Bitcoin Ключи



bitcoin kraken bitcoin server bitcoin сайт amazon bitcoin ethereum supernova bitcoin tools ledger bitcoin nxt cryptocurrency trading bitcoin bitcoin free bitcoin sweeper bitcoin xbt bitcoin стоимость ethereum habrahabr bitcoin майнер ethereum developer блокчейн ethereum bitcoin book java bitcoin shot bitcoin invest bitcoin bitcoin обсуждение теханализ bitcoin tether криптовалюта tracker bitcoin логотип bitcoin bitcoin flip купить ethereum

cardano cryptocurrency

okpay bitcoin форки bitcoin dwarfpool monero sell ethereum bitcoin earnings bitcoin основы bitcoin перспектива bitcoin habrahabr ropsten ethereum

ethereum pos

bitcoin казахстан registration bitcoin wikipedia cryptocurrency

bitcoin заработок

ethereum rig bitcoin simple invest bitcoin calc bitcoin краны monero лотереи bitcoin

ethereum serpent

ccminer monero bitcoin сатоши bitcoin red bitcoin traffic day bitcoin вход bitcoin monero обменять panda bitcoin bitcoin лайткоин bitcoin пулы ethereum упал bitcoin футболка bitcoin chain bitcoin торги луна bitcoin bitcoin adder bitcoin rotator bitcoin таблица nonce bitcoin

bitcoin best

bitcoin автомат 999 bitcoin торги bitcoin checker bitcoin заработка bitcoin Making and accepting payments for servicesSome U.S. political candidates, including New York City Democratic Congressional candidate Jeff Kurzon have said they would accept campaign donations in bitcoin.miner monero bitcoin прогноз rigname ethereum planet bitcoin games bitcoin bitcoin tx

cryptocurrency magazine

ethereum сайт moneybox bitcoin проблемы bitcoin

bitcoin qazanmaq

satoshi bitcoin monero free разработчик bitcoin bitcoin explorer bitcoin slots usb tether

сервисы bitcoin

bitcoin euro bitcoin drip ethereum бутерин monero core куплю bitcoin bitcoin world конвертер ethereum trader bitcoin ставки bitcoin ethereum pow

maining bitcoin

mac bitcoin bitcoin frog bitcoin venezuela bitcoin портал weekly bitcoin dapps ethereum locals bitcoin

code bitcoin

avatrade bitcoin

bitcoin отзывы

ethereum виталий

bitcoin ukraine

магазин bitcoin

reddit cryptocurrency

blockstream bitcoin ставки bitcoin tp tether bitcoin capitalization monero обмен ethereum прибыльность

bitcoin блокчейн

bitcoin форекс bitcoin cloud cgminer ethereum love bitcoin bitcoin бизнес bitcoin создать

bitcoin rub

bitcoin опционы

kurs bitcoin

gift bitcoin

Pile of litecoin coins on fabricиндекс bitcoin lavkalavka bitcoin ethereum пулы bitcoin reward land bitcoin monero coin bitcoin переводчик bitcoin 4 bitcoin hashrate tether download

box bitcoin

bitcoin покупка bitcoin word bitcoin ukraine alipay bitcoin sgminer monero Written inC++

обновление ethereum

bonus bitcoin bitcoin tails java bitcoin fire bitcoin краны monero bitcoin вирус tether обмен bitcoin wallpaper ethereum настройка sell bitcoin carding bitcoin enterprise ethereum faucet cryptocurrency nanopool ethereum конференция bitcoin local ethereum

исходники bitcoin

0 bitcoin why cryptocurrency

почему bitcoin

half bitcoin bitcoin отзывы bitcoin all best cryptocurrency cryptocurrency bitcoin tether верификация android tether carding bitcoin bitcoin save bitcoin desk bitcoin пополнить ethereum casino ru bitcoin bitcoin путин blogspot bitcoin bitcoin node bitcoin protocol ethereum web3 перевести bitcoin

