Apa maksud bitcoin

Ketika sesebuah nodus mendapatkan penyelesaian yang tepat, maka ia akan mengumumkannya ke sisa rangkaian dan menuntut sekumpulan daripada bitcoin. Ahli-ahli rangkaian akan menerima blok yang telah dipecahkan dan menvalidasikannya sebelum menerima secara penuh, dan menambahkannya ke rantai. Dikarenakan setiap satu blok akan dihasilkan setiap 10 minit, maka setiap node secara berasingan menetapkan semula kesukaran dari masalah yang dicoba untuk dipecahkan setiap dua dua minggu sekali untuk setiap perubahan dari kuasa keseluruhan unit pemproses pusat CPU dari rangkaian peer-ke-peer.

Ekonomi Bitcoin masih kecil berbanding dengan ekonomi yang sudah lama didirikan dan perisian masih dalam tahap perkembangan beta. Tetapi barang pakai dan servis, seperti kereta bekas dan kontrak pembangunan perisian freelance, sekarang sudah dapat diperdagangkan. Bitcoin diterima untuk kedua hal, baik servis maya mahupun barang nyata. Self-published inline Sesiapapun dapat melihat rantai-blok dan mengamati transaksi secara real time. Pemindahan-pemindahan dimudahkan secara langsung tanpa menggunakan sebuah pemproses kewangan di antara nodus.

Jenis transaksi ini membuat chargeback mustahil. Pelanggan Bitcoin akan menyiarkan transaksi ke nodus sekitar yang akan menyebarkan pembayaran ke semua rangkaian.

Transaksi-transaksi yang gagal atau salah akan ditolak oleh pelanggan-pelanggan yang jujur. Transaksi-transaksi kebanyakan bebas pungutan kos, tetapi sebuah kos biasanya dapat dibayarkan ke node lainnya untuk mempriotiskan pemerosesan transaksi. Kesahan penggunaan Bitcoin di sisi undang-undang berubah-ubah secara cepat di seluruh dunia, beberapa negara seperti Thailand melarang Bitcoin, negara Jerman memberikan status sah dan beberapa negara seperti China menyekat kegunaan bitcoin.

Rangkaian Bitcoin secara rawak membuat dan mengedarkan bitcoin yang baru sekitar 6 kali dalam satu jam ke seseorang yang menjalankan perisian dengan opsyen 'menghasilkan syiling' yang telah dipilih sebelumnya.

Setiap pengguna berpotensi menerima sekumpulan dengan menjalankan opsyen itu, atau program yang telah dikhususkan untuk dijalankan di alat yang pengguna punya contohnya kad grafik - VGA. Menghasilkan bitcoin ialah sering diistilahkan sebagai "melombong", sebuah istilah yang sama dengan analogi perlombongan emas. Mengenai kebarangkalian kemungkinan bahawa seorang pengguna akan menerima sekumpulan sangat bergantung pada kuasa komputasi yang disumbangkan ke rangkaian yang juga berhubungan dengan gabungan kuasa komputasi dari semua nodus.

Seiring dengan pembayaran berkurang, maka motif dari pengguna tersebut diharapkan akan berubah untuk mendapatkan kos transaksi. Semua nodus yang menghasilkan dari rangkaian ialah berkompetisi untuk menjadi yang pertama dalam mencari sebuah penyelesaian untuk sebuah masalah kriptografi mengenai blok kandidatnya, sebuah masalah yang menghendaki pengulangan percubaan dan kesalahan.

Ketika sebuah nodus mendapati sebuah penyelesaian yang benar, maka akan mengumumkannya ke baki rangkaian dan menuntut sekumpulan bitcoin. Oleh sebab setiap satu blok akan dihasilkan setiap 10 minit, maka setiap node secara berasingan menetapkan ulang kesukaran dari masalah yang dicoba untuk dipecahkan setiap dua dua minggu sekali untuk setiap perubahan dari kuasa keseluruhan unit pemproses pusat CPU dari rangkaian peer-ke-peer.

Oleh sebab nodus tidak diwajibkan untuk menyertakan transaksi-transaksi dalam setiap blok yang dihasilkan, penghantar Bitcoin dapat juga secara sukarela membayar kos transaksi.

Melakukan demikian akan mempercepat transaksi tersebut dan membekalkan insentif untuk pengguna-pengguna yang menjalankan nodus, terutamanya ketika kesukaran dari menghasilkan bitcoin ditingkatkan atau hadiah dari setiap jumlah blok berkurang seiring masa.

Nodus menghimpun kos transaksi yang dikaitkan dengan semua transaksi-transaksi yang dimasukkan dalam blok-kandidat mereka. Ekonomi dari Bitcoin masih kecil berbanding dengan ekonomi-ekonomi yang sudah lama didirikan dan perisian masih dalam tahap perkembangan beta. Tetapi barang pakai dan servis, seperti kereta bekas dan kontrak pembangunan perisian freelance , sekarang sudah dapat diperdagangkan.

