35 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 ...
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  • 821
23 votes
Accepted

What are the equations to convert between bits and difficulty?

Answer shamelessly stolen from stackexchange: Difficulty encoding is thoroughly described here. Hexadecimal representation like 0x182815ee consists of two parts: 0x18 -- number of ...
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  • 28.7k
21 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 ...
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  • 9,819
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. ...
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12 votes

BlockChain.info Investments? Sounds like a scam

It seems obvious to me that this is a scam. No legitimate investment in the world can guarantee a rate of return of 20 percent per day. At that rate, with a 5 btc initial investment, you'd own all the ...
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12 votes
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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 ...
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  • 61.4k
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; ...
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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 ...
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  • 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 ...
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  • 7,629
9 votes
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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 ...
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  • 11.3k
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/...
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7 votes
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What does the "Cost per Transaction" chart on BlockChain.info show?

On the chart overview page you find the description "Cost per Transaction: A chart showing miners revenue divided by the number of transactions.". Meaning, it's the total value of the block reward of ...
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  • 63.4k
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 ...
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7 votes
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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 ...
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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 ...
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  • 17.3k
6 votes
Accepted

What's the mnemonic seed for in Blockchain.info, if they use non-deterministic wallets?

From the source code, one can see that the mnemonic in fact only encodes your password and wallet identifier. You would still need to access you wallet data somehow to recover you coins.
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6 votes

Is there a blockchain.info for testnet?

www.blocktrail.com/tBTC now supports testnet too and has an API for it too (including wallet API)
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6 votes
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Blockchain.info Wallet Format

I mostly detailed the various encryption schemes used in version 1 wallets over here: https://bitcointalk.org/index.php?topic=1012475.msg11105755#msg11105755 Incidentally, it's not trivial to create ...
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6 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 ...
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  • 8,724
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 ...
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  • 1,892
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 ...
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  • 17.3k
5 votes
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Dumping private keys from wallet.dat from command line (pywallet.py alternatives)

This is an old question but just to say that the dumpwallet command has been added to bitcoin core. This will give you all the private keys in a text format.
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  • 66
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 ...
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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 ...
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  • 671
5 votes
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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 ...
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  • 3,569
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 ...
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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 ...
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  • 3,220
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 ...
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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 ...
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4 votes

Is there a blockchain.info for testnet?

Blockcypher supports testnet3 and has their own testnet.
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  • 1,034

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