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'.

learn more… | top users | synonyms (1)

1
vote
1answer
20 views

Can I run bitcoind without downloading new blocks?

I want to run bitcoind to interact with the daemon, but having bitcoin download new blocks and verify them is taking a toll on my CPU. I do not want the latest data - I just want the daemon to be ...
0
votes
1answer
97 views

Trust Less Database Design?

I'm a young developer and have been following the bitcoin community for some time now and have wanted to contribute to a project. Have not fully read through the bitcoin protocol, but from my ...
3
votes
1answer
66 views

How is a side-chain merging back to Bitcoin chain protected against double-spend? Where are the side-chain mining fees?

I am struggling to understand the concept of "side-chains" that's discussed a lot lately, but never trully explained. How I understand "side-chain": it's an altcoin, with a separate blockchain, with ...
-1
votes
1answer
30 views

Using blockchain to publish downloadable software verification codes

What is the point of comparing sha256 of downloaded file with published on the same website code? Why can't developers of currencies publish file version and sha256 hash on blockchain as alias or ...
0
votes
2answers
193 views

How to decode very huge (!) raw transactions?

I'm parsing the blockchain to extract certain information I need for a script. One thing I do is parsing transactions. What I do is: getrawtransaction <tx> decoderawtransaction <rawtx> ...
1
vote
1answer
37 views

Possible to use BlockChain.info and Bitcoin-QT synced?

I've used both BlockChain.info and Bitcoin-QT. Is it possible to use the same addresses on both? I don't have a incredibly large amount of bitcoins, so I'm not worried about it getting hacked into, ...
-1
votes
0answers
6 views

Bitcoin accept on web site [duplicate]

We are owner of investment company. We want to accept bitcoin in our web site, please let us know about your system and I highly appreciate if you answer our questions: At first: Do you have any ...
1
vote
3answers
125 views

How much space does the blockchain take up per day and per hour when running bitcoinQT on my computer?

the blockchain is about 20GB today, but i was wondering how much space does it take up each day if i were to leave bitcoinqt on regularly? also by hour? reason why im asking is im thinking about just ...
0
votes
1answer
57 views

Given that contracts can be formed in the blockchain using scripts, couldn't a contract include a mechanism for facilitating chargebacks?

While I understand that chargebacks, or the lack thereof are an important feature for encouraging merchants to adopt bitcoin, the reverse may be true for consumers. There is probably a balance to be ...
1
vote
1answer
16 views

Listening for changes to my own wallet in the blockchain

I would like to be notified of changes to any of my many wallet address as soon as they happen and then programmatically take action. I have been using wallet notify but this has been giving me really ...
2
votes
1answer
33 views

How can I download the blockchain from own, trusted source?

I have two computers with two different bitcoin-qt wallets: Very heavy-weight desktop with a great internet connection. Less powerful laptop with relatively slow internet. I would like to download ...
1
vote
0answers
29 views

Can I download blockchain updates from somewhere?

I use Bitcoin only on rare occasions - say once every month. I want to avoid long waiting times for downloading and verifying blocks that consequently await me when I reopen bitcoin-qt. There are many ...
0
votes
1answer
104 views

Blockchain API support - receive payment IPN

I'm having some real trouble setting up the Blockchain API on my server First off is it possible to test it offline with local host? Secondly, how do I set it up so when a tx is made through my ...
1
vote
2answers
78 views

Can the Bitcoin blockchain eliminate the need for Trusted Computing in Smart Contracts?

Let me preface this by saying that I'm a novice, but this is my rough understanding of how Bitcoin's blockchain works. (This is largely based on blog posts like this one.) If person A wants to ...
1
vote
1answer
50 views

Chronologically sorting transactions within a block

Is there any way to chronologically sort transactions within a block?
1
vote
1answer
46 views

multibit balances wrong, not correct for any individual address

In my multibit wallet, it reports X bitcoins. But no address in that wallet contains exactly X bitcoin, and the total reported amount should be greater than X. The reason this is stranger than ...
1
vote
1answer
98 views

Is there a database of all transactions?

The blockchain is a database of all valid transactions, but is there a company/project that also logs all transactions which were broadcasted, but didn't made it to the chain? Blockchain.info for ...
1
vote
1answer
326 views

Armory client shows transaction unconfirmed

I am new to btc and am using the Armory client. Yesterday I transferred some btc to wallet from my MtGox account. The wallet showed the btc received within minutes, but, after 12 hours it still shows ...
2
votes
2answers
306 views

Can blockchain size become a blocker for bitcoin adoption?

When I run bitcoin-qt, I noticed that it is taking lot of time to download recent blocks. It gives me impression that the more transactions, the bigger the blockchain. Even today the download is ...
0
votes
1answer
176 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? ...
2
votes
1answer
598 views

Saved .bitcoin directory full ~9 GB block data, won't work when copied to another system

I had to delete my .bitcoin directory in Ubuntu 12.10, after months of getting the near 9 GB of blk data files. I copied everything over to another machine (and back to the original too) and it gives ...
0
votes
2answers
168 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 ...
0
votes
1answer
75 views

pending payment

Three days ago I sent a payment via my MultiBit wallet but it is still marked as unconfirmed, only 4 confirmations. How long it will take this transaction to become fully confirmed? Thanks.
0
votes
2answers
75 views

RPC calls fail in testnet mode, but not normal mode?

