nyuuzyou/wikis huggingface dataset:
NLockTime

nLockTime is a parameter of a transaction, that, if any input indicates so (by having nSequence not equal to UINT_MAX), mandates a minimal time (specified in either unix time or block height), before which the transaction cannot be accepted into a block. If all inputs in a transaction have nSequence equal to UINT_MAX (0xFFFFFFFF), then nLockTime is ignored.
* If nLockTime < 500000000
** Specifies the block number after which this transaction can be included in a block.
* Otherwise
** Specifies the UNIX timestamp after which this transaction can be included in a block.
Note that since the adoption of BIP 113, the time-based nLockTime is compared to the 11-block median time past (the median timestamp of the 11 blocks preceding the block in which the transaction is mined), and not the block time itself. The median time past tends to lag the current unix time by about one hour (give or take), but unlike block time it increases monotonically.
For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.
The behavior of a transaction's nLockTime can be modified by the sequence number of an input when using OP_CHECKSEQUENCEVERIFY. That particular opcode is used inside input scripts to assert that the input's sequence number, which in normal transactions is set to UINT_MAX, is greater than or equal to the top item of the stack (usually the transaction's nLockTimehttps://bitcoin.stackexchange.com/questions/38845/what-does-op-checksequenceverify-op-csv-do). OP_CHECKSEQUENCEVERIFY is used in some proposed Layer 2 protocols, such as eltoohttps://blockstream.com/eltoo.pdf.
==See Also==
* lock_time in the protocol specification
* Transaction
* Timelock
* BIP113
* The CHECKLOCKTIMEVERIFY opcode in BIP65
==References==
Category:Technical
NamecoinUs

NamecoinUs! is a project intended to bridge namecoin domains to common users that do not have the .bit available by their default DNS provider. The project also runs an in-line proxy (http://example.bit => http://example.bit.namecoin.us), a namecoin WHOIS server, and an expiry tracker for namecoin domains. It also offers various namecoin-related tools.
==See Also==
* Namecoin
This site appears to be offline.
==External Links==
* NamecoinUs! project website
Nanaimo Gold

An operation by Shane Smith, an independent business operator, located in Nanaimo BC Canada.
Bitcoins and other digital currencies may be purchased and sold using any of a number of different payment methods. 
==History==
On April 08, 2011 the exchange described the availability of automated trading between bitcoins and oter digital currenciesNanaimo Gold automatic LR <---> BTC service.
==Currency type:==
* Bitcoin
* Pecunix
* c-gold
* HD-Money
* EuroGoldCash
* Bitgold
==Accept payment by:==
* Western Union Money Transfer
* Moneygram International Money Transfer
* Canada Post Money Order [by mail]
* Cash by mail or deposited at a BofA (U.S.) or RBC (Canada) bank.
==See Also==
* Buying bitcoins
* Selling bitcoins
==External Links==
* Official website
* Automated Bitcoin <--> Liberty Reserve exchange
* Buying digital currency
* Selling digital currency
==References==
Category:Exchanges
NewSendCoins

Proposal for an updated, more feature-full 'sendcoins/sendmany' command.
This command requires a confirmation or else it will be forgotten on the next NewSendCoins request.
== NewSendCoins ==
Request
newsendcoins <send list{Address, Amount}>, <fee> (optional)
Reply
newsendcoins <status:good|warning|error>, <in list{Private Key, Amount}>, <out list{Address or Private Key, Amount}>, <fee>, <error/warning text>, <tx id>
Confirmation
newsendcoins <tx id>, <confirm, reject>
New York Agreement

The Bitcoin Scaling Agreement at Consensus 2017, better known as the New York Agreement (abbreviated NYA), was a scaling proposal made jointly by over 50 companies. The agreement intended to put an end to Bitcoin’s long-lasting scaling debate by increasing the block capacity through activating Segregated Witness and then doubling the block size.
The protocol change specification is given in PCS-0002. It is based on the "Segwit2Mb" thread on the bitcoin-dev mailing list and the NYA blog post.
Ninki

Japanese wallet service provider Ninki intends to become a social network for payments with Bitcoin.
==Features==
* Ability to add contacts
* Uses PGP to validate contacts 
* Support BIP 32 Addresses
== Developers == 
Benjamin Smith - Lead Developer
==History==
Ninki was in open Beta in August, 2014 Wallet Service Integrates Bitcoin Payments with Social Networking
==See Also==
* BIP 32 Hierarchical Deterministic Wallets
==External Links==
* Ninki Website
* How to Setup a Ninki Bitcoin Wallet Online
==References==
Category:EWallets
Nixon shock day

