The blockchain is a list of all transactions that have occurred using the Bitcoin currency. DON'T USE THIS FOR THE SERVICE NAMED 'blockchain.info'!

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Random numbers using blockchain

How are the block hashes generated? Are they trully 100% random (generated by hardware) or is it pseudo-random (generated by software)? Can i rely on it or any other blockchain data to make a 100% ...
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1answer
87 views

If all block chain copies get deleted, what would happen?

What would happen if all block chain copies get deleted at one time? At first, all clients would try to get the block chain from other clients, right? But this would fail. Would the "network" then ...
0
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2answers
241 views

Difference between a bitcoin wallet and the blockchain

As the title said, what is the difference between the bitcoin wallet and the bitcoin core, do i have to install both of them to work? Can I just have a bitcoin wallet?
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3answers
914 views

What is a soft fork?

When people talk about possible changes to how Bitcoin works they sometimes say a particular change can be implemented as a soft fork. What does that mean? How does this compare to a hard fork?
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2answers
110 views

Can decentralized blockchain technology like bitcoin be used to store medical information? [closed]

For example patients get private key, providers get public key?
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1answer
164 views

Blockchain transaction message length limit

When I perform a transaction on the blockchain, I can add a message to the transaction, which will then exist forever in the blockchain. Say for example I wanted to use the blockchain to store ...
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4answers
504 views

How to find a specific bitcoin address from all the addresses?

Recently, I found a site that show all the addresses in a huge list, divided in 904625697166532776746648320380374280100293470930272690489102837043110636675 pages. The site's link is ...
0
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2answers
170 views

How much binary data (bytes) could I put in a transaction and how?

I know that some people had put text, pdf and images in the blockchain. I wonder which are the limits in order to have a minimum "bytes/btc" value in regarding the blockchain as a permanent database. ...
0
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1answer
131 views

Blockchain Parser not working on blockchain generated in regtest mode using bitcoind. Any help?

Has anyone used this blockchain parser for Bitcoin https://code.google.com/p/blockchain/ ? http://codesuppository.blogspot.in/2014/01/a-command-line-interface-for-blockchain.html I tried to parse ...
0
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1answer
53 views

Bitcoin-qt and lost local blockchain files

For some reason I've lost all data in my .bitcoin directory except the wallet.dat file. Now bitcoin-qt shows 0 balance, and it's 5 years behind sync. Is this possible to restore coins in this case?
0
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1answer
68 views

Local Testnet3, where do the new coins get sent to?

I'm trying to setup a local testnet with multiple nodes. Currently I have three nodes, and their mining powers are almost the same. When I use listaccounts RPC call, all the wallets have 0 coins. ...
0
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1answer
30 views

Why do Bitcoin API services offer Block details?

I understand having APIs around addresses and transactions, but I'm less clear why I need to know what's happening with a Block(s). This is to confirm one's transactions? Might someone provide some ...
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1answer
109 views

Bitcoin testnet: “Bitcoin is downloading blocks…” and other problem

I'm trying to setup a local testnet with multiple nodes. Currently I have three nodes, and their mining powers are almost the same. Things have been quite ok so far, except some problems that I need ...
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2answers
114 views

Where can I find a chart of the daily supply?

there is the blockchain.info one for total supply but that very low resolution. I really was a graph of the actual new bitcoin mined on the market on a daily basis because it seems like a strangely ...
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1answer
105 views

Can you switch the method of blockchain download?

I torrented bootstrap.dat and used am using it to populate the blockchain. It is close to being complete, but my server has ran out of room. There is room for one copy but not enough for two. Is it ...
2
votes
1answer
451 views

Best way to anonymize bitcoin transactions?

https://en.bitcoin.it/wiki/Mixing_service How do sites like this work? "Mixing services". I know it can be broken and traced back with coinsuduko but how exactly does it wash your coins. I doubt they ...
2
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2answers
132 views

How to get correct block details url with block height on blockchain.info

I need to generate urls to block details page of blockchain.info when I have block height as input but cant find the relationship between block height and the number they are using in the url. Eg: ...
4
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1answer
95 views

Can I use Blockchain API to get number of transactions at BTC address?