Bitcoin diterima untuk kedua hal, baik perkhidmatan maya mahupun barang nyata. Self-published inline Sesiapa pun dapat melihat rantai-blok dan memerhatikan transaksi secara real time.

Seiring dengan masa, jumlah keseluruhan bitcoin akan meningkat mengarah ke 21 juta. Archived from the original on 10 January Retrieved 10 January Retrieved 17 February Turku University of Applied Sciences. Archived PDF from the original on 18 January Retrieved 8 January Archived from the original on 30 June Archived from the original on 9 November Archived from the original on 28 April Archived from the original on 1 January Retrieved 10 October Archived from the original on 16 June Retrieved 20 September Archived from the original on 31 December Retrieved 30 December The network's 'nodes' — users running the bitcoin software on their computers — collectively check the integrity of other nodes to ensure that no one spends the same coins twice.

All transactions are published on a shared public ledger, called the 'blockchain'. Archived from the original on 10 October Archived from the original on 5 December Retrieved 25 January Archived from the original on 9 February Archived from the original on 10 August Retrieved 23 February Privacy-preserving proofs of solvency for Bitcoin exchanges" PDF.

International Association for Cryptologic Research. Archived PDF from the original on 10 March Retrieved 22 February Archived PDF from the original on 15 February Retrieved 15 February Archived from the original on 13 February How much Capacity does SegWit really Give? Retrieved 20 February Retrieved 22 June Archived from the original on 6 October Archived from the original on 20 February Archived from the original on 20 October Retrieved 21 October The New York Times.

Archived from the original on 14 October Retrieved 6 May A type of digital cash, bitcoins were invented in and can be sent directly to anyone, anywhere in the world. Archived from the original on 1 May Archived from the original on 12 January Retrieved 13 January Chronic deflation may keep Bitcoin from displacing its rivals".

Archived from the original on 25 March Retrieved 25 March Archived from the original on 4 December Archived from the original on 11 December Retrieved 11 December Archived from the original on 18 July Retrieved 18 July Archived from the original on 25 January Archived from the original on 12 December Retrieved 12 December Archived from the original on 28 August Retrieved 28 August Archived from the original on 17 April Archived from the original on 23 February Archived from the original on 3 February Retrieved 9 January Archived from the original on 11 February The Sydney Morning Herald.

Archived from the original on 24 January Archived from the original on 7 December Retrieved 23 March Archived from the original on 27 June Retrieved 13 June Retrieved 16 December Retrieved 11 August Archived from the original on 10 July Retrieved 10 July Archived from the original on 13 December Archived from the original PDF on 28 December Retrieved 23 December Archived from the original on 15 March Retrieved 14 March Archived from the original on 19 February Archived from the original on 9 January Archived from the original on 29 December Retrieved 29 December Retrieved 14 October Bitcoin Recruits Snap To".

Retrieved 9 December Archived from the original on 23 October Archived from the original on 9 March Retrieved 9 March Principles, Trends, Opportunities, and Risks". Social Science Research Network. Archived from the original on 20 December It's 'the Harlem Shake of currency ' ". Archived from the original on 1 March Retrieved 2 May Archived from the original on 11 January Archived from the original on 7 February Archived from the original on 20 September Archived from the original on 26 October Archived PDF from the original on 11 November Retrieved 11 November Archived from the original on 5 November Retrieved 15 November Archived from the original on 20 April Retrieved 20 April Archived from the original on 23 April Retrieved 22 April Electronic Commerce Research and Applications.

Retrieved 5 October Retrieved 2 July The second biggest Ponzi scheme in history". Archived from the original on 17 June Retrieved 23 May Archived from the original on 29 March Retrieved 1 April Archived PDF from the original on 31 October Retrieved 30 October Archived PDF from the original on 5 December Retrieved 28 November Archived from the original on 24 September Archived from the original on 23 September Archived from the original on 13 January Archived from the original on 22 October Here's what Warren Buffett is saying".

Retrieved 11 January Archived from the original on 7 January Archived from the original on 19 December Archived from the original on 1 December Archived from the original on 3 October Retrieved 6 October Then the suitcases of cash started arriving". Retrieved 16 March Good Or Bad For Bitcoin? Archived from the original on 26 November Retrieved 25 November Retrieved 12 January Archived from the original on 14 January Retrieved 14 January Archived from the original on 19 January Retrieved 20 October Guardian News and Media Limited.