On August 15 1971 US President Nixon announced the "temporary" suspension of USD gold covertibility. This transformed the US Dollar into a pure fiat currency with no ties to any physical element and no limit to its creation.
On August 15th bitcoiners remember the importance of limits to money creation. We remember the 21 million coin limit. We celebrate Bitcoin as a stable and measurable unit of account.
*See also: Bitcoin holidays
NoFeeMining

A No Fee Mining pool created to fix the problems with current pools and improve on their features.
This pool pays out using a proportional share reward system (your shares / total shares for the round) = % share of the rewards.
The service was opened in June, 2011 and was announced on June 18, 2011Newbie Friendly Mining Pool.
==See Also==
* Comparison of mining pools
* Pooled Mining
==Exernal Links==
* NoFeeMining pool
==References==
Category:Pool_Operators
Node.js Example

var querystring = require('querystring'),
 https = require('https'),
 crypto = require('crypto');
function MtGoxClient(key, secret) {
 this.key = key;
 this.secret = secret;
}
MtGoxClient.prototype.query = function(path, args, callback) {
 var client = this;
 // if no args or invalid args provided, just reset the arg object
 if (typeof args != "object") args = {};
 // generate a nonce
 args['nonce'] = (new Date()).getTime() * 1000;
 // compute the post data
 var post = querystring.stringify(args);
 // compute the sha512 signature of the post data
 var hmac = crypto.createHmac('sha512', new Buffer(client.secret, 'base64'));
 hmac.update(post);
 // this is our query
 var options = {
 host: 'mtgox.com',
 port: 443,
 path: '/api/' + path,
 method: 'POST',
 agent: false,
 headers: {
 'Rest-Key': client.key,
 'Rest-Sign': hmac.digest('base64'),
 'User-Agent': 'Mozilla/4.0 (compatible; MtGox node.js client)',
 'Content-type': 'application/x-www-form-urlencoded',
 'Content-Length': post.length
 }
 };
 // run the query, buffer the data and call the callback
 var req = https.request(options, function(res) {
 res.setEncoding('utf8');
 var buffer = ;
 res.on('data', function(data) { buffer += data; });
 res.on('end', function() { if (typeof callback == "function") { callback(JSON.parse(buffer)); } });
 });
 // basic error management
 req.on('error', function(e) {
 console.log('warning: problem with request: ' + e.message);
 });
 // post the data
 req.write(post);
 req.end();
};
var client = new MtGoxClient('mykey', 'mysecret');
client.query('1/BTCUSD/public/ticker', {}, function(json) {
 // do something
 console.log(json);
});
Non-custodial wallet

==Light (Non-custodial) wallets==
These may be web, paper, mobile, desktop and hardware wallets — as is the case with custodial ones. ​However​ light (non-custodial) wallets allow you to fully control your funds and therefore are more secure.
:Web wallets​ — non-custodial web wallets do not keep your keys, they are stored in your browser. Such wallets as MyEtherWallet and Guarda allow ​you​ to access your account from any device, ​all​ ​you​ need to enter ​is​ your private key.
:Hardware wallets​ are considered to be the most secure cryptocurrency storage solution. They are physical devices, similar to flash ​drives​ that ​don’t​ have access to the Internet. Thus, hackers cannot access ​these wallets.
:Mobile Light wallets​ can be installed on a smartphone or a tablet. There are a huge number of such wallets, but you need to choose them carefully, paying attention to their security and authenticity. Before installing the wallet, be sure to read the reviews. ​In addition, it is recommended to download applications from the developer’s site — for example, Guarda has links to applications in the AppStore and Google Play, so you will be protected from the possibility of downloading a fake application.
:A desktop wallet ​is an application that is installed directly on your computer. There are many such non-custodial programs, for example, Electrum and BitGo. Choose ​this type of program according to the cryptocurrency ​you​ need to store, and the operating system. You can use this wallet only when you are connected to the Internet. But since the keys are stored on the computer itself, there is a possibility of theft if the fraudster takes ​physical possession of your computer.
:Paper wallets ​mean that you print your public and private keys on a piece of paper. Thus, the cryptocurrency is stored offline, but you can always connect to the network from any device and enter your keys. Storing the cryptocurrency on paper is like keeping money in cash under the bed.
So the custodial wallet is the easiest way to use cryptocurrency and does not require any knowledge from the user, but it is very unsafe. If you plan to store large amounts of money, it is better to choose a light (non-custodial) wallet.
Category:Wallets
Nonce

