0
votes
1answer
30 views

What is the purpose of Merkle Tree in blocks?

The leaves of the Merkle Tree has the hash of the transactions. How are transactions stored in the block? What is the purpose of Merkle Tree.
2
votes
1answer
52 views

Verifying Bitcoin ownership

Suppose Alice has 30 bitcoins from David. Now Alice wants to transfer amount 20 bitcoins to Bob. Now, Alice creates a transaction with Bob's bitcoin address. To prove authenticity and integrity, ...
0
votes
1answer
32 views

Problem while compiling altcoin scrypt based cryptocurrency

I've successfully build my crypto on mac (deamon and qt) but I'm experiencing troubles with windows. I've solved many errors but still having the last one displayed on the attached screenshoot. Thanks ...
0
votes
1answer
24 views

Can I use bitcoin to so that my non bitcoin friend can receive CNY?

Can I send money to my friend's Chinese Bank account using bitcoin? How easy and safe are the resources for a Chinese person to convert bitcoin to cash? OT: apparently the remittance tag doesn't ...
2
votes
1answer
28 views

Is it possible to create bitcoind regtest network on Ubuntu (which itself is on Virtualbox)?

I am getting into Bitcoin development and it seems that bitcoin regtest mode is perfect for testing our applications. I am trying to create a network, following Fred Tingey's answer but, ...
0
votes
2answers
110 views

Which is best for mining bitcoin?

I am wanting to buy a hardware for mining bitcoin and namecoin using Bitminter. But then Genesis Mining offer online cloud mining. I want to know if it's better to buy a hardware for mining bitcoin or ...
0
votes
0answers
15 views

iOS BTC express thin client

I'm developing thin client for Bitcoin on iOS. I tried to use Bitcoin Express but can not find any documentation for it. How to use it on my xCode project? Is there any obj-c wrapper on it? I've ...
0
votes
0answers
21 views

Bitcoin-qt doesn't get a server connection?

I have created a new altcoin, and I run a server on one machine and connect bitcoin-qt on another machine. In this case it's blink the network connection, sometimes it shows one connection and after ...
0
votes
1answer
41 views

Solving PyCrypto 2.6.1 errors for Python 3.4 (Windows7 x64)?

Whilst there's less of an issue with Python 2.7, Python 3.4 relies on the pycrypto library for numerous wrappers/APIs/tools such as BlockTrail, pycoin, pybitcointools, etc etc. The error I'm ...
2
votes
1answer
24 views

Why are Lighthouse campaigns limited to 684 pledges?

I'm curious to why is there a 684 transaction limit for each campaign when using the lighthouse crowd funding app. If I was wanting to raise 25 BTC for a project, the minimum that someone that would ...
1
vote
1answer
36 views

What services let you trace the history of Bitcoins?

What services let you trace the history of Bitcoins? For instance, if the goal is to trace all transactions associated with Bitcoins owned by a certain individual or company, what's the best way to ...
1
vote
0answers
17 views

How to identify large block of coins referenced in this article, reportedly mined by Nakamoto?

This article refers to a large block of Bitcoins mined in 2009, potentially by Nakamoto. What's the best way of identifying which block of Bitcoins are referenced in the article?
4
votes
2answers
45 views

How does an SPV node verify an unconfirmed transaction?

Alice pays Bob 1 BTC with a simple pay-to-address type transaction. Three seconds after Alice broadcasts her transaction, Bob's Simplified Payment Verification (SPV) wallet displays a message saying ...
2
votes
2answers
103 views

Are the huge transaction fees mostly mistakes or some other market indicator?

I am trying to understand why there are numerous days in Bitcoin's history that show huge transaction spikes. See this blockchain.info chart. The Jan 10th, 2012 spike is due to a mistake by this ...
3
votes
3answers
118 views

Can same private key generate multiple addresses?

Is this possible using some clever bitcoin script? The intention is to get more privacy. I can give different addresses to different people still no one can guess how much I make in total. I can do ...
0
votes
1answer
20 views

Multibit Wallet missing

I recently closed down my multibit wallet and when I opened it back up my wallet was completely missing. I've searched everywhere online on how to recover it, but nothing is helping. I'm really ...
4
votes
1answer
29 views

How big is the UTXO database?

