All Questions

Filter by
Sorted by
Tagged with
36
votes
1answer
4k views

ELI5: What's the difference between a child-key and a hardened child-key in BIP32

I've read BIP32, and I do understand it more or less. Could someone please explain to me like I'm 5 years old what the difference between a child-key and a hardened child-key is? I'm trying to add ...
36
votes
4answers
12k views

Why can’t the genesis block coinbase be spent?

According to the bitcoin wiki: The first 50BTC block reward went to address 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa, though this reward can't be spent due to a quirk in the way that the genesis block is ...
36
votes
6answers
8k views

How do I reduce the size of the block chain data on my machine?

The block chain file is getting rather large, ~500MB. Is there a way to trim it or clean up, or maybe configure it to be limited in the future? I am using the stock Bitcoin client on Ubuntu.
35
votes
6answers
131k views

What are stale shares and what can I do to avoid them?

When I mine at a pool, only a part of my shares are accepted. There is a small percentage which is marked as stale. As far as I know I only get paid for accepted shares, so what are these stale ...
35
votes
5answers
35k views

How do you get a Bitcoin Public Key from a Private Key

How do I, in extreme specificity, convert a given private bitcoin key into a public bitcoin key (Talk to me like I'm 5 and I have to do this step by step or the evil witch will cook me alive in her ...
35
votes
9answers
20k views

How is it possible to launder bitcoins?

Some services, such as bitcoinlaundry.com, claim that they can launder your bitcoins. Since all bitcoin transactions are publicly logged, how is this done? Wouldn't it be possible to trace back the ...
35
votes
5answers
7k views

What is a deterministic wallet?

It sounds as if it's a process that enables a wallet to be rebuilt from a passphrase, or from several fragments scattered about. Could someone provide a detailed technical explanation?
35
votes
1answer
5k views

My raw transaction destroyed 0.0284377 BTC. What did I do wrong?

Years ago I designed a .NET module which facilitates the transmission of BTC to my customers. It creates a binary representation of the desired transaction based on the material presented here and ...
35
votes
3answers
29k views

Who gets Bitcoin transaction fees?

Whenever I send bitcoins from one wallet or one exchange to the next there is always a fee. This makes sense with the exchange sites, they are just collecting the fee so they can make a living. What ...
35
votes
3answers
17k views

Is there any point to casual mining?

Is there any point to casual mining anymore? I recently discovered bitcoin and was wondering if there was any point to running mining software on my laptop while I work on essays or other non-...
35
votes
3answers
49k views

How can I start mining Bitcoin?

Ok. I don't care if I make only a small amount of bitcoins mining. I want to mine. How do I setup my machine (amd x64 4.6Ghz 6GB/RAM with GeForce Nvidia 7300, LinuxMint 10) to start mining? Is it ...
35
votes
9answers
12k views

Is there a Bitcoin bank, which gives interest on my deposit?

Is there any Bitcoin bank I can place my Bitcoins in that will give me a decent interest rate. It should be at least 1% for it to be worth it.
34
votes
2answers
12k views

What are the keys used in the blockchain levelDB (ie what are the key:value pairs)?

I am wondering if I can use node.js and levelup to access a copy of the blockchain database directly. But from what I can see, I need to know the name of the key(s) before I can get any data, as this ...
33
votes
9answers
7k views

I am new to Bitcoin, how can I get started?

I am new to both StackExchange and to the new online currency called Bitcoin. I understand what Bitcoin is and how it works, but I was wondering: how do you actually get started with Bitcoin? I have ...
33
votes
10answers
28k views

How to check if the block chain is up to date using bitcoind or json-rpc?

I read the full api method list and did not seem to find one. I suppose there is no command specifically for that purpose, so what is the general way of doing this? I would consider checking the ...
33
votes
2answers
14k views

What is a Finney attack?

What is a Finney attack? Extra points for explaining its purpose, the prerequisites for it to be possible, how the attack can be performed and the origin of the name "Finney attack".
33
votes
4answers
5k views

Why are hashes in the bitcoin protocol typically computed twice (double computed)?