The "nonce" in a bitcoin block is a 32-bit (4-byte) field whose value is adjusted by miners so that the hash of the block will be less than or equal to the current target of the network. The rest of the fields may not be changed, as they have a defined meaning.
Any change to the block data (such as the nonce) will make the block hash completely different. Since it is believed infeasible to predict which combination of bits will result in the right hash, many different nonce values are tried, and the hash is recomputed for each value until a hash less than or equal to the current target of the network is found. The target required is also represented as the difficulty, where a higher difficulty represents a lower target. As this iterative calculation requires time and resources, the presentation of the block with the correct nonce value constitutes proof of work.
== Golden Nonce ==
A golden nonce in Bitcoin mining is a nonce which results in a hash value lower than the target. 
In many practical mining applications, this is simplified to any nonce which results in a block hash which has 32 leading zeroeshttps://bitcointalk.org/index.php?topic=75609.msg837556#msg837556, with a secondary test checking if the actual value is lower than the target difficulty.
=== Etymology ===
The term golden nonce most likely evolved from the term golden ticket as used to refer to a nonce satisfying the mining requirements as early as April 8th, 2011https://github.com/progranism/Bitcoin-JavaScript-Miner/blob/master/miner.js#L5
== References ==
Category:Technical
Category:Vocabulary
Novello Technologies

Novello Technologies, Ltd. was a company that attempted to crowdfund the development of Bitcoin mining hardware via the crowdfunding platform Indiegogo, starting June 3rd, 2014, with a goal of $4,200,000https://indiegogo.com/projects/ultra-low-cost-bitcoin-mining-systems--2
Soon after it was announced, concerns regarding the viability of the project were raised at the BitcoinTalk Forumhttps://bitcointalk.org/index.php?topic=638729.
On June 12th, 2014, Novello Technologies posted on the BitcoinTalk Forum that they would be issuing refunds.https://bitcointalk.org/index.php?topic=638729.msg7267601#msg7267601. On June 13th, 2014, Novello Technologies issued an e-mail to supporters of the crowdfunding campaign that the crowdfunding goal was unlikely to be attained and noted the plan for refunds as wellhttp://pastebin.ca/2807363
Due to the nature of the crowdfunding campaign's funding method - flexible funding - any funds received by Novello Technologies would remain theirs to keep regardless of the outcome of the project. On July 8th, 2014, the campaign ended with approximately $6,000 in funds.
On August 5th, 2014, refunds were issued through Indiegogo.http://pastebin.ca/2829309
On August 11th, 2014, Novello Technologies issued an e-mail to supporters of the crowdfunding campaign that they would change their business model to perform in-house hashing using custom hardware only, to come online 'about 1 year from' the time of the e-mail.http://pastebin.ca/2831393
No new information has appeared since that time, and as of March 24th, 2014, their website is defunct.
== References ==
OP RETURN

OP_RETURN is a script opcode used to mark a transaction output as invalid. Since any outputs with OP_RETURN are provably unspendable, OP_RETURN outputs can be used to burn bitcoins.
== Is storing data in the blockchain acceptable? ==
Many members of the Bitcoin community believe that use of OP_RETURN is irresponsible in part because Bitcoin was intended to provide a record for financial transactions, not a record for arbitrary data. Additionally, it is trivially obvious that the demand for external, massively-replicated data store is essentially infinite. Despite this, OP_RETURN has the advantage of not creating bogus UTXO entries, compared to some other ways of storing data in the blockchain.
From Bitcoin Core release 0.9.0:
This change is not an endorsement of storing data in the blockchain. The OP_RETURN change creates a provably-prunable output, to avoid data storage schemes – some of which were already deployed – that were storing arbitrary data such as images as forever-unspendable TX outputs, bloating bitcoin's UTXO database.
Storing arbitrary data in the blockchain is still a bad idea; it is less costly and far more efficient to store non-currency data elsewhere.
== OP_RETURN applications ==
OP_RETURN can be used for digital asset proof-of-ownership, and has at times been used to convey additional information needed to send transactions (see ECDH address).
OfflineAddress

OfflineAddress.com can be used to generate offline Bitcoin addresses with maximum possible entropy (making them as secure as possible).
Private keys used to generate addresses are constructed from truly random numbers provided from user's mouse movements.
Generated addresses can be printed and used as paper wallets or for secure offline storage.
== Motivation and security ==
* Easy to use service capable of providing maximum security for non-technical users.
* Open Source JavaScript implementation which supports HTML5 caching - so that user needs to load the site just once.
* Service is capable of producing private keys with maximum entropy.
* Runs only in user's browser and never sends private keys to the internet.
* Service can be used offline and always warns the user if he's attempting to generate Bitcoin addresses while being connected to the internet.
* Hints how to be even more secure can be found here
==External Links==
* OfflineAddress web site.
* Forum discussion
Category:Tools
Offline transactions