андроид bitcoin

инструкция bitcoin

bitcoin services

A 2006 paper by Mihir Bellare enables signature aggregation in O(1) size, which means that it will not take more space to have multiple signers. Bellare-Neven reduces to Schnorr for a single key. Bellare-Neven has been implemented.January 12, 2018, Amidst rumors that South Korea could be preparing to ban trading in cryptocurrency, the price of bitcoin depreciated by 12 percent.To ensure the security of bitcoins, the private key must be kept secret.:ch. 10 If the private key is revealed to a third party, e.g. through a data breach, the third party can use it to steal any associated bitcoins. As of December 2017, around 980,000 bitcoins have been stolen from cryptocurrency exchanges.криптовалюты bitcoin 'Block' refers to the fact that data and state is stored in sequential batches or 'blocks'. If you send ETH to someone else, the transaction data needs to be added to a block for it to be successful.6See alsobitcoin china

bloomberg bitcoin

tera bitcoin faucet bitcoin заработок ethereum payoneer bitcoin bitcoin now bitcoin будущее

panda bitcoin

bitcoin converter ethereum покупка

bitcoin автор

tails bitcoin миксеры bitcoin bitcoin вконтакте nanopool ethereum bitcoin evolution

майнить monero

monero xmr

Project fork ofBitcoinbitcoin exchange rpc bitcoin bitcoin quotes серфинг bitcoin 50 bitcoin рейтинг bitcoin panda bitcoin coin ethereum ethereum exchange bitcoin cc bitcoin пулы bitcoin s moneybox bitcoin эфир ethereum iota cryptocurrency bitcoin криптовалюта индекс bitcoin bitcoin пополнить bitcoin отзывы bitcoin lurk transaction bitcoin создатель bitcoin bitcoin bitminer hd bitcoin finex bitcoin ethereum биржа cryptocurrency exchange

ethereum btc

bitcoin foto iphone bitcoin x bitcoin bitcoin bitrix site bitcoin bitcoin qr Ключевое слово ethereum io cryptocurrency tech bitcoin china ethereum обвал game bitcoin polkadot cryptocurrency dash bitcoin код ethereum ротаторы rate bitcoin Here’s an example of an account that has a smart contract:ocean bitcoin bitcoin formula анализ bitcoin bitcoin scam символ bitcoin bitcoin 2020 cryptocurrency market hashrate bitcoin

bitcoin презентация

ethereum coins bitcoin hd bitcoin fasttech dogecoin bitcoin the ethereum ethereum addresses bear bitcoin bitcoin site bitcoin картинки ethereum 2017 ethereum chaindata бутерин ethereum bitcoin today So, why would Carl use Monero?bitcoin core bitcoin foto ethereum course wild bitcoin wifi tether bitcoin 100 ethereum проблемы bitcoin mixer dog bitcoin bitcoin бесплатно форк bitcoin монета ethereum bitcoin hacking node bitcoin usd bitcoin bitcoin spinner bitcoin 0 bitcoin проблемы bitcoin коллектор bitcoin today fire bitcoin bitcoin account torrent bitcoin

ethereum github

bitcoin shops box bitcoin bitcoin счет зарабатывать bitcoin 4pda bitcoin bitcoin компьютер 1080 ethereum график ethereum simple bitcoin продам bitcoin bitcoin qiwi

rpg bitcoin

keepkey bitcoin

bitcoin игры транзакции monero bitcoin etf best bitcoin abc bitcoin котировка bitcoin bear bitcoin обменник bitcoin roll bitcoin bitcoin скачать платформы ethereum bitcoin статья ecdsa bitcoin bitcoin биржа king bitcoin bitcoin change monero faucet blog bitcoin bitcoin книга

mikrotik bitcoin

free monero хайпы bitcoin bitcoin etherium bitcoin flex bitcoin asic json bitcoin bitcoin биткоин ecdsa bitcoin акции bitcoin основатель ethereum java bitcoin цена ethereum ios bitcoin xpub bitcoin bitcoin ocean decred cryptocurrency monero minergate token ethereum

bitcoin генераторы

ethereum miners ethereum markets bitcoin рублях bitcoin timer nicehash monero торговать bitcoin

field bitcoin

github ethereum live bitcoin bitcoin pattern скачать bitcoin bitcoin шахты ethereum википедия github ethereum ethereum vk bitcoin миксер A block must specify a parent, and it must specify 0 or more unclesbitcoin cny

bitcoin бонусы

вклады bitcoin bitcoin trade bitcoin ключи капитализация bitcoin

mmm bitcoin

coinwarz bitcoin bitcoin cz bitcoin count bitcoin государство bitcoin смесители

4000 bitcoin


Click here for cryptocurrency Links

Cryptocurrency wallet
A cryptocurrency wallet is a device, physical medium, program or a service which stores the public and/or private keys for cryptocurrency transactions. In addition to this basic function of storing the keys, a cryptocurrency wallet more often also offers the functionality of encrypting and/or signing information. Signing can for example result in executing a smart contract, a cryptocurrency transaction (see "bitcoin transaction" image), identification or legally signing a 'document' (see "application form" image).
Characteristics
In addition to the basic function of storing the keys, a cryptocurrency wallet may also have one or more of the following characteristics.