An Analysis of Google Search Data". Retrieved 24 March Archived from the original on 19 September Archived from the original on 23 December Archived PDF from the original on 22 September Archived from the original on 18 May Retrieved 8 May Every 2, blocks approximately 14 days at roughly 10 min per block , the difficulty target is adjusted based on the network's recent performance, with the aim of keeping the average time between new blocks at ten minutes.

In this way the system automatically adapts to the total amount of mining power on the network. The proof-of-work system, alongside the chaining of blocks, makes modifications of the blockchain extremely hard, as an attacker must modify all subsequent blocks in order for the modifications of one block to be accepted. Computing power is often bundled together or "pooled" to reduce variance in miner income. Individual mining rigs often have to wait for long periods to confirm a block of transactions and receive payment.

In a pool, all participating miners get paid every time a participating server solves a block. This payment depends on the amount of work an individual miner contributed to help find that block. The successful miner finding the new block is rewarded with newly created bitcoins and transaction fees. To claim the reward, a special transaction called a coinbase is included with the processed payments. The bitcoin protocol specifies that the reward for adding a block will be halved every , blocks approximately every four years.

Eventually, the reward will decrease to zero, and the limit of 21 million bitcoins [f] will be reached c. Their numbers are being released roughly every ten minutes and the rate at which they are generated would drop by half every four years until all were in circulation. A wallet stores the information necessary to transact bitcoins. While wallets are often described as a place to hold [59] or store bitcoins, [60] due to the nature of the system, bitcoins are inseparable from the blockchain transaction ledger.

A better way to describe a wallet is something that "stores the digital credentials for your bitcoin holdings" [60] and allows one to access and spend them. Bitcoin uses public-key cryptography , in which two cryptographic keys, one public and one private, are generated. There are three modes which wallets can operate in.

They have an inverse relationship with regards to trustlessness and computational requirements. Third-party internet services called online wallets offer similar functionality but may be easier to use. In this case, credentials to access funds are stored with the online wallet provider rather than on the user's hardware. A malicious provider or a breach in server security may cause entrusted bitcoins to be stolen.

An example of such a security breach occurred with Mt. Physical wallets store offline the credentials necessary to spend bitcoins. Another type of wallet called a hardware wallet keeps credentials offline while facilitating transactions. The first wallet program — simply named "Bitcoin" — was released in by Satoshi Nakamoto as open-source code.

While a decentralized system cannot have an "official" implementation, Bitcoin Core is considered by some to be bitcoin's preferred implementation. Bitcoin was designed not to need a central authority [5] and the bitcoin network is considered to be decentralized. In mining pool Ghash. The pool has voluntarily capped their hashing power at Bitcoin is pseudonymous , meaning that funds are not tied to real-world entities but rather bitcoin addresses.

Owners of bitcoin addresses are not explicitly identified, but all transactions on the blockchain are public. In addition, transactions can be linked to individuals and companies through "idioms of use" e. To heighten financial privacy, a new bitcoin address can be generated for each transaction.

Wallets and similar software technically handle all bitcoins as equivalent, establishing the basic level of fungibility. Researchers have pointed out that the history of each bitcoin is registered and publicly available in the blockchain ledger, and that some users may refuse to accept bitcoins coming from controversial transactions, which would harm bitcoin's fungibility. The blocks in the blockchain were originally limited to 32 megabyte in size. The block size limit of one megabyte was introduced by Satoshi Nakamoto in , as an anti-spam measure.

Transactions contain some data which is only used to verify the transaction, and does not otherwise effect the movement of coins. SegWit introduces a new transaction format that moves this data into a new field in a backwards-compatible way. The segregated data, the so-called witness , is not sent to non-SegWit nodes and therefore does not form part of the blockchain as seen by legacy nodes.

This lowers the size of the average transaction in such nodes' view, thereby increasing the block size without incurring the hard fork implied by other proposals for block size increases. Bitcoin is a digital asset designed by its inventor, Satoshi Nakamoto, to work as a currency. The question whether bitcoin is a currency or not is still disputed. According to research produced by Cambridge University , there were between 2. The number of users has grown significantly since , when there were , to 1.

In , the number of merchants accepting bitcoin exceeded , Reasons for this fall include high transaction fees due to bitcoin's scalability issues, long transaction times and a rise in value making consumers unwilling to spend it. Merchants accepting bitcoin ordinarily use the services of bitcoin payment service providers such as BitPay or Coinbase.

When a customer pays in bitcoin, the payment service provider accepts the bitcoin on behalf of the merchant, converts it to the local currency, and sends the obtained amount to merchant's bank account, charging a fee for the service.

Bitcoins can be bought on digital currency exchanges. According to Tony Gallippi , a co-founder of BitPay , "banks are scared to deal with bitcoin companies, even if they really want to". In a report, Bank of America Merrill Lynch stated that "we believe bitcoin can become a major means of payment for e-commerce and may emerge as a serious competitor to traditional money-transfer providers.