The term "offline transaction" refers to the practice of keeping the private keys on an offline device (not connected to the internet), and signing on individuals transactions. The signature is then copy-pasted from this device into a connected device, and broadcast into the Bitcoin network.
Assuming the offline computer is malware-free is [sic] easier than a connected device. If this assumption is held, then this practice is virtually risk-free of bitcoin theft.
Offline transactions can also be used when talking to an Overlay Network (e.g. Stratum) or equivalent - an ultra thin client can send only signatures to the Overlay server, thus mitigating the risk of a malicious server running away with one's BTC.
Omnicoins

Formerly a service allowing the purchase of bitcoins with Australian Dollars (AUD). Omnicoins Pty Ltd is an Australian registered company, incorporated and operating out of the Australian Capital Territory. 
==History==
The service was launched on August 14, 2012.Omnicoins - Buy Bitcoins, Litecoins and Namecoins in Australia 
On July 5, 2013 it closedOmnicoins closed.
==See Also==
* Buying bitcoins
==References==
OnionWallet

Warning: Services that are run anonymously have a very poor track record. See the Critisism section for specfic complaints and warnings.
==Warning==
OnionWallet is a scam run by the same person(s) as EasyCoin.net and several other "anonymous" wallet services. Once a wallet address with the service recives a set amount (over 1BTC) the funds will automatically be sent to 1NRMGqPYXwPoAGHiPAMzBgkqCcmgms3hjH. Do not use this service. URL is here only to warn others who might be searching for it. 
Address: http://ow24et3tetp6tvmk.onion 
==Critcism==
OnionWallet is a scam! Lost my bitcoin!
WARNING OnionWallet and EasyCoin
bitcoin scammers easycoin.net
bitcointalk - Scam: OnionWallet
bitcointalk - easycoin.net warning
Category:Scams
Open-source useful tools

Closed-source softwares are not allowed in this page. Please check you can access the sources before using a program listed here, if not, warn a moderator.
Anyway, in general, never use closed-source tools when bitcoins are involved, for obvious reasons.
== Client forks ==
piotrnar's fork
:Import/export transactions
== Scripts ==
Pywallet
:Wallet managing: import/export/delete addresses and transactions, recover *coins sent to Bitcoin addresses
:Sign/verify messages and files with Bitcoin addresses
:Recover previously deleted key
Bitcointools
bitcoin-wallet-recover
:Recover wallets from reformatted drives
== Online ==
Blockexplorer.com (info)
:List of blocks and transactions
Bitcoin Charts (info)
:List of unconfirmed transaction
Bitcoin Monitor (info)
:Visualize the activities on the Bitcoin network
BitAddress (info)
:Generate an address and private key for an offline wallet. ("Paper wallet") Generate bulk addresses. Verify keys.
BitcoinPaperWallet.com (info)
:Generate an address and private key for an offline wallet ("Paper wallet"). Implements a unique two-sided tamper-evident folding design.
OpenBazaar

OpenBazaar, formerly known as DarkMarket, is an open source decentralized online marketplace designed for e-commerce, using the cryptocurrency bitcoin.
== History ==
Programmer and bitcoin enthusiast Amir Taaki and a team of other developers created the prototype of a decentralized marketplace, entitled "DarkMarket", in April 2014 at a Toronto Bitcoin Hackathon. DarkMarket was developed as a proof of concept in response to the seizure of the online marketplace Silk Road in October 2013. Taaki compared DarkMarket's improvements on Silk Road to BitTorrent's improvements on Napster.
Soon after DarkMarket was revealed at the hackathon, developer Brian Hoffman forked the project and renamed it "OpenBazaar", which continues to receive active development as of June 2015. OpenBazaar, like DarkMarket before it, was initially licensed under the GNU AGPLv3, but after a discussion by the developers it was relicensed under the MIT license on September 8, 2014.
== See also ==
* Silk Road (marketplace)
* Nxt
* Darknet market
== External links ==
* Official project page at GitHub
* Network statistics at BazaarBay
== References ==
OpenBitASIC