Is there a query that will return the size of the UTXO database? Specifically, the total number of unspent outputs.
0
votes
2answers
43 views

bitcoin-0.9.3 won't syncup on TESTNET stuck at height 26859

Downloaded the latest bitcoin core tar ball 0.9.3. New install for test and development. This thread relates only to the TESTNET, I haven't tried on the production network. When launching the bitcoind ...
4
votes
1answer
50 views

Was the time warp attack the only reason it was not safe to compare chains by length?

One of the weaknesses of bitcoin listed on that wiki is that it was once vulnerable to the time warp attack. This attack lets a miner with >50% of the hash power to solve many more blocks in a short ...
0
votes
1answer
17 views

Electrum: seed is 0 length / empty

I installed electrum a while back and noted down the 12 word seed. Haven't used it for a few months, but now when I go to view my seed (clicking on the seed icon on the bottom right of the GUI), it ...
0
votes
1answer
65 views

How to avoid price pumps & dumps when trading with bot?

Recently I recieved $500 USD in credits for trading with Coinsetter, a NYC based bitcoin exchange, so I decided to use them and coded a bitcoin trading bot for myself (never have done such thing ...
1
vote
1answer
58 views

Double spend / bitcoin Bots

As you all know it's not very secure to send bitcoins on known addresses, some bots are watching. Could someone explain me how these bots manage to propagate several transactions of the very same ...
0
votes
0answers
20 views

Multiple bitcoin transactions between addresses in the same wallet

I have two wallets: one in coinbase and one in blockchain.info. I imported several outside addresses(created in bitaddress.org) in my blockchain.info wallet. However, sometimes when I transfer ...
0
votes
0answers
14 views

Why there is a no way to remove the encryption from bitcoin-qt UI [duplicate]

I encrypted my wallet with a passphrase in bitcoin-qt and I didn't find a way to remove this encryption from the UI , is there any way to do it? I wonder why there is no option for that ?
0
votes
1answer
35 views

Bootstrap.dat on Mac OSX 10.9 - Difficulty

Been trawling through a lot of information (I know this similar issue has probably come up a fair bit) on this issue and going round in circles a bit. I am not the most tech savvy individual, and ...
11
votes
1answer
2k views

How is the whitepaper decoded from the blockchain (Tx with ~1000x m of n multisig outputs)

The whitepaper is apparently encoded at 54e48e5f5c656b26c3bca14a8c95aa583d07ebe84dde3b7dd4a78f4e4186e713, which is an m of n multisig Tx with 947 outputs (just under the scriptsig limit of 20kB!). ...
1
vote
1answer
91 views

How do I compose a transaction with OP_RETURN in Python?

Currently trying to figure out how to use Python to construct a transaction with OP_RETURN. I tried to encode the message myself, and had no luck. I found a function, OPReturn(), on the internet, but ...
2
votes
2answers
77 views

Non standard Tx with obscure OP codes: examples

I've been writing Python code to fetch various transactions and came across this: 77822fd6663c665104119cb7635352756dfc50da76a92d417ec1a12c518fad69. The script field is as follows: scriptPubKey: ...
0
votes
0answers
85 views

Bitcoind stuck loading blockchain after -reindex -rescan

I am running bitcoind on EC2. I did portforward 8333 and tried -reindex -rescan. My debug.log shows 2015-02-08 20:02:19 ProcessBlock: ACCEPTED 2015-02-08 20:02:19 ProcessBlock: ACCEPTED 2015-02-08 ...
0
votes
1answer
25 views

blockchain webgame - use api or actual blockchain to build database?

I am currently designing a blockchain based web game, and part of the game is to display data from the blockchain in table format on the site. The data will be updated peroidically, or in short ...
0
votes
1answer
71 views

Locating Server-Grade PSU-to-PCIe Power Cables for Bitmain Antminers?

Does anyone know where breaker boards and cables can be purchased online that provides four PCIe 6-pin connectors to power an Antminer C1 from a server-grade power supply unit (PSU)? Background: I ...
-1
votes
0answers
43 views

How can i withdraw my BitCoins to PayPal or Bank Acc..? [duplicate]

I have recently started earning some Bitcoins & DOGE etc. from various sites and i have withdrawn them to some diff.. wallets too, but i cant find any way to withdraw my BitCoin or other ernings ...
1
vote
0answers
47 views

How to get BTCChina full Orderbook (FIX or alt API)

I have worked through BTCChina's FIX APi (using their java example). Creating a subscription request message such as: public static Message marketDataIncrementalRequest(String symbol) { ...
4
votes
1answer
68 views

Correct Citation Format for a Bitcoin Transaction

When writing an academic style paper where specific bitcoin transactions are used as examples, is there a standard format to "cite" a bitcoin transaction? If not, what do you think an appropriate ...
0
votes
1answer
30 views

Where does MultiBit keep its data directory?

