36 votes
Accepted

How to unstuck a low-fee transaction with blockchain.info?

this is a generic answer applying to "light" wallets - I don't know much about the blockchain.info-wallet There are several approaches that may work. I'm not sure which methods are most ...
tobixen's user avatar
  • 831
20 votes

My BTC was stolen using my Blockchain pairing code

Blockchain.info pairing code allows you to sync wallets. For example, it's for when you have coins on your phone and you want to be able to spend them from your computer. So, they synced their wallet ...
MCCCS's user avatar
  • 10.1k
15 votes

How do I cancel my blockchain transaction (still unconfirmed)?

Cancelling unconfirmed transactions is easy. Just submit a higher fee double-spend transaction. For example: if you sent a 0-fee transaction, it could take a day before it gets mined onto a block. ...
Erik Aronesty's user avatar
12 votes
Accepted

Download single and specific block for study purposes

However this is JSON, I imagine I can't use it to verify the nonce. You can. You can build the block header using the data at the beginning of the JSON object and then hash that. Of course it would ...
Andrew Chow's user avatar
  • 68.5k
10 votes

Can I find out on which website I got my Litoshi address?

Look at a list of Litecoin web wallets to see if any one them sound familiar to you: LiteVault - Online Litecoin Wallet; private keys encrypted locally Hive Web Wallet - Online BTC/LTC wallet; ...
Closet Inventor's user avatar
9 votes

BlockChain.info Investments? Sounds like a scam

Obviously, he is a scammer trying hard to look similar as the Blockchain's Official Investment scheme but there isn't anything like this ever before. Many scammers are there, one of the most luring ...
Pandit's user avatar
  • 191
9 votes

Generating a Bitcoin Address QR code with current USD price embedded?

You can't include the USD amount, but you certainly can include the btc amount in the QR code. The QR code essentially embeds a text like this: bitcoin:1ArmoryXcfq7TnCSuZa9fQjRYwJ4bkRKfv?amount=0.005 ...
Jimmy Song's user avatar
  • 7,749
9 votes
Accepted

What does "Unable to decode output address" mean?

If you look at the output script for that output, you can see it looks like this: RETURN PUSHDATA(32) [some garbage] This script, beginning with OP_RETURN, is called a null-data output, and is used ...
meshcollider's user avatar
  • 11.8k
8 votes

Shared Coin in BlockChain new wallet?

You cannot. That feature has been was "temporarily" cancelled due to numerous reports of stuck transactions and growing awareness of its privacy limitations: https://blog.blockchain.com/2014/03/17/...
seek adventure's user avatar
8 votes
Accepted

If the nonce is 32 bits why the proof of it is difficult?

The vast majority of the time, none of the 2^32 possible nonces in a particular block header template will result in the header having a hash that meets the proof-of-work target. In fact, the ...
Nate Eldredge's user avatar
7 votes

Transaction with Multiple Inputs having Same Address

Inputs do not refer to addresses, but rather unspent transaction outputs (UTXOs). If there are multiple UTXOs payable to the same address, then a transaction spending those UTXOs will have to list ...
Jestin's user avatar
  • 8,822
7 votes

What does "Unable to decode output address" mean?

Click "Show scripts and coinbase" to see what that output really is. In this case it's RETURN PUSHDATA(32)[8013...] RETURN (or OP_RETURN) causes the output to be unspendable. The PUSHDATA then is ...
Nate Eldredge's user avatar
7 votes

Why was giving someone else my 12 word backup a bad idea?

someone on blockchain support ask me to tell him my back up fund 12 word in order to reverse my bitcoin which was unconfirmed in my transaction Sorry to say, you were definitely scammed. You cannot ...
chytrik's user avatar
  • 18k
6 votes

How block explorer technology works?

blk.dat files contain blocks data in raw format. Also a leveldb index is maintained that helps to quickly lookup blocks/utxo. You can find the details here and here. Blockexplorers will not directly ...
dark knight's user avatar
  • 1,997
6 votes

Longest unconfirmed transaction?