I'm running bitcoind on a debian web server. If I run in normal mode, i.e. "bitcoind -daemon," then it seems to work completely fine. [birdseye]$ ./bitcoind -daemon Bitcoin server starting ...
1
vote
4answers
913 views

Different balances Bitcoin-Qt vs. Blockchain.info

Why is the balance in my Bitcoin-Qt wallet different from the balance when I check the information about my address on blockchain.info? All transactions are confirmed.
1
vote
2answers
37 views

Is block height always sequential?

Is block height always sequential? Can it serve as a 100% reliable block counter in case if I want to check whether I missed a block or I need to account for any corner cases?
1
vote
2answers
169 views

Is it possible to know my ip address by simply connecting to the Bitcoin network?

It is saying that in order to stay anonymous, it is usefull to use Tor whenever connecting to the Bitcoin network. How does someone can discover my ip adress if I'm simply connecting to the bitcoin ...
0
votes
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
votes
2answers
263 views

How to get current BTC rate for BRL(real) using php cURL or javascript

Is there anyway to get current rate of BRL = BTC. I saw the blockchiain ticker. But the value for BRL currency is not updated As listed here in preev. I want to get the current 1BTC= how much BRL ...
2
votes
1answer
250 views

“offline” blockchain querying library

Is there a library which provides all the same address/transaction querying information as blockchain.info, depending only on having a bitcoind synchronised database? There are a number of queries ...
3
votes
1answer
72 views

How did transaction malleability/DDOS attacks allow an exchange's internal accounting system to get “out of sync”?

This Coindesk article says that: “So as transactions are being created, malformed/parallel transactions are also being created so as to create a fog of confusion over the entire network, which ...
2
votes
2answers
50 views

How to create a SPV client?

What are the steps a SPV client takes in order to sync? Connect to a peer Set bloom filter for wallet addresses Download all block-headers since latest checkpoint Request every block again with ...
0
votes
2answers
376 views

Where are my bitcoins?

I recently bought 18 euros of bitcoins (16 dec 2013). I finally got my wallet synchronized, but I still do not see my balance, nor my transactions. On the blockchain I see that I received my ...
1
vote
1answer
84 views

Why there are blocks with single transaction in blockchain?

Just opened blockchain.info and found two blocks with single transaction on the main page: 292942 292947 Isn't it strange? More than this, block 292941 was issued just minute before 292942 and has ...
-1
votes
2answers
63 views

Bitcoin URGENTLY Need Blocks Files - Download them from some Website [duplicate]

I have been doing this synchronization procedure (first time) in bitcoin-qt for over 85 hours and it only came to 31 Weeks Behind. Withdrawed from localbitcoins like 95 hours ago and obviously this ...
0
votes
0answers
28 views

If more than one coin did the “mini-blockchain” proposal, would that make the weaker coin vulnerable?

So, I was reading this paper as a proposal to the ever growing blockchain problem. In summary, it's security is provided without a full blockchain by having a proof chain with these fields: Previous ...
-2
votes
0answers
37 views

Transaction tracker in microsoft excel format

Say I made a business which takes care of thousands of bit coin transactions. The problem is how can I track how much is coming in and from which address at what date and what time (and how many ...
0
votes
2answers
120 views

Is there any altcoin with improvements in blockchain download time?

Let me introduce my idea. Given: sizeof( Blockchain ) = 16Gb Downloading of one avi film 16GB from the pirate bay ( 5mb/s ) = 2-3 hours Downloading of bitcoin's blockchain ( 5mb/s ) = 2-3 days One ...
0
votes
1answer
44 views

get public key from wallet.dat

Is there a way to get the public key of a given wallet.dat to check the balance in the blockchain to avoid having to install the wallet and read all blocks?
0
votes
2answers
82 views

Does there exist a SPV-client in another language than Java?

The only (active) project I know that implements a full SPV client is BitcoinJ, which is in Java. Does somebody if there are any SPV implementations in other languages (like C) too?
3
votes
3answers
81 views

How is over-spending one block apart prevented?

So, let's say you have a wallet with 20BTC, and you have a flow like so: You send 15BTC to A in block 1 You send 15BTC to B in block 2 What happens if at block 1 there are two chains across ...
0
votes
1answer
36 views

Location of blockchain locally on different platforms, and structure of blockchain file?

I just downloaded Bitcoin-QT, and torrented a snapshot of the block chain that is a couple weeks old. I put the bootstrap.dat in ~/Library/Application Support/Bitcoin and started up the app. Right now ...
0
votes
0answers
19 views

Most transacted account & how many?

I cannot seem to find this data on any of the major data provider sites. What Bitcoin address has performed the most blockchain transactions to date? How many?
1
vote
3answers
95 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 ...
0
votes
1answer
169 views

LiteCoin Wallet balance does not match block-explorer.com

My Litecoin wallet version v0.8.6.2-beta is showing a balance of 26.579 ltc When I query http://block-explorer.com/address/LejrG23b2HcjqPRbZU8UWFxZhdJTUc75pS it is showing 0 balance. I just sent 2 ...
0
votes
1answer
446 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
votes
1answer
211 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
289 views

Bitcoin-qt falls behind on blockchain, how to replace?

On Apple Mac, bitcoin-qt is 14 days behind. Never approaches current time. Have downloaded current blockchain from trusted source. Where to install? What procedure?
1
vote
2answers
180 views

Is Bitcoin database cross platform compatible?

I want to use my Windows 7 Bitcoin database (the block chain I downloaded + my wallets) on Linux (Debian). I run Debian as VirtualBox guest on Windows 7 host and share the Bitcoin data folder ...
1
vote
2answers
499 views

Query Transaction data based on past transaction id?

The blockchain.info API allows for quering information about a particular Transaction by its ID. But if you want to follow the coins to the next transaction, I'm not seeing what the next query should ...