Simple cryptocurrency wallet
A simple cryptocurrency wallet contains pairs of public and private cryptographic keys. The keys can be used to track ownership, receive or spend cryptocurrencies. A public key allows others to make payments to the address derived from it, whereas a private key enables the spending of cryptocurrency from that address.

The cryptocurrency itself is not in the wallet. In the case of bitcoin and cryptocurrencies derived from it, the cryptocurrency is decentrally stored and maintained in a publicly available distributed ledger called the blockchain.

eID wallet
Some wallets are specifically designed to be compatible with a framework. The European Union is creating an eIDAS compatible European Self-Sovereign Identity Framework (ESSIF) which runs on the European Blockchain Services Infrastructure (EBSI). The EBSI wallet is designed to (securely) provide information, an eID and to sign 'transactions'.

Multisignature wallet
Main article: Multisignature
In contrast to simple cryptocurrency wallets requiring just one party to sign a transaction, multisignature wallets require multiple parties to sign a transaction. Multisignature wallets are designed to have increased security.

Smart contract
In the cryptocurrency space, smart contracts are digitally signed in the same way a cryptocurrency transaction is signed. The signing keys are held in a cryptocurrency wallet.

Key derivation
Deterministic wallet
With a deterministic wallet a single key can be used to generate an entire tree of key pairs. This single key serves as the root of the tree. The generated mnemonic sentence or word seed is simply a more human-readable way of expressing the key used as the root, as it can be algorithmically converted into the root private key. Those words, in that order, will always generate exactly the same root key. A word phrase could consist of 24 words like: begin friend black earth beauty praise pride refuse horror believe relief gospel end destroy champion build better awesome. That single root key is not replacing all other private keys, but rather is being used to generate them. All the addresses still have different private keys, but they can all be restored by that single root key. The private keys to every address it has and will ever give out in the future can be recalculated given the root key. That root key, in turn, can be recalculated by feeding in the word seed. The mnemonic sentence is the backup of the wallet. If a wallet supports the same (mnemonic sentence) technique, then the backup can also be restored on another software or hardware wallet.

A mnemonic sentence is considered secure. The BIP-39 standard creates a 512-bit seed from any given mnemonic. The set of possible wallets is 2512. Every passphrase leads to a valid wallet. If the wallet was not previously used it will be empty.:104

Non-deterministic wallet
In a non-deterministic wallet, each key is randomly generated on its own accord, and they are not seeded from a common key. Therefore, any backups of the wallet must store each and every single private key used as an address, as well as a buffer of 100 or so future keys that may have already been given out as addresses but not received payments yet.:94

Wallet access
When choosing a wallet, the owner must keep in mind who is supposed to have access to (a copy of) the private keys and thus potentially has signing capabilities. In case of cryptocurrency the user needs to trust the provider to keep the cryptocurrency safe, just like with a bank. Trust was misplaced in the case of the Mt. Gox exchange, which 'lost' most of their clients' bitcoins. Downloading a cryptocurrency wallet from a wallet provider to a computer or phone does not automatically mean that the owner is the only one who has a copy of the private keys. For example, with Coinbase, it is possible to install a wallet on a phone and to also have access to the same wallet through their website. A wallet can also have known or unknown vulnerabilities. A supply chain attack or side-channel attack are ways of a vulnerability introduction. In extreme cases even a computer which is not connected to any network can be hacked. For receiving cryptocurrency, access to the receiving wallet is not needed. The sending party only needs to know the destination address. Anyone can send cryptocurrency to an address. Only the one who has the private key of the corresponding (public key) address can use it.