A transaction could go unconfirmed indefinitely. The order in which transactions are confirmed is decided by miners, and generally they will be incentivized to include only the highest fee-rate ...
chytrik's user avatar
  • 18k
5 votes

Is there a blockchain.info for testnet?

Blockcypher supports testnet3 and has their own testnet.
Steve Ellis's user avatar
  • 1,062
5 votes

Can a clever hacker still steal everyone's money from the blockchain.info wallet?

They anticipated this type of attack and they are monitoring their JavaScript files, check this website of theirs http://blockchain-status.com/javascript_verifier Also, CloudFlare (the reverse proxy ...
Onur Yapar's user avatar
5 votes
Accepted

Transaction with Multiple Inputs having Same Address

The UTXO that are being used as inputs are tuples of (txid, vout), where the former refers to the transaction the UTXO originated from, and the latter gives the position in the output list. The ...
Murch's user avatar
  • 72.6k
5 votes

Download single and specific block for study purposes

Download a block is easy! Here is a link to an online explorer with a specific block, for your experimental purposes I suggest storing the block in its raw hex format (or binary). Blocks don't have a ...
Penquin's user avatar
  • 671
5 votes
Accepted

Blockchain Address gap limit solution

Blockchian.info is not really qualified to provide Bitcoin API's for business, 20 empty addresses are really cool and enough as a personal wallet but for business, it's not. I suggest you find an ...
Adam's user avatar
  • 3,649
5 votes

How do you know that your private key has been stolen?

If your private key was stolen, then the thief can provide you with definitive proof that he possesses the key---for example, by spending your funds. But unless you have such proof, all you can do is ...
David A. Harding's user avatar
5 votes

How can i look into the Blockchain

All of the transaction history is communicated between peers over a binary gossip protocol. You can request specific blocks, sequences of blocks, or specific transactions, and clients will normally ...
Mark H's user avatar
  • 3,324
5 votes
Accepted

How Bitcoin nodes validate a new wallet

How Bitcoin nodes validate a new wallet They don't Bitcoin nodes validate blocks and they validate the transactions within those blocks Other nodes don't have access to your wallet and can't validate ...
RedGrittyBrick's user avatar
5 votes
Accepted

What is the request limit number in the blockchain.info API?

Should be 1 request every 10 seconds: https://www.blockchain.com/api/q
Riccardo Masutti's user avatar
5 votes

"Needed Turnover" / "Missing Turnover" - How to get my money out?

What you describe is absolutely typical of what happens when someone inexperienced or relatively new to Bitcoin gets tricked by criminal confidence tricksters. The victim is often contacted by someone ...
RedGrittyBrick's user avatar
4 votes

What are the equations to convert between bits and difficulty?

There are 3 representations of the same thing (with varying degrees of precision) in Bitcoin: bits - unsigned int 32-bit target - unsigned int 256-bit difficulty - double-precision float (64-bit) ...
mulllhausen's user avatar
  • 1,713
4 votes
Accepted

Can a clever hacker still steal everyone's money from the blockchain.info wallet?

Yes, the attack you describe is possible. But this isn't specific to blockchain.info nor to online wallets. If an attacker manages to run code on your machine, you're pwned. As long as an attacker ...
shx2's user avatar
  • 803
4 votes

Transaction with Multiple Inputs having Same Address

In the transaction you just listed 1LS1h8UJFgAFqRsw8WqjszBdJWDQg3hj6d is both an input and a change address. Most of the transaction funds were sent to 187SRqCeXctTbfaqErNqUN5kDzv2PjHVeQ and the ...
254123179's user avatar
  • 345
4 votes
Accepted

Does the mempool size equal roughly the unconfirmed transactions?

Every node owner can set their own policy for the mempool. The mempool is limited two-fold: With -maxmempool=<n> you can set an explicit limit of MB that it will not exceed. The default is ...
Murch's user avatar
  • 72.6k
4 votes

fetching unconfirmed utxos from blockchain.info

This is most likely something on blockchain.info's end. You have a very similar call available via API to blockcypher.com here: https://dev.blockcypher.com/#address-endpoint unspentOnly=true will ...
Jimmy Song's user avatar
  • 7,749

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