The blockchain is a list of all transactions that have occurred using the Bitcoin currency. Please don't use this tag for the service named 'blockchain.info'.

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4
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1answer
271 views

Scalability of namecoin

It seems that an idea to store all information inside a blockchain would lead to its bloating. There are about 250MM of domains in the web, namecoin allows to store 1Kb of data per record, it leads ...
1
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1answer
117 views

do transaction merkle trees have any use outside individual blocks?

as i understand it, merkle trees are useful for operations within individual blocks, but do they have any use outside of each block? for example, are the merkle-roots from each block ever used in ...
0
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1answer
4k views

No accepted shares on cgminer (sync issue ?)

I don't really understand how cgminer works. I try to mine using cgminer + cgwatcher on a BtcGuild pool but even after 1 hour mining I don't have any accepted or share block. What I don't understand ...
0
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1answer
179 views

How does blockchain.info get the addressbalance / seen date?

I am trying to figure out how blockchain.info gets the following API functions and is there any way to do these calls on a server (without using their API) perhaps through bitcoind? ...
0
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2answers
171 views

How do I scan my bitcoin receipt into my wallet?

I bought Bitcoins from the Robocoin ATM (I'm told it's the only one) and it gave me a receipt with a QR code to scan into my wallet. I downloaded Blockchain, but don't see where in the app I can scan ...
2
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1answer
50 views

Can a blockchain transaction history be updated by text messages using a mobile network?

Is it possible to update Bitcoin transactions over mobile networks using texts or voice data transmission?
-1
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1answer
95 views

>50% crash induced by stakeholders of current financial systems

This is a though I had a few days ago. There are stakeholders of our current financial systems who would like to secure their wealth. If these stakeholders sense bitcoin as a threat to their wealth, ...
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0answers
133 views

Bitcoin increased?

So a while ago I got some 0.00000020 bitcoins and then a month later I went back and it increased to 0.00000200. This was in the transaction page, if I sent the bitcoins to my wallet would it still ...
2
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2answers
102 views

Are any hashes (Tx or block) actually stored in the blockchain?

...or is each client responsible for storing hashes for blocks and transactions in their own database? So when I send a transaction, I indicate the prev_out by its hash, and I just assume everyone on ...
3
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1answer
304 views

What attacks are possible with a malicious bootstrap.dat?

The standard Bitcoin client normally needs to download the entire blockchain from the p2p network when first installed, but a shortcut is to provide it with a snapshot of the blockchain (at some point ...
0
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1answer
102 views

Re-indexing blocks taking more than a week - Cant access my wallet

I've bought Bitcoins and had them directed to a wallet on the Bitcoin-Qt software. Unfortunately I was not aware of the sync process. And now I've got no access to the Btc's and I feel like the ...
1
vote
1answer
101 views

Are there any Web Crawlers for Bitcoin addresses?

In an effort to "track the chain" I wonder if there are any Bitcoin web crawlers that specifically look for Bitcoin addresses. Following on to that question, are there any groups/volunteers/ people ...
0
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1answer
181 views

How to retrieve all addresses with non-zero balance and their balances?

I'm looking for a way to retrieve all address balances of addresses with a non-zero balance in the blockchain. Is there a software tool that can calculate the balances in an accessible format? Or ...
0
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3answers
100 views

When is a Bitcoin Adress considered even and when odd? [closed]

When is a Bitcoin Adress considered even or odd?
2
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2answers
336 views

Longer fake block chain with “valid” transactions

What is preventing the bitcoin client from switching to a fake block chain that would be longer that current official chain? The faked chain would contain fictional transactions, but within the faked ...
5
votes
1answer
692 views

Will the blockchain get too large? [duplicate]

As the entire blockchain gets much larger, it will be impractical for ordinary users to maintain all of it. Will it be maintained by a diminishing number of powerful systems, and would that create an ...
1
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2answers
298 views

How can I specify transaction fee size when creating a raw transaction?