Plans were announced to include a bitcoin futures option on the Chicago Mercantile Exchange in Some Argentinians have bought bitcoins to protect their savings against high inflation or the possibility that governments could confiscate savings accounts.

The Winklevoss twins have invested into bitcoins. Other methods of investment are bitcoin funds. The first regulated bitcoin fund was established in Jersey in July and approved by the Jersey Financial Services Commission. Forbes named bitcoin the best investment of The price of bitcoins has gone through various cycles of appreciation and depreciation referred to by some as bubbles and busts. According to Mark T. Various journalists, [78] [] economists, [] [] and the central bank of Estonia [] have voiced concerns that bitcoin is a Ponzi scheme.

In , Eric Posner , a law professor at the University of Chicago, stated that "a real Ponzi scheme takes fraud; bitcoin, by contrast, seems more like a collective delusion. Zero Hedge claimed that the same day Dimon made his statement, JP Morgan also purchased a large amount of bitcoins for its clients. You can have cryptodollars in yen and stuff like that. Bitcoin has been labelled a speculative bubble by many including former Fed Chairman Alan Greenspan [] and economist John Quiggin.

Lee, in a piece for The Washington Post pointed out that the observed cycles of appreciation and depreciation don't correspond to the definition of speculative bubble. It's a mirage, basically. Because of bitcoin's decentralized nature, nation-states cannot shut down the network or alter its technical rules. While some countries have explicitly allowed its use and trade, others have banned or restricted it.

Regulations and bans that apply to bitcoin probably extend to similar cryptocurrency systems. Bitcoin has been criticized for the amounts of electricity consumed by mining. As of , The Economist estimated that even if all miners used modern facilities, the combined electricity consumption would be To lower the costs, bitcoin miners have set up in places like Iceland where geothermal energy is cheap and cooling Arctic air is free.

The use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, law enforcement, and the media.

Senate held a hearing on virtual currencies in November Several news outlets have asserted that the popularity of bitcoins hinges on the ability to use them to purchase illegal goods. It will cover studies of cryptocurrencies and related technologies, and is published by the University of Pittsburgh.

Authors are also asked to include a personal bitcoin address in the first page of their papers. The documentary film, The Rise and Rise of Bitcoin late , features interviews with people who use bitcoin, such as a computer programmer and a drug dealer. In Charles Stross ' science fiction novel, Neptune's Brood , "bitcoin" a modified version is used as the universal interstellar payment system.

From Wikipedia, the free encyclopedia. For a broader coverage related to this topic, see Blockchain. For a broader coverage related to this topic, see Cryptocurrency wallet. Legality of bitcoin by country or territory. Cryptography portal Business and economics portal Free and open-source software portal Internet portal Numismatics portal.

The timestamp of the block is This block is unlike all other blocks in that it doesn't have a previous block to reference. The fact is that gold miners are rewarded for producing gold, while bitcoin miners are not rewarded for producing bitcoins; they are rewarded for their record-keeping services. Archived from the original on 7 August Retrieved 25 May Archived from the original on 20 June Retrieved 20 June Archived from the original on 20 January Retrieved 30 September Archived PDF from the original on 20 March Retrieved 28 April Financial Crimes Enforcement Network.

Archived PDF from the original on 9 October Retrieved 1 June Archived from the original on 9 October Retrieved 8 October Archived PDF from the original on 21 September Retrieved 22 October Archived from the original on 24 October Retrieved 24 October The Economist Newspaper Limited. Archived from the original on 21 August Retrieved 23 September Bitcoin and its mysterious inventor".

Archived from the original on 1 November Retrieved 31 October Archived from the original on 31 October Retrieved 16 November Archived from the original on 28 November Retrieved 20 November Archived PDF from the original on 10 April Retrieved 14 April The Age of Cryptocurrency: Archived from the original on 2 January Retrieved 28 December Archived from the original on 27 July Retrieved 22 December Standards vary, but there seems to be a consensus forming around Bitcoin, capitalized, for the system, the software, and the network it runs on, and bitcoin, lowercase, for the currency itself.

Is It Bitcoin, or bitcoin? The Orthography of the Cryptography". Archived from the original on 19 April Retrieved 21 April The Chronicle of Higher Education chronicle. Archived from the original on 16 April Retrieved 19 April Archived from the original on 5 January Retrieved 28 January Retrieved 2 November Archived from the original on 27 October Archived from the original on 2 November Archived from the original on 18 June Retrieved 23 April Archived PDF from the original on 14 October Retrieved 26 August Archived from the original on 11 October Retrieved 11 October Archived from the original on 21 July Archived from the original on 26 March Retrieved 13 October Archived from the original on 15 October And the Future of Money.