Where does MultiBit keep its data directory? What is the wallet inside called?
0
votes
1answer
32 views

Move MultiBit from Mac to Windows

I'm an IT consultant in Australia and I'm pretty green when it comes to BitCoin and wallets and the like. I've been contacted by a client with a MacBook Pro that cannot be repaired and he is looking ...
0
votes
1answer
42 views

Lost bitcoins on smartphone after resetting it, although I backed it up before

I lost my bitcoins after resetting my android smartphone. Is it possible to get hold of my lost bitcoins?? I did back up my smartphone before I reset it. So after I reset the phone all my apps were ...
1
vote
1answer
57 views

Which cryptocurrency has the lowest block generation time?

What is the lowest block time of any cryptocurrency? Not for an individual transaction but for the lowest time/block. What is the lowest reasonable block generation time?
2
votes
1answer
79 views

Vanitygen: Impossible addresses?

I'm currently attempting to modify Vanitygen to suit a particular purpose. However, I'm running into an issue with "impossible" addresses. For example, from the stock Vanitygen available on Github I ...
1
vote
1answer
28 views

How does the Bitcoin network checks if the miner has changed the mining reward? [duplicate]

You know the mining reward is just a number in the code,what if a miner changed it?
2
votes
2answers
45 views

Do P2Pool nodes always accept real blocks over share blocks?

The standard rule in bitcoin is that if you see two blocks on a chain that has the same work, you accept the one that you saw first as the correct one. If this extended to P2Pool chains, some nodes ...
1
vote
1answer
29 views

Where are the Main network magic bytes stored in bitcoin's source code?

Bitcoin uses F9 BE B4 D9 as its main network magic bytes. I've searched the source but cannot find where these values are stored. Presumably they're computed, but I'm not sure where. Can someone tell ...
-1
votes
0answers
24 views

If I mined for 1 hour, at 10 terahashes, at the current difficulty, roughly how many bitcoins would that make? [duplicate]

I just need to know, because I am currently in need of money and would like to try bitcoin as a potential way of making profit. I have done some research, but I've currently been basing my equations ...
3
votes
1answer
76 views

Is multisig address belong to the same wallet created by?

I created 2-of-3 multisig address using bitcoinqt by three public keys from my wallet . when I tried to validate this address after creation it shows : "isvalid" : true "ismine" : false should it ...
0
votes
0answers
21 views

Blockchain.info Wallet Format

I've noticed that BCI's Wallet version has been updated to version 2 in recent times (and also employs key stretching, amongst other security features). I've referred to BCI's Wallet Support Page and ...
0
votes
1answer
30 views

What does the keypoololdest field mean?

After reading this question I watched the keypoololdest. It was 1392447127 (Sat, 15 Feb 2014 06:52:07 GMT) I created a new address. Then, it was 1392449568 (Sat, 15 Feb 2014 07:32:48 GMT) Should ...
-1
votes
0answers
38 views

Condition false while Mining Bitcoin Coins?

When I tried to Mine a Coin by using Premine-Coin source code in BitcoinMiner() in main.cpp, My one condition is always false, I didn't know what is issue, because it working with Premine-coin ...
1
vote
2answers
106 views

Bitcoin nodes voting

I'm just watching Adam Back & Gregory Maxwell: Blockstream and Sidechains interview, and wondering how the decision of further Bitcoin core development are made. I know about Bitcoin Foundation, ...
8
votes
2answers
221 views

How much of BIP 62 (“Dealing with malleability”) has been implemented?

BIP 62 lists nine source of malleability: Non-DER encoded ECDSA signatures Non-push operations in scriptSig Push operations in scriptSig of non-standard size type Zero-padded number pushes Inherent ...
0
votes
1answer
30 views

Does the power supply matter?

I have a Gridseed 5-chip ASIC miner and am running 2 amps into it. Will this impact how it works and if it works at all if I use 2 amps instead of 5?

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