone wants to check his tx sent to coldstorage or a mobile wallet.

Do you think there would be any consensus in adding such a feature to the Bitcoin Core GUI? Something like Help -> Verify external txid. This would greatly increase the use of Bitcoin core for the ease of validating a transaction.


texts:
Where can I read the original Bitcoin script for verifying the transactions?
Also, who controls the GitHub profile of bitcoin?
Thanks.


texts: If using Bitcoin core client am I constantly going to be downloading data from the blockchain?

texts:
I understand you have to download the entire blockchain and sync in the beginning but don't you also have to constantly keep the software on if you want to buy/sell stuff, which means more data being downloaded to my personal comp every instant there is a transaction.

If this is true, what is the average amount of data per month being downloaded so that I can use bitcoin.

Also if this is true, why isn't this point highlighted on bitcoin.org, they say you have to initially download the blockchain but not that its constantly going to be downloading data on your comp, data is expensive!


texts:
I am using bitfinex websockets v2 api in a Java application, to get the candles from a market. But I don't get any message back from the socket(not even an error).
I wonder what I am doing wrong. Also I noticed that I can't subscribe to the ticker.

v1 of the api works fine for me I can subscribe to messages with no problem. But in v2, I only get the ping pong to work but I can't subscribe to messages such as ticker or candles.

Let me show you the code that I have, maybe I am forgetting something:

Here I create a client and open a websocket to the new api address:

@SpringBootApplication(scanBasePackages = "application")
public class Application {

    private static Object waitLock = new Object();

    public static void main(String[] args) {
        ApplicationContext applicationContext = SpringApplication.run(Application.class, args);

        WebSocketClient webSocketClient = new WebSocketClient();
        webSocketClient.startWebSocketClient("wss://api.bitfinex.com/ws/2");
    }
}

This is the client that manages the connection to the socket

   public class WebSocketClient {

        final static CountDownLatch messageLatch = new CountDownLatch(1);

        public void startWebSocketClient(String address) {
            try {
                WebSocketContainer container = ContainerProvider.getWebSocketContainer();
                System.out.println("Connecting to " + address);
                container.connectToServer(WebSocketEndpoint.class, URI.create(address));
                messageLatch.await();
            } catch (DeploymentException | InterruptedException | IOException ex) {
                Logger.getLogger(WebSocketClient.class.getName()).log(Level.SEVERE, null, ex);
            }
        }

    }

This is the endpoint that I create to handle the responses

@ClientEndpoint
public class WebSocketEndpoint {

    private Session session;

    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        System.out.println("Connected to endpoint: " + session.getBasicRemote());
        RemoteEndpoint.Async asyncRemote = session.getAsyncRemote();
        asyncRemote.sendText("{event:\"subscribe\",channel:\"candles\",key:\"trade:1m:tBTCUSD\"}");
    }

    @OnMessage
    public void processMessage(String message) {
        System.out.println("Received message: " + message);
    }

    @OnError
    public void processError(Throwable t) {
        t.printStackTrace();
    }

}


texts:
On this website, we can see that the the private key 1 is written in this format.

  5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreAnchuDf

I would like to know what is this format.


texts: Is it possible to trace BTC or cryptocurrencies?

texts: There are input and output addresses in each transaction of cryptocurrency. So everyone can trace the flow back. If someone send me some BTC or other cryptocurrency to my address, and I regenerate a new address in my wallet and send some BTC to other one with the new address. Is it possible to trace it back to the original sender?