When I go to blockchain to look at a BTC address I can see a count of the number of transactions that have been sent to that address. So can I use the blockchain API to get this information? I have ...
2
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1answer
248 views

What are the equations to convert between bits and difficulty?

If we take transaction hash 0000000000000006770c3806960539ca83a24facbd99ea212f37f2a0e6a5629a for example. The difficulty as a 32 bit float is 50810339.04827648. The difficulty in bits as an unsigned ...
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0answers
80 views

json RPC Blockchain not Working

I am unable to connect to the Blockchain API, here is the code: $rpc_host = 'rpc.blockchain.info';$rpc_port = '80'; $rpc_user = 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX'; $rpc_pass = 'PASSWORD'; ...
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0answers
84 views

Bitcoind randomly stops downloading the blockchain

I have bitcoind running from a 2 GB CentOS 6 box in order to check balances of addresses. The problem is that it just randomly stops downloading the blockchain sometimes, and I have to use ./bitcoind ...
4
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2answers
79 views

Accelerated block generation

According to http://btc.blockr.io/ : Height Block created Transactions Block fee Size (kb) Days destroyed 318525 2 minutes ago 28 0.00370000 8.36 kB 2.00 318524 3 ...
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3answers
120 views

How many OP_RETURN transactions in the Blockchain would be too many?

I realize this question may not have an answer and therefore might not be suitable for SE, but I'm very curious about OP_RETURN transactions. OP_RETURN transactions appear to be the accepted ...
4
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3answers
573 views

How can I search for transaction text on the blockchain?

Is there a google like search engine which can search for any text that is included with a bitcoin transaction? As I understand it each transaction includes 80 characters of text as well. Update It ...
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0answers
131 views

Overview of Blockchain 2.0 smart contracts for the layman?

I have a pretty good understanding of how the Blockchain secures data using hashed inputs of the previous block and being secured by the P2P distributed network. What I'm interested in is a layman ...
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0answers
9 views

Can I force the Bitcoin core client to keep the blockchain on another drive instead of AppData/Roaming? [duplicate]

I have been profiling my disk space and found that the blockchain has become pretty big 25GB or so. I would like to force the core client to save the chain on another drive that is much larger. Is ...
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1answer
204 views

Lost private keys. Help to recover

I have blockchain wallet but have lost the private keys of it, is tr any way to restore my private keys. Plz help
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1answer
136 views

Blockchain command line tools

I was under the assumption that the bitcoind server allowed you to query the blockchain and run commands like bitcoind getbalance on any address. I'm finding out that you may query addresses in your ...
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1answer
870 views

Unconfirmed Transaction >22 hrs [duplicate]

I realise that this might be a duplicate however I have not actually seen a sufficient answer to the question aside from 'wait'. I submitted a transaction yesterday from a blockchain wallet to a ...
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1answer
86 views

Tie Breaking in bitcoin transaction

If two nodes broadcast different versions of the next block simultaneously , some nodes may receive one or the other first. In that case, they work on the first one they received but save the other ...
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3answers
6k views

Where to place Bitcoin bootstrap.dat

I'm sure this has been asked many times before, but I've recently gotten into the whole cryptocurrency thing starting with Dogecoin, and I now want to use Bitcoin as well. I am on Windows 7. I found ...
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5answers
415 views

How do you create a planet-specific cryptocurrency that will ignore longer block chains from other planets?

I'm sure that cryptocurrencies will play a huge part of the economy across the solar system, when we have colonized many different planets, moons, and asteroids. But there are problems with using a ...
0
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1answer
46 views

multiple parties to sign a transaction before being broadcast (or after, but either way be associated with)

Lets say someone was writing a transaction solely to denote the existence of something, or a timestamp, or writing something in OP_RETURN Could that transaction be signed by other addresses, kind of ...
3
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1answer
86 views

How frequent are side-chain reorganizations of various lengths?