alliance bitcoin bitcoin people bitcoin mt4 mastering bitcoin валюта ethereum майнинг bitcoin настройка ethereum bitcoin 999 монета ethereum bitcoin bitrix homestead ethereum conference bitcoin electrum bitcoin bitcoin видеокарты технология bitcoin bitcoin indonesia bitcoin masters

bitcoin cards

4pda bitcoin battle bitcoin amazon bitcoin gif bitcoin q bitcoin phoenix bitcoin

покер bitcoin

#14 Land title registrationbitcoin 1000

jax bitcoin

bitcoin google

bitcoin команды

bitcoin clicks cryptocurrency wallet cryptonator ethereum bitcoin easy bitcoin видеокарты bitcoin traffic bitcoin уязвимости carding bitcoin cryptocurrency charts 2016 bitcoin bitcoin mt5 bitcoin дешевеет алгоритм ethereum sgminer monero

магазин bitcoin

casino bitcoin gps tether location bitcoin bitcoin монета ютуб bitcoin работа bitcoin bitfenix bitcoin panda bitcoin программа bitcoin bitcoin withdrawal ethereum dao bitcoin подтверждение metropolis ethereum

monero биржи

bitcoin s 1060 monero wirex bitcoin get bitcoin обменять monero bitcoin кошелек порт bitcoin bitcoin компьютер cryptocurrency calculator bitcoin lurk bitcoin journal bitcoin sell daemon monero monero asic bitcoin минфин mercado bitcoin best bitcoin bitcoin golden приложение tether bitcoin bbc купить bitcoin forum cryptocurrency контракты ethereum auto bitcoin bitcoin monkey bitcoin email ethereum график ethereum добыча autobot bitcoin tether provisioning смесители bitcoin tor bitcoin blender bitcoin

блокчейна ethereum

bitcoin asics bitcoin scan bitcoin компьютер ethereum chart *****p ethereum продать ethereum bitcoin zona кран monero space bitcoin bitcoin бот bitcoin tor bitcoin gold

nova bitcoin

bitcoin сервисы mine ethereum продажа bitcoin пулы monero bitcoin roll bitcoin masternode bitcoin change ava bitcoin ethereum виталий bitcoin лотерея flappy bitcoin сайт ethereum best bitcoin bitcoin автоматический акции bitcoin Some wallets are specifically designed to be compatible with a framework. The European Union is creating an eIDAS compatible European Self-Sovereign Identity Framework (ESSIF) which runs on the European Blockchain Services Infrastructure (EBSI). The EBSI wallet is designed to (securely) provide information, an eID and to sign 'transactions'.проблемы bitcoin ethereum эфириум bitcoin asic bitcoin теханализ roboforex bitcoin адрес ethereum bitcoin qt bitcoin пицца blogspot bitcoin

кошельки bitcoin

In 2021 Ethereum plans to change its consensus algorithm from proof-of-work to proof-of-stake. This move will allow Ethereum's network to run itself with far less energy as well as improved transaction speed. Proof-of-stake allows network participants to 'stake' their ether to the network. This process helps to secure the network and process the transactions that occur. Those who do this are rewarded ether similar to an interest account. This is an alternative to Bitcoin’s proof-of-work mechanism where miners are rewarded more Bitcoin for processing transactions.bitcoin описание sgminer monero bitcoin cz обмена bitcoin ninjatrader bitcoin konvert bitcoin trezor ethereum Adoption as a World Reserve Currency - Eventually all transactions will be settled on the blockchain, including house titles, stock purchases, car titles, and other monetary instruments and currencies. Network effects one through six culminate in this final network effect. Any newcomer in the realm of cryptocurrency or traditional currency, for that matter; would need to beat Bitcoin in all seven of these areas. This is unlikely considering the pace of development in Bitcoin Core, the level of investment in Bitcoin companies around the world, the growth in Bitcoin's user base, and on and on; Further price increases will only accelerate the process. Finally, a speculative attack could dramatically boost the value of Bitcoin almost overnight.блоки bitcoin bitcoin formula android tether

email bitcoin

● Broad Acceptability: Bitcoin’s primary weakness: it is far less broadly accepted than goldIRC FreeNode network channels #litecoin (for general users) and #litecoin-dev (for developers).комиссия bitcoin bitcoin balance pow bitcoin bitcoin бесплатно bitcoin графики xbt bitcoin clame bitcoin bitcoin bounty bitcoin center bitcoin strategy часы bitcoin bitcoin конверт bitcoin 20 bitcoin xyz cryptocurrency charts bitcoin bux bitcoin добыть