According to the wiki specification of the bitcoin protocol, hashes are typically "computed twice". For example: hello 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824 (first round of ...
33
votes
7answers
14k views

How to generate a valid bitcoin address for destroying bitcoins?

(Following up to this question.) In order to put a bitcoin beyond use, the answer was to select a made up address. As this isn't a formal destruction of bitcoins, there's a risk that the private keys ...
33
votes
5answers
11k views

Bitcoin Mining ASICs used for cryptographic application? Rainbow tables?

What is the potential that the ASICs being developed for mining could be used for other cryptographic applications such as building rainbow tables? I know that for instance those that crack GSM with ...
33
votes
4answers
50k views

How to fork Bitcoin and build own cryptocurrency

Is there any step-by-step tutorial about how to build own cryptocurrency based on Bitcoin code?
33
votes
6answers
3k views

What would a country adopting Bitcoins as official currency have to reinvent?

Let's say that a country decided to ditch their currency and go for Bitcoins. What would this country have to reinvent. The reason why I ask, is because I believe that if a tiny country was to adopt ...
33
votes
7answers
58k views

Why do the price of bitcoins vary wildly between exchanges?

▼ mtgoxUSD 95.0000 108.452 -12.404% 2428892 ▼ btc24EUR 67.5047 89.036 -24.183% 348160 ▼ btceUSD 82.9900 106.794 -22.289% 277286 ▼ bitstampUSD 75.9900 109.320 ...
33
votes
5answers
52k views

How to make a new blockchain from scratch

In the same vein as setting up a private DNS root server and using whatever domain names you want, how do you generate your own blockchain and mine your own coins? P.S. I don't want any answers ...
32
votes
4answers
7k views

Are there any _true_ anonymous cryptocurrencies?

I've been looking into Bitcoin recently and stumbled upon numerous notes how Bitcoin is not anonymous at all, or how it's only partially anonymous and you can easily trace your funds. So, this ...
32
votes
6answers
24k views

How does one attain 1,000+ connections like blockchain.info?

At this moment, blockchain.info has over 1,900 nodes connected to their bitcoin client. I have been running an m1.small ubuntu 12.04 server and bitcoind for ~4 days straight now with no reboots. My ...
32
votes
10answers
118k views

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

I've sent a transaction from blockchain.info, but accidentally included too little fee. What can I do to cancel the transaction or speed up the transaction's confirmation? This is a complementary ...
32
votes
1answer
51k views

How can I restore my wallet?

I just purchased a new laptop and I want to decommission my old one. I have a back-up of my wallet.dat file copied to my new PC. What do I need to do to restore it to my Bitcoin (Windows) client? ...
31
votes
6answers
31k views

How to safely shutdown bitcoind ?

Surprised this one hasn't been asked yet. But how / what is the recommended best practice for shutting down bitcoind ? Right now I'm manually killing the process with either sudo kill {pid} or if ...
31
votes
6answers
123k views

Do these new ASIC miners really pay for themselves in 5 days?

The Bitforce 50GH/s miner costs $2,500 today, and according to the following calculation it would mine enough coins in about 5 days to pay for itself. I am sure I am missing something here. Why would ...
31
votes
7answers
9k views

Is a private blockchain better in any sense than a database?

Since the banks appear to be currently looking into the idea of "blockchains" but don't want to be dealing with "Bitcoin", it seems that there is a lot of hype for private blockchains out there like ...
31
votes
2answers
11k views

What is the coinbase?

I searched the bitcoin wiki and found references to coinbase, but no clear cut explanation of what exactly it is. I know that miners can tag their coinbases (that is how some sites tell who mined a ...
31
votes
2answers
2k views

Do mining pools centralize the Bitcoin network and make it less secure?

A mining pool with a significant percentage of the hash rate could allow double spend attacks by the pool manager. There are a number of pools that approach this level. However, most people say that a ...
31
votes
1answer
15k views

How do I build Bitcoin source in Windows 7?