I'm wondering if anyone has collected statistics on how often reorganizations of side-chains with length 1 happen in comparison with lengths of 2, 3, or more. Related: What is the longest chain ...
2
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1answer
31 views

On quering the blockchain, can someone read what transaction took place? [closed]

Like considering the Alice Bob ex where Alice is the customer and Bob is the merchant. If Alice and Bob signed a contract where alice will pay bob on the delivery of a service. The transaction took ...
2
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1answer
151 views

Blockchain growth projections and risks

What is the projected block chain growth over time and could an attack on Bitcoin be lauched that creating an enourmous number of micro-transations to fracture the currency (e.g. spamming the system ...
2
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2answers
203 views

Block nonce predictable

Is the block nonce predictable in any way? It seems to be a proof of work on his own just like the block hash, but may a miner force a mined block to have a specific nonce? (if his hashrate allows him ...
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1answer
56 views

Include checksum in a transaction

Is it possible to include a file's checksum in a transaction? Not necessarily in Bitcoin's current blockchain due to the now limited OP_RETURN feature, but just in the blockchain/transaction concept ...
4
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1answer
111 views

How does NXT prevent blockchain bloat since it does so many different things with its blockchain?

How does NXT prevent blockchain bloat since it has a built in message system and other features? Wouldn't the NXT blockchain grow to be really big in the future and pose a problem for people storing ...
4
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2answers
643 views

Why does Bitcoin store all transaction inputs and outputs, instead of just an “account/balance” ledger?

From what I can tell, the Ethereum blockchain just stores accounts and balances - why did the original Bitcoin developers choose the method of storing all transactions for validation instead of just ...
2
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1answer
424 views

Strongest vs Longest chain and orphaned blocks

Satoshi writes at the bottom of page 3 of his white paper that "If two nodes broadcast different versions of the next block simultaneously, some nodes may receive one or the other first. In that case, ...
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1answer
66 views

Is it possible that someone forks the chain?

I'm not sure I understood everything but all the clients always keep the longest chain, ok. So, what happen if an evil person inject bad transactions in a block and successfully mine it (given the ...
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1answer
83 views

Confirmation limit

When seeing transactions I see that the number of confirmations keeps increasing without any limit. I wanted to know if there is any time limit on including a already confirmed transaction in a block ...
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3answers
560 views

How To Lower The Disk Space Needed For Full Blockchain?

I'm looking to run bitcoind on a virtual machine. However the main nets Blockchain size is over 21GB, and growing. Is there a way to compress this down or lower the amount of disk-space needed for ...
0
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1answer
46 views

Blockchain and Bitcoin client difference of amount

I just made a transfer of 0.06 BTC, you can look it up on Blockchain.info The problem now is that my receiving client (Multibit) doesn't show those 0.06 BTC, it only shows 0.0001 BTC have been spend ...
2
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1answer
103 views

Can you assume that all inputs to a Bitcoin transaction are controlled by the same person?

When you are looking at a Bicoin transaction in the block chain and it has inputs from multiple addresses is it safe to assume that those addresses are all controlled by the same ...
4
votes
1answer
136 views

What percentage of Bitcoins stored in a multi sign address?

I am looking for a statistic of the usage of multi-sig addresses over time. More concrete: what is the percentage of Bitcoins stored in a multi-sig address over time.
0
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1answer
289 views

What is current size of various databases in Bitcoin Core as of July 2014?

This question is related to question: What is the database for? What is size in MB of: blockchain itsef - blocks/blk*.dat blocks/index/* chainstate/* blocks/rev*.dat Is the size of chainstate and ...
3
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2answers
168 views

Are NXT messages stored on the blockchain and are they encrypted or publicly viewable?

Are nxt messages stored on the blockchain? What is the character limit on these messages? And are the messages encrypted or publically viewable? If they are public, is there a site to just view all ...
0
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1answer
183 views

getrawtransaction doesn't work for every transaction with -txindex=1?

i put txindex=1 in bitcoin config and reindex blockchain after that when i call getrawtransaction for some transactions didn't exist in my wallet and work well like: [Working] getrawtransaction ...