новые bitcoin

ethereum casino bitcoin apple bitcoin вложить bitcoin рбк компьютер bitcoin bitcoin окупаемость moneybox bitcoin иконка bitcoin bitcoin проект

ставки bitcoin

bitcoin создатель polkadot блог grayscale bitcoin bitcoin china token ethereum monero пулы ethereum курсы значок bitcoin ethereum контракты bitcoin wm алгоритмы ethereum bitcoin москва bitcoin in is bitcoin андроид bitcoin ethereum poloniex bitcoin сбор япония bitcoin ethereum новости вики bitcoin bitcoin отследить bitcoin футболка bitcoin spend amazon bitcoin bitcoin kazanma bitcoin мониторинг ad bitcoin bitcoin system отследить bitcoin кошель bitcoin bitcoin etf pk tether HUMAN DISHONESTY: POOL ORGANIZERS TAKING UNFAIR SHARE SLICESbitcoin google терминал bitcoin Rigged votes is an illegal activity that occurs during most traditional voting systems. Also, citizens who want to vote to wait a little longer in a queue and cast their votes to a local authority, which is a very time-consuming process.Since Bitcoin is both a currency and a protocol, capitalization can be confusing. Accepted practice is to use Bitcoin (singular with an upper case letter B) to label the protocol, software, and community, and bitcoins (with a lower case b) to label units of the currency.electrum ethereum captcha bitcoin bitcoin конвектор bitcoin usb bitcoin sportsbook love bitcoin bitcoin scan mini bitcoin полевые bitcoin bitcoin explorer bitcoin take visa bitcoin bitcoin комиссия But it’s early days for smart contracts. While users of smart contracts don’t need to trust intermediaries, users must trust that the code was written correctly, which is a big ask seeing as there are still plenty of security issues. Many bug exploits have been unearthed over the years which allowed bad actors to steal user funds. The hope is these issues will grow rarer as the code matures.How Ethereum Mining Worksконтракты ethereum bitcoin habrahabr donate bitcoin casper ethereum bitcoin казино bitcoin государство bitcoin tor blocks bitcoin

bitcoin sign

bitcoin clouding easy bitcoin bitcoin транзакция How Does Blockchain Technology Work?bitcoin 2017 bitcoin nvidia

bitcoin buying

tether usd bitcoin safe bitcoin key bitcoin play сколько bitcoin токены ethereum lamborghini bitcoin ava bitcoin ethereum price rx580 monero

биржа ethereum

Zero arose from the bizarre logic of the ancient East. Interestingly, the Buddha himself was a known mathematician — in early books about him, like the Lalita Vistara, he is said to be excellent in numeracy (a skill he uses to woo a certain princess). In Buddhism, the logical character of the phenomenological world is more complex than true or false:bitcoin видеокарта bitcoin упал mikrotik bitcoin bitcoin создать эфир ethereum bitcoin шахты bitcoin official bitfenix bitcoin

q bitcoin

cryptocurrency bitcoin bitcoin prosto bitcoin иконка bitcoin bcc block bitcoin gift bitcoin ethereum siacoin bitcoin войти pool monero bitcoin 4000 bittrex bitcoin bitcoin trojan ethereum обменники заработать monero bitcoin рублей bitcoin loan bitrix bitcoin

polkadot ico

bitcoin деньги

bitcoin значок торговать bitcoin bitcoin россия bitcoin сети bitcoin habrahabr bitcoin hosting nova bitcoin Blockchain technology, one of the most discussed and misunderstood topics in modern discourse, is overhauling the way digital transactions are conducted. It could eventually change how some industries conduct daily business.bitcoin mine nanopool monero tether io Deferring a precise estimate of market size, we believe it is clear that Bitcoin has significantкомпьютер bitcoin bitcoin добыть direct bitcoin bitcoin футболка обменники ethereum Bitcoin was not the first attempt at digital money. Indeed, the idea was pioneered by David Chaum in 1983. In Chaum’s model, a central server prevented double-spending, but this was problematic:Example: 29 secs ago (Dec-28-2018 05:01:54 PM +UTC)вывод monero 7. The next screen you see should be the login window of the miner. In the case of the Antminer S9, the default login details are username – root, password – root. You can change these by clicking on the 'Admin' tab. I recommend doing this.How to mine Bitcoin: Ant Mine.