Question: Am I able to specify the transaction size in a raw transaction without having to send "change" back to myself? I get some unspent bitcoins listunspent() I grab the txid, vout, and ...
0
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2answers
4k views

What is a bitcoin tumbler?

I have recently heard of a bitcoin theft where the thief used a bitcoin tumbling service in an (apparently unsuccessful) attempt to cover their tracks. From this event I have several related ...
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0answers
130 views

(JAVA) Get address balance from the blockchain

I'm a merchant that is currently developing client that I will use for receiving transactions for my business. I would like my client to be able to check how much Bitcoin the address sending to me ...
2
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2answers
752 views

Number of transactions per block

I am just starting to understand the internals of bitcoin. I am a CS graduate and familiar with most bitcoin terminologies. I've read Satoshi's paper and researched the question but I couldn't find ...
1
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0answers
84 views

Are transactions possible when setting up/ sync wallet Qt2

Hi any help really appreciated.. About 12 months ago I purchased some bit coins from 2 different merchants and began to sync my wallet on Qt 2. Frustrated with tedious progress I put the project on ...
2
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4answers
416 views

How can I generate a bitcoin address?

Is there any way to generate bitcoin addresses other than the Blockchain API? (given the fact that it is not public)
0
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0answers
89 views

Moved btc qt wallet to blockchain - can see my funds but can't send them?

please, I need some advice. It all started the other day when I sent some coins to bitcoin qt, a 'safer' wallet ... was soooo slow to sync and was crashing etc.. Anyway, I imported the wallet.dat to ...
0
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2answers
223 views

syncing no block source

Recently synced bitcoinqt fully over around 36 hours or so without problem. I'm now trying to tentatively test it out as a newcomer and when I run it, it says "out of sync" No block source available ...
1
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3answers
101 views

What does “prev_out” and “n” mean in blockchain.info's API data?

When getting information about transactions with blockchain.info's API, every transaction contains exactly one "prev_out" object, and within that object "n" is always equal to either 0 or 1. What do ...
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0answers
91 views

download testnet block chain?

I suspect the router in my network prevents the block chain from being sucked into my machine, using the classic way, i.e. bitcoin-qt or bitcoind. Is there a way of dowloading the testnet block ...
0
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0answers
57 views

qt 8.5 blank icon

using qt v0.8.5-beta at the bottom it says: No block source available 152 weeks behind the icon on the lower right corner - two file windows has a red x in the corner of the file icon next to that ...
1
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1answer
353 views

Is there a way to maintain a continually updated copy of blockchain without running a wallet?

This question is in response to being stupid, as I just tried to spend from my B-Qt wallet before it was finished syncing (power outage fun yesterday). Was scary when it froze after hitting send, had ...
2
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0answers
156 views

What exactly is checked at various -checklevel's?

The standard bitcoin-qt/bitcoind client has an option -checklevel which purports to perform various checks on the block data stored on disk. Is there current documentation (other than the source) ...
2
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2answers
295 views

I'm making an infographic on Bitcoin. How can I download all Bitcoin transactions to do some analysis?

I would like to do some analysis of Bitcoin transactions in the last 3 months and share my insights by preparing an infographic. What would be the best way to get all Bitcoin transactions in the past ...
0
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2answers
137 views

Is there any part of a bitcoin transaction that is 'random' or could not be predicted?

I am just curious if when a transaction is sent and you view it on the blockchain. Is any of that information impossible to predict what it will be? I am looking at perhaps the time received ? (you ...
5
votes
1answer
213 views

Bandwidth required for Bitcoin going global?

Something that I feel might be the obstacle against Bitcoin going global -- but which I've never seen anyone mention -- is this: If Bitcoin goes global, I think it's possible that the number of ...
1
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1answer
116 views

Storing HTML websites in the blockchain?

I see that the blockchain has enabled lots of different distributed networking principles, other than just enabling cryptocurrency. For example Namecoin uses the blockchain for storing DNS data. I am ...
0
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0answers
82 views

Bitcoin-QT Custom Blockchain

Can I change the blockchain my bitcoin-qt client is using to a downloaded .dat file? Once I've replaced it, how do I run CGMiner so it is mining off those blocks? Can I mine without internet ...
2
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1answer
167 views

Can a miner steal another one's block?

