texts: How does each miner know when to create a block?

texts:
I have been trying to understand the protocol and reading related documents, there is a point where i get stuck.

As far as i understand (correct me if not), when a transaction occurs, it is broadcast to the network and some miners receive it. When a certain number of transactions is reached, they are packed in a block and hash race begins.

What i fail to understand is; in this scheme, don't all the miners have to be in perfect memory coherence and time sync, so that they know when a block is to be sealed and start to iterate for hashes? Or do they not need to mine and hash the same global block, but have separate blocks which are later validated by other miners and interblock transaction collisions don't matter?

I know i misunderstand a very basic point in the protocol, but i can't figure what.


texts: Where are the Main network magic bytes stored in bitcoin's source code?

texts: Bitcoin uses F9 BE B4 D9 as its main network magic bytes. I've searched the source but cannot find where these values are stored. Presumably they're computed, but I'm not sure where. Can someone tell me where they exist or are computed in the source code? I'm wanting to find this value for other altcoins.


texts: I found evidence Hal Finney was working on Bitcoin (05 Jan 09) before v.0.1 was released (09 Jan 09). Is there any evidence he was involved earlier?

texts:
I found evidence Hal Finney was working on Bitcoin (05 Jan 2009) before v.0.1 was released (09 Jan 2009). Is there any evidence he was involved earlier?
https://web.archive.org/web/20090105145118/http://sourceforge.net/project/memberlist.php?group_id=244765


texts: Blockchain.com wallet was compromised and btc stelon

texts:
I lost some money in a ico scam and googled and found a reclainfund ltd to recover fund. They ask me to  set up a blockchain.com account and then share account wallet id and password so they can transfer stolen fund. I did that. then I transferred 0.51 btc to my account and then changed my password.  now it seems to be hacked and my btc is gone and all transaction history is gone.  The weird thing is the blockchain's account left panel is totally empty now once I login and I can't see any transactions. how could that happen ? I wonder if someone inside blockchain.com is associated with hacker or scammer. that is really some high level scam I have ever see.
my question is in my blockchain.com account, where is the private key that they can steal and copy and it can bypass my changed password ?


texts: How safe is Nicolas Dorier's BCCSpliter?

texts:
I noticed a link to this resource on an article talking about safely splitting your BTC and BCH(/BCC):

https://github.com/NicolasDorier/BCCSpliter

Has anyone reviewed the source code and is it safe to use?  Could someone provide a run-down on how it works?  I read the readme but am hoping for a bit more detail.


texts: Why are existing distributed database technologies not applicable to cryptocurrencies

texts:
Why are existing distribued database technologies such as mongodb not useful for hosting the blockchains of large cryptoapplications, after all they are just distributed key-value stores?

how does something like ethereum nodes actually store data? In some custom database? Why not use existing tech?


texts:
How can merchants be alerted of Double-spending attacks? Let us take a hypothetical case where a merchant offer a BTC deposit wallet to his users, User deposits Bitcoins and it's credited to his account on 6 confirmations. Let's say, theoretically, the attack has been pulled off and he got his bitcoins back + the funds on the wallet remained as the database haven't been updated due to no alerts of any double spend attacks.

Question regarding this scenario:

How can merchant be alerted of any double-spend attacks ?
Procedures to consider in the time of the attack ? e.g Shutting down servers to avoid confusion and recheck balances to avoid dead ends on user withdrawals
How safe is it to run an out of the box Bitcoin Daemon?
Will Bitcoin XT be alerting on any double spend transactions that occurred no matter how the attack succeeded ?
Is it Okay to host a high bandwidth and Intensive website along with a bitcoin daemon?
If a double-spend attack is pulled off, how to manually verify transactions via the bitcoin daemon and how to know how much amount lost ? Will the saved transaction hash can be re-usable to obtain info about the transactions using gettransaction?
How Unlikely is it to pull of an attack to a website that credit users on 6 confirmations?

:::UPDATES:::

I've read most of the answers and seems nobody is able to answer this question:

If a double-spend attack is pulled off, how to manually verify transactions via the bitcoin daemon and how to know how much amount lost ? Will the saved transaction hash can be re-usable to obtain info about the transactions using gettransaction?
Will the attack be able to pull off after 48 hours?


texts:
Back around the small panic during mid April, I tried to sell a large qty of XBT to USD quickly on an exchange. I expected that I would get current USD/XBT quoted on that website times # of XBT in my account. I was very wrong.

Instead, the exchange broke my transaction into several smaller transactions of various sizes, sold some quickly while others took as long as 30 minutes to convert to USD, and none of these sub transactions were converted at the price quoted on the site.

As I understand, that's because every exchange has Buyers and Sellers whose Orders are like virtual post-it notes on a bulletin board announcing their desire to buy or sell A amount of currency at P price, and the exchange just tries to "find good matches".

Is that true? And is it true that every exchange has its own algorithm for doing so and there is no "standard" for how such an algorithm should operate? If so, what info do I have to go on if I want to have a good idea of how much USD I will get for my XBT when I place a Sell order at Exchange X?


texts: How to save the bitcoin core (bitcoin-qt) database for later?

texts:
Say I've received some Bitcoin using the Bitcoin Core wallet on some linux machine. Say I'm done playing for now.

So now I want to free some disk space by deleting the huge database from this machine (and maybe uninstalling the program after backing up wallet.dat?), but I do not want to have to download the whole blockchain again (which took forever the first time), so I want to back it up on some external drive, so I can just copy it back when I want to use Bitcoin Core again (on the same machine or on any other).

What are all the files and directories that I need to copy?
Are there any extra steps needed to be done other than copying the files?
What are the steps to load the saved database to a new installation of Bitcoin Core?

This will help me with my situation, but also, I thought our community could use such a guide posted here. Thanks!


texts: Is there a list of established sites that have started accepting Bitcoin?

texts:
Cross posted to Reddit.

I believe the Trade page mostly has new sites, not a lot of existing ones. To me, any existing, established site that goes Bitcoin is worth more than ten new Bitcoin-accepting sites.


texts:
If I had my BTC in a multibit HD wallet prior to the fork, and I exported my wallet to Electrum after the fork, will the BCH still be tied to the multibit HD wallet?

And if so, how can I access the BCH stored in the multibit HD wallet?


texts: Where can I learn how to build a blockchain from scratch?

texts: I am a newby programmer, I am learning python and objective C and I want to learn how to build a blockchain from the beginning. Are there any resources that could help me.


texts: How can I remove the charity features in my Devcoin clone?

texts:
I'm trying to produce a SHA256 altcoin which is merge mined with Bitcoin.  I'd like to use some recent code, rather than base in on a 0.8.* or earlier codebase.  I've found this source:
https://github.com/sidhujag/bitcoin-0.9.2-Merge-Mining-fork

However, it's based on Devcoin, so it sends some of the mining proceeds to other parties.  I'm finding it very difficult to extract this feature, while keeping the merged mining.  For instance, in the miner.cpp file I've modified the CreateNewBlock function to remove the "Prepare to pay beneficiaries" section, but when I do so the compiled code segfaults.

Thanks to anyone who can help with this.

EDIT:
I've run the node with GDB, this is the error and backtrace:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffd49e4700 (LWP 2385)]
0x000055555562ca50 in CreateNewBlock (scriptPubKeyIn=...)
    at miner.cpp:375
375         pblock->vtx[0].vout[0].nValue = GetBlockValue(pindexPrev->nHeight+1, nFees);

(gdb) backtrace
#0  0x000055555562ca50 in CreateNewBlock (scriptPubKeyIn=...)
    at miner.cpp:375
#1  0x000055555562dc4f in CreateNewBlockWithKey (reservekey=...)
    at miner.cpp:513
#2  0x000055555562de51 in GreedycoinMiner (pwallet=
    0x555556502c70) at miner.cpp:597
#3  0x00007ffff7547a4a in boost::(anonymous namespace)::thread_proxy (param=<optimized out>)
    at libs/thread/src/pthread/thread.cpp:164
#4  0x00007ffff5cc2182 in start_thread (arg=0x7fffd49e4700)
    at pthread_create.c:312
#5  0x00007ffff59ef30d in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111


texts: Bitcoin Core JSONRPC only accept requests with 0.0.0.0 in configs

texts:
I've lunched a Bitcoin Core server, and trying to connect to it via JSON-RPC.
This is my configuration settings:

server=1
rpcuser=admin
rpcpassword=password
rpcport=1234
rpcallowip=94.183.32.151

But all cURL connections to this server via the IP 94.183.32.151 has the same error result as:

cURL error 7: Failed to connect to 94.183.32.151 port 1234: Connection refused

I tried adding this option too, but it did not solve the problem:
rpcbind:94.183.32.151

Only when I put 0.0.0.0 as a bined RPC IP, Bitcoin core returns true response. I've checked many pages but did not find any other appropriate way to allow some certain IPs to Bitcoind. May you help me please?

Note: IP, Port number, username and password are changed from real values.


texts: How many zeroes does the current target have?

texts:
I'm trying to get my head around the difficulty setting of Bitcoin.
How can I calculate how many zeros the target string needs to start with?


texts: How do exchanges and atms introduce bitcoin

texts:
As far as I know, Bitcoin is "mined", introduced into the system as part of the protocol, a reward to the miners for verifying everyone's transactions and keeping the network up.

But how do exchanges and ATMs introduce Bitcoin into the system?

Say I bought $10 worth of Bitcoin from an ATM. ATM takes my cash, I get $10 worth of Bitcoin assigned to the address I provided. Where did that $10 worth of Bitcoin come from? Surely it wasn't "mined on the spot". Is there a protocol for such transactions? Does the ATM/Exchange have "spare Bitcoins" that they just assign to the buyer? If so, how did they obtain those coins in the first place? They must have traded it with something too.


texts: Transaction shows transferred instead of sent and zero bitcoins sent to zero recipient

texts:
I sent 0.00185 BTC to this bitcoin address 14UdCugXpW3ukYgGPNM18v3VqVxyp3S3Ak using blockchain.info wallet,
But transaction log shows 0.0 BTC transferred to zero recipient with transaction fee boldly written.

The transaction has been confirmed in blockchain but the recipient address is not showing on the transaction log and blockchain.

Don't know if the recipient have seen the bitcoin.
Please help.

TX ID :
https://blockchain.info/tx/6e4c6f24326f922201f90874663d609bf787639f13c8ca9378dd09183b09dc11


texts: How to prevent lightening network spend two times the balance?

texts: If I choose off-blockchain transaction in Lightning network is it any mechanism to check wether balance covers mount of transaction? So is it, or isn't it possible spend two times the same amount of balance?


texts: How do nodes verify Bitcoin Transactions?

texts:
I am trying to understand the role played by various nodes in the Bitcoin Network in verifying the transactions that are taking place in real time. I think that I understand the process of Transaction (using Input and Output Scripts) and how the Transaction is formed. However I am trying to correlate it with how a Transaction is Broadcasted to other nodes and then verified?

Consider an example:

if A wants to send some BTC to B, then 2 things will occur:

(a) A will form the input script of the new transaction. It will reference the output script of a previous transaction where A received some BTC (in the past). It will prove the ownership of those BTC by using its Public Key and verifying the Signature.

(b) The output script for the new transaction will be formed by A's client. It will store the hash of the BTC Address of B and enable it to spend these BTC in future.

Now, my questions are:

All these actions are performed by the Bitcoin Client of A and it does not require any interaction with the Peer to Peer Network. It has its own local copy of the Block Chain which it can use to perform the step a. So, isn't the transaction verified by the bitcoin client of A?
I am guessing that this new transaction that was created (input and output scripts formed as described above) will be broadcasted to the entire Bitcoin Network. Now, what type of verification is being performed by other nodes on this transaction?

On what basis is a Transaction accepted by the Bitcoin Network and integrated into the Block which is a part of the Block Chain?

Thanks.


texts: Why is it impossible to get a straight answer as to whether Bitcoin is anonymous or not?

texts:
Yesterday, I asked a question which got linked to this answer: Is it true that all the bitcoins in existence are on the blockchain (the ledge), but it just depends on who the owner (address) is?
Judging by that, if I interpret it correctly, there's no way to track people on the Bitcoin blockchain. Okay? So what's with the constant pointing out about how "Bitcoin is a fully open ledger blablabla not anonymous by design bladiblableblablu everyone knows exactly who does business with who forever etc."?
I swear, I've probably asked this and similar questions hundreds of individual times over the years, in chat rooms, on forums, on here, etc. I've watched endless videos and read mile-long articles on the subject, I've thought really long and hard about it, I've implemented a Bitcoin payment system on my own, I've use Bitcoin myself, etc.
I still truly have no idea if Bitcoin is anonymous or not.
The answer seems to be "kinda, but we don't wanna talk about it".
I see companies specializing in trying to determine Bitcoin ownership and who does business with what... Are those just fake? Complete BS? Are people just constantly spreading ill-intentioned FUD about Bitcoin? Is it actually anonymous after all? Is it safe for me to use the same wallet (with unique receive addresses) for my private use as my commercial project and not have them associated with me?
Is it possible to get a straight answer on this once and for all?


texts: I sent btc from my wallet to my web site balance, deposit never showed

texts:
I have had hundreds of confirmations but the funding never made it from my wallet to the balance I was maintaining on a Web site (Alhabay). On blockchain the transaction is listed as "unspent." Where did my funds go? Can I get them back? I've been trying with zero success to get help from Alphabay.

Thank you.


texts: I deposited 300.00 into a bitcoin ATM. 222.00 showed up in my wallet. I sent what was in my wallet to DreamMarket. This transaction has been pending for 4 days. I entered both addresses into BlockChain.....nothing very helpful came from it. Please help.


texts: "At first, anyone could spend anyone's coins"?

texts:
I've been watching this Bitcoin video: https://youtu.be/ZIugzFygviw?t=294
At the linked-to timestamp, he claims that:

Due to bugs, at first, anyone could spend anyone's coins!

I'm not saying that I think he's lying, but was Bitcoin really that buggy initially? That's honestly a bit shocking to hear for me. I did think that Bitcoin was quite solid from the very first v1.0, and has only been "expanded upon" with BIPs ever since. I did not know that such serious bugs existed early on.
Exactly how early are we talking? I had coins in 2009 or 2010. So, back then, anyone could just spend those even though only I had the private keys? And this extremely serious bug was somehow fixed without breaking Bitcoin?


texts: What is better for Bitcoin mining: More stream processors or faster clock?

texts:
I'm trying to understand the relationships between components in a video card and how it impacts Bitcoin mining.

What aspect of a video card is used during mining?

For example, I can find a Radeon 7950 or 7870 card with a price ranging from $100 to $700 with mainly these specs differing.  I haven't found any performance metric that track Bitcoin to the underlying hardware with this in mind.

Any links would be appreciated.


texts:
I created two bitcoind service in my server.
First using default configuration, and second use new configuration.
I am able to stop first bitcoind using bitcoin-cli stop, but the second bitcoind still running. How to safely stop the second bitcoind without forcing to kill it ?


texts: lower bound of block size towards increased speed of propagation

texts:
As far as I know there is an upper bound of a block, which is one megabyte, is there a lower bound?

It was in terms of a race condition that I was considering this.

Imagine you make a double spend and then you try to propagate a block that contains only your second transaction. If so it would be much smaller, ipso facto easier to propagate around the network and get validated by nodes, isn't that right?

Maybe someone in the mean time would find a valid block for one containing many transactions, in which case it would be longer than yours, and maybe other miners would extend that- but maybe not.

Does anyone want to try this out on the testnet with me?


texts: How is crypto being priced at introduction?

texts:
If a crypto currency starts at value $0,0001 and it is $1 today, is it fair to state the growth has been 1,000,000%? Mathematically it is correct, but are all these coins available publicly at the introduction price?

With regular stocks, a price is set at introduction (public offering) and growth is offset against that introductory price. How does this work with crypto?


texts:
I'm trying to get the balance of a specific address in my PHP session, I currently have this:

<?php
  require 'header.php';
  include 'Includes/Bitcoin/easybitcoin.php';
  $bitcoin = new Bitcoin('user', 'password', 'localhost', '8332');
  $wallet = $_SESSION['UserWallet'];
  $balance = $bitcoin->getbalance($wallet);
?>
<!DOCTYPE html>

<meta charset="utf-8">

  Wallet address: <?php print_r($wallet); ?>

  Account balance: ฿<?php print_r($balance); ?>

Where the $_SESSION['UserWallet'] contains the bitcoin address, when I run this it returns an error, how does it work?


texts: Computer broke, how to obtain the private key?

texts:
I tried to install Bitcoin Core on my PC. The synchronization was not completed when my computer crashed. I am unable to restart it.

I had bitcoins in the wallet already. I have the Bitcoin address but I don't have the private key that can make the funds spendable. How can I obtain this private key to move the bitcoins to another wallet without having to repair my computer?


texts: i sent bitcoin from my coinbase account to my bittrex account but i used the Bitcoin cash address on accident

texts:
I have sent bitcoin from my coinbase account to my bittrex account but i have used my bitcoin cash address from bittrex on accident, Where did my money go and is there a way i could access it thru chain block and if so how can i do that? Please help me out with this i'm fairly new to this and don't know what to do, How can i get my money back?

Thank you in advance


texts: XPT (x.pushthrough) is used by some mining pools (e.g. ypool.net, primecoin). I have googled but could not find any reference to the details of this protocol. What is the protocol to be able to write a basic client?


texts: How to generate Ed25519 public key from private key using libsodium?

texts:
Not all crypto currencies are using secp256k1 technology for keypair generation and digital signatures. Curve25519 technology (frequently used to support ECDH key exchanges) is being used by a few other cryptocurrencies. Ed25519 cryptography (meant to support EdDSA functionality) and Curve25519 cryptography are closely related through transformations and the trend is to start with Ed25519 keys and transform them to Curve25519 key pairs.

Been using this reference as a source of eight ED25519_SECRET_KEYS and corresponding ED25519_PUBLIC_KEYS to use as test vectors for applying Ed25519 package implementations.

Got floodyberry/ed25519-donna to function as expected. However, I could not compute the ED25519_CURVE25519_PUBLIC_KEYS from the reference using ed25519-donna using its curved25519_scalarmult_basepoint() function to match. This pushed me towards trying jedisct1/libsodium. Got crypto_scalarmult_base() function results from libsodium to match those from ed25519-donna:-)

However, it is unclear how jedisct1/libsodium can be applied to generate public Ed25519 keys only from secret Ed25519 keys that are natively in an ASCII hexadecimal format:-( It seems that jedisct1/libsodium requires keys to always be generated from it native keypair generation process, opposed to an externally supplied private key.

Used the sodium_hex2bin() to stuff an ASCII hex encoded private key from the reference into the 64 unsigned char ed25519_skpk variable:

sodium_hex2bin( ed25519_skpk, 32, ED25519_SECRET_KEYS[ii], 64, NULL, NULL, NULL );

Results from the following libsodium function were as expected:

crypto_scalarmult_base( curve25519_pk, ed25519_skpk )

Was a bit frustrated when I discovered that crypto_sign_ed25519_sk_to_pk() was coded to extract the public key from ed25519_skpk that was never initialized.

crypto_sign_ed25519_sk_to_pk( ed25519_pk, ed25519_skpk );

Becoming a bit disappointed not locating a libsodium function to compute the ed25519_pk key when ed25519_skpk is loaded with a working private key from an external source. Any assistance will be greatly appreciated.


texts: Getting individual block by height from Bitcoin P2P network

texts:
Is it possible to request an individual block from the bitcoin network, using the block height as parameter? Or would one have to start a node and wait until all blocks up to the desired height have been retrieved?

I'd like to be able to retrieve the actual, raw, serialized data, but e.g. blockchain.info, even when saying format=raw doesn't give you the raw block data.

N.B. If I understand bitcoin correctly though, I fear that if I don't build up a node by myself, starting from block 0, I can never be sure what I'm getting is true data from the bitcoin blockchain, no matter if I get it from blockchain.info (which could be compromised) or from a p2p peer, which is just one (potentially malicious) peer.


texts: How to read blockchain.info transactions in the blockchain?

texts:
so i'm learning about bitcoin, and i've purchased overpriced bitcoin for 1USD.
the flow was as follow:

i've created an account in https://localbitcoins.com and contacted a seller.
the seller sent me 0.0007 BTC to that account, the site switches addresses as i understand to keep it secured - this is the address that i have there 1DZPyyLMcu1jKaEJ5fskeEpsMbjY49L9JL
i've created a paper wallet and transferred the funds there: https://blockchain.info/address/12Egs85EKjDpDLLRigbszSR9TnyGRKqhnD

my questions are:

i do see the 0.0007 transaction, but why is the previous transaction it's linked to is ~69BTC? shouldnt it be linked to a signle 0.0007 transaction from the old wallet?
why can't i see any transaction at https://blockchain.info/address/1DZPyyLMcu1jKaEJ5fskeEpsMbjY49L9JL ? as i think i've transferred the localbitcoins from there.

so, i'm quite confused, how do i read the history, starting from the last transaction (12Eg...)?


texts: In this transaction, some bitcoins are sent to bc1qp6k6tux6g3gr3sxw94g9tx4l0cjtu2pt65r6xp which appears to not be a valid bitcoin address. What is bc1qp6k6tux6g3gr3sxw94g9tx4l0cjtu2pt65r6xp  ?


texts: Anyone know of an API I can get historical price time series for multiple coins

texts:
I'd like to build some historical price charts, to use in my cryptocoin portfolio tracking app, using time series data (with HighCharts js).

Anyone know of an API that provides this price data, preferably for multiple coins (btc, ltc, eth, etc)?


texts: If pruning is so safe, why aren't 100% of the Bitcoin nodes pruning? Why keep the unnecessary data?

texts:
I have a fully synced, non-pruned Bitcoin Core on this computer.
I have an almost-fully synced, pruned Bitcoin Core on another computer.
What exactly is the motivation for keeping those 368.5 GB of "unnecessary" data? Aren't those old transactions "accounted for" with the "data bundling" that goes on with pruned wallets? Are pruned wallets/nodes less secure somehow? Why is it necessary for any node to keep all this data if it's not actually necessary once it's been "accounted for"?


texts: Correct Citation Format for a Bitcoin Transaction

texts:
When writing an academic style paper where specific bitcoin transactions are used as examples, is there a standard format to "cite" a bitcoin transaction?

If not, what do you think an appropriate format would be?  What data should be included?  What about altcoin chains, what would be different for those chains?


texts: Can I restore a blockchain.info wallet into a electrum wallet?

texts:
If I have a blockchain.info wallet, I got the 12 words. Can I use these 12 words to restore into a new Electrum wallet?

After that, will the blockchain wallet still operational? Say, can it still receive funds or spend fund? If fund is received/spent, will it appear in the new Electrum wallet?

On the other hand, if I send fund / receive fund in the new Electrum wallet, will those transaction appear in the blockchain.info wallet?


texts: Why do Anchor Outputs need to enforce an nSequence of 1?

texts:
Quote from https://bitcoinops.org/en/topics/anchor-outputs:

As of this writing, the most recent versions of the design add two outputs to the commitment transaction—one for each LN party—and require all other outputs in the commitment transaction to have their scripts encumbered by a 1 OP_CHECKSEQUENCEVERIFY (CSV) condition that prevents them from being spent for at least one block.

As far as I understand https://github.com/lightningnetwork/lightning-rfc/blob/master/03-transactions.md#offered-htlc-outputs , the addition of  1 OP_CHECKSEQUENCEVERIFY (CSV) is the only thing that changes within the output scripts of the Bitcoin transactions used by the Lightning protocol.
But why is this necessary? Why can't we just use CPFP without that relative delay of 1 block?


texts: Does Ethereum support the features necessary to create the Lightning Network?

texts:
The Lightning Network of micropayment channels is a concept first conceived by Joseph Poon and Thaddeus Dryja. It requires a few features of bitcoin that are not available yet.

OP_CHECKLOCKTIMEVERIFY - to make scriptPubKeys which cannot be spent until some predefined time.
OP_CHECKSEQUENCEVERIFY - to make scriptPubKeys which cannot be spent until some set time after the original transaction. (Also called OP_RELATIVECHECKLOCKTIMEVERIFY)
Segregated Witness - Referencing which output you are spending by (TXID, n) should not reference the malleable signatures of the transaction with the output.

Does Ethereum support these, or equivalent, features?


texts: How to accept bitcoin and giving each user a unique address amd automatic withdrawal

texts:
I want to create a website when users on singing up will get a unique address and after getting my websites service,they can withdrawal the money also automatically.
Is that bitcoin integration free ? Plz help i am noobie to this.


texts: How do I see my wallet address? I use MultiBitHD. When I tried to use bitvisitor, it told me to type my wallet address. But, I don't know where it is written on.


texts: Does Bitcoin have a built-in life expectancy?

texts:
I understand that the supply of Bitcoins, by design, will not continue to grow to infinity, but is "capped" at 21,000,000. This amount is not in circulation, however, because there are coins that have yet to be mined. I also understand that the reward for a successful miner is 25 coins, but that the reward will be reduced by a factor of 0.5 at certain points. It seems like the supply of coins will always approach 21,000,000 but never actually get there - a limit. If this is all accurate (please correct me if it isn't), does this imply that the incentives for miners will also be reduced? As time goes on, following this logic, miners should stop working altogether, at which point, new transactions can no longer be added.

Assuming this all plays out, would people simply "roll" into a new blockchain at that time?


texts: Where is the change from the output stored in?

texts:
I'm learning that Bitcoin doesn't have a way to represent the account balance, but it's, rather, a sum of UTXO owned by the users of the private key.  Then where is the change from the output stored?

What I mean is, when the output of a transaction is used as the input of another transaction, it must be spent in its entirety. Sometimes the coin value of the output is higher than what the user wishes to pay. In this case, the client generates a new Bitcoin address, and sends the difference back to this address.

Does the change get stored back in UTXO?


texts:
I’m told that their is a total number of bitcoins that can be mined, 21 million bitcoins I’ve heard. I’ve heard that the more bitcoins that are mined there is a direct increases in the level of difficulty and in resources, required to mine more bitcoins.

I’ve heard many estimates from 10 years to 100 years to mine all 21 million bitcoins.

With the unknown variable of future increases in processing power, how could anyone make a educated guess as to how long it will take?

Additionally, if it is true that Moore’s law will be ending as we currently know it due to limitations in our current manufacturing methods of Processors, then this would lend even more weight to my theory that estimating the time of will take to mine all 21 million bitcoins is a guess, at best.

Please explain if I’m wrong and what I’m failing to understand about this, as I’m pretty new to crypto but eager to learn!

Cheers!


texts: How do I know if an output is unspent when looking through the raw transaction data of a transaction?

texts: When looking through the data represented in JSON, how do I know if a particular output has been spent as input in another transaction?


texts: How to access bitcoins with my private key but no passphrase?

texts:
I  utilized a website, bitcoinpaperwallet.com, to randomly generate a Private and Public key pair for Bitcoins storage.

This new Public address is now available for anyone to send bitcoins into.
If I want to make transactions with those newly acquired bitcoins I have to open my bitcoin wallet (it my case it would be bitcoin-qt) and introduce this new private key from the console window to be able to access the funds.
Instructions for such operation apparently is as follow:

importprivkey 5KsomeCaracteresAndNumers765whichIsTheactuaLPrivKey  NameOfKey false

This does not work because the wallet require a PassPhrase. Here is the generated error:

Please enter the wallet passphrase with walletpassphrase first. (code -13)

bitcoinpaperwallet.com  did not issue any PassPhrase for my private-public key.

THE QUESTION:
How do I enter my private key into bitcoin-qt to get access to the funds ?


texts:
Currently there isn't a graph of the ripple trade values.

I'd like to know if each trade is recorded in the Ripple's equivalent of the blockchain, so that if in future someone wants to build such graph, it will be able to include old data instead of just newer one.


texts: What is the cheapest way to pull the data from bitcoind/bitcoin-core?

texts: I am wondering if there is a cheap way to scrape the bitcoind data. I am using a remote server and cannot spend too much time running this program otherwise it would be expensive. I am wondering if there is a way to speed up the RPC scraping (meaning a setting like dbache which could DRASTICALLY speed things up) which I wrote a python script or another way to do this. Any thoughts?


texts: How to solo-mine bitcoins with bfgminer?

texts:
I'm completely new to Bitcoin, so my understanding of mining is still improving.
I downloaded BFGMiner, and now I would like to perform some solo mining.
(I would rather have it use my GPU, but if a CPU is noticeably easier than I'll go that route first.)
How can I use BFGMiner to perform solo mining?

What arguments do I give to bfgminer on the command line?

What information do I need, aside from my BitCoin wallet address?

What other program(s), if any, do I need?

Again, I know very little about mining at this point, so please assume no prior knowledge -- all I know is basically my wallet address. :)


texts: Why can't I spend my reserve XRP and delete my address from the network?

texts:
I understand the Ripple reserve system. You need some XRP in order for you to preserve your account into the Ripple network and additional XRP to assign trust line to your account. I also understand that you cannot spend this reserve because otherwise your account will be removed from the network and forgotten.

However, what if I want to recover the XRP from an account because I don't need the account anymore? Shouldn't it be possible to spend the reserve XRP on your own risk?


texts: What am I doing wrong with my BitcoinXT test net setup?

texts:
I installed bitcoind and bitcoin-cli, set the configuration file so that I am using test-net and requested funds from TP's TestNet Faucet. The funds never appeared in my account.

I thought at first that it was a matter of syncing the blockchain.  I waited several days, and my block count remains at least 400 blocks behind the most current block displayed on this blockchain (testnet) viewer.  The network traffic displayed in my system monitor makes it clear that no new blocks are being downloaded to bridge the 400 block gap that exists between my block height and the block height displayed on the public testnet blockchain; blocks are being downloaded once every 10 minutes allowing my system to at least keep pace with the network with a constant gap.

It took several more days for me to get to a block height that includes the faucet transaction described in the first paragraph, but even after my block height exceeded the needed block number in which the transaction occured, my account balances remained at zero.

I display a screen shot below that includes the confirmed transaction as viewed on the publicly visible blockchain (testnet), and the terminal window that shows the results of my "getinfo", "getaccountaddress", and "getblockcount" commands.  There are 12 peers, which are a mixture of inbound and outbound connections, none-of-which were manually entered, all of which were automatically discovered through P2P discovery.

Thinking there was something wrong with the faucet, I installed the Mycelium Testnet Wallet on my phone and made a faucet withdrawal to that new account.  That faucet transaction appeared in my phone immediately with 0 confirmations and has since been fully confirmed.

Given all the above, I am thinking that my "failed" testnet connection with 12 peers is somehow on a separate testnet that uses a different blockchain than the one that is used by the faucet.  It is my understanding of BitcoinXT that it should be fully compatible with the Bitcoin testnet in the same way that BitcoinXT is designed to be fully compatible with the real Bitcoin network, unless in test-net that condition has been met which causes the networks to diverge and separate.

If this is the case, is there a separate BitcoinXT faucet that can be used?

Or, have I set up my system incorrectly, perhaps?

The graphic of the browser window below shows the successful and confirmed faucet transaction visible in block number 68146. It also shows that the block is in the testnet. The terminal window inside that graphic shows that my server is running on testnet and that my blockchain includes the block numbered 68146, which should have included the transaction depicted, but does not.  As confirmation that the account is right, I display the account address in the terminal, and it is the same address that displays as the recipient of the testnet transaction appearing in the browser window.


texts: How can I delete an address (private key) in the list of received Bitcoins?

texts:
For every transaction I wanted to get, I was creating a new address, but soon I realized that there is just no way to delete all these addresses from the UI.

To make it clear, here is a picture:

I am using Bitcoin-Qt

Is there an easy way to delete all these addresses?


texts: Can one set how many confirmations MultiBit requires for a transaction to be accepted?

texts:
Is there any way for users to specify the number of confirmations for a transaction?
If not, how many confirmations does Multibit require to complete a transaction?
And does the required default number of confirmations vary by size of the transaction?


texts:
I know I can add recipients to a transaction on bitcoin-qt and I am looking for a similar way to do it on bitcoind CLI on linux and in bash script.

I tried using createrawtransaction and multi-sig but with no avail, I'm probably missing something, can someone enlighten me?


texts: Serialized transaction bigger than the actual transaction object? CVE-2013-4627

texts:
I'm surveying old Bitcoin DoS vectors and came across CVE-2013-4267, for which there appears to be little public information available. This thread should shed some light on this CVE.

There's a description in this blog post:

  Transactions are also first deserialized in order to be parsed, but they are stored “as is” in a temporary cache called MapRelay, and forwarded without being serialized again. I really don’t know why this is done. But the point is that the storage of messages as they are received leads to the possibility that an attacker creates messages much bigger than the actual transaction object contained, which, when stored in MapRelay memory, can be used to exhaust the memory of a node.

There is also this relevant thread which appears to say the network was under attack using this vector.

Based on the transaction serialization and deserialization code in ~v0.8.2, it looks like the attack may have been: add large amount of random data at the end of a valid serialized transaction. The deserializer finds what it looks for (the valid blob prefix), but appears to ignore what comes after. If a serialized transaction with random data at the end of the transaction is sent to the victim node, it will be deserialized, passed to the mem-pool and then placed in mapRelay in its full size (and then possibly forwarded further, which seems like a pretty powerful attack vector).

So: was the attack described by CVE-2013-4267 based on adding random data at the end of (valid) serialized transaction data?


texts: If my service only accepts Bitcoin, will there be a lot of missed customers who only have non-Bitcoin crypto currencies?

texts:
I'm about to release a service which only takes payments in Bitcoin.
I'm wondering if this will impact me negatively in terms of not getting business from people who own other crypto currencies.
I don't reject the others out of ideological reasons, but for practical ones:

My hard disks are already overflowing from the 335.8 GB Bitcoin blockchain.
I barely trust Bitcoin Core to run on my computer -- I don't trust non-Bitcoin clients whatsoever.
Even if I did have the storage space and the trust, I would have to learn the respective RPC APIs (assuming they exist) for each "altcoin" as well. It took me a very long time to grasp the Bitcoin Core API.
Any kind of reliance on a third-party service is unthinkable due to KYC/AML BS, as well as the obvious risk with getting my money stolen if somebody else "holds them for me".

Is there any way around this? Is there some kind of mega-trusted "multi-coin" client which doesn't need to download the entire blockchains, yet is able to securely and locally handle multiple of the biggest altcoins, so that I could support those for payments?
Or would anyone who has altcoins also have Bitcoin? I get the feeling that they are very, very few, but perhaps they are also more likely to spend their coins compared to the stubborn "HOLDers" of the increasingly valuable Bitcoin?
I know myself that I'm very unwilling to part from any of my Bitcoin, especially as the price is increasing... It's just a fact for me, but I can't speak for others. I don't have any other crypto currencies myself, and the times I've looked into them, I've just been put off by their software. (In the cases where software even exists!)
Advice?


texts: In bitcoin core, how to avoid the dust exception?

texts:
When I try to broadcast a transaction, my bitcoin core throw a "dust" exception.

amount: 0.00029
fee: 0.00001
bitcoin core version: v0.16.0

The same transaction can success in testnet, but fail in mainnet.

When I send 0.0003 BTC to an account in my bitcoin core, it can success. So, I think send 0.00029 BTC out of the node is still possible.

I set the fee to such a small number to lower the transaction cost, since there will be many transactions like this one. If this fee will not work, then what is the lowest fee?

I try to set the option "discardfee", but didn't make anything change.

Any advice is helpful, thanks in advance.


texts: How is the construction of atomic swaps improved by Schnorr?

texts: How does the availability of Schnorr signatures improve the ability to perform cross-chain atomic swaps?


texts: what relation is between transaction size or a number of input and validation cost? for example, It's o(n) or o(n^2)?


texts: After I have bought a crypto currency at an exchange like Binance can I sell for dollars if it is going down. Basically if I have a profit from a currency what can I do with it to protect it?


texts: Backtesting mtgox for historical trade analysis?

texts:
I want to test out a few trading ideas for bitcoin. It seems to work on a small time horizon, and I'd like to backtest the past year or so of MtGox data. Is there a service that provides this? If not, is there a place I can buy the historical data dump?

Update

It looks like there are several projects around getting mtgox historical data out.

Nitrous' MtGox Trades Tool: This one seems to be the most useful to my needs. You get a dump, and can manipulate the data to create candles for backtesting. https://bitbucket.org/nitrous/bq

If you are more into Quantopian, there is a way to use weighted daily pricing data already imported: https://www.quantopian.com/posts/anyway-to-import-bitcoin-data


texts: Risk of a certain machines being compromized

texts: Is it possible for a sinister entity to peek into the p2p network of bitcoin and manipulate it in such a way so as to compromise a certain transaction?


texts: A couple of days ago I installed bitcoin-qc and loaded the latest block from eu1.bitcoincharts.com/blockchain/. Then to test it out I withdrew a small amount of BTCs from my mtgo account to the address that appeared in the client upon install. Not having received anything yet, I today went to blockexplorer.com and search for that address. The record shows "First seen?: Block 164269 (2012-01-28 19:37:08)" and "Received transactions: 1", but also says "Public key?: Unknown (not seen yet)". The client says today, "Catching up... Downloaded 164146 blocks of transaction history. Last received block was generated 2 days ago". Do I have to send a public key separately? If so, how do I do it? Thanks for taking the time for a beginner.


texts:
I am building an altcoin using the litecoin source code.

I have removed all of the Emplace Seed calls in chainparams.cpp for DNS seeding, changed my default node communication port to port 421 and commented out all of the baked in seed nodes from chainparamsseeds.h, even added the dnsseed=0 and seed=0 to my config file and deleted my peers.dat before launching the core daemon, yet I still see clients connecting to my VPS for all different kinds of coins and swiftly ending up banned.

What am I missing? I can't find a single reason why these peers are connecting to my VPS.. Though it's not the end of the world because it has latched to my chain and only syncs blocks/headers with my other nodes, it looks very unprofessional. Any help would be appreciated!

Thanks!

Schwifty


texts: Is there a site (or formula) that easily calculates returns using difficulty / hash rate?

texts:
I'm just a novelty miner, looking to be cool and do my part to decentralize. Not looking for a return on my investment.

However if I'm going to spend $100 or so I'd like to calculate how my options will fare. Any sites that have no affiliation to hardware, just calculate returns on current difficulty & a hash rate that I specify?


texts: Why doesn't RBF include restrictions on the outputs?

texts:
Why didn't the RBF specification include additional constraints on the replacing transaction, such as that it would need to contain the same outputs (with at least the original output amounts) as the transaction being replaced? Couldn't this have made it safer to assume that zero-confirmation RBF transactions would eventually settle on-chain?

The one downside I can think of is that every RBF replacement would then need an additional input since the fee increase needs to come from somewhere. Are there any others?


texts: What is EUR to USD conversion rate at bitstamp?

texts:
Bitstamp allows deposits/withdrawals using SEPA (EUR only), but all traidings are done using USD. It is nowhere described what exchange rate is used when doing these deposits/withdrawals.

There are some indications that amount of money lost in conversion may be significant:

The order book only offers bitcoin-dollar trading so conversion fees apply on deposits and withdrawals (the conversion spread can be queried by API). [1]
Bitstamp has an EUR bank account in Slovenia to which I deposited euros, then it converted to USD. Then it converted the EUR deposit to USD but I checked the daily EURUSD forex range and Bitstamp converted my EUR to USD at a rate worse even the worst rate in the 24-hour daily range; I have to say, clever: another small profit source for them. [2]

Does anybody know how big the EUR/USD spread at bitstamp really is? Is it significant?

[1] http://blog.kraken.com/post/97016109057/what-does-it-really-cost-to-buy-and-sell-bitcoins

[2] https://bitcointalk.org/index.php?topic=825459.0


texts: Who first defined/coined The Double-Spending Problem?

texts:
The Double-Spending problem is a variant of the Byzantine Generals Problem which has a nice write up by Lamport, Shostak and Pease. But who first coined/defined the specific Double-Spending problem? Or linked the BGP to the digital currency domain? Does there exist a proper academic write up, defining the problem, that predates bitcoin?

I searched for a bit and can only find write ups after Nakamoto's publication.


texts:
Where are the treestates stored?
In other words, when a JoinSplit transaction is being validated, where is the anchor being checked?
A look at https://github.com/zcash/zcash/blob/master/src/primitives/block.h brings me to conclude that the commitments (i.e., notes) merkle-tree is not stored in the block-header.
Is it in a LevelDB database?
What is the data-structure it uses for storing the mapping of trees roots for blocks?

Any answer with a specific reference to code will be very appreciated.


texts: What would be the second greatest bottleneck in the mining process? after the hash generation of course.

texts:
Lets pretend theres a fantasy world where I can produce an infinite amount of hashes no time at all...

What is the next biggest bottleneck for bitcoin mining?

Is it the bitcoin client? Is the client multi-threaded?
How many requests per second can I send into a bitcoin client for trying hashes?

Or will it be another factor?


texts: Android Bitcoin Wallet freshly installed, two addresses. Why two?

texts:
First off, I am rather new to Bitcoins — will be obvious after I asked my question I guess. I have read some theory about it, like it's a distributed crypto-currency based on the Bit Torrent protocol, but I still have some difficulty putting everything together.

I have freshly installed Android Bitcoin Wallet on my phone, just wanted to start somewhere. I opened the preferences and I see I have two addresses without a label — which I guess I shall define. My first question is : why are there two addresses?

I understand an address is like an SSH private public (EDIT: sorry for the confusion, seems obvious indeed) key and I think I understood it's best to have one address for my phone, one for my computer... whatever. Since I read an address shall be a single-use token, is one of them for giving and the other for receiving bitcoins?

Since an address is a single use token does that mean I should create an address each time I want to pay using bitcoins? What about receiving bitcoins then? How do people send bitcoins if change my addresses constantly?

And what if I delete an address? Will it have an effect on bitcoins I'd eventually "collected"?


texts: Are there any mining pools operating on the Testnet?

texts: Are there any mining pools operating on the Bitcoin Testnet, or do pool owners just test their code using their own machines without keeping the test pool up for too long?


texts: Storing wallet key for automatic transactions

texts:
Is there any way to do this? For example I don't even want to know what my wallet is, only my server (intranet), so that it can make automatic transactions for me based on thresholds.

Or should I not be looking at this approach at all? How do the big exchanges do it? Can I automate transactions securely without needing to type a password every time?

The context here is a mining network


texts: What does "Not yet redeemed" mean in a BlockExplorer transaction output?

texts:
Just digging around BitCoin Explorer and I came across a neat transaction. More so, curious, does the second output where it lists "Not yet redeemed" mean that someones BitCoin wallet didn't accept that transaction or something?

http://blockexplorer.com/tx/01ccb4aff48836c9ebe93caa83d7090eb2f76fa71275a9d6766cc8f32c82af39


texts: With peerblockfilters=1 hundreds of "btcwire 0.5.0/neutrino" connections are downloading TB from my Bitcoin node

texts:
I run Bitcoin Core 0.21.0 from a data center, unmetered, with compact block filters enabled (blockfilterindex=1 peerblockfilters=1).
Soon after the restart, I get a huge number (140-200) of connections identifying as btcwire 0.5.0/neutrino, from all over the world. They are responsible for vast majority of download bandwidth (90%+).
This only happens when node is signalling CBF support via peerblockfilters=1.
I am aware "Neutrino" is a proof-of-concept light wallet using CBF but it doesn't explain neither the vast dominance in terms of connections number (~75%), nor in terms of bandwidth (90%+).
Incidentally, "Neutrino" is also a surveillance company owned by Coinbase :)
Any guidance is welcome!


texts:
I'm using Litecoin RPC in my app. I created two wallets on my server. Make some send-receive operations and last result is like that:

{
    "result": {
        "": -0.381788,
        "wallet1": 0.11,
        "wallet2": 0.271788
    },
    "error": null,
    "id": 12729
}

What it means? When I send some coins from wallet2 then ("") this wallet is decreasing but wallet2 staying same value. I think wallet2 must decrease. What is the issue on this? Thanks.


texts: Is four confirmations enough if the network hash rate is so high?

texts:
The point of waiting for six confirmations is that it becomes near impossible to create six blocks vs the network. So double spends a effectively eliminated.  With the hash rate of the network so high, is four blocks enough to have the same security?

Also, what about in the case of a fork like the one that resulted in 23 blocks?


texts: RippleAPI how to issue IOUs using preparePayment

texts:
I'm trying out the API, and I've set up one 'user' account, and one 'gateway' account. The only difference between the two is that the user has extended a trustline to the gateway account. I would now like to issue USD IOUs from the gateway to the user account.

I assume the functionality for this is built into api.preparePayment(). So far, I am able to transfer XRP using code found in the payment example of ripple-lib. The essence is:

const address = SENDER_ADDRESS;
const secret = SENDER_SECRET;

const payment = {
  source: {
    address: address,
    maxAmount: {
      value: '0.01',
      currency: 'XRP'
    }
  },
  destination: {
    address: RECEIVER_ADDRESS,
    amount: {
      value: '0.01',
      currency: 'XRP'
    }
  }
};

api.connect().then(() => {
  console.log('Connected...');

  return api.preparePayment(address, payment, instructions).then(prepared => {
    console.log('Payment transaction prepared...');
    const {signedTransaction} = api.sign(prepared.txJSON, secret);
    console.log('Payment transaction signed...');
    api.submit(signedTransaction);
  });

A few lines of code are missing but this is the basic structure. It works when I make either the Gateway or the user the sender, and the other the receiver. How should I modify it so that I can issue USD IOUs from the Gateway to the user?

My trustline object was:

var trustline = {
  "currency": "USD",
  "counterparty": GATEWAY_ADDRESS,
  "limit": "100",
  "qualityIn": 0.91,
  "qualityOut": 0.87,
  "ripplingDisabled": true,
  "frozen": false,
};


texts: How can I get the private key from wallet.dat from 2011 Bitcoin software on WinXP?

texts:
I set up Bitcoin (application) software on a WinXP machine in 2011 and received some Bitcoin. I set the machine aside, disconnected from the internet. Now I want to access the 2011 Bitcoin.

Lately I verified my Bitcoin address/public key on blockchain.info, and the BTC is still there. I backed up the public key and wallet.dat* onto a flash drive. The WinXP machine is functioning.

I am a former coder but new to Bitcoin under the hood, but willing and able to learn whatever is necessary to retrieve, control, and move the BTC. *I suspect that the wallet.dat file "contains" the private key, but I can't read the file contents with Notepad.

What secure tools do I need, and what is the best way to fill my knowledge gaps so that I can resume control of the BTC?


texts: Help regarding Error loading blkindex.dat, and process to get online again

texts:
Can someone help me please,
I had the error loading blkindex.dat
I've deleted everything as per another post regarding this error, my wallet is still working ( I think) but it won't sync, showing offline, 0 active connections to the internet, not staking because wallet is offline.
how do I get it sorted so that it all works again please?
Many Thanks,
Kelly


texts: Do wallets always require a private key to spend coins?

texts:
I recently imported a very old (2012) bitcoin qt wallet address to a new blockchain wallet, but since it's imported, the coins are "watch-only." i was hoping that i could simply send them from my old wallet to my new one, and then i'd be free to spend them. i attempted 1 relatively small transaction as a test, and it broadcast to 4 nodes, but never got any confirmations after a day or so. my transaction fee was set at .01 (about $48 at the time), so i'd assume that a low fee wasn't the issue. i eventually aborted the transaction, and decided to try again with a newer version of that wallet - one that would actually be able to sync the entire blockchain. so that's what i'm doing now... just waiting for it to sync.

my new blockchain wallet won't allow me to spend my coins without a private key because they're "watch only." i found a lot of stuff from way back when that i thought was (or should have been) my private key. various passwords, a 6-word (no, not 12 words) recovery combo (which were not random - i chose them), and some long gobbledygook that looked like a private key (found in a jason file), but none of them worked.

all this to say that my old bitcoin qt wallet never asked me for my private key, and as i had mentioned, my attempted transaction was broadcast to 4 nodes, which i'm hoping someone can confirm means that either a) no private key is needed to complete a transaction from that wallet, or b) the private key is saved in the app (possibly from way back when it was originally installed). of course "c" would be that the transaction was not, and never could have been confirmed, and my coins are just gone forever. can anyone tell me if wallet apps back in early 2012 used private keys? i'm just trying to figure out whether i lost mine, or if there never was one, and therefore don't need one.


texts: Bitcoin protocol: How do I build my block to get the newly generated coins?

texts:
I am writing a software to mine bitcoins (in golang) as part of a college project. I'd like to know how is it that I build a block (which would potentially get appended to the end of the block chain) so I can send the 25 newly generated bitcoins to myself. You may assume I already know how to build a basic block header.

An example would be greatly appreciated, any dummy data may be used.

Also, I'd like to know if I would need to insert in the merkle tree any information regarding the transaction that gives the 25 newly generated coins to the miner.

Thanks in advance!


texts: NXT, Ignis, and Ardor Confusion. Purpose of NXT when there is Ignis / Ardor?

texts: If NXT is switching to Ardor, what is the purpose of holding NXT? There is another snapshot that's happening with NXT for the coin Ignis, but how what's the purpose of Ardor then? So is Ignis the new NXT? Very confused.


texts: Is there a reason transactions aren't compressed?

texts:
I have two similar questions

Why aren't transactions compressed in the P2P layer (and why wasn't this discussed in the agenda)?
Why aren't transactions compressed before they're added to a block? (Effectively a block size increase) Are there reasons other than avoiding a hard fork?


texts: Why doesn't Bitcoin return lost coins back into the block reward?

texts:
The idea of putting back lost Bitcoins back onto block rewards seems like a great idea.

I acknowledge that there were quite a handful of early adopters who were generating blocks daily, but had no idea what they were doing. Time passes, they forget about Bitcoin and they format their hard drive or whatever. Their coins enter the nether, never to be seen again.

I wouldn't be surprised if >5% of the current coins in circulation were lost due to mishandling. My question is, why isn't there something implemented for this? I can't find any disadvantage for this feature, it would simple as invalidating coins that haven't been transferred in x amount of time, which is probable for only sorting lost coins.


texts: Did I pay a fee to transfer from Coinbase to Blockchain?

texts: I recently transferred from Coinbase to my Blockchain wallet. At the time and in my transaction summary it shows a fee of .0002 . However I still have the same amount I started with. Who paid this fee? It didn't seem to come out of my btc.


texts: Decoding a Block beyond the Coinbase transaction

texts:
I am attempting to decode a Block and have managed to decode the Coinbase transaction but after the transaction, there is huge gaps in them that I do not understand.

Taking this Block as a sample: 0000000000000000002e5b55bf93c89cc3a41de24d762fa4f68e725da3b089ba

Here is my attempt to decode this block:

  ===== Block Begin =====

  00000020 - Transaction Version

  15F11A82BE84CCCAF4E59CFC0C89EF01CAD854DC15F33D000000000000000000 -
  Block Hash

  CC2DCEAF96439181993C564CBE889F60FDB98E8EFD4E524D9EEA3C54CF400504 -
  Merkle Root

  2BDF8F5A - Timestamp

  DC975D17 - Bits

  3E2A4065 - Nonce

  FD8704 - Total Transaction

  01000000 - Transaction Version

  01 - Coinbase has 1 transaction

  ===== Coinbase Begin =====

  0000000000000000000000000000000000000000000000000000000000000000 -
  coinbase hash

  FFFFFFFF - index

  45 - txin script length (69)

  -> 03 - bytes in height

  -> 43CA07FA - height

  ->
  BE6D6DCAEEFE495F6BCA08E10FF6D24555166C2456D8129213354E32FD73EB1B141AB00100000000000000036507000F312D7B080100275C012F736C7573682F
  - txin

  00000000 - sequence

  03 - 3 output in coinbase

  AA5CB94C00000000 - output satoshis from coinbase

  19 - Coinbase Output Script Length (25)

  76 - OP_DUP

  A9 - OP_HASH160

  14 - 20 bytes

  7C154ED1DC59609E3D26ABB2DF2EA3D587CD8C41 - hash data

  88 - OP_EQUALVERIFY

  AC - OP_CHECKSIG

  00000000 - Lock Time

  ===== Coinbase End =====

  000000002C6A4C2952534B424C4F434B3AA5BA6C5D1EFFA2034E994BEEE65C619DE2D2A1
  - outpoint ?

  B91892F193C170CAB74F152EAE0000000000000000266A24AA21A9ED85F7D06CCF8014D990E0242ACC0433EAF134732094E9A083A45AC3799259C9170000000001000000014FFBE86D2805AF78459BBF5FA3432A5E9C84D408F7921BF2095488B9DDC39D33
  - ?

  02000000 - Tx Version

  6B - TxIn SigScript Length (107)

  48 - TxIn SigScript Length (72)

  3045022100FAD6F0A91A89A90D17800B55B1B1E424338BFB5D72D3970ED95310AFEB4734A50220120B24AF1444E520EB77ECE73DB6D9775159220B089D28948BC9DBC156C2492F01
  - TxIn SigScript

  21 - TxIn SigScript Length (33)

  02227CEDFAB55D1B7642D47A5AC92638ED8822A23C3DDADF88DEFEA45A37F5935E -
  TxIn SigScript

  FFFFFFFF - TxIn Sequence

  02 - TxOut Count

  F0874B0000000000 - Satoshis (BTC 0.0495)

  17 - Length (23)

  A9 - OP_HASH160

  14 - 20 bytes

  98808E526D3737F044F2DD5445A27DB39BAD821D - hash data

  87 - OP_EQUAL

  92F6E73600000000 - Satoshis (BTC 9.21171602)

  19 - Length (25)

  76 - OP_DUP

  A9 - OP_HASH160

  14 - 20 bytes

  B08F46E4D21CD0547A8A1E2E43E5440284F710A4

  88 - OP_EQUALVERIFY

  AC - OP_CHECKSIG

  00000000 - Lock Time

  =====================

  01000000 - ?

  01 - ?

  DE74875C17CE6730AF727B52913FAB9FF7922BBA806932785A824A8CAA649E8D0100000000FFFFFFFF02D5C267130000000017A91433A9DB4ED408225EFE4B00DC55F962B52E8769B987A7C6D10200000000220020701A8D401C84FB13E6BAF169D59684E1 ... more data ...

It seems like after I have decoded the Coinbase transaction, the first proper transaction after the Coinbase, I hit a problem trying to resolve:

  000000002C6A4C2952534B424C4F434B3AA5BA6C5D1EFFA2034E994BEEE65C619DE2D2A1B91892F193C170CAB74F152EAE0000000000000000266A24AA21A9ED85F7D06CCF8014D990E0242ACC0433EAF134732094E9A083A45AC3799259C9170000000001000000014FFBE86D2805AF78459BBF5FA3432A5E9C84D408F7921BF2095488B9DDC39D33

Only after that point, does the data look abit more familiar with the 02000000 which I have guessed is the Tx Version followed by what seems to be TxIn Script data and so on.

I would like some help to understand how to decode the Block as this is only that far I can guess after reading the Bitcoin documentations found online which are not documented in a uniformed and easy to ready manner.

Thanks for the help in advance.


texts: Using ASIC for password cracking - mad concept?

texts:
All ASIC for Bitcoin do a double SHA256 hash on an arbitrary string. But maybe they might be used for pen testing :-)

Lets assume we have single SHA256 hash we want to crack. We also have an ASIC that does double SHA256. Well if we compare results computed by double SHA256 to passwords that generated SHA256 hash we will get nothing. But what if we do single SHA256 on SHA256 hash that we got on start using CPU, and then try to find SHA(SHA256(x))? If we find goodX it would be our password.

Would modifying firmware, or just mining proxy that feeds miner with work do the job?


texts: I've read (i.e. here https://en.bitcoin.it/wiki/Accounts_explained) about the concept of "accounts" in bitcoin.  However I can't see how to create them in bitcoin-qt.   How do I use accounts?


texts: Procedure to restore Bitcoin Core backup

texts:
I am looking for the procedure necessary to restore a backup of Bitcoin Core v0.15.1 official release version.

Assuming I safely exit Bitcoin Core, take a backup of the ~/.bitcoin folder and put it away safely. I use my wallet for possibly many years making many transactions and eventually, my computer dies.

I get my new computer, install (let's assume the same version of) Bitcoin Core and copy my backup back to the correct location. Obviously, it will need to sync with the network once I start it up and, I may need to upgrade to a newer version of Bitcoin Core but; surely the restored backup will not know of my many new addresses used for transactions since the backup when checking for transactions during synchronisation?

Does anybody have the actual steps necessary for this procedure?


texts: Why would Bitcoin-QT attempt to charge a processing fee, when I have my transaction fees set to zero?

texts:
I'm attempting a test transaction of an amount less than 0.0015 BTC with my transaction fee set to 0 BTC, yet I'm getting this message:

  The total exceeds your balance when the 0.0015 BTC transaction fee is
  included.

The transaction fee should be free, right? Why would this happen?


texts:
I have an MSI Z77a-GD65 and I need to short one of the slots to get it to work. The MB was working fine with 5 GPUs until a couple of weeks ago when one of the slots stopped working. I know it's the slot because when I plug this GPU and riser into another slot it works and when I plug another GPU and riser into this slot it doesn't work.

So, I see posts about presence shorting a 1x slot. I found a page here that provides description of pins for all slots (1x, 4x, 8x, 16x).
http://pinouts.ru/Slots/pci_express_pinout.shtml

All slots except the 16x seems easy enough but the 16x has multiple presence detect, hot plug detect, hot plug present detect, etc pins. Any idea how to do a presence short?

I'm using a 1x to 16x powered riser.

Help will be truly appreciated.


texts: How transactions will take place once all the blocks have been mined

texts:
I understand there can be maximum of 21M BTC. Also, new BTC are added into system as a reward of mining blocks. So is there any hardcap on the number of blocks that can be mined? Or there is no limit on blocks to be mined, instead, there would be no rewards for mining after 21M coins?

Let's say there is a cap on blocks, how the new transactions can be verified after 21M mined coins?


texts:
My main devices: 12x U1 AntMiner + Raspberry Pi B 512 MB (Included 32GB SD containing MinePeon)

As normal I should:

Plug in those miners & Raspberry Pi's micro USB-cable into hubs
Connect the hubs to Raspberry Pi
Connect R-Pi to the internet (88 MBit/s, if it's important)

It should start from here, where I could setup my pool but none of my miners were found.

P.S. I'm sure that cable and software are OK (Checked 4 times)


texts: decompressing Multibit wallet private key in another wallet

texts:
I have some bitcoin amount in my Multibit wallet. unfortunately i can not figure the password I put on it for transferring coins for the life of me despite trying all possible passwords i could think of. But i do have a back up copy of my private key and if you are familiar with multibit wallet you know upon backing private key it asks you to password protect your backup and i do have that password. so how can i impart this private key in another wallet and decompress it there? is there any wallet that can do it?
I do appreciate your help and comment.


texts: What does message "Server is lagging (9 blocks)" mean in Electrum?

texts:
When opening Electrum, the bottom of the window showed message "Server is lagging (9 blocks)".

What does this mean? Is the Electrum server not up to date with the blockchain? Can I expect the problem to resolve itself quickly?


texts: Why aren't balances appended to transactions?

texts: As far as I know, you need to travel back through the entire blockchain to verify your balance. Surely adding the balances of the sender and receiver to each transaction would be easier? If balances are included, and after 6 blocks a transaction is considered 'final', why then can we not just go back 6 blocks and look at the balance there for verification, instead of travelling all the way back to the genesis block?


texts: Will the increasing difficulty in Bitcoin mining push miners to a different currency?

texts:
I've been reading all of the "Is mining still profitable?" questions, and the consensus appears to be the following: Yes, difficulty is increasing, but profitability is uncertain due to the speculative nature of mining.

What incentive is there to keep miners on the Bitcoin blockchain? If their ROI is positive, but marginal return is decreasing, why not switch to mining a new currency?

I'm new to Bitcoin, I apologize if the question is unclear or illogical.


texts:
This question appears many times on SO, but there's something in the answers I'm not getting.

I'm designing a system predicated upon API calls made to blockchain.info, but I'm having real trouble getting my head around the relationship between Pubkey, Address and digital signatures for my use-case.

Say user Jane has previously transacted using Bitcoin and we assume the transaction is confirmed on the Bitcoin blockchain. Jane now makes a request from her app-based wallet software for some metadata concerning that specific transaction via the system's web-service.

The web-service requires Jane to prove that her wallet really instigated that transaction in order to permit her wallet access to the data, but here I get a bit hazy: From all my reading over the last 6 or 7 days, I gather the wallet software would need to sign some pre-determined message containing e.g. the TXID using the wallet's private key, sign it and send it to the system along with the public key, but once the system receives the data, and can verify the message using the public key, so what? How does that prove the txid (or address or whatever) in that signed message, was signed by the same private key from which the transaction in question is indirectly derived? There's some part missing for me that "reconciles" remote blockchain data with the data sent from the wallet app.

I understand basic PKI and that addresses are hashed derivations of a public key, but the digital signature part is messing with my head.

Thanks for reading. Any help would be greatly appreciated.


texts: why bip 34 uses two step on MASF(Miner Activated Soft Fork)?

texts:
in bip 34, which change to bitcoin version 1 -> 2, uses two step for network's consensus.

step 1. check if 750 of the last 1000 blocks are version 2 or greater.
step 2. check if 950 of the last 1000 blocks are version 2 or greater.

but in my opinion, step 1 is useless process in consensus step.
we just need :
check if 950 of the last 1000 blocks are version 2 or greater.
 if blocks < 950 :
   if block_height_limit > current_height :
     accept()
 if blocks > 950 :
     return accept_new_version();
     drop version_1_block

why step 1 is needed on MASF step?


texts: How do I protect my paper wallet from use by a different human who has used a random generator?

texts: Since millions of people use Bitcoin and Bitcoin Wallets that use their own addresses use several addresses per day, it is obvious that generators can generate the same characters for the Bitcoin address multiple times. So please therefore simply tell me how one would prevent others from accessing or spending the coins that are stored at my paper bitcoin address.


texts:
Try to get balance :

var bitcoinPrivateKey = new BitcoinSecret("xxxx");
var network = bitcoinPrivateKey.Network;
var address = bitcoinPrivateKey.GetAddress();

var client = new QBitNinjaClient(network);
var balance = client.GetBalance(address).Result;

but i get a error One or more errors occurred in line var balance = client.GetBalance(address).Result; . Private key is valid. Previously, everything worked well, but now not. Where my mistake ?

Edit:
i wanted to check inner exc

try
{
  var client = new QBitNinjaClient(network);

  var balance = client.GetBalance(address).Result;

  Console.WriteLine(balance);
}
 catch(Exception e) {
  if (e.InnerException !=null)
      Console.WriteLine("error"+e.InnerException.Message);
 }

but now he didnt go to exception, he show me balance. what could be the problem ? why doesn't it always work ?


texts: Does PoS forging require having private key on the computer connected to the internet

texts:
Does PoS forging require having private key on the computer that do actual forging process?

If it depends on the realization of specific cryptocurrency, please, give some examples of such cryptocurrencies.


texts: What are the best criticisms of blockchain technology? Specifically, what are the top flaws of the blockchain as it's currently implemented by Bitcoin?


texts: Can the Government step in, to ban bitcoins?

texts:
The price of bitcoins increase with demand. Demand increases because people can spend the bitcoins. I think the price of bitcoins started as a drug money. The main advantage of bitcoins is that the sender or buyer is anonymous.
However that does not cause the increase in demand to what it is now.
I believe the current demand is increasing as more people are accepting bitcoins, and seeing this, more people are buying it.

If the government makes bitcoins illegal, people would loose trust in the bitcoins and the prices will go down.
Cant this cause the prices to go down?


texts: Do you have to be a node to use the Lightning Network

texts:
I am new to the use of the Lightning Network and had a question.

To run a bitcoin node, one would need to start btcd. What would one need to run for a Lightning Node? One can specify the port a Lightning Node runs on as well - right?

Also, when a channel is opened, between 2 entities, must each entity be a Lightning Node?

For example, Bob wants to buy a coffee from Starbucks on 9th Street.

To open a channel, Bob's wallet needs to run a Lightning Node - and - the Starbucks on 9th street must also run a Lightning Node?

TIA


texts: How many proof-of-work algorithm exists for crypto currencies?

texts: How many proof-of-work algorithm exists for crypto currencies ? We know PoW in Bitcoin and Etherium are different. Is there any other algorithm used for crypto currencies ?


texts:
I checked my wallet (Monarch wallet) about a week ago and I had a small amount of bitcoin in  it. I looked at it again a few days ago and it had vanished. I tried recovery, uninstalled wallet and reinstalled, but no luck.

I have been in contact with Monarch support, they say the coin is there, but they have run out of ideas on how to recover. Is there anything I myself can do to recover my wallet, without needing the help of the wallet's support team?


texts: Bitcoin balance vanished when transferring from bitcoin trading wallet to bitcoin wallet balance on blockchain app

texts: I tired to move my full bitcoin balance from my bitcoin trading wallet to my bitcoin wallet balance on the blockchain app, but when I transferred it to my bitcoin wallet balance it never gave me confirmation but has taken my full bitcoin balance from my bitcoin trading wallet. I normally receive a pending confirmation and once that’s done My bitcoin is normally ready and in my bitcoin wallet balance. But this didn’t happen this time and my whole balance of bitcoin has disappeared without any transaction activity. I am concerned because I cannot see any transaction history about my transfer from wallets and now have no bitcoins available.


texts: Is there a transaction propagation delay built in?

texts:
When a node receives a transaction it verifies it and then sends it to its neighbors.
My question is: does the node broadcast the transaction right away or is there a delay built in (privacy concerns) and if there is a delay built in can anyone point me to the code where that happens?


texts: How can I "redeem" a private key without downloading a client?

texts:
Let's say that I have generated some private keys offline and use them for my savings. For my spending money I prefer to use an online wallet instead of downloading the client.

Is there any service online where I can enter

My private key
A destination address (the online wallet)

and simply click a button to send the whole balance to the destination address?


texts: Move bitcoins from one address to another using JSON RPC

texts:
I am developing a website where each user has a unique bitcoin address and each user can receive or send money. I have a bitcoin node running, so I connect to it to run json-rpc api calls.

The problem which I have is the following:
If one user has 1BTC and send 0.5BTC to the external wallet. I want that the user has 0.5 BTC in his wallet but right now with sendtoaddress api call the 0.5 BTC remaining aren't in the original wallet, the 0.5 BTC is moved to a new address from the wallet.

I don't see right now how can achieve it through json-rpc calls, if someone could help I'd be grateful!


texts: Can bitcoin system get itself into resonant oscillations

texts:
I assume that the PoW system has been designed in the way it controls itself. If the difficulty is too high and mining hash rate is low, then it takes more time to mine a block. The system detects that and adjusts the difficulty so the mining is easier. And vice versa.

What if the decrease in difficulty would be too large? Then the block generation rate would rise quickly. The system would sense that and next raise of difficulty would be so large, that it would be greater than it was before it was lowered. Repeating this would cause the system to go into resonant oscillations and it would cause the difficulty to go into level that it would not be possible to mine a block and whole system would overload.

Is the block mining system protected from such scenario?


texts: Technological contractor for an ICO legal advise

texts:
I was recently offered to hire my services to create and maintain a cryptocurrency.
My responsibilities would be to create a website and issue the tokens

While I think the project as some merit, I am concerned about any legal liability I could hold.

The contract I want to sign against will be an SLA (as to my understanding it will mitigate my legal risks as opposed to a partnership agreement).

The company that wants to hire me has declared to me that the ICO would be available to US residents and that I shouldn't worry about kyc or aml.

Also, the mentioned company states that its practices are legal and that it has a legal team on board.

I am aware this sounds a bit obscure, but these are all the details I can provide as to the signed NDA.

To what degree will I be accountable if the company breaks any law (not using a kyc to verify residence for example), or if one day the SEC decides that this ICO (or all ICOs for that matter) were illegal?


texts: looking for api for huobi.com for last price data

texts:
I'm looking for last price data from huobi.com.

Does anyone know where I can get data from an API for them?

Huobi is the largest Bitcoin exchange in China and I'm looking to add them to http://tradeli.st


texts:
Discovering a new block is a task about generation of millions of hashes in order to find one valid hash, which is a hash less than the current target.

The question is: Are there more than 1 valid hash? Is it possible to find more than 1 hash valid for the same block? Maybe there are multiple nonce suitable to valid block hashes.


texts: Merkle tree structure inside blocks - what are they for?

texts:
I'd like to check if my understanding is correct. This is regarding the purpose of having the Merkle tree structure for all transactions inside a block. Is the only reason it exists so that thin clients can verify that a transaction exists in a block without being told about all the other transactions of that block?

Seems quite complicated to implement that (instead of just concatenation of transactions) for a rather special case. Particularly since the maximum size of a block is not very large - so there isn't really a problem with verifying all the transactions and ensuring that the hash of the block matches up to those.


texts: Does being connected to more peers relay transactions faster?

texts: If I'm connected to 500 peers, will I know about transactions faster than if I'm only connected to 8 peers?


texts: bitcoin transfer without creating wallet

texts:
My question is about transferring bitcoin between two addresses without having a wallet.

Here is my idea of transferring bitcoins in following way:

Idea:

I have my own Android Application. I am willing to send/receive bitcoin using blockcypher Apis

I will keep private and public keys generated from above apis in my own database by encrypting it.

Does it make sense?

This might be a stupid question to experts, but as a newbie in block-chain technology I am curious to know the right direction of the concept.


texts: What are the perceived advantages of bitcoin as a store of value?

texts:
This complements What are the perceived advantages of bitcoin as a means of exchange?

To some, Bitcoin today is considered "better" than other stores of value. Why do some people think it's a good store of value, or even investment?


texts:
please note I have made this question previously (link) and I was indicated to visit here.

I am writing a program using GoLang to mine bitcoins. It's part of my college conclusion project and likely won't be used to mine bitcoins since it's not gonna be efficient enough running on regular PC's (facing a race against those huge chinese mining pools). Though it's not originally intended for real usage, my college expects nothing less than a flawless piece of software to mine real bitcoins (in parallel).

So far, I have implemented quite an extensive code, therefore, you guys may assume I already have means to achieve:

  Get pending transactions to fill my block (from https://blockchain.info)
  Build the merkle tree over the transactions data retrieved
  Calculate a sha256 of a given data input (I also understand the concepts behind such hash functions)

I have organized my questions regarding this subject below:

Question 1) I can't precisely tell how to build a block header which would be appended to the block chain. I know it has fields like the root of our merkle tree (which I already know how to calculate) or a version field, but if I was to produce a block header as an array of bytes, how would I do it ? I'd like to see how to calculate each field we need to build the header and how our byte array (representing the header) would look like.

Any dummy data may be used for this example, my focus stays on understanding the process and the data structure.

Please, note I have already read this: https://bitcoin.org/en/developer-reference#block-headers

I have studied quite a lot regarding how the bitcoin protocol works to achieve the code I currently have, but I feel extremely limited on the information I can find online regarding the internal details of the bitcoin protocol:

Question 2) Is there any online technical information you guys would consider useful for me to read regarding the headers subject and/or anything else in bitcoin? Keep in mid that I still have quite some code to write, therefore, I'm taking all the information I can get : )


texts: I'm a developer, trying to land a job at an exchange. What type of software would an exchange need? Want to build something to use as a resume

texts:
I'd like to give a good impression by solving a problem they already have, but I'm not sure what could it be.

Thanks!


texts: What are the risks of exchanging Bitcoins via Near Field Communication? The transaction Parameters might be negotiated via NFC and the actual transaction via Internet.


texts: What happens to Dash wallet if PC is formatted?

texts:
I am new to cryptocurrency. Let's say I setup a DASH wallet using this link https://www.dash.org/wallet/ on my Windows PC.

I encrypt my wallet using passphrase now after 1 year my PC's hard disk has corrupted. What happens to my DASH coins?

Would I loose them forever or can I recover them using the passphrase I entered while setting it up?


texts: How can one remain relatively anonymous while using Ripple?

texts:
Inspired by this and that.

What can an individual that uses Ripple do in order to remain as anonymous as possible? How do Ripple's "anonymity profile" compare to Bitcoin?

One specific difference is that Ripple accounts need XRP to be opened, and that XRP has to come from somewhere, while Bitcoin accounts are free to create.


texts: Can I anonymously self-publish books on Amazon and get paid in Bitcoin?

texts:
I want to publish the book under a pseudonym, or better yet, anonymously! I had been looking into Amazon Kindle Direct Publishing. I’d also like to use an anonymous e-mail address. Would it be possible to get paid in Bitcoin when I publish my book there?

I want to get paid in Bitcoin/Litecoin only (possibly some other cryprocurrencies too, but I really don’t want centralized payments).

If there’s no way to do this, please tell me about any other alternatives for self publishing and/or advertising!


texts: What is the differenct between 13.5TH and 14TH

texts:
I would like to buy an S9, checking the bitmain site found that they are selling two S9 versions.
- S9i-14TH/s
- S9i-13.5TH/s

Apart from the obvious difference in Hash rate, is there any other differences I should be considering before buying? I can't seem to find the full spec for these miners


texts: How does one generate a paper wallet for a Lightning Bitcoin address?

texts: Is there a paper wallet generator for a Bitcoin Lightning addresses? How can one generate it in javascript?


texts: How to move coins into the website of poloniex, for example convert my bitcoins in bitshares

texts: I am just interested in know how to transfer into the website of poloniex from bitcoins to bitshares


texts:
I have recently learned about best practice for storing private keys with hardware wallets. I understand the necessary information including backups from seed phrases, the concept of cold storage, safely storing seed phrases, and having multiple HD wallets incase one goes missing, etc.
Ok. But now, I want to actually use bitcoin in the real world, because what better way to support btc than to actually use it!
So I want to have a wallet, preferably on my phone that I can use for quick and easy payments with friends and merchants in public. I plan to keep $100 or less on this account, similar to my debit account with my usual bank.
But I still want to do my best to be secure, and I don’t understand a lot of the vulnerabilities with my public keys being stored somewhere on my phone. Can someone please perhaps recommend a mobile based platform for btc transactions and outline the vulnerabilities and how I can avoid them? I understand that my hardware wallet is offline, what vulnerabilities come with my phone being online?
Example: I have heard people mention to never connect to public WiFi. How does this make me vulnerable? So when I leave the house should I disable WiFi? Are there any vulnerabilities with using 4g?


texts:
Is it possible to use colored coins with stealth addresses?

My main consideration being that coloring a unit of cryptocurrency requires being able to keep track of its exact location at all times with a public blockchain


texts: Should I send the remaining balance from a paper wallet to a new paper wallet?

texts: If I withdraw all my money from a paper wallet, but don't end up spending the whole balance, should I create a new paper wallet and send that remaining balance to it as opposed to the old wallet?


texts: I have 8 Antminers, is there a way I could change their pool credentials all at the same time like through ssh with a script

texts: As title says, I have 8 identical mining machines I just want to be able to point them at the same pool all at once, is this possible with a combination of python and ssh?  If someone else already invented something could you point me to that?  If not, could you give me a basic idea on how I would tackle this myself?


texts: is there any daemon available for bitcoin cash (eg-bitcoind for bitcoin)?

texts: I am developing a pool for my client. i have already setup bitcoind for bitcoin but can't find daemon for bitcoin cash?


texts: I bought bitcoins from coin.mx and I understand that the government shut them down,what happens to the wallet and the bitcoins


texts: How does Base58Check prefix character prediction work?

texts:
I'm trying to implement Base58Check as a learning exercise and I came across the different types of prefixes as summarised here.

I wonder however how to arrive in the expected prefix characters from the prefix Byte.
Why the same byte can lead to different characters, and how those come to be.

My initial assumption was that the first character is the Base58 encode of the prefix byte, but that seems wrong, the address byte 0x00 maps to "1" because it's a leading zero, but the second example of P2SH with 0x05 should map to char "6" but instead it maps to "3". And the WIF prefix of 0x80 can map to either "5" (uncompressed), "K" or "L" (compressed) even though the prefix is the same.

Also on my tests that mapping only seems to work after I add the 4 byte checksum in the end of the array. If I encode the array without the checksum the result has different prefix characters.

So, how is the expected prefix characters of Base58Check derived from the prefix?


texts:
Someday, my bitcoind was running and I opend another terminal and typed bitcoind on the terminal but, bitcoind which is running was shutdown. so I should have run the first node and have another node connected to the node.
Definitely, I think there is some critical reason that developers set the policy in this case, but I don't know why.

Do you know?

Sorry for my English.


texts: How to start Bitcoin-qt with Bitcoin Cash?

texts:
First of all I do not trust online wallets so I download full blockchain with Bitcoin-ABC. Unfortunaly bitcoin-abc does not contain bitcoin-qt binary. So my question is it possible to start original Bitcoin-QT with bitcoin-abc?

if this is not possible, what is the other way to use my wallet under bitcoin-abc?

Thanks!


texts: Bitcoin Transaction Stuck, Attempt to double spend with higher fees

texts:
I made a BTC transaction a few days ago, where I set the fee amount way too low. It seemed that the transaction was lost in limbo.

I did some research, and apparently you are able to double spend your btc, if the transaction hasn't been confirmed yet.

So I imported my wallet into Bitcoin Core, where the unconfirmed transaction wasn't shown, and I was able to initiate another transaction with higher fees.

Now it seems that Blockchain.info doesn't show my transaction, and pushing it manually results in a mempool conflict. The same happened with this service: https://coinb.in/#broadcast.

But I was able to push the transaction through https://localbitcoinschain.com/. Now the transaction ID is unconfirmed on localbitcoinschain, but can't be found anywhere else (Blockchain.info, coinb.in).

Can this second transaction be approved, or is it impossible, if its only recognized by localbitcoinschain.com?
How should I proceed? At this rate, my transaction seems to be lost for a long time.

Kind regards


texts: Which kinds of transactions show quadratic signature-hashing scaling?

texts:
It has been stated:

  A major problem with simple approaches to increasing the Bitcoin blocksize is that for certain transactions, signature-hashing scales quadratically rather than linearly.

https://bitcoincore.org/en/2016/01/26/segwit-benefits/#linear-scaling-of-sighash-operations

What are some examples of transactions with this behavior, and what do they have in common?

Does a simple one-input-two-output Alice-pays-Bob transaction show quadratic signature-hashing scaling?


texts: Would it be possible to provide a downloadable blockchain that is updated and verified by a mass of people?

texts:
As of November 2012, the blockchain is nearly 3 GB in size with a near-linear growth of about 500 MB/month (cut from exponential growth by the hard-coded block size limit, I guess).

I want to install Bitcoin on my average notebook:
Downloading and verifying the latest bootstrap.dat from Bitcoincharts took some hours (5–9, I guess), but that was only 2.3 GB! Now, I’ve been waiting for Bitcoin to catch up on the last 2–3 months, in which blocks have been considerably bigger and each block takes about 5 seconds of being processed, with my CPU at ~25% and my hard drive at max workload.

This is, to be put lightly, unsustainable.

We need a system, in which an already verified blockchain can be downloaded and directly copied to the bitcoin folder, maybe in an incremental form.
The source has to be trusted, for this, one needs a verifying system in which everyone can control the correctness of the blockchain and then sign it, I’d propose to use gpg keys for this.

The source can then be distributed via server-backed torrent, for example.

Is this technically possible and how?

Edit: Since I approached this with a wrong mindset, I posted kind of a follow-up question about the security risks of lightweight clients. Should an end-user download the whole blockchain? Or is a “lightweight” client sufficient?


texts:
I'm attempting to validate a p2sh transaction from the live bitcoin blockchain, however it is failing the checksig. I am using pybitcointools for the checksig and I have successfully validated lots of other txhash/pubkey/signature sets so I don't think the problem lies in the ECDSA library.

I think I must be evaluating p2sh incorrectly. Please could someone tell me where I am going wrong:

tx hash 7edb32d4ffd7a385b763c7a8e56b6358bcd729e747290624e18acdbe6209fc45 spends txout with index 0 from tx hash 40eee3ae1760e3a8532263678cdf64569e6ad06abc133af64f735e52562bccc8.

First I evaluate the scriptsig:

OP_FALSE
OP_PUSHDATA0(72)
3045022100ad0851c69dd756b45190b5a8e97cb4ac3c2b0fa2f2aae23aed6ca97ab33bf88302200b248593abc1259512793e7dea61036c601775ebb23640a0120b0dba2c34b79001
OP_PUSHDATA0(69)
5141042f90074d7a5bf30c72cf3a8dfd1381bdbd30407010e878f3a11269d5f74a58788505cdca22ea6eab7cfb40dc0e07aba200424ab0d79122a653ad0c7ec9896bdf51ae

This leaves the stack like so:

0 - 00
1 - 3045022100ad0851c69dd756b45190b5a8e97cb4ac3c2b0fa2f2aae23aed6ca97ab33bf88302200b248593abc1259512793e7dea61036c601775ebb23640a0120b0dba2c34b79001
2 - 5141042f90074d7a5bf30c72cf3a8dfd1381bdbd30407010e878f3a11269d5f74a58788505cdca22ea6eab7cfb40dc0e07aba200424ab0d79122a653ad0c7ec9896bdf51ae

I back this up as stack_copy.

Then I evaluate the scriptpubkey:

OP_HASH160
OP_PUSHDATA0(20)
e9c3dd0c07aac76179ebc76a6c78d4d67c6c160a
OP_EQUAL

This passes fine.

Finally I evaluate the p2sh - I restore stack_copy and pop the last item (2) off the stack. I deserialize it to get the following script:

OP_TRUE
OP_PUSHDATA0(65)
042f90074d7a5bf30c72cf3a8dfd1381bdbd30407010e878f3a11269d5f74a58788505cdca22ea6eab7cfb40dc0e07aba200424ab0d79122a653ad0c7ec9896bdf
OP_TRUE
OP_CHECKMULTISIG

And then evaluate this using stack_copy (without element 2 which has just been popped). The data for the checksig evaluation is:

serial tx: 0100000001c8cc2b56525e734ff63a13bc6ad06a9e5664df8c67632253a8e36017aee3ee4000000000455141042f90074d7a5bf30c72cf3a8dfd1381bdbd30407010e878f3a11269d5f74a58788505cdca22ea6eab7cfb40dc0e07aba200424ab0d79122a653ad0c7ec9896bdf51aefeffffff0120f40e00000000001976a9141d30342095961d951d306845ef98ac08474b36a088ac0000000001000000
txhash: 8fcf56ee75816930fb141fdc19b2aa1bc721b124d2a76d5f0c1be17bcd21ccdc
pubkey: 042f90074d7a5bf30c72cf3a8dfd1381bdbd30407010e878f3a11269d5f74a58788505cdca22ea6eab7cfb40dc0e07aba200424ab0d79122a653ad0c7ec9896bdf
signature: 3045022100ad0851c69dd756b45190b5a8e97cb4ac3c2b0fa2f2aae23aed6ca97ab33bf88302200b248593abc1259512793e7dea61036c601775ebb23640a0120b0dba2c34b790

However this is failing! Let me know if you need more information and I can provide it.


texts:
I made a new altcoin based on "INSaNe" https://github.com/CryptoCoderz/INSN

I changed genesis hashes using this code:

    if (true  && (genesis.GetHash() != hashGenesisBlock)) {
                     //This will figure out a valid hash and Nonce if you're
                    // creating a different genesis block:
                        uint256 hashTarget = CBigNum().SetCompact(genesis.nBits).getuint256();
                        while (genesis.GetHash() > hashTarget)
                           {
                               ++genesis.nNonce;
                               if (genesis.nNonce == 0)
                               {
                                   printf("NONCE WRAPPED, incrementing time");
                                   ++genesis.nTime;
                               }
                           }
                    }
            printf("block.GetHash() == %s\n0x", genesis.GetHash().ToString().c_str());
            printf("block.hashMerkleRoot == %s\n", genesis.hashMerkleRoot.ToString().c_str());
            printf("block.nTime = %u \n", genesis.nTime);
            printf("block.nNonce = %u \n", genesis.nNonce);

So i started coin with two clients on localhost and tried to mine it with cpuminer-multi by tpruvot https://github.com/tpruvot/cpuminer-multi, but miner always gives me booo, please help me...

My OS: Kubuntu 16.04

There is no setgenerate or generate function in this cryptocurrency

00:15:45 setgenerate
00:15:45 Method not found (code -32601)
00:16:03 generate
00:16:03 Method not found (code -32601)

Cpuminer output:

Current block is 1
[2017-07-19 00:16:32] Switching to getwork, gbt version 7
[2017-07-19 00:16:36] CPU #2: 26.28 kH/s
[2017-07-19 00:16:38] accepted: 0/1 (diff 0.000), 26.28 kH/s booooo

Here is difficulty for mainnet:

bnProofOfWorkLimit = CBigNum(~uint256(0) >> 18);

Here is block time:

static const int64_t BLOCK_SPACING = 5 * 60;
/** Block spacing minimum */
static const int64_t BLOCK_SPACING_MIN = 3.5 * 60;
/** Block spacing maximum */
static const int64_t BLOCK_SPACING_MAX = 7.5 * 60;

Here is block version:

static const int CURRENT_VERSION=1;


texts: What are the advantages and disadvantages of 24/7 Bitcoin trading?

texts: What are the advantages and disadvantages of 24/7 Bitcoin trading over traditional stock market which operates only 6 - 8 hours a day and 5 days a week? Any threats?


texts:
What sites for block exploring besides blockchain.info exist?

I try to find some qualities of API for my needs, and ask you to help me to find the list of such services as full as possible.

Thank you!