On April 12th, 2012, a project to develop an open source Bitcoin mining ASIC, using a topology based on a direct copy of an FPGA design, was announced under the name OpenBitASIC.https://bitcointalk.org/index.php?topic=76351
On April 14th, 2013, the project was declared as having been canceled, citing a lack of a suitable chip manufacturer.https://bitcointalk.org/index.php?topic=76351.msg1834760#msg1834760
== References ==
OpenCL miner

An OpenCL miner is a bitcoin miner that uses the OpenCL framework to perform the hashing computations. When used with a modern GPU, this can produce hash rates orders of magnitude higher than what can be achieved with a CPU. 
==Overview==
OpenCL is a computing framework which allows programmers to write code which works across a variety of hardware, both CPUs and GPUs included. OpenCL was originally developed by Apple.
The use of an OpenCL miner allows one to hash using a GPU (Graphics Processing Unit), which has a vastly larger ability to perform algorithmic calculations than an CPU (Central Processing Unit).
==Requirements==
Hashing on a GPU requires an OpenCL compatible (ATI/AMD) or CUDA compatible (NVIDIA) graphics card.
The python Poclbm open source OpenCL bitcoin miner was created by m0mchilm0mchil's announcement on the forum based on the open source CUDA client originally released by puddinpoppuddinpop's open source CUDA miner. 
Subsequently the java DiabloMiner based on m0mchil's was created by Diablo-D3Diablo's announcement on the forum. 
Puddinpop has also released a C++ OpenCL client capable of being compiled into the GUI client or daemon, or as a stand alone RPC minerpuddinpop's RPC miners.
Another miner was released by Jedi95 & CFSworks released Phoenix minerJedi95 & CFSworks phoenix miner which can work with memory underclocked to 300MHz and scans whole 232 nonce space.
BitTornado is another OpenCL Miner that supports ATI and NVIDIA Cards. It was released by Chris EvansBitTornado by Chris Evans.
See the Mining Hardware Comparison page for detailed statistics on the hash rates that can be achieved with various hardware.
==See Also==
* Mining hardware comparison
* Miners
* ATI Stream SDK downloads
* ATI Stream vs. NVIDIA CUDA - GPGPU computing battle royale
* Processing Cores vs. Stream Processing Units
==References==
OpenSSL and EC Libraries

== OpenSSL Without Elliptic Curve Support ==
Some algorithms in OpenSSL library may be restricted by patent law. Due to strong coupling between the elliptic curve support Bitcoin requires and these nominally non-free algorithms, some Linux distributions (most notably Fedora) ship OpenSSL libraries with elliptic curve support disabled. Since Bitcoin depends on elliptic curve cryptography (although not on any restricted algorithms), it cannot be used with such libraries.
== Fixes / Workarounds ==
One workaround is to compile your own OpenSSL and use this rather than the distribution package manager's library. Some hints how to do this can be found in the answers of How to upgrade OpenSSL (stackoverflow.com).
Open Transactions

A financial crypto and digital cash software library. The software's author likens it to "PGP for money".
Open Transactions (a centralized transaction system) is complementary to Bitcoin in that it provides some features that Bitcoin cannot, such as untraceable anonymous (versus pseudonymous) transactions, no latency (instant finality of settlement / no risk of double spending) and more.
Featuring: 
* Untraceable Digital Cash (real blinded tokens)
* Anyone An Issuer (Ricardian-style Contracts) 
* Bearer-only, Fully-Anonymous (when used cash-only)
* Pseudonymous User Accounts (user account == PGP key)
* No Account History (asset account == the last receipt)
* Many Financial Instruments (cheques, cash, vouchers, invoices...)
* Basket Currencies (10 "baskets" == 5 gold, 3 silver)
* Markets with Trades (stop, fill-or-kill, limit orders...)
* Payment Plans
Includes an API, server and client.
The author of this software also released Moneychanger, a reference implementation of a currency accounting application that accesses the Open Transactions API and integrates with Bitcoin.
==See Also==
* Blinded bearer certificates
* Moneychanger
* Bitcoin mixer
* Anonymity
* In-store Transactions
==External Links==
* Open Transactions project on GitHub
* Readme
Category:Open Source
Opencart-bitcoin-payment-module

An extension for opencart that accepts bitcoin as payment. The extension integrates with the MyBitcoin SCI utility.
Note: This only worked with the now-defunct MyBitcoin.
This project was first discussed in April, 2011 OpenCart Bitcoin payment extension.
==External Links==
* Official Bitcoin Extension for OpenCart 3 and 2.2+
* Bitcoin Payment via MyBitocin.com extension info
* opencart-bitcoin-payment-module project site on GitHub
==References==