I am trying to build the current Bitcoin source in Windows 7x64 - Does anyone know of an idiot-proof tutorial? Some of the steps in the included doc give me errors. When I try to tar openssl with ...
30
votes
6answers
3k views

Why doesn't Bitcoin return lost coins back into the block reward?

The idea of putting back lost Bitcoins back onto block rewards seems like a great idea. I acknowledge that there were quite a handful of early adopters who were generating blocks daily, but had no ...
30
votes
4answers
53k views

What are orphaned and stale blocks?

If I understand it right, a stale block is a block for which an earlier confirmation has been found and was accepted by majority of people. This block is considered invalid and is later never used. ...
30
votes
2answers
42k views

What is an “unspent output”?

What is the meaning of the term "unspent output" in the Bitcoin protocol?
30
votes
2answers
8k views

What is TxIn's sequence?

I'm currently trying to generate the genesis block with my code and I've stumbled upon the TxIn sequence field that is not explained in the Protocol Specification wiki page, nor does it seem to appear ...
30
votes
5answers
10k views

In getrawtransaction, what is the vout integer in the vin list?

I'm working on trawling the bitcoin transactions coming in via getrawtransaction. I haven't been able to find the neccessary documentation to describe the vout integer in the vin array: {"txid"=>"...
30
votes
5answers
33k views

How to get an address's balance with the bitcoin client?

I want to see the balance of some address using bitcoind. I set txindex=1 and did a -reindex to get all transactions indexed. But still, there doesn't seem to be a way to get balances of an address. ...
30
votes
2answers
6k views

Are there any studies into the size of the blockchain scaling over time?

After watching some of one of the 28c3 talks, It got me thinking about just how scalable Bitcoin really is. With the size of the blockchain currently, given the number of transactions/users, will the ...
30
votes
3answers
3k views

Are there algorithms that could have been chosen for mining that balance CPU/GPU?

The mining algorithm for Bitcoins (and most alternative but similar currencies as well) is purely computation hard, but not decision hard or memory hard. This caused the unexpected effect that GPUs ...
30
votes
1answer
9k views

What are colored coins?

What exactly are colored coins? I've tried understanding, but I don't quite get it yet . . . Do any examples exist?
29
votes
5answers
14k views

How are public & private keys in an address created?

I understand the high level concept I am more interested specific details. How is a private key generated. How exactly is public key generated, how is address generated from public key.
29
votes
1answer
10k views

What is the database for?

I see the block chain is stored according to the block chain format specification. But I also see there is a database, which is currently a leveldb database. Why is the block chain stored in two ...
29
votes
3answers
8k views

Can I use Bitcoin mining as a data furnace to heat my home?

One of the waste products from Bitcoin mining is the heat that is given off by the GPUs. On cold days could this excess heat be used to warm a home, essentially creating a data furnace? When it gets ...
29
votes
1answer
33k views

What is a bid wall?

On the bitcointalk forums I hear a lot of talk about "bid walls". I have never heard of these in other types of financial markets. It seems that people use them as a way to support the price of a ...
28
votes
4answers
18k views

What are pros and cons of txindex option?

I am reading "Mastering Bitcoin" written by Andreas and I found this explanation about "txindex option" Transaction Database Index and txindex Option By default, Bitcoin Core builds a database ...
28
votes
6answers
7k views

Why is the disappearance of Mt Gox a problem?

I'm sorry if this is a stupid question, I'm not a bitcoin user and may lack important information. My understanding was that each bitcoin user has a wallet on his harddrive or wherever, where he ...
28
votes
3answers
47k views

How useful is a JavaScript miner?

I don't have a great understanding of how bitcoin mining works, but how useful would a JavaScript miner be for collecting revenue from visitors? Stupid question, but if I put the user in as part of a ...
28
votes
2answers
22k views

Why are there two transaction outputs when sending to one address?

I did a small transaction some days ago: https://www.blockchain.com/btc/tx/4c07a07dfd9d5b79d168ec6835df876c64e82350a8f9211bf586d858a5aeb9ba Some info: 1JFWE8THcAQQRYx99c43DXSGyoPL9Zs62D is my ...

15 30 50 per page