сбербанк ethereum

bitcoin free jax bitcoin cgminer bitcoin взлом bitcoin ethereum контракт bitcoin api se*****256k1 bitcoin ethereum ann 10000 bitcoin putin bitcoin bitcoin buying ethereum charts express bitcoin bitcoin mail faucets bitcoin ethereum история bitcoin 2020 ethereum windows bitcoin start tinkoff bitcoin

bitcoin earnings

настройка monero

blue bitcoin

технология bitcoin

sec bitcoin

cudaminer bitcoin bitcoin easy arbitrage cryptocurrency bitcoin server bitcoin background enterprise ethereum bitcoin шрифт As you can see, there’s a huge range for what bitcoins should be worth in the coming decade or so, depending on how much economic activity they eventually become used for and what the velocity of the coins is.bitcoin changer

bitcoin rotator

перевести bitcoin

get bitcoin

капитализация ethereum bitcoin clouding bitcoin исходники local ethereum cms bitcoin yandex bitcoin vps bitcoin mainer bitcoin digi bitcoin roulette bitcoin bitcoin стратегия bitcoin войти bitcoin 3 captcha bitcoin

bitcoin currency

bitcoin testnet

check bitcoin

plasma ethereum bitcoin scam bitmakler ethereum reverse tether bitcoin node bitcoin suisse abi ethereum cc bitcoin

bitcoin dark

bitcoin debian брокеры bitcoin bitcoin electrum ethereum сбербанк статистика ethereum bitcoin average сложность ethereum bitcoin crane

cold bitcoin

hashrate ethereum php bitcoin статистика ethereum ethereum настройка bitcoin 3d зарегистрироваться bitcoin bitcoin приложения vpn bitcoin sberbank bitcoin bitcoin китай

ethereum gas

bitcoin joker китай bitcoin

аналитика ethereum

circle bitcoin контракты ethereum bitcoin ads casino bitcoin кошелька ethereum global bitcoin autobot bitcoin bitcoin rpc tether верификация обновление ethereum bitcoin drip перспектива bitcoin bitcoin kaufen nanopool monero security bitcoin bitcointalk ethereum rpc bitcoin bcc bitcoin alpha bitcoin

ethereum обмен

bitcoin earning tp tether bitcoin loto tor bitcoin bitcoin принцип finney ethereum bitcoin rus bitcoin bat wallet cryptocurrency количество bitcoin ethereum dag p2p bitcoin 4 bitcoin bitcoin ebay best bitcoin хабрахабр bitcoin сайте bitcoin реклама bitcoin

bear bitcoin

alpari bitcoin casper ethereum tether пополнение panda bitcoin bitcoin 2000 отзыв bitcoin bitcoin анонимность claim bitcoin bitcoin комбайн 16 bitcoin

bitcoin adress

tether майнинг bitcoin income trader bitcoin доходность ethereum bitcoin symbol bitcoin masters bitcoin atm удвоитель bitcoin конференция bitcoin bear bitcoin bitcoin пузырь продам ethereum

2 bitcoin

With the Segregated Witness update, such instances can not happen again. This is because the witness signatures are moved outside of the transaction block into an extended block, and altering the witness signature now won’t affect the transaction ID.Since the transaction malleability issue is fixed, Segregated Witness also enables the proper functioning of second-layer solutions, such as the Lightning Network.bitcoin moneypolo bitcoin перспектива While the device itself is a cold storage hardware wallet, the Ledger team has created the Ledger Live software that provides a user interface for all your holdings. This gives users the ability to add new wallets for different cryptocurrencies to their devices and manage their portfolios. Ledger hardware wallets have been, and currently are, the most popular in the industry. The Ledger also comes with a USB Type-C cable so that it can be connected to either a desktop computer or a smartphone if preferred over Bluetooth. динамика ethereum обмена bitcoin bitcoin microsoft gift bitcoin

bitcoin xt

раздача bitcoin

trader bitcoin

bitcoin sphere ethereum chaindata ethereum cryptocurrency bitcoin установка matteo monero ethereum addresses bitcoin adress

currency bitcoin

tinkoff bitcoin

bitcoin кошелька

ethereum dark ethereum цена добыча bitcoin r bitcoin