Say we have two miners, Alice (an honest miner), and Eve (an evil miner). My understanding is that when Alice mines a block she advertises it to the network, and once it's part of the longest block ...
2
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0answers
56 views

What metadata can be captured by a single miner? What about a group of miners?

It is my understanding that the blockchain consist of the following information for every transaction in the network: From address To address Amount of bitcoins What additional information can a ...
0
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1answer
116 views

Is original bitcoin program needed with multibit?

I have only MultiBit installed. Is this enough, or do I have to install the original bitcoin program to download the blockchain?
0
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1answer
151 views

Bitcoin client warning

I get this warning on my Bitcoin client: "Warning: Displayed transactions may not be correct! You may need to upgrade, or other nodes may need to upgrade." I am also downloading the blockchain and i ...
14
votes
4answers
12k views

Is bitcoin mining itself compromising the security of SHA256

Following good scientific practice I propose a Theory/Hypothesis and now ask you to test it. Initially this is a "thought" experiment but may progress to real testing depending on your thoughts. Back ...
0
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1answer
448 views

Uses of computing power by bitcoin miners

How much of what this article says is true? I thought I had read that bitcoin miners are the ones who maintain the blockchain. Do they also do something other than maintaining the blockchain? In ...
0
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1answer
212 views

bitcoind is not downloading blockchain

I have installed bitcoind on Ubuntu Server. It didn't download a single block bitcoind getblockcount This returns 0 everytime I run. Here is bitcoind getinfo { "version" : 80500, ...
3
votes
1answer
1k views

Bitcoin Transaction from MtGox hasn't shown up after several hours

I have withdrawn bitcoins from my account in MtGox to my Multibit installed in my computer. Several hours after BTC are not in MtGox and neither in my account. I have verified the address and it is ...
2
votes
5answers
847 views

Is it possible to spam the bitcoin network with 'dust'?

Someone could buy or mine bitcoins, and send them in small transactions all day to spam the blockchain. Is this possible? And could this mean the end of the trust people have in bitcoin? edit: And ...
3
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1answer
1k views

MtGox withdrawal transaction not in blockchain

I just withdrew some BTC from Mt Gox to address 1Mvk4YAtKZAP43wEhZ6ZQrTzLZwZzPxtTJ, transaction id 3dfa979af56ff061efbceed0dd7c9dc9fd8c774249544018f6bbf646323ff03b, but didn't receive the coins and ...
0
votes
1answer
4k views

Is it possible to transfer BitCoins from BlockChain to CoinBase?

I have BitCoins in BlockChain - is it possible to transfer these into my CoinBase account?
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0answers
119 views

Ways to verify SatoshiDice earnings?

After sending a bitcoin to a SatoshiDice address (e.g. 1dice9wVtrKZTBbAZqz1XiTmboYyvpD3t), how do we know whether we have won or lost (besides waiting for the winnings to enter our wallet)?
1
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1answer
368 views

Multibit - Failed to create a Selector

I installed MultiBit a few weeks ago and today it's not loading anymore. It displays the following Error in the logs: The Blockchain "C:\Users\USER\AppData\Roaming\MultiBit\multibit.spvchain" ...
0
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1answer
69 views

If a block chain is considered invalid, how about transactions in this block chain?

Say if at current time there exist split of block chain, we call them A and B. A is "longer" then B, as the result B will be eventually forgotten, but what happened about the transactions in blocks on ...
2
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2answers
124 views

two block are broadcast almost at same time, which will be accepted?

Because miners can choose which transaction will be added in block by themselves, so what if two miners broadcast two blocks almost at the same time, one is bigger(has more transactions), another is ...
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1answer
117 views

Some question about block and block chain…really confuse me! [closed]

Here are my questions: Because miners can choose which transaction will be added in block by themselves, so what if two miners broadcast two blocks almost at the same time, one is bigger(has more ...