Vitalik Buterin picked the name Ethereum after browsing Wikipedia articles about elements and science fiction, when he found the name, noting, "I immediately realized that I liked it better than all of the other alternatives that I had seen; I suppose it was the fact that sounded nice and it had the word 'ether', referring to the hypothetical invisible medium that permeates the universe and allows light to travel."[9]

Ethereum was initially described in a white paper by Vitalik Buterin,[10] a programmer involved with Bitcoin Magazine, in late 2013 with a goal of building decentralized applications.[11][12] Buterin had argued that Bitcoin needed a scripting language for application development. Failing to gain agreement, he proposed development of a new platform with a more general scripting language.[4]:88
Armed with the knowledge of Ethereum’s price history, future predictions and the associated risks to investing in this cryptocurrency, you may now be considering a purchase. Buying Ethereum has evolved from a niche and slightly cumbersome process to one which has been polished into simplicity. Ethereum can now be bought through debit/credit card, epayment platforms, bank transfer, cash or even Bitcoin and other cryptocurrencies. Speculators can bet on the asset (both long and short) through “contracts for difference” (CFDs) or they can purchase and secure the asset themselves to “become their own bank”.
الجدير بالذكر بأن بعض المواقع كانت تنشر سابقا تقديرا لمقدار الخسارة/ الربح الذي يُسجله المنقبون لكن يبدو بأنهم توقفوا عن القيام بذلك لأسباب نجهلها. قد يعتقد البعض بأنه لم يكن بالإمكان إعطاء تقدير دقيق لمقدار الخسارة أو الربح الذي يُسجله المنقبون، ولذلك تم التخلص من ذلك. إلا أنه من المُمكن جدا أنه تم التخلص من ذلك لكيلا يتم تنفير المُنقبين من عمليات التنقيب.
Bitcoin prices were negatively affected by several hacks or thefts from cryptocurrency exchanges, including thefts from Coincheck in January 2018, Coinrail and Bithumb in June, and Bancor in July. For the first six months of 2018, $761 million worth of cryptocurrencies was reported stolen from exchanges.[64] Bitcoin's price was affected even though other cryptocurrencies were stolen at Coinrail and Bancor as investors worried about the security of cryptocurrency exchanges.[65][66][67]

^ Chan, Edwin. "China Plans to Ban Cryptocurrency Mining in Renewed Clampdown". www.bloomberg.com. Retrieved 10 April 2019. While China was once home to about 70 percent of Bitcoin mining and 90 percent of trades, authorities have waged a nearly two-year campaign to shrink the crypto industry amid concerns over speculative bubbles, fraud and wasteful energy consumption.


The successful miner finding the new block is allowed by the rest of the network to reward themselves with newly created bitcoins and transaction fees.[88] As of 9 July 2016,[89] the reward amounted to 12.5 newly created bitcoins per block added to the blockchain, plus any transaction fees from payments processed by the block. To claim the reward, a special transaction called a coinbase is included with the processed payments.[7]:ch. 8 All bitcoins in existence have been created in such coinbase transactions. The bitcoin protocol specifies that the reward for adding a block will be halved every 210,000 blocks (approximately every four years). Eventually, the reward will decrease to zero, and the limit of 21 million bitcoins[f] will be reached c. 2140; the record keeping will then be rewarded solely by transaction fees.[90]
Every 2,016 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.[7]:ch. 8 Between 1 March 2014 and 1 March 2015, the average number of nonces miners had to try before creating a new block increased from 16.4 quintillion to 200.5 quintillion.[86]

Ethereum has recently created a new standard called the ERC721 token for tracking unique digital assets. One of the biggest use cases currently for such tokens is digital collectibles, as the infrastructure allows for people to prove ownership of scarce digital goods. Many games are currently being built using this technology, such as the overnight hit CryptoKitties, a game where you can collect and breed digital cats.

By comparison to government-backed global currencies, Bitcoin remains fairly complex for the typical user to acquire and use in regular transactions. Growing interest and significant global investments in Bitcoin wallet and Blockchain technology have nonetheless made buying and selling Bitcoin far more accessible to the average user. And indeed growing acceptance by government entities have ameliorated the ambiguity of legal and regulatory status for Bitcoin and Bitcoin exchanges.
The first wallet program, simply named Bitcoin, and sometimes referred to as the Satoshi client, was released in 2009 by Satoshi Nakamoto as open-source software.[11] In version 0.5 the client moved from the wxWidgets user interface toolkit to Qt, and the whole bundle was referred to as Bitcoin-Qt.[107] After the release of version 0.9, the software bundle was renamed Bitcoin Core to distinguish itself from the underlying network.[108][109]
Ethereum can also be used to build Decentralized Autonomous Organizations (DAO). A DAO is fully autonomous, decentralized organization with no single leader. DAO’s are run by programming code, on a collection of smart contracts written on the Ethereum blockchain. The code is designed to replace the rules and structure of a traditional organization, eliminating the need for people and centralized control. A DAO is owned by everyone who purchases tokens, but instead of each token equating to equity shares & ownership, tokens act as contributions that give people voting rights.

To lower the costs, bitcoin miners have set up in places like Iceland where geothermal energy is cheap and cooling Arctic air is free.[205] Bitcoin miners are known to use hydroelectric power in Tibet, Quebec, Washington (state), and Austria to reduce electricity costs.[204][206] Miners are attracted to suppliers such as Hydro Quebec that have energy surpluses.[207] According to a University of Cambridge study, much of bitcoin mining is done in China, where electricity is subsidized by the government.[208][209]
If the private key is lost, the bitcoin network will not recognize any other evidence of ownership;[32] the coins are then unusable, and effectively lost. For example, in 2013 one user claimed to have lost 7,500 bitcoins, worth $7.5 million at the time, when he accidentally discarded a hard drive containing his private key.[78] About 20% of all bitcoins are believed to be lost. They would have a market value of about $20 billion at July 2018 prices.[79]
حاليا لا يُملك مالكو عملات بيتكوين خيارات كثيرة لإنفاق أموالهم من خلالها، وهو ما يدفع ببعضهم إلى استبدالها مقابل العملات التقليدية. يتم ذلك عادة عبر منصات خاصة بذلك حيث يتم استبدال البيتكوينات مع مُستخدمين آخرين لها. يبدو أنه وفي حال ما إذا رغبت الحكومات في معرفة هويات أصحاب بعض الحسابات فما عليها سوى أن تقوم بتقنين عمليات التحويل بدل منعها، حيث سيصبح بالإمكان معرفة اسم صاحب كل حساب بُمجرد أن يرغب في استبدال ما بحوزته مقابل عملات تقليدية، وهو ما يُمثل نقطة انطلاق لتتبع الأموال المسروقة.
• غطاء تمويلى للمنظمات الإرهابية: قامت دار الإفتاء المصرية بتصريح أن عمليات الإستثمار والتداول في البيتكوين تُعتبر عمليات مُحرمة من قبل الدين والشرع حيث إنها تعمل كغطاء لتمويل المنظمات الإرهابية وعصابات المُخدرات. كما لعدم وجود هيئات حكومية وبنوك مركزية كان لذلك آثر رهيب على استخدام إستثمارات البيتكوين في عمليات غسيل الأموال والتى بالطبع نهانا الرسول عنها، بل ويُحاسب عليها القانون أيضاً.
حاليا لا يُملك مالكو عملات بيتكوين خيارات كثيرة لإنفاق أموالهم من خلالها، وهو ما يدفع ببعضهم إلى استبدالها مقابل العملات التقليدية. يتم ذلك عادة عبر منصات خاصة بذلك حيث يتم استبدال البيتكوينات مع مُستخدمين آخرين لها. يبدو أنه وفي حال ما إذا رغبت الحكومات في معرفة هويات أصحاب بعض الحسابات فما عليها سوى أن تقوم بتقنين عمليات التحويل بدل منعها، حيث سيصبح بالإمكان معرفة اسم صاحب كل حساب بُمجرد أن يرغب في استبدال ما بحوزته مقابل عملات تقليدية، وهو ما يُمثل نقطة انطلاق لتتبع الأموال المسروقة.
Here’s why. Ethereum is based on blockchain technology where all transactions are meant to be irreversible and unchangeable. By executing a hard fork and rewriting the rules by which the blockchain executes, Ethereum set a dangerous precedent that goes against the very essence of blockchain. If the blockchain is changed every time a large enough amount of money is involved, or enough people get negatively impacted, the blockchain will lose its main value proposition – secure, anonymous, tamper proof & unchangeable.

The "Metropolis Part 1: Byzantium" soft[citation needed] fork took effect on 16 October 2017, and included changes to reduce the complexity of the EVM and provide more flexibility for smart contract developers. Byzantium also added supports for zk-SNARKs (from Zcash), with the first zk-SNARK transaction occurring on testnet on September 19, 2017.[citation needed]
According to the Library of Congress, an "absolute ban" on trading or using cryptocurrencies applies in eight countries: Algeria, Bolivia, Egypt, Iraq, Morocco, Nepal, Pakistan, and the United Arab Emirates. An "implicit ban" applies in another 15 countries, which include Bahrain, Bangladesh, China, Colombia, the Dominican Republic, Indonesia, Iran, Kuwait, Lesotho, Lithuania, Macau, Oman, Qatar, Saudi Arabia and Taiwan.[169]

In October 2015,[63] a development governance was proposed as Ethereum Improvement Proposal, aka EIP, standardized on EIP-1.[64] The core development group and community were to gain consensus by a process regulated EIP. A few notable decisions were made in the process of EIP, such as EIP-160 (EXP cost increase caused by Spurious Dragon Hardfork)[65] and EIP-20 (ERC-20 Token Standard).[66] In January 2018, the EIP process was finalized and published as EIP-1 status turned "active".[63]
Here’s why. Ethereum is based on blockchain technology where all transactions are meant to be irreversible and unchangeable. By executing a hard fork and rewriting the rules by which the blockchain executes, Ethereum set a dangerous precedent that goes against the very essence of blockchain. If the blockchain is changed every time a large enough amount of money is involved, or enough people get negatively impacted, the blockchain will lose its main value proposition – secure, anonymous, tamper proof & unchangeable.
Venture capitalists, such as Peter Thiel's Founders Fund, which invested US$3 million in BitPay, do not purchase bitcoins themselves, but instead fund bitcoin infrastructure that provides payment systems to merchants, exchanges, wallet services, etc.[154] In 2012, an incubator for bitcoin-focused start-ups was founded by Adam Draper, with financing help from his father, venture capitalist Tim Draper, one of the largest bitcoin holders after winning an auction of 30,000 bitcoins,[155] at the time called "mystery buyer".[156] The company's goal is to fund 100 bitcoin businesses within 2–3 years with $10,000 to $20,000 for a 6% stake.[155] Investors also invest in bitcoin mining.[157] According to a 2015 study by Paolo Tasca, bitcoin startups raised almost $1 billion in three years (Q1 2012 – Q1 2015).[158]
حاليا لا يُملك مالكو عملات بيتكوين خيارات كثيