texts: Is there anything wrong using a cold wallet from BitKey in watch-only mode on my normal desktop Electrum?

texts:
I followed the instruction for cold-offline in BitKey and created my cold wallet on a USB key with BitKey burned and booted from a CD-ROM. I noted the encryption password and the seed phrase on a paper which I will store in a secure location.
The workflow described on the BitKey website would use cold-online mode for watching the wallet (and preparing transactions).
Now, is there anything wrong in adding the watch-only mode (I think BitKey stores the proper information unencrypted on the USB key) to my normal work PC running Electrum on Win 10?
In my opinion, it shouldn't because no single secret will be exposed. However, I am wondering why the documentation is so keen on emphasizing the workflow with cold-offline and cold-online.
Lastly, I intend to store my Bitcoins for long term. In 10 years I may have forgotten details about the sofware, BitKey may not exist any more, I may not have a CD drive any more, Electrum may be at a completely different version and who knows, it may be hard to import the data.
For that reason I really love the simplistic idea of paperwallets. But individual paperwallets are hard to deal with. Hence I would like to store an export of the public/private key list of my wallet as well. I feel this format will be most barebone and most likely to be importable also in ten years or more (I know that the seed could re-generate them but I hope you get my point).
For backup purposes, I also want to store the AES encrypted contents of the USB key on my NAS. I am thinking of packing the public/private key export into this file as well. Using a very long passphrase and storing it in a KeePass database.


texts: Bitcoin QT "No block source available"... stuck at "180200 out of 225430"

texts:
I have downloaded Bitcoin-qt and have encountered similar problems that others have on here. However, the offered solutions don't apply to me, because I run Mac OS.

I get a status message that says "No block source available", when hovering over "Catching up... 180200 out of 225430 (estimated) blocks of transaction history last received block was 67 weeks ago..." the client informs me that I have "0 active connections to the bitcoin network". My client has been in this state for more than 12 hours. I've tried locating the "bitcoin" folder in the "Library Support" folder as I have read on another page to delete the program files to re-install & attempt to re-index the block but I am unable to locate it the bitcoin file... any help?


texts: Any Innovations in altcoin tech for Bitcoin’s Script language?

texts:
Bitcoin’s Script is the forth-like, non-Turing complete language used for transactions. However, in practice, a very limited number of kinds of scripts are allowed, a number of opcodes have been disabled, and even a number of bugs in script have to be replicated to maintain consensus.

Have there been any innovations by the altcoin community, in their forks of Bitcoin’s Script? Any with non-secp256k1 crypto? Any with more functional bignum / arbitrary integer functionality that can do cryptographic primitives? Any that add Turing complete functionality?


texts: Sent Bitcoins to an expired address - how do I get back?

texts:
I sent bitcoins to my CampBX address, and I was unaware that addresses expired, and it had.  So I sent them, they were taken out of my account, and now they are gone...

How do I get them back?

Bitchain says they were sent - but they are not in either account:

https://blockchain.info/address/1aPb2GVC3YVcaRce17EAjEZL9ZsT1Ssqi

Any help would be greatly appreciated.

Thank you!


texts: I need to make a block explorer for some alternative cryptocurrencies. I'm using Litecoin for testing, but JSON-RPC requests through PHP are very slow. Maybe JSON-RPC isn't the right thing for such purposes? What other tools you can recommend?


texts: How to send bitcoins from one address to another without wallet

texts: I generated btc address and put some coins into it. Now I want to send coins to another address. I can't find any infomation about how I can do it. I don't have wallet, I only have address: public key and private key.


texts: Why verifying later blockchain is slower?

texts:
I'm truly lost about how bitcoin works.

I understand a blockchain contains all transactions ever made. So, what things need to be verified while I'm downloading the whole blockchain? If it's just the hash of each block, the processing/verification speed of earlier blocks should be same as later blocks, right?

Only better guess I have, is that if anything need to be indexed, then that would explain why later blocks are slower. So is this the case?


texts: How to create the   part in "scriptSig"?

texts:
I've decoderawtransaction and see in the vin part a "scriptSig" ,which
I believe to be the "unlocking script"  . Assuming I have
the private key in a paper wallet and someone send me transaction to
my bitcoin address, How do I generate the    to unlock it
?
My second question is: after I generated it, can someone copy this
part and use it in the future to unlock a future transaction made to
my same bitcoin address ?


texts: How many hops does Coinbase and other exchanges track your movement of BTC when it leaves their exchanges?

texts: I've read reports of Coinbase users getting an email stating that they detected their Bitcoins being moved to an unapproved exchange or site after removing their bitcoins off of the exchange. What is a safe way to move your Bitcoins without nosey exchanges seeing where its going? How many hops does coinbase and other exchanges check before sending you an email that you are "being watched".


texts: how bitcoin reject invalid transaction? (with createrawtransaction)

texts:
i'm studying 'Mastering Bitcoin' and have a questions,

in this book, we can send coin to other wallet by createrawtransaction but there is no enough secure method.

we can find other's wallet addresses at https://www.blockchain.com. and unused coin value too.

for example - https://www.blockchain.com/en/btc/address/34bN2MQcqA4JpbEVRU9KBsvhXgSEHQrqBz

  718ae88f0eb13d2f2d3bc74cbf18721a82739b80f1bfc0658ed699263fca76fd(Fee:
  0.00002057 BTC - 3.11 sat/WU - 8.33 sat/B - Size: 247 bytes) 2019-01-14 04:57:04 34bN2MQcqA4JpbEVRU9KBsvhXgSEHQrqBz (1.13215222 BTC
  - Output) 32T5urH6uN4jhKenhW4LWM66WouzSCERbA - (Spent) 0.03213165 BTC 3LnZGyRAeCA3LAMBU2RSQn6dAkHw8rWquw - (Unspent) 1.1 BTC

than we can make fake transaction such as

  $bitcoin-cli createrawtransaction '[{"txid" :
  "718ae88f0eb13d2f2d3bc74cbf18721a82739b80f1bfc0658ed699263fca76fd","vout":0}]'
  ' {"MY WALLET ADDRESS": 1.0, "3LnZGyRAeCA3LAMBU2RSQn6dAkHw8rWquw":
  fee}'

in conclusion, it doesn't works but i want know why this code not working


texts: Does the U.S. Securities and Exchange Commission govern Bitcoin?

texts:
Do SEC regulations apply to:

Exchange of Bitcoin for US dollars
Investing in companies with Bitcoin
An exchange that sells shares of company stock for Bitcoin
Bitcoin futures contracts


texts:
A friend suggested I use Jaxx Wallet so I downloaded the software and sent my BTC using their QR Code from Coinbase. Looking back, I should've left it where it was!

It never arrived. I also sent LTC using the same QR Code method. That has arrived and is in my Jaxx Wallet now.

I see my transaction completed and verified on the blockchain. How do I locate where it is?

How can I trace that this transaction was actually sent (and maybe received) by Jaxx although it doesn't show in my wallet?


texts: Ripple: only a sub-network reaching a consensus is largely enough to be decentralized&secure system?

texts:
I spent  a while  reading ripple protocol, specially the consensus process,
the protocol works based only on a sub-network ( from a huge network) reaching a consensus for the current state, it's supposed to prevent double-spending and other attacks.  There is no analysis about fork events!

First, any one can explain step by step the underlying consensus mechanism?
Second, what's in the mechanism that prevents double-spending, attacks and fork events?


texts: How the difficulty of the network affect the average block mining time if we have static hash power?

texts:
Let's suppose that I have 500 KH/s of hash power overall from my mining rig. I'm about to start mining coin X and its network difficulty is Y. Current hashrate of the whole network is 100 KH/s and calculations are showing that average time of mining one block by my rig is about 1 minute.

I've connected my rig to mine this coin and mined 10 blocks within 10 minutes and let's suppose that difficulty gradually was doubled and became 2Y. Will my rig have to mine next block for 2 minutes instead of the last one?


texts: Can a coinbase transaction contain only data: 03 - length and 030303 - coinbase itself, or should the coinbase itself contain the height of the block?


texts: To get the master private key of HD wallet

texts: How can I get the master private key of HD wallet bitcoin core satoshi client 0.14.2? Any command for that  on bitcoin core console? Currently I am on Testnet3.


texts:
i want to create an API. where do Crypto Currency exchanges get their data from, Like the exchange rate, difficulty of coins, blocks and rewards.

I want to create a website which displays all the data related to the coins and i dont want to use any existing API.

Can Anyone suggest how to create an API.

Thanks


texts: Bitcoind clear / reset my testnet to retest some things

texts:
I'm running bitcoind on centos and want to reset my testnet. I tested one way and now I want to test something else a different way.

For example, I want to clear it so when I do:

bitcoin-cli listaccounts

No accounts are returned.

AND

bitcoin-cli listtransactions

No transactions are returned.

What is the easiest way to do this?


texts: The Legit & Safe—Windows Command Line Miner

texts:
I read over the "Is there a command line Bitcoin CPU miner for Windows?" post and GCMiner looked promising for a Windows command line scriptable solution that allows pool mining.

I tried downloading the GCMiner client right from GitHub links from Windows via the Chrome, Firefox, and Internet Explorer web browsers and all of them say something is unsafe and prevents me from downloading the CLI tool. I tried to download from Linux Mint via the Firefox web browser from the GitHub links and got the same unsuccessful result.

Question

Is there a safe Windows client that is command line that I can use to mine in a pool such as SlushPool for CPU mining I suppose?

I'm setting this up to play with and become familiar with the pool management side more than the configuration so I'm not worried about CPU being ineffienct over GPU.
If I can safely download CGMiner to start playing with it on Windows that'd even work.

Note: I'd prefer to use a pool like SlushPool where I can put in my unique username and whatever miner names I define only. I don't want a client that requires an email address in the logic to mine.


texts: what is Create wallet using blockchain api (PHP)

texts:
Im wondering to know, what is use of Create wallet programitically Block chain API  Block Chain api here

What it will provide?

Where can i get the api code? Any tutorials ?

Can i provide my website users to Create Block Chain wallet. And provide funds transfer?


texts:
I have a couple thousand dollars in a savings account. I am getting almost no return since the bank accounts interest rates are so very low.

I know nothing about the stock market, so investing there is not at the top of my list. If I put the money into a bitcoin wallet, theoretically, isn't it gaining value faster than the savings account? Even with any fees involved, it might be a good place to hold my money.

Also if things go bad here in the USA, I'd like to have some money safe.


texts: Why doesn't a change address just point back to the address that sent the transaction?

texts: Why over complicate things with additional private and public keys that are hidden from the user and make it possible for backed up wallets to go out of date?  Why can't the change address just be the address that started the transaction?


texts:
It seems that bitfloor is a well designed trading platform, and a competitor to MtGox. However, the trading volume is low.

How long has bitfloor been in business?

Have there been any negative accusations such as fraud?

How safe is my money/bitcoins at bitfloor?


texts: How does lighting network ensure all parties cooperate

texts:
I somewhat understand the two way channels used in lightning. But I fail to see how trust is avoided.

If I'm the middle node I'm perfectly fine with forwarding a payment, if I received the payment first. The initial payer can reason that he will only make the payment if all intermediate nodes have shifted the payment to the receiver. It seems like until at least one party takes the risk the payment is in some kind of Mexican standoff.

How is this avoided / cryptograpically enforced?


texts: What does it means "get a new address and then make the Bitcoin offline" and make it extremely secure?

texts:
I have been reading about Bitcoin, and one thing was about making Bitcoin extremely secure, which is to get a new address so that nobody knows, and then making it offline right away?
Is it like
0.01 Bitcoin    Address 123-456-789-876    encrypted by my public key

and then immediately change my address to something new, and then use the existing public key to encrypt it and publish it to the Ledger / Blockchain?
Should I get a new public / private key pair as well? The thing I don't understand is, don't I need to publish this new address to the Ledger?  If it is, then other people know too.  If I don't publish and other people don't know, then 1 year later, if I want to sell this 0.01 Bitcoin, how does the Ledger know it is a valid address?


texts: Error: Non-canonical DER signature when attempting to broadcast signed Segwit Transactions

texts:
I'm trying to build a native Segwit transaction programmatically, however, whenever I attempt to broadcast the transaction, it returns this error:
non-mandatory-script-verify-flag (Non-canonical DER signature)
My raw, unsigned tx (testnet) is here:
0200000001fd45159c94d5dcf0804e7aba6e5862445a3c41fb5ec21184fe3a41a1a6dbb5b40000000000ffffffff02a351000000000000160014d1ca74222bb5a5c1b43fae117e811b2320a286a66500000000000000160014d1ca74222bb5a5c1b43fae117e811b2320a286a600000000

My signed tx here:
02000000000101fd45159c94d5dcf0804e7aba6e5862445a3c41fb5ec21184fe3a41a1a6dbb5b40000000000ffffffff02a351000000000000160014d1ca74222bb5a5c1b43fae117e811b2320a286a66500000000000000160014d1ca74222bb5a5c1b43fae117e811b2320a286a6024630440220465c93c725454f7bda3e3453ce09e99f7636560935be9377c3ae1138cfa0bb4702206f45290b2c06fc7e2298c6778fbccd1a805e34535247c49e098bc7229e74533421034ac1bb1bc5fd7a9b173f6a136a40e4be64841c77d7f66ead444e101e0134812700000000

Both decoded look okay to me, so I I think it it's either the sighash or signing of the sighash that's going wrong.
The sighash I get of the unsigned tx, for the only input is:
e54c499bfef6f5f0b12b819de82220aa7de532f9b72ae0f74638a647e147f884
This is created using:
https://docs.rs/bitcoin/0.25.1/bitcoin/util/bip143/struct.SigHashCache.html#method.signature_hash
using SigHashType::All passing the pubKeyScript and value (22,000)
and when signing the sighash I get:
30440220465c93c725454f7bda3e3453ce09e99f7636560935be9377c3ae1138cfa0bb4702206f45290b2c06fc7e2298c6778fbccd1a805e34535247c49e098bc7229e745334
I am completely stuck on what to try next. Any direction would be appreciated.


texts: How bitcoin daemon search nodes  to connect? What file in github responsible for this? How they often change? How is the veracity of the data of these nodes checked? Bitcoin daemon have function not save blockchain data on device?


texts: What other purposes can I use my [obsolete] hashing hardware for?

texts:
It's pretty easy to reuse CPUs or Video cards that were previously used for Bitcoin hashing, but what can I do with FPGA hardware when the difficulty becomes too high for it to be worthwhile to mine?

Are there competing networks I can mine for?  Are there other technologies (like email/hashcash) that can reuse the hardware with little modification?

Is there a similar way to recycle old ASIC's when the time comes?


texts: What order does Bitcoin Core place the inputs it spends in?

texts: What order does Bitcoin core place the inputs it spends in? Is it random? Is it sorted by anything? What, if anything, can you tell about the originator of a transaction by the input ordering?


texts:
I am trying to recover my old LTC account. I still have the address (on blockchain I can still see the correct amount of LTC) and I still hold the old wallet.dat file, which I saved in the past.

I've downloaded LTC core in order to make a few transactions, but obviously I couldnt see the LTC balance. I've checked out this website and read I had to replace the wallet.dat file by the old wallet.dat file, which I did. Restarted LTC Core, but still can not see anything.

The synchronising seems to be up to date though.

What to do?

Many thanks!!


texts:
People have been talking a lot about side chains, but I thought this has been around for a while under a different name. Coins like Namecoin, Devcoin, ixcoin, i0coin, groupcoin, etc are all merge mined and have existed long before I ever heard the term "Side Chain".

Am I correct in my assumption that side chains are just a rose by another name (previously merge mined coins)? Or is there something I am missing here?


texts: What is the value of these bitcoin certifications that have popped up recently?

texts:
Are bitcoin related certifications viewed favorably amongst the bitcoin community? I work in a related field and I am interested in pursuing a certification to distinguish myself, but I'm not sure how valuable these things are.

For example the following organizations:

CryptoCurrency Consortium

Digital Currency Council


texts: What exactly is forking in cryptocurrency?

texts:
My understanding was that forking is essentially update made to the blockchain software associated with the cryptocurrency, until I came across this:
A “fork” is the term used to describe a single blockchain diverging into two paths. Generally this occurs as the result of a significant change in the network’s protocol that effectively splits the blockchain into an old way of doing things and a new way of doing things.
What exactly does "diverging into two paths" mean? Should the whole blockchain be updated after the forking (no matter whether the forking is soft or hard)? (Which seems to be the case according to the description in the same section on the webpage.)


texts: Easy way to compare bitcoin node block to total block, check sync status

texts: I am familiar with bitcoin-cli getblockcount, but is there an easy way to compare this to the total block count to check my sync status?


texts:
Referenced in this thread about a 51% attack on feathercoin.

  This would have been a hell of a lot worse without automatic coin
  choice pools. They routed a ton of hashpower at FTC. This broke the
  attacker's control of the blockchain.


texts: publicly available json-rpc node for bitcoin-cli connection

texts:
There is a service provided by blockchain.info described on json_rpc_api page.
More or less it describes the API that user can use to access their blockchain similar way as using bitcoin-cli to own daemon.
It usage is currently demonstrated as:

$ ./bitcoin-cli -rpcconnect=rpc.blockchain.info -rpcport=443 -rpcssl -rpcuser=YourWalletIdentifier -rpcpassword=YourPassword getinfo

It looks nice but there is an information on the site which states:

  From the 1st December 2014, in order to use this API, access must be explicitly enabled, and all client ip addresses whitelisted by the wallet owner. Manage access in [Account Settings] -> [IP Restrictions]

And that's the problem, because I'm interested just into fetching some block or transaction details. I don't need any RPC which would require authorization. I don't even want to create an account.
So the question is:
Are there any free services (or maybe it is still available on blockchain.info somehow?) which allows to use JSON-RPC against their bitcoin daemon?
I don't care about the speed or waiting 10 seconds between each call etc.


texts: relationship between bitcoin miner and verification of transactions

texts:
Bitcoin miner mines a block, which can't be submitted to the network without proof of work. And the new block contains all of the new transactions. Hence the new block acts as a security measure, and authority.

My puzzle is following:
In the scenario I just described, the miner of the new block, in some sense, authorized the new transactions to be true. Yet the miner has never looked into the new transaction he just authorized.

This somehow relates to orphaned blocks, and longest chain(?)

Links I found useful to help me understand:

How do nodes verify Bitcoin Transactions?
http://timothyblee.com/2011/04/19/bitcoins-collusion-problem/
http://spectrum.ieee.org/img/06Bitcoin-1338412974774.jpg
Why is blockchain necessary?
Which is the relation between transactions and blocks?


texts: How do I download specific blocks directly from peers, without downloading the entire chain?

texts:
My dev environment is quite limited in terms of bandwidth and storage. I need to make a database out of transactions containing opcode 0x6a since a given epoch.

[Scan blocks, going backwards from the latest, until a given blockheight]
[If the transaction outputs contain OP_RETURN, save it with associated metadata]

Is there a way I can do this with bitcoind without having to store the entire chain?


texts:
I have a harddrive with an old wallet but I am not sure what I need to do to see how much BTC I have.

I have read quite a few notes, but I am looking for the latest information. I want to continue leaving my BTC in my private wallet until I decide to move it to an exchange or online.

How do I see how much BTC I have?


texts: Can I restore a Litecoin wallet with Public / Secret?

texts:
I apogolize if this has been asked, I have spent several hours trying to figure this out.

I found an old document of my with a Litecoin Public and Secret key.

I don't have a *.dat file, is this a problem?
I do have The Public key is 34 characters
I do have The Private key is 51 characters
I am using Litecoin Core Qt - Wallet (Which I used in 2015).
The blockchain is downloaded (About 10GB), yet it just sits here
Q1: Do all I supply is my private key?
Q2: Is there a way to check balance with any of my keys, or conversions below?
Q3: Are coins lost if you don't have the .dat file anymore?

In the Application, I can run the Debug > Console and run:

# (This is a fake address, but it's in this format)
importprivkey "6vpo4RFWLcGhk4VsdFk34K3243K3kdsk4k23k32kAkasdkewkwe" "Jesse"`

The above gives me a "Receivable" key under Receiving Address which is identical to my Public key (34 characters).

I used some Online Bitcoin tools to convert the Public key, I thought I might need to run importpubkey, key it's must be there since it's visible in my Receiving Address?

I'm not sure what for but I was able to get:
(a) (Address to Hash): 40 character hash
(b) (Hash to 160 Address Bitcoin, using a): 34 characters
(c) (Pubkey to Hash, using a): 40 characters

I'm not sure what all this means, this is terribly confusing I don't remember how I did this in the past. If anyone could give me a plain answer I'd really appreciate it and I'll be sure to tick it off as correct and settle the issue :)


texts:
A transaction can be RBF if itself is a RBF, or it spends outputs from a RBF transaction.

Is there a way to use bitcoin RPC node to check if a transaction is spending outputs from a RBF transcation?


texts: I am running the unit tests from bitcoin source using make check, and would like to debug the tests using LogPrint in the bitcoin source files. I read in the Test Docs that logs are only output to test_framework.log, but I'm unable to locate this file. Where should I be able to find it? Or perhaps there is a better approach?


texts: Which is the official site to download the NXT (nxtcoin) wallet app?

texts: Where is the official site to download the NXT wallet app?


texts: Does outbound port have to be open to make an Json-RPC call

texts:
lets say i am making a json-rpc call with the following connection :

 $connect = new jsonRPCClient('http://user:password@ipaddress:9332');

does outbound port 9332 of the sender need to be open as well as that the 9332 inbound port of receiving machine?

if not then which outbound ports need to be open?

the reason i am asking is because i am connecting via json-rpc to a  VPS that hosts bitcoind with a simulated webserver on my PC  (usbwebserver) and it is successful ,  but when i try to do the identical thing from a shared web-server (hosted by a company) i get an error: Unable to connect and they only have specific outbound ports open.

thanks for the help :)


texts: Anyone know how to configure pybitcointools to bitcoin testnet?

texts:
Anyone know how to configure https://github.com/wizardofozzie/pybitcointools
to bitcoin testnet?

thanks,


texts: Does the 1 MB block size limit include the header?

texts:
I was able to follow the code to validation.cpp:

// Size limits
if (block.vtx.empty() || block.vtx.size() > MAX_BLOCK_BASE_SIZE || ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) > MAX_BLOCK_BASE_SIZE)
    return state.DoS(100, false, REJECT_INVALID, "bad-blk-length", false, "size limits failed");

and serialize.h:

template <typename T>
size_t GetSerializeSize(const T& t, int nType, int nVersion = 0)
{
    return (CSizeComputer(nType, nVersion) << t).size();
}

But for the life of me I can't figure out what CSizeComputer is doing. Does GetSerializeSize include the block header in the value it returns?


texts: How do I know if the Bitcoin page has been hijacked

texts: With so many hackers hijacking websites these days, what do I look for to show me that I'm not on a hijacked page?


texts: bitcored + vmware: disk space increases INCREDIBLY fast

texts:
I installed ubuntu-16.04.3-desktop-amd64 within a vm maschine from vmware. After downlading and installing bitcored (I did these steps: https://bitcore.io/guides/full-node) the blockchain starts to syncronize but keeps adding disk space incredibly fast.
Insight says the blockchain is 1 % synced and already takes 30gb+ (I just installed ubuntu and there is nothing more on this system). Maybe this is some error with cache/temp not beeing deleted after progressing a block or something?

If I let it run it creates 400gb+ until the virtual maschine crashes. After that, vmware is not able to start the vm again. (current bitcoin blockchain is <200 gb. I dont know why this thing needs to write 400gb+ of data to my disk space).

Opening "disks" on ubuntu says the system uses ~13gb (which should be right). Where does the other endless GB come from?

Any help is highly appeciated!


texts: What is the motive of a miner to include transaction in a block?

texts:
My question is divided into different parts :

Can a block include only coinbase transaction ?
Why should a miner wait \ include more transaction after starting to create a block ?
If a miner stops the mining process for including new arrived transaction, does that makes him re calculate the previous nonce possibilities for creating the block ?


texts: What are the relations between these number theorems and ECC?

texts:
I'm currently working on a bigger assignment where I have to write about the connection between bitcoin/blockchain and maths. I've gotten far, but one of my tasks is to talk about principal rest, modulus, greatest common divisor, the fundamentals of arithmetic theorem, fermats theorem, eulers theorem and function.

The point of the assignment is to make everything as a flow, and not go out of context, so I'm wondering what all of these mathematical theories has to do with bitcoin and blockchain.

Any answers or sources to where I can read about it, would be highly appreciated!


texts: Why is the change address for a transaction the same as the originator address?

texts:
I was under the impression that if address abc has 100 BTC assigned to it, and it pays address def 20 BTC, 80 BTC will be transferred from abc to a new address ghi. But in this transaction:

https://blockchain.info/tx/15bf8b35c9210efe7e448c5fc6b69b47b3a8cac9c148c7cc57c65f266384d9b8

The change address is the same as the originator. Why is that?


texts: I lost my 12 or 24 words to my bitcoin wallet. I just have my password. How can I get them back? Is there a software or a website where I can enter my password and get my asset back?


texts: Bitcoin-Qt listing all Transactions as occurring at same date and time

texts: Any ideas about this one? I've imported addresses into my wallet and on rescan, all transactions come up as same date and time?


texts: Importing private key to bitcoin node is slow. Can it be faster?

texts: I have launched the bitcoin node and synchronized it. The issue is that importing the private key forces the node to scan the blockchain for the operations with the key. Is there a way to import the key in a fast way?


texts:
I have the black cube miners that work via cat5/network and have yet to be able to connect them to cgminer. I have looked all over the internet and haven't found anything about how to do it.

So my question is can CGMiner connect to network miners?
If so how?

Thanks for the help.


texts: Where are the Diablominer Config Settings stored in Mac OSX?

texts: I can't find them any where.  Note, I'll admit I'm a new Mac user, so I may be missing an obvious location, however, I can't find it in my personal folder.  Any suggestions?


texts: What does it mean to go negative on exchange?

texts:
I know this is a very basic question, but I am just curious about all this exchange stuff and I'm new to this.. so here goes

If I trade at a bitcoin marketplace (exchange) lets say Kraken, Bitstamp or wherever.. and I for example buy 100$ worth of Bitcoin.

The next day Bitcoin falls and I go negative eg. -7,8

What does this mean?
a) did I just loose 100$ and have to pay this extra 7,8 to get back to 0,0?
b) or did I just loose 100$ because the price fell but am still the owner of that 0,0001 BTC and I wait a couple of days so the value goes up again and I go positive, or sell everything and accept the fact that i blew 100$?

Which one is it?


texts: What are the pros/cons of preferring sending the latest commitment or the oldest commitment?

texts:
Roasbeef mentioned on IRC that the Lightning specification allows a client to either assume that the latest co-signed commitment has been received by the counterparty, or that it hasn't. (as far as I understand that linked discussion. If I got it wrong, please edit the question)

For an implementation, what are the consequences of preferring to send the oldest co-signed, or sending the newest co-signed? (both unrevoked)


texts: "New rules activated" warning after upgrading to 0.20.0

texts:
I've upgraded a node from the previous release. It's up and running but for some reasons I get this warning.
How can it be related to the upgrade?

$ bitcoin-cli -testnet getblockchaininfo | jq
{
  "chain": "test",
  "blocks": 1764182,
  "headers": 1764182,
  "bestblockhash": "0000000000004a0e9cc1fbc2a21938feef1a26cd480483b3c498ae2ef16b46f8",
  "difficulty": 65536,
  "mediantime": 1591710673,
  "verificationprogress": 0.9999998260147338,
  "initialblockdownload": false,
  "chainwork": "00000000000000000000000000000000000000000000015bbad4a75d4239391e",
  "size_on_disk": 27411142847,
  "pruned": false,
  "softforks": {
    "bip34": {
      "type": "buried",
      "active": true,
      "height": 21111
    },
    "bip66": {
      "type": "buried",
      "active": true,
      "height": 330776
    },
    "bip65": {
      "type": "buried",
      "active": true,
      "height": 581885
    },
    "csv": {
      "type": "buried",
      "active": true,
      "height": 770112
    },
    "segwit": {
      "type": "buried",
      "active": true,
      "height": 834624
    }
  },
  "warnings": "Warning: unknown new rules activated (versionbit 28)"
}


texts: What is the oldest Bitcoin Core Client that can in theory sync to the chain tip?

texts:
I've seen this question regarding the original Satoshi Client being able to sync to the chain tip. The main issues why it doesn't work were:

Change in protocol messages
IRC Node discovery is now disabled
Number of BDB locks too low

When have these issues been resolved? What is the oldest bitcoin core client that can sync to the chain tip (disregarding any problems with the client itself being very slow).


texts: Which of the alternative clients support any/some/all of the standard API calls? I am looking for a possible alternative client to replace Bitcoind on my server.


texts: Getting the lasthash on a bitcoin full node using bitcoin-cli

texts:
I'm trying to figure out how to get the last block hash using bitcoin-cli.  I read the help:

$ bitcoin-cli help
== Blockchain ==
getbestblockhash
getblock "hash" ( verbose )
getblockchaininfo
getblockcount
getblockhash index
getchaintips
getdifficulty
getmempoolinfo
getrawmempool ( verbose )
gettxout "txid" n ( includemempool )
gettxoutproof ["txid",...] ( blockhash )
gettxoutsetinfo
verifychain ( checklevel numblocks )
verifytxoutproof "proof"

== Control ==
getinfo
help ( "command" )
stop

== Mining ==
getblocktemplate ( "jsonrequestobject" )
getmininginfo
getnetworkhashps ( blocks height )
prioritisetransaction <txid> <priority delta> <fee delta>
submitblock "hexdata" ( "jsonparametersobject" )

== Network ==
addnode "node" "add|remove|onetry"
getaddednodeinfo dns ( "node" )
getconnectioncount
getnettotals
getnetworkinfo
getpeerinfo
ping

== Rawtransactions ==
createrawtransaction [{"txid":"id","vout":n},...] {"address":amount,...}
decoderawtransaction "hexstring"
decodescript "hex"
getrawtransaction "txid" ( verbose )
sendrawtransaction "hexstring" ( allowhighfees )
signrawtransaction "hexstring" ( [{"txid":"id","vout":n,"scriptPubKey":"hex","redeemScript":"hex"},...] ["privatekey1",...] sighashtype )

== Util ==
createmultisig nrequired ["key",...]
estimatefee nblocks
estimatepriority nblocks
validateaddress "bitcoinaddress"
verifymessage "bitcoinaddress" "signature" "message"

And trying something like bitcoin-cli getbestblockhash doesn't seem to print a hash that matches up with https://blockchain.info/q/latesthash

and I'm not seeing a good option, did I miss something?


texts: Static receive address instead of dynamic?

texts:
I have 2 BTC QT wallets (and 1 LTC QT wallet), and am looking for a generic receive address for my wallets. In Electrum, Mist/Ethereum and Rippex, I get a single unique address to receive. In the QT apps however, I need to "Request payment", which then gives me a new receive address every time I make this request. It also says [checkbox] Reuse an existing receiving address (not recommended).

Is there such a thing as a generic receive address for a QT wallet? If I need to create a new request every time I want to receive coin, that's not ideal.

Am I missing something, or how does this work?

Or can I just create a receive address once off and keep using that, not sure why it's not recommended..


texts: Best Python API for sending Bitcoins from a Multi-Sig wallet

texts:
I want to create a multi-sig wallet which I can broadcast transactions through an API. I would like a wallet with a permanent public address not one that changes every time I run the code. I was going to use Blocktrail but some of their API features are broken. Does anyone know any other good API`s?

Some context as to what I want to do: automate the sending of coins to certain addresses at a certain time each week.

Thanks,


texts: BitcoinCore wallet still 3 years in sync, funds in account

texts:
I use bitcoin core and the thing is still syncing after a week and a bit.
I received btc into the account and the transaction was confirmed over 150 times.
Can I move these funds to another wallet with the wallet.dat or is there any alternative or something I can do besides sitting through this sync process? Is there any one I can contact about this? I don't think my computer has 140gb spare space :L.


texts:
The Bitcoin-Wiki page for Electrum says it's a Bitcoin wallet.

However, there is also a Litecoin version.

What currencies does Electrum support?


texts: Does secp256k1 library provide API for generating uncompressed key?

texts:
Hi I am right now want to do a make a small tool to generate some test vector for ecdsa.
Openssl is quite good, for support secp256k1 bitcoin provides an excellent library.

However, it looks what I get from secp256k1 API only the compressed key.
I find some post about how to convert the compressed key (Qx) to uncompressed key (Qx,Qy). But I just wondering if I can directly get the uncompressed key?

Thanks!


texts: How to decode private key from Android Bitcoin Wallet?

texts:
I want to import my private key from the android's Bitcoin Wallet (the one created by Andreas Schildbach) but it can export it only in an encrypted way.

How do I decrypt the file so I can import the key to my Bitcoin Qt?


texts: Can a full node provide a bogus block bloomfilter to a Neutrino node?

texts:
When a thin client using BIP157/BIP158 (Neutrino) requests the block filter for the latest block, would it be possible for the full node serving this request to attack the Neutrino node by providing a fake block filter that omits certain transactions?

Do block filters include a mechanism that enables the thin client to verify that it is an accurate representation of the corresponding block's content? Would it be possible to construct the block filters in a fashion that lying by omission becomes impossible when the thin client is aware of the correct latest block's header already?


texts: Are SegWit signatures all required to follow BIP143?

texts: ...or is there any way for a SegWit witness to contain a "legacy" signature?


texts:
BIP 50 describes the 2013 event in which a block chain fork persisted for several hours. Its first paragraph reads:

  A block that had a larger number of total transaction inputs than previously seen was mined and broadcast.  Bitcoin 0.8 nodes were able to handle this, but some pre-0.8 Bitcoin nodes rejected it, causing an unexpected hard fork of the chain [my emphasis].  The pre-0.8 incompatible chain at that point had around 60% of the hash power, ensuring that the split did not automatically resolve.

I interpret this to mean that the term "hard fork" describes a state of the network.  Some nodes have accepted a block, but others have rejected it.  The nodes accepting the questionable block keep and extend it.  The nodes rejecting the block neither keep nor extend it, but rather build their own branch.  The resulting "fork" is only visible to nodes which have accepted the questionable block.

However, the Wiki has this to say about a hard fork:

  A hardfork is a change to the bitcoin protocol that makes previously invalid blocks/transactions valid, and therefore requires all users to upgrade.

In other words, a hard fork is a kind of update to Bitcoin Core (given that Bitcoin Core is the protocol).  The idea was repeated in the top answer to this SE question.

The difference is subtle, but important.  For example, consider the question: has a hard fork ever occurred?

At least one Core developer says that Bitcoin has never experienced a hard fork, apparently using the Wiki definition.  The 2013 fork was not caused by a software update (according to some new, but undocumented information), but rather was (caused by?) nondeterministic behavior that would have happened even without the update.

The answer seems to depend on how you define a hard fork. If a hard fork is a condition of the network, the answer seems to be "yes".  But if a hard fork is a kind of software update, the answer seems to be "no".

It's not hard to see how a software update could lead to a persistent block chain fork as seen by some nodes.  So clearly the two ideas are connected.  But imprecise language around hard forks can lead to confusion, and, more importantly, to incorrect conclusions.

So which is it?  Does "hard fork" describe a condition of the network, or a software update?


texts: When and where did the term come up for the first time? Did Satoshi Nakamoto comment on the naming?


texts: Can an exchange or marketplace benefit from private key encryption?

texts:
A powerful security technique to prevent theft of Bitcoins from a user's online wallet is to encrypt the user's private key with his password without ever stroring the PK directly in the database. Even if a hacker compromises the server they still won't be able to access the user's wallet without his password.
In case a website needs to have custodial control over a user's funds (for example, an exchange or escrow service in a marketplace) this solution isn't viable as the exchange needs to have complete control over the user's funds to move funds from one party to another (say from the buyer to the merchant or to a trader in an exchange). So it cannot be expected that the exchange must ask one party "permission" to transfer funds to the other party. Of course, the exchange or marketplace can encrypt the PK but since it would also need to host the decryption key somewhere on the server there's little benefit in encrypting the PK in the first place.
Is there a variation of this technique that might work even in a marketplace or exchange environment which requires that the owner (of the marketplace or exchange) maintain full control over a user's deposit?
Thanks


texts:
How was bitcoin private/public key created in 2009, I observed in the blockchain some bitcoin transaction took place early 2009 Feb - April.
In the original bitcoin core in github the first bitcoin core was released September 2009.
My confusion how were the users able to generate the address ?


texts: What is the minimum amount of network messaging needed to get the latest block hash from a node?

texts:
Reference: https://en.bitcoin.it/wiki/Protocol_documentation#inv

I want to be able to write the simplest possible script that is able to contact a Bitcoin full node (given it's IP and port) and get the latest block hash.

I don't need to verify blocks or send transactions or even be a good peer.

Are the messages all http? And how many messages (handshake? Network magic bytes? Service bits?) are required to get to the point where I can get useful information?


texts: How is a USD-chained currency like Tether economically possible?

texts:
(I'll try my best to keep it relevant to Bitcoin, but feel free to close it if it seems inapplicable to Bitcoin trading. It's more about economics)

Say there's a currency whose supply is controlled (e.g GBP in 1990, or USDT) to keep the exchange rate fixed (GBP/EUR or USDT/USD)

But sometimes the exchange rate is slightly higher or lower than intended. If it's higher, one can borrow more of the valuable currency, sell it, and then pay back with interest, and profit from the difference, because there's no doubt that the currency's value will be lowered to reach the exchange rate target.

In the end, George Soros and his $15 billion budget made at least 20% profit, according to the source, and GBP was forced to become free instead of 1.2 GBP/EUR .

My question is, what protects USDT from this kind of economical strategy which is guaranteed to make Bitfinex, the minter of USDT, a loss? Is that because they hold the majority of USDT?


texts: Electrum wallet not restoring with the right address?

texts:
I have the address and i can see my bitcoins in it. I have the 12 word seed, but when restoring my wallet with it in Electrum the address with my bitcoins isnt included in the ones generated.

I'm a noob at this please help :)


texts:
Update: This related question focusses on users own data. My question is mostly asked from the perspective where a person may enter someone elses personal data, like someones sexual preference.

In the data world GDPR is currently a very hot topic:

personal data must be protected and not retained too long.

For normal companies and systems it is already very difficult to meet the letter of the regulation in practice, however I image that for bitcoin it is even challenging on a much deeper level. Two core principles:

Data must be visible by all
The full history must be preserved

This brings me to a question:
How does Bitcoin respond to the introduction of GDPR?

And as bonus question:
What does this mean for other blockchain applications (like corporate concepts, not specifically for currencies)


texts: How to get my c-lightning node's private key?

texts: lightning-cli getinfo outputs my node's id, which is its public key. How can I get its underlying private key?


texts:
good afternoon

I set myself a task to understand the work of the miner, but as you understand it is difficult for a beginner. Constantly there are questions.
Without conditionally, I turn to Google search and find the answers but not always.

Guys help sort out a few points

How to compose a block header?
I appeal to the instructions on such sites as:

I understand the headline is formed by the principle:
Version + prevhash + merkle_root + ntime + nbits + '00000000' +
'000000800000000000000000000000000000000000000000000000000000000000000000000080020000'

Where merkle_root should be in the reverse order of the byte and only it.
But other sources and sources give different examples of header formation. Someone does not translate merkle_root in the reverse order of a byte, but translates ntime and nbits

The question is how to properly form the header of the block and what incoming data should be specified in the reverse order of the byte. Most likely something I do not understand until the end and I hope for help.

And can someone tell me a good manual


texts: By whom and when can transaction malleability be applied?

texts: Once I create a transaction and relay it to the network, who can alter the transaction id? Can the transaction id change at any time or only when the transaction is confirmed or unconfirmed?


texts:
Using the BTC-E API 'm getting an error of You incorrectly entered one of fields. when I post this as the data in a buy order.

{'pair': 'btc_usd', 'amount': 0.1, 'rate': 44.7084704, 'type': 'buy', 'method': 'Trade'}

Does anyone know where I'm going wrong?


texts: what are private keys (essentially) how can i make them using any given data?

texts:
private keys decode pub keys so how can they reveal other things?
can i reveal a web address from a private key?

I should be able to unpack anything from a private key seen as I can unpack something that can read/wrire decoide/encode

right?!


texts: how to validate testnet and mainnet bitcoin address via online api or offline for Android App?

texts:
I would like to know web api provider to validate Mainnet & Testet3 Bitcoin Address.

How to validate a Bitcoin address is a real one?

Validate bitcoin address from android application

Gone through above references but Want a web service provider or local bitcoinJ type java library class.


texts: Negative time estimation from estimatefees + mempool data

texts:
I am currently writing a time estimation tool for Bitcoin, and it gives me wrong estimations, so I am not sure if it's accurate and if I am not doing some error in logic.

For example, I have this transaction

https://blockchain.info/tx/388f99d51cfce4f18f0c76257fff7666ffd272394ee0316df529383c6d22ed66

It has 10 sat/B (both virtual size and real size). It has 0 ancestors in mempool, all its inputs are confirmed. (all from getmempoolentry call)
Estimatesmartfee returns 11.089 sat/B for 192 blocks, that is 1 day and 8 hours.
The transaction was seen about 4 days ago (again, according to time in its mempool entry) and is still unconfirmed.

That means it should have been confirmed 3 days ago. So its estimated confirmation time is -3 days, which is impossible.

What am I doing wrong?


texts:
I am writing a program (in golang) to mine bitcoins. Supposing I have this dummy transaction, how may I encode it so it can be used in the block im trying to mine?
Also, supposing I have a block header as below:

// binary header data encoded as a hex string:
000000000000000003e6d3647001d1f455d585cdd3c298093902fe52ea4529ba01000030cd0594ebccfe15b205125165cc3b66986ed5b2a311cd8805000000000000000037022f7a3b9a2b199d53fbf1552be32c141892319966c3ef999d348d74cfb5827f476357a09b0518ae5ae1c1
// original header data that has been encoded to build the above header:
Version: 01000030
prev_block: cd0594ebccfe15b205125165cc3b66986ed5b2a311cd88050000000000000000
Merkle root: 37022f7a3b9a2b199d53fbf1552be32c141892319966c3ef999d348d74cfb582
Timestamp: 7f476357
nbits:  a09b0518
Nonce:  ae5ae1c1
Block header: 01000030cd0594ebccfe15b205125165cc3b66986ed5b2a311cd8805000000000000000037022f7a3b9a2b199d53fbf1552be32c141892319966c3ef999d348d74cfb5827f476357a09b0518ae5ae1c1
computed_hash: 000000000000000003e6d3647001d1f455d585cdd3c298093902fe52ea4529ba

How may I add our dummy transaction to the given header (suppose the header already have the merkle root in it)? What if I wish to add multiple transactions like our dummy transaction data to our block header ?


texts:
Thanks for your great content. I've got a question regarding Bitcoin Private Key.
If a hacker stole a Private Key and took possession of the coins by entering the Private Key into his own preferred wallet, then sent the coins to his own Bitcoin wallet or sold it via an online exchange"
1. Would the primary/main owner of the Private Key be able to figure out what has happened to his/her money and/or find the real name of the person who stole it?
2. Can the primary owner open a legal action against this?
3. What's the best course of action for the primary owner to do if this happened to get their money back to find the person who stole their money?
Thanks.


texts: Looking to store .145 of bitcoin in a strong wallet. Should I use Bitpay for this? If not, please recommend better wallets. No hardware wallets please, I am trying to save money.


texts: Where can I observe cryptocurrency bid/offer spreads?

texts: When I look on Coinbase, all I see is the last price that traded, correct?  How do I see the bid/offer spread before I trade?  Is there a place to put in limit orders? Is there another site where I can see the spreads for the different currencies?


texts: Why aggregating transactions into blocks?

texts:
I'm just wondering why do we need blocks. I mean, I could have my tx (signed), with its outputs/inputs, make a hash of it and broadcast it. Basically 1 tx per block, if you want to see it like that.
Then, a miner could run a lighter version of PoW (or any alternative, e.g. PoS) over the single transaction (with low difficulty). This way, we wouldn't have to wait over 10 mins/block to be created. Couldn't this achieve more TPS on a blockchain? (not talking about Bitcoin specifically).
Probably the answer is no, but I just want to know why. I found several related questions here but no one seems to solve my question...
PS: I read about the relay times on the Bitcoin network to be about 14s. My question is ignoring this delays.
Thanks :)


texts: Is there any exchange website that directly converts to a specific currency once a cryptocurrent payment is received?

texts: I wonder if there is some exchange service that I can use for my webshop (Woocommerce) that directly when a customer pays in the webshop, convert the cryptocurrency money to a specific currency like USD or Euro.


texts: where can I get realtime ticker data for robots?

texts:
I am writing a trading bot and concerned about rate limits.

I need realtime notifications for change in price either like a PUSH api service.

Bitfinex appears to be the only major exchange that offers PUSH notifications, so I am not concerned with Bitfinex. But all other major exchanges such as Kraken are of concern.

How can I get realtime ticker data for the major bitcoin exchanges?


texts: How to write OP_CHECKMULTISIG for the following 1-of-2 multisig P2SH script

texts:
OP_IF
  OP_SHA256
  <hash of secret>
  OP_EQUALVERIFY
  <pubKey of swap>
  OP_CHECKSIG
OP_ELSE
  <relative locktime>
  OP_CHECKSEQUENCEVERIFY
  OP_DROP
  <pubKey of refund>
  OP_CHECKSIG
OP_ENDIF

Actual code which i am using for the above script is

const script = this.app.env.bitcoin.script.compile([
      hashOpcode,
      Buffer.from(secretHash, "hex"),
      this.app.env.bitcoin.opcodes.OP_EQUALVERIFY,
     Buffer.from(recipientPublicKey, "hex"),
      this.app.env.bitcoin.opcodes.OP_EQUAL,
      this.app.env.bitcoin.opcodes.OP_IF,
      Buffer.from(recipientPublicKey, "hex"),
      this.app.env.bitcoin.opcodes.OP_CHECKSIG,
     this.app.env.bitcoin.opcodes.OP_ELSE,
    this.app.env.bitcoin.script.number.encode(lockTime),
      this.app.env.bitcoin.opcodes.OP_CHECKSEQUENCEVERIFY,
      this.app.env.bitcoin.opcodes.OP_DROP,
      Buffer.from(ownerPublicKey, "hex"),
      this.app.env.bitcoin.opcodes.OP_CHECKSIG,
      this.app.env.bitcoin.opcodes.OP_ENDIF
    ]);

As we see that this script has just one  public key(pubKey of swap) to sign with. But i want to sign it with two public keys.
I searched for it but found nothing, can anybody guide me?

I just want to follow this pattern

 OP_0 [Sig 1] OP_1 [PK 1][PK 2] OP_2 OP_CHECKMULTISIG


texts: Can I store the whole blockchain yet keep my actual wallet with bitcoins offline?

texts: I want to have the full blockchain "just in case" yet have my wallet be OFF the internet.  Like, on a laptop that's just for bitcoin, with wireless turned off.  Or possibly on an external drive that is backed up on multiple other external drives.  So can I use bitcoin core, and just store the blockchain there.  And use my other wallet when I want to receive money.  I have a substantial amount of money in coinbase and I don't trust keeping it there.


texts:
I have recently wanted to get into mining some crypto currency. And would like to use a GUI based miner for ease and convenience.

But I haven’t found any that seem to be any good yet it that are easy to manage and control.

Any suggestions would be fantastic


texts: Can I use curl to call getInfo from a the Bitcoin server?

texts:
I am wondering if its possible to use curl to getinfo from the bitcoin server thanks.

<?php
// init the resource
$ch = curl_init();

// set a single option...
$username = 'usernamefromconfig';
$pwd = 'passwordfromconfig';

curl_setopt_array(
    $ch, array(
    CURLOPT_URL => "$username:$pwd@127.0.0.1:8336",
    CURLOPT_RETURNTRANSFER => true
));

$output = curl_exec($ch);
echo $output;

// free
curl_close($ch);
?>


texts:
Are UTXOs signed by a private key?
I'm trying to understand exactly which parts of Bitcoin use public and private keys. You need a private key in order to generate transaction output, and to create a transaction that uses those outputs, but I'm not sure what happens in the middle.
My current guess is that they aren't signed. The transactions generating the UTXOs are signed, and the block containing the transactions can be validated and then traced back to the miner. It doesn't seem necessary to sign the UTXOs, and even if we wanted to, the only private key available would be the miner's.


texts: Do we need to maintain the ability to do a reorg over 100 blocks?

texts:
The protocol requires that freshly generated coins wait 100 blocks before they can be spent in order to avoid polluting bitcoin addresses with bitcoins that are "uncreated" by a reorg that invalidates the block that created them.

If we decide that "the chain with the most difficulty" means "the chain with the most difficulty over the last N blocks" and pick a good N, it could make some things simpler AND make transactions at a depth of at least N immune to a 51% attack.  Thus, it limits the value of cornering the market in hashing power.  Such "cornering" could happen without being noticed, so it has begun to worry me.

If I remember correctly, we've already done this by (sometimes?) making checkpoints in the Satoshi client at sufficiently large depths when new clients got compiled.

N = 4032 would ensure that two difficulty levels are spanned.
N = 100 would change the pain of a 100-block reorg from something barely tolerable to something impossible.

If the protocol were changed to use this, then a UTXO database based on the results of the blockchain up to the checkpoint block could replace the gigabytes of blockchain that we currently use for validation.

EDIT: Why I asked: It would be nice to validate a UTXO database so that one didn't have to build it from (always increasing GBs of) downloaded block data.  We validate transactions before passing them on, but do we validate them when we download a(n old enough) block?  I think we trust that whatever (old enough) block we get from a peer contains good transactions, so we don't hunt all previous blocks to validate them.  If this trust is already being used, as I suspect, perhaps it is more useful than we know.  I asked a related question: Would a normalized, hashed, protected chainstate reduce miner storage costs?.  I'll have to explore the work on making a UTXO Merkle tree as that seems promising.


texts: Is there a guide to learn how to program smart contracts for the Bitcoin blockchain?


texts: Disabling GreenAddress 2FA ∵ Google Authenticator doesn't generate the correct OTPs for it

texts:
According to the section "I lost my two-factor/mobile/etc (email/OTP|Authenticator/etc), what can I do?" of the GreenAddress FAQ page,

  You should always have at least two two-factor options enabled.

Unfortunately, I did not. I only kept the Google Authenticator one enabled.

  Additionally for OTP/Authenticator you should back up the initial seed number and/or QR code displayed. Provided you keep these backups you can maintain access to your coins even if you lose access to one method for any reason.

I did keep a backup of the Google Authenticator QR code (is this the same as the "initial seed number"?), but when I use the Google Authenticator or Authy apps to generate a OTP, GreenAddress / GreenBits doesn't recognize it.

Why would this be?

Is there a way to disable GreenAdress 2FA using the mnemonic and/or PIN?


texts: Is it possible to run HD derivation with an encrypted master node or seed?

texts: Given either a seed or the private part of a master node, that is encrypted using AES-256-CBC (or another secured symmetrical cypher) with key K, is it possible to run derivation such as described in BIP32 to obtain derived private keys also encrypted using the same algorithm and the same key K?


texts: How to calculate conversion exchange fees?

texts: According to Exchange A, I can withdraw 1 BTC as 90 fiat. Or I can send them 1 fiat in return for 0.01 BTC. How do I calculate percentage fees for one way conversion?


texts: How can we use Blockchain for Land Registration Use Case?

texts:
How and where can we integrate Blockchain in this use case?

Say buyer and seller visits the registration office with sale deed they prepared.
The details in the sale deed is compared by the registration analyst with the land database.If the details match the registration officer will sign off the document.


texts: GetAddr not returning connected node addresses

texts:
I am writing a simple program that connects to nodes in order to index them, kind of like blockchain.info nodes works. Doing this in GLang using the btcd/wire library to create the messages, the message sequence is as follows:

Version ->
<- Version
<- Version Acknowledge
<- Ping
Pong ->
GetAddr ->
<- Addr

However upon reading the list of addresses returned they all are either empty or contain a single address that corresponds to that nodes address (I.E. it returns its own address).

From reading the wiki I know nodes only return addresses of connected nodes that have a timestap less than 3 hours ago, and that there are certain dns nodes and seed nodes. Are there any nodes that will always return connected peers regardless of their age? Or any way to bootstrap the process? How does a normal full node connect to more than a handful of nodes when these may never return anything (if they have been alive for more than 3 hours, then they will only return something on new connections)?


texts: I own some bitcoin, but forgot how and where i stored them. How can I find my lost bitcoin?

texts: I purchased one bitcoin back on 2/8/14 and now don't recall having any kind of account information.  I actually forgot about the purchase until recently.  My email address has not changed since I purchased the one bitcoin back in 2014.  Not sure how to access that one bitcoin in the event I would ever want to sell it or just know how to get to it.  Thanks for any guidance you can provide.


texts: Is this an ok "poor man's 2 out of 3" key solution?

texts:
In the situation that you want no individual to have the complete private key, but you do want  to share the complete key between 3 individuals, of which any 2 can construct the complete key, what is the downside from doing something like this:

Orig key = 1 2 3 4 5 6 7 8 9 (abbreviated for demo)

key 1 = 1 2 _ 4 5 _ 7 8 _

key 2 = 1 _ 3 4 _ 6 7 _ 9

key 3 = _ 2 3 _ 5 6 _ 8 9

obviously any 2 keys would construct the entire key again.

Apart from the decrease of key strength to 1/3 of the original, are there any other potential issues ?

This would be used for "short term" escrow accounts where, in the case of a "winner takes all", the escrow would just communicate their key to whichever counterpart won. If the escrow failed to send, then the counterparties could choose another (trusted) escrow and transfer the funds to them.


texts: Two identical transactions and hashes in Block Hashing algorithm

texts:
As I was reading Bitcoin hashing algorithm, I see that a Block Header contains hashes in the form of fields like
hashPrevBlock , hashMerkleRoot . I have following questions:

1) Are the transactions 100% secure? If yes, then I am wondering if Hash is the reason behind it? Since moving forward in a hash is
easy than backwards.

2) Suppose there are two identical transactions happening at the same time, are those transactions are going to get differentiated
based on the Hashes ?

Please elaborate.


texts: How do you download blockchain data (transactions etc.) using a node? Best ways to get a node?

texts: I am just curious how one can download bitcoin data and blockchain using a node. Where should I start?


texts: getnewaddress and watch-only addresses (importaddress)

texts:
I am aware it is possible to use "importaddress" to import bitcoin addresses without their associated private keys.

For an online shop that uses "getnewaddress" in order to present a customer with an address, is it possible for "getnewaddress" to only ever serve up "watch-only" addresses?

Ie - I do not want the Bitcoin core wallet to create new addresses. I want to use "importaddress" to import 10k watch-only addresses.

Is the above possible? And, if so, what is the expected behaviour of "getnewaddress" in the event of all 10k watch-only addresses being used up?


texts: Can't decrypt bitcoin core wallet, did I made a backup at the wrong time?

texts:
I am confused on why my bitcoin core wallet password would not work. I am 90% sure I tried the right password(s).

wallet has many receiving addresses (10 000), I generated them with Linux from command line in 2017
I encrypted the wallet (probably after generating the addresses).
started receiving payments, made copies of wallet.dat after some of them, I see the different wallet.dat backups have same size (probably normal).
now in 2019 I downloaded Bitcoin Core 0.18.0 on Windows 10
put my wallet.dat in the bitcoin data folder
I can see the received coins
wallet shows as encrypted in the lower right corner
if I try to send and enter password, it says it is the wrong one

1) Can this be because my wallet.dat is since before I encrypted it ? If so, it would not show as encrypted when I start the program, right ?

2) Can errors like this happen because wallet is too large (10 000 addresses, 5.7 MB) and maybe it got corrupted while generating that many addresses ?

3) Any known issues of incompatibility between wallets created on linux ubuntu vs windows, that can cause such problems ?

4) Can password stop working because the Bitcoin Core version changed ? I can see the wallet was first created in Oct 2017 so I used whatever Bitcoin Core version it was then.

// It is kind of hard to make experiments with different wallet configs because of the large address list, it takes forever to load the program/blockchain.


texts:
Is there any validation service that tests/validates/vets wallet implementations?

I use bitcoin-qt on the desktop and I'm not worried about that wallet, I assume it's been well vetted, but if I were to get a wallet for my (Android) phone, is there a way I can be assured the implementation is correct, secure, and not malevolent?

Added elaboration: It seems feasible for a trusted 3rd party to be in the business of validating wallet implementations. Wallet implementers would submit their implementation to the service, the service would run the wallet through a test suite, examine the code, etc. and if the implementation passed the service would publish a hash of the wallet. When you get a copy of the wallet implementation you could check its hash and against the published hash so you'd know it hasn't been tampered with.

Likewise an online wallet service (Mt. Gox) could submit its implementation for 3rd party validation to increase its trust factor.


texts: How can I find the transaction that spends a specific output via an API?

texts:
I am wondering how I can find the transaction that spends a specific output (for a large number of transactions). So for example, I have a transaction like the following: https://www.blockchain.com/btc/tx/ebd4a554faff31dd2a07135913fa073012a4495b195c1a5d5a9a7bca3e88de61. It has two outputs which are both spent. I would like to find the transaction that spends that output. Blockchain.com has a link to the spending transaction via the tx index (https://www.blockchain.com/btc/tx-index/355543195). However, they do not offer this an API endpoint and just in the GUI. I was wondering if there exists an API that offers to find the transaction via either the tx-index or other means.

Background
I just started doing research on the lightning network and I was interested in the closing of channels. In particular, I took a snapshot of the lightning network in January from https://graph.lndexplorer.com/api/graph and scan all the channel transactions to see if the channel is closed. If the channel is closed I want to know if it was a mutual close, unilateral close, or a disputed unilateral close (an old commitment tx which should have a revocation tx following the commitment tx on the chain). Since the dataset has around 16.000 channels, I need an automated way of parsing through the transactions.


texts: Does assumevalid lower the security of Bitcoin?

texts:
Bitcoin's assumption was to download the blocks and verify it in order to prevent getting fooled.

But by default, the assumevalid option is enabled in the software, which, as I understand it, makes some data (until 2017?) real without verification.

So, can we consider Bitcoin nodes safe? If so, why?

Of course, you can disable this option, but 99% of people may not even know that this option is enabled.


texts: Any wallet that support cancellation of transaction?

texts: Does anyone know what free bitcoin wallet can support the cancellation of unconfirmed transactions?


texts: Transaction unconfirmed, send with Multibit HD, too low fee

texts:
2 days ago I tried to send BTC to a different address, using Multibit HD (then not knowing Multibit is dead).
It was send with a fee of 0,0001 (52.083 sat/B).
I now know this fee was too low.

The transaction is not being confirmed by the network. And after using the repair wallet in multibit a couple of times it is still saying sending. Older transactions are now saying receiving isntead of received...

I have not used BTC in a while and did not know that multibit is dead.
I am trying to google my way out of this but so far no luck.

Is there any way for me to cancel the transaction and resend it with more fee?

By the way I am not so good with software so some of the options I have come across are too risky for me.

Thanks in advance

EDIT: TX 4b0e68e0ca47f45f8adfbe749ff117ab91f871161b3c81e9a831550cf5c61899


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

texts:
I was to trade Bitcoins for PayPal quite frequently and I know that PayPal doesn't allow Bitcoin exchanges to accept PayPal payments.
But there should exist a person-to-person trading site that works like a forum and where people choose how to pay each other, no?

I know about bitcoin-otc, but I'd prefer a forum-like concept better instead of IRC.

Thanks in advance!


texts: All my funds are showing up as unconfirmed. What can I do?

texts:
The last transactions were taking a lot of time to confirm and now I find my funds are unconfirmed. What is happening? What can i do?
Thank you for your help


texts:
As I understand, the client send the following information to server
 1.the hash of the message,
 2. public key
 3. signature made by private key

And the server verified the signature with the public key and hash, to check if it belong to the certain private key, server also need to check if the public key correspond to the ripple address.

Am I right?

And I have seen that there is a public key recovery method for ECDSA signature.https://crypto.stackexchange.com/questions/18105/how-does-recovering-the-public-key-from-an-ecdsa-signature-work

If my previous judgement is right, then is it possible for client only send the signature and the hash to the server? I guess there is a problem because we can't derive the curve from both the signature and the hash.


texts: Issues when creating Bitcoin Cash wallet

texts: I created a Bitcoin cash wallet on https://bcc-wallet.btc.com, entered the Bitcoin Cash address into Coinbase to transfer my BTC, and Coinbase shows the transaction as successful, but I am not seeing it in my BCC wallet. Could you guys please throw some light on it? Any help will be highly appreciated.


texts:
What will happen if someone does not copy and paste the "To" address properly?

For example:
If my address is 1xxxxxxxxxxxxxxxA

and the person tries to send money to 1xxxxxxxxxxxxxxx
(note the missing last alphabet)

will the transaction go through and will the coins be lost?

Thanks!
Ryan


texts: Why universities and charity don't accept Dogecoin or Bitcoin donation?

texts:
I just tried to contact the top universities in the USA and other countries. i also contacted the charity organizations such as Red cross and united way, etc. but no response at all. seems they don't care the donation of crypto currency like Dogecoin as the price is too low?
The fact is that most of us are ordinary people who can't donate millions like those billionaires. but we do can donate 10k dogecoin or 1 million dogecoin instead. we also wanna show our support to the chariting causes to make the world better. if i donate 100 usd, need pay 25 usd or more to pay wire transfer fee. card has lower fee but i don't want to show my card info. so finally i would choose to quit donation. that ruins my passion toward charity cause. that's really bad. while with doge, only need pay 1 doge as fee.
Yes, they may want BTC as 1 BTC equals to near 60k usd. the question is how many people can donate 1 btc? this is really unreasonable. many people waiting for support while they are rejecting the support from general people like us. they are too lazy to converting doge into dollars. they only waiting for the millions dollars donation from rich guys.
I predicate the first University that accept Dogecoin donation will gain a Huge amount donation.but which university or charity organization will be the first? Let's see. :)
Pursue your university to accept Dogecoin. i would be pleased to donate $500 valued dogecoin to the first one that accept dogecoin donation. will you donate doge if they accept?
“No accumulation of steps,can't lead to thousand miles. No integration of streams,can't result in sea”


texts: Multibit : transferring coins between local wallets

texts:
I've created a second local wallet in my multibit. The first wallet is aimed for receiving and sending coins, while the second one is aimed to separate savings.
Is there a way to transfer coins between these two local wallets without paying fees ?
It is possible in a normal bank account but the fees here are really too big.
Thanks for your help :)


texts: What happen if the Bitcoin network is down, or all miners stop keeping records?

texts:
I am not sure I understand Bitcoin very well. What I understand is that Bitcoin is there because of the network.

What happens if the network is down for any reason?

What happens if the miner that keeps my records of Bitcoin dies or doesn't want to open his computer again?


texts:
If I pay someone in bitcoin, presumably I have to utilise both my private and public key in some way, and presumably this has to be verified by the network.

Now does the network thus obtain my private key as part of the verification process?  If not, how do they verify without it and if they do, does this mean my private key is now compromised?


texts: Have network DDoS attacks ever been successful on any coin?

texts:
Has a cryptocurrency network ever been fully DDoSed so that the blockchain did not advance during the attack?

If so, which one and how?


texts: What exactly happens when a node detects a double spend?

texts: Does the node drop both transactions? Does the node choose which one to keep? What exactly happens? Will both transactions be rejected by the network or will one of them be eventually accepted?


texts: Is the nonce in Bitcoin the answer to the puzzle from the previous block?

texts: If, in Bitcoin, the nonce is included in the header of the proposed block, is it the answer to the puzzle from the previous block?


texts: Can a 'free' Bitcoin 'marketing' ad be checked in any way

texts:
Total Bitcoin newbie here. I have no bitc, nor a wallet, nor am I sure I want one. I've been intrigued for a while, but security is a big passion of mine...

Today just now youtube pointed me to an interesting lecture by Bill Gates and others. [1] Apparently it was at the SF, CA exploratorium in the 'morning', but that would not fit with the current timezone if it is live. (That part just came up at the end of the Bill Gates section a few minutes ago.)

This video is supposedly by Microsoft Europe - but the author has only this video.

There was a big picture on the screen while Mr. Gates was speaking at the "Village Global" event. It advertised free bitcoin if you send in bitcoin, eg they will send you back 10x what you send in from 0.1 to 20 Bitcoins.

The address per "Microsoft admin" in chat is: 1w1AQvpK4ixo9YQ3KHFYi4BgKHuDqg1hR

Online I looked that up [2] and found this:

Total Sent
0.00000000 BTC

I believe that indicates the ad is definitely a scam.
Did I get it right???

Are there other ways to check for scammers that I may not know?
Thank you so much!

[1] Bill Gates about Microsoft Future, Quantum Power, Bitcoin Evolution - YouTube: https://www.youtube.com/watch?v=oKzuP-Pljpw

[2] Blockchain Explorer - Search the Blockchain | BTC | ETH | BCH: https://www.blockchain.com/btc/address/1w1AQvpK4ixo9YQ3KHFYi4BgKHuDqg1hR


texts: Is there a simple reference implementation of ECDSA algorithms?

texts: I'm using Node.js's elliptic library to do some signing on my app, but there is some chance I'll migrate it to another language. That library is kinda big and not easy to port, so, I wonder, is there a reference, siple implementation of ECDSA algorithms (key generation, signing and recovery) anywhere?


texts:
I have Toast Wallet in order to store my XRP properly. Now I want to perform my first transaction from my wallet to my exchange in order to understand how it works.

In a note of the Toast Wallet is written:
"The Ripple Network requires a minimum 20 XRP balance at all times and charges fees based on congestion even for failed transactions"

Do you know how much are the charges fees more or less and if even in my case I have to pay that?

With what probability I receive a failed transaction? (supposing I'm typing all address and informations required well) .. [EG If there is a lot of traffic in the network is possible that I receive a refund and so I lost my fees?

How many XRPs can I transfer? Can I transfer only 1 XRP? (obviously I must have 20 XRPs on my balance wallet)

Thanks for the ansewrs,
Marco.

P.S. Sorry for my bad english but I'm Italian :)


texts: What is the difference from coinjoin and a coinshuffle transaction?

texts: Coinjoin and coinshuffle creates an anonymous transaction. But how are they different? And which services implemented these features?


texts: Are generated public/private keypair the most random possible?

texts:
The number of possible Bitcoin private/public keypair is very strong (2^160 which is 1,461501637×10⁴⁸).

However, if the random generator is not good enough, only a subset of all that "space" could be used which would considerably break the security of Bitcoin.

That kind of problem has already happened, like that Debian bug in the OpenSSL package.

How can we be sure that random generation is done so it could generated all private/public keypair from the possible "space" ?


texts: Wallet's dollar value of transaction is WILDLY off my actual dollar payment

texts:
I was using Safepal Wallet and moved my funds to Trust Wallet.
I am currently tracking those original transactions for tax purposes next year.
I was simply using hash/txid provided in the transaction overview, but have an odd problem. The amount that shows up on my wallet is correct, but when I click to see the details, the hash/tax id links to a transaction where I received 5 BTC for around $250,000, but the original and true amount was around $30.
I have no idea what to do. I have checked on different searches and this is the same information. How on earth? Will this somehow screw me for taxes--be reported?
I have the correct number reflected on my wallet balance, but the "details" of this transaction are blatantly wrong. I have other coins and transactions with similar issues and some that are exactly correct. PLEASE HELP.


texts: What database engine does Bitcoin and other top altcoins use?

texts:
I'm curious to what database engine does Bitcoin and other altcoins use to store their blockchain data. Do they all support sql queries or is it something else?

The main ones I'd like to know are:

Bitcoin, Litecoin, Monero, Ethereum, Dash, Ripple, Factom, NXT, and other ones.


texts: Can the Lightning Network work and live independently from Bitcoin?

texts: Is the Lightning Network Protocol capable to serve micropayment services without broadcast any transaction to the blockchain?


texts: Need help with a .conf file to run a lighting node?

texts:
This is my configuration file and i followed all of the instructions for the program but it always gives me the error message about something missing. I don't even know what programming language .conf files are written in. if someone can give me some guidance that would be much appreciated.

eclair.chain=mainnet
eclair.bitcoind.rpcport=8332
eclair.bitcoind.rpcuser=foo
eclair.bitcoind.rpcpassword=bar
eclair.server.port=9735
eclair.node-alias=<myalias>
eclair.node-color=00ff00
eclair.bitcoind.zmq="tcp://127.0.0.1:29000"


texts: Transaction with unparsed input address ? What does it means?

texts:
I just see this transaction which is special : one of input address is spending a valid amount… But why is it unparsed ? Why no ScriptSig while stil being valid ?

Also what’s the purpose ?


texts: Bitcoin Halving - What is it? How is it calculated? Does it affect my bitcoin balance?

texts: I have read a lot about the halving that is set to take place later this year, but my question is how is halving calculated? Will it also effect my bitcoin balance as a whole?


texts: So, I generated a new address with getnewaddress and made a payment to it. Soon after the computer bitcoind ran on shut down (due to loss of power) and after booting it up again my wallet doesn't know of the address anymore. I'm assuming all that happened was that the newly generated address wasn't written to disk in time. But the keys should still be in the keypool, right? How do I restore the keys and import them into the wallet? I still have the address.


texts: Can I have multiple working public keys per wallet?

texts:
My Android Bitcoin wallet changes the Public key (the one I give to others) after every transaction for security.

However, I want to put up a Public key online for donations.

Does this mean that my one wallet has multiple public keys (and I keep all the bitcoins given to any address owned by me) or is it that my private key changes also, and all BC given to my old key gets sent into the void?


texts: How to migrate wallet from namecoin to namecore?

texts:
Today I updated namecoin by building the new "namecore" reimplementation  but when starting namecoind I got this message:

Error opening block database.

Do you want to rebuild the block database now?

and before I could do anything namecoind crashed.
So I moved away the Namecoin folder and let it regenerate everything, blockchain included.
This time it started without errors, so I copied my wallet.dat into the folder and restarted namecoind but I got an Error: and it crashed again.
The debug.log shows this:

2015-06-29 15:36:51 Using wallet wallet.dat
2015-06-29 15:36:51 init message: Verifying wallet...
2015-06-29 15:36:51 CDBEnv::Open: LogDir=/home/michele/Library/Application Support/Namecoin/database ErrorFile=/
2015-06-29 15:36:51 Renamed wallet.dat to wallet.1435592211.bak
2015-06-29 15:36:51 CDBEnv::Salvage: Database salvage found errors,     all data may not be recoverable.
2015-06-29 15:36:51 Salvage(aggressive) found no records in wallet.1435592211.bak.
2015-06-29 15:36:51 Error:

I figured the wallet format has changed somehow, so using the old client I dumped the private keys and I succefully imported them using importprivkey. I can see the address, the balances and all but name_list shows nothing.

How do I get back my names now?


texts:
Is there a minimum limit of bitcoin that can be added into a channel during the initialization?

And, if I decided to open a channel with a lightning node, also that node has to add money to the channel?


texts:
Came across this post while researching, and it claims:

This mnemonic: weary weapon unseen like like like like like like like like like and this one: sister glide dude near muse sent like like like like like like both produce the same binary seed (which is this
in hex: 0x1003ca7a7000000000000000000000000) and they both produce
the same address list (starting with
17A2fgCpcKEbg7CbfiJwAb8sjdEzUWD2y2)
4/1000 number comes from this: (# of mnemonic permutations / # of
binary seeds) - 1 == (1626^12 / 2^128) - 1 == about 4/1000. So about 4
in 1000 mnemonics correspond to two binary seeds / two address lists.

Can someone explain/verify the reality of this? Is this true? Applicable to only 12-words mnemonic or to all? Or not valid at all?
When I went ahead and tried to use the 12-word mnemonic provided, I found out that "weary" is not even a word in BIP39 English wordlist, but words are not chosen on the basis of security but rather to reduce human error in reading and transcribing the words. Does the claim hold up? And after reading tons of information on the subject, this is the first and only source that I have seen mentioned mnemonic -> seed collision.


texts: Bitcoin transaction with 0.0001 BTC fee not getting confirmed?

texts:
I sent the following transaction a few hours ago with Bitcoin-QT:
https://blockchain.info/tx/b5682b48484a8752be62c6b4036eaf8a8f005d9ea75cbff434476b7506a9e3a2

And the transaction still has not been confirmed. I attached 0.0001 BTC transaction fee.

Did I lose the money? Can I do something to speed up the confirmation of the transaction?


texts: Are change addresses generated on the fly or pre-generated with wallets?

texts:
What is the precedence in terms of generating new addresses?

Do wallets generate 10 on the go, then switch them out or do they generate a new one, each time the old one has been used?

Also, do they generate new change addresses as soon as they see that a transaction will need a change address?


texts: I have read on twitter that WBTC has solved bitcoin scaling issues. Is it true? I want to know more about WBTC


texts: Is there a way to migrate from c-lightning to LND without having to close and reopen all channels?


texts: Options to automatically invest to Bitcoins each month in EUR?

texts:
I am looking for options to have automatic transactions to buy bitcoins each month. Trading currency I need is Euro.

What are options to invest each month to buy bitcoins?


texts: If a court orders mining pools to seize funds, they will modify their software to do it, or be shut down' - can this happen?

texts: I thought nodes could prevent this too.  but if enough miners did do this, what could happen in worst case?  thanks in advance for responding


texts: How can I officially prove that a Bitcoin private key is owned by an entity?

texts:
I am the co-founder of an early-stage startup that aims to prove existence of various qualifications (academic, professional...) via the Bitcoin Blockchain.

In order to validate a piece of data, an issuer (say a university or other issuing body) would have to send a small transaction from their wallet which is managed by us.

Is there any way to officially prove (in this case in UK legislation) that a specific legal entity is in possession of a bitcoin private key and, therefore, to the coins associated with it? I know of a "statutory declaration" but is there anything more specific I can do?

Basically I would like to transfer ownership of the wallet to the customer, in order for myself to be criminally punishable if I upload qualifications to the Blockchain without their consent.

Is this at all possible?

Thanks!


texts: How do I check the checksum of a Bitcoin address?

texts:
I'm working on a Bitcoin ATM. We want to detect addresses that are entered incorrectly.

There's a checksum on Bitcoin addresses - but how can we check it?


texts: How is this 1 input 2 output tx larger than this 2 input 2 output tx?

texts:
I saw the following liquid transaction with one input and two outputs is byte-wise bigger than another liquid transaction with two inputs and two outputs. How is this possible?

One input transaction (2772 vB): https://blockstream.info/liquid/tx/35d4db9621c70d3bcfe258487fd74447e12f5c9b71b3161e22e15bdeb157eea8

Two input transaction (2102 vB):
https://blockstream.info/liquid/tx/75621a91c3b3d779c646ecfd8278462040e743ef6535343ae0dc41e2ed7b6fa8


texts:
I just saw that Gavin is employed with a company called TruCoin. Any idea what does it actually do besides help develop and QA the bitcoin client?

The about page (odd URL) doesn't explain it much.


texts: How much do nodes get from blocks, including fees?

texts:
I am trying to evaluate how much one could earn as pool owner/solo miner if bitcoin really appreciates in price. To get a number i try to get a figure how much one mined block generates in for example a month, week, year.

How much fees does one mined block generates actually in a given timeframe?
What percentage of that is from the block reward, and what percentage is from fees?


texts: How can I regain coins on a device with insufficient memory to fully synchronize?

texts: I have started syncing the blocks and didn't know how much room was need, I am about 40 gb through and my device is full. I already have money on the account, but it isn't synced far enough to send the bitcoins out.


texts: Running Miner as embedded system (No OS) - Can it be done?

texts:
I've been messing about with TCP/IP stacks on some fairly powerful MCU's lately (mostly the ARM M4 series), and this sort of led to the crazy idea, that I could somehow create an embedded platform specifically for mining (using FPGA's as co-processors). I've dabbled in pool mining just for fun, but came to the realization I actually have no idea how it works,
protocol wise. I already have the hardware scattered around my house somewhere, so it could be a fun (ie, time consuming) project!

I understand the bitcoin client does several things, such as validation of all blocks, handling transactions, address, wallets etc. But for an embedded miner solely involved in a pool operation, what exactly would be the minimum functionality? As I understand it, the pool largely handles everything, and all you are required to do is receive/send data through JSON-RPC and process it. Is that really all there is to it? Or am I missing something absurdly important? Any clarifications would be awesome!


texts: How can I see which values bitcoind is using for eg. dbcache, or other memory and connection params ? If the value is NOT set in bitcoin.conf. Is there a bitcoin-cli command to check all the params ?


texts:
I'm getting a connection error, or just a "connecting..." message that doesn't stop. though the connection on my end seems to be fine. This is a printout of my console. If there is already a fix for this, would someone please direct me to it? This is a screenshot of my console. I'm connecting to slush's pool if that helps.
http://i.imgur.com/vcdAY9k.png


texts: Looking for a comprehensive ICO dataset (prices & dates)

texts:
I'm working on a short research project on the performance of ICOs and how that relates to the overall sentiment in the crypto market. Unfortunately, I've had no luck so far looking for the required data. I need data on ICO dates and prices as well as price series for the post-ICO period. I've so far only found disjoint sources and no comprehensive dataset. Can anybody point me in the right direction?

Thanks!


texts: My multibit wallet (Ver. 0.5.15) shows nothing after being sent part of a coin?

texts:
I've reset the blockchain about 5 times over a week and still nothing

I upgraded multibit wallet to version 0.5.15 and still nothing.

Any ideas or help would be greatly appreciated!!! :-)


texts: Does anyone keep a track of various Bitcoin-related malware, such as the recent DevilRobber Trojan?


texts: Why this alternative method to mining will fail?

texts:
From what I understand, we need mining to validate the block, we need the proof of work to limit the number of miners can add a block, and we need the block interval to give time to the new block to spread across the chain.
And usually it's said mining is like a lottery, and hence the alternative idea:

Instead of proof of work, we choose randomly some of the miners registered on the network, only that miner can validate and add the next block, and it has let's say 2min to do it, if not another miner is chosen randomly.
In this way we don't need to waste a lot of energy to solve the hash problem.

What is the problem with this solution?
(I know it has a problem, but I can't see it and I think knowing this will help me to understand better why we need the proof of work)


texts: Why are Transactions sending out randomly?

texts:
I see in the sourcecode this two lines:

// Do this infrequently and randomly to avoid giving away
// that these are our transactions.

in the method ResendWalletTransactions. Why is this necessary? If a client send out his transactions every 30 minutes and the receiver put these transactions in his own queue and send this transaction list every 30 minutes to all his neigbors I don't see why someone should recover the own transactions of the client.

The full beginning of the method is something like:

void CWallet::ResendWalletTransactions()
{
    // Do this infrequently and randomly to avoid giving away
    // that these are our transactions.
    static int64 nNextTime;
    if (GetTime() < nNextTime)
        return;
    bool fFirst = (nNextTime == 0);
    nNextTime = GetTime() + GetRand(30 * 60);
    if (fFirst)
        return;


texts: How does crypto exchange secure private keys?

texts: I'm wondering on what is the current common apporach that is used by centralized crypto exchange to secure the private keys of the bitcoin wallets


texts: My btc to refill my cardrockcafe was never recieved

texts:
I send  0.007 btc to the following address : 18pdflGW7Mz6KqXFTjX7bg7Ta3grhMCJYK.
BUT THEY never received it.but my btc account is been deducted that amount.can u pls check into that and tell me what to do or what I did wrong.thanx


texts: How do I determine the balance of an address I don't own? (WebAPI or local API)

texts:
I have an arbitrary address.  How can I get the current balance of the account through a Web API? ... how do I get it for a local API?

I'm also interested in all transaction history for that address.  Let me know if the API can offer that as well.


texts: OS X 10.7 - Where is Bitcoin data stored?

texts:
Possible Duplicate:
  Is there wallet.dat for OSX?

Upgrading my HD; clean install and I want to copy the wallett etc from old hard drive. What do I need to copy? Thanks in advance.


texts: How difficult is it to determine the owner of some bitcoins?

texts:
When Bitcoin was making the media waves back in 2011, a lot of it focused on the anonymity aspect of bitcoins, the hacks, and the illegal contents of the silk road onion address. From my limited understanding, it didn't seem like bitcoin wallet owners and transactions were all that anonymous, only merely obfuscated.

I feel like one would have to go out of their way to really make their bitcoin ownership anonymous.

I would like empirical resources on:

1) finding a user through a block chain

2) further obfuscating ownership of bitcoins

and any other currently relevant or useful literature. Perhaps a case study of an actual investigation on a bitcoin holder. (Like tracking down perps in the bigger security breaches)


texts: electrum wallet help needed funds missing

texts:
I have a problem and not sure if it’s a hack or my back up has not worked.

I was sent a laptop replacement and asked to send the old one back on the warranty so I was removing all my stuff across, I first formatted the new replacement laptop put updates and anti-virus on before downloading a new wallet from electrum.org , using my seed (offline) inputted it into the into the downloaded wallet it asked me for my password and started synchronizing.
Stupidly the day after I reformatted the replacement laptop and when I referred back to the old laptops electrum wallet, there are now 2 transactions from the same date as I tried restoring the wallet. I’ve used electrum and it kept my coins safe for over 2 years but now I’m cleaned out 

I’m finding it hard to understand if it would have been possible for me to somehow to have created a new wallet address and somehow imported the funds from the old seed would this be a possibility
I have ran some software and it’s found the file Default_wallet on the formatted laptop, do you think it’s worth getting the software to recover the file or is it a waste of time?

I really appreciate anyone’s help on this matter and more then happy to make a donation to if I can get them back.

I can all so provide the block chain link id if needed as says there was 2 transactions at this time this happened


texts:
Bitcoin's taking a lot of space on my C drive, and I would like to move it to another drive. I've figured out to do it using symbolic links, but the problem is that my Bitcoin client is currently synchronizing with the network. Is there a way to pause it, so I can move the data and then go back to synchronizing?

My C drive's almost running out of space.


texts: Why was Blockchain.info DecryptWallet removed?

texts:
https://blockchain.info/DecryptWallet.html has been removed for quite some time. Anyone know why?

PS. FWIW, an archived copy at Pastebin


texts: What value should nonce be when mining bitcoin ?

texts: When the miner program start, the value of nonce is zero or a random number? Which of them is better?


texts: Link my bitcoin address with multiple wallets

texts: I created a CoinBase bitcoin wallet address, can I share this address with Electrum desktop software instead of having different addresses and paying the transfer fees. Or is there another wallet like coinbase that has less fees and good security. Bear with me, I am new.


texts: What are the most notable attacks on pools?

texts:
Since Bitcoin's inception there have been several attacks on mining pools. There was the Linode problem, where some 46,000 BTC were stolen from pool accounts.

What are some other notable attacks on mining pools?


texts: How many peers does bitcoind try to connect to?

texts:
Let's say a new node try to connect to the network.
Since it doesn't have any node in its peers.dat it makes a request to the DNS seeder and receives a list of addresses.

Now, how many of these addresses will it try to connect to?
What about the same when retrieving addresses from peers.dat?
Is it possible to alter this number by using some option?


texts: Using bitcoind RPC to identify an incoming transaction that has been replaced using BIP125 Replace-By-Fee

texts:
In the context of running a web service that accepts payments in Bitcoin, how can we use bitcoind to identify a transaction that has been replaced using BIP125 Replace-By-Fee?

When RBF is used, a new txid is created, resulting in two unique transactions. We show unconfirmed transactions to the sender, resulting in the tx that was originally replaced continuing to appear as 0-conf.

We have considered using the following logic but suspect there is a better way.

("confirmations" == 0) and ("bip125-replaceable" == "yes")

Looking up the original txid on blockchain.info results in "Transaction rejected by our node. Reason: Transaction was previously accepted but has been pruned from our database."


texts:
Reports indicate that there are three default addresses to which victims of Wanna Cry are asked to send funds.

Assuming that Wanna Cry actually does decrypt once payment is verified, how can the software know that the specific computer is the one that should be decrypted in association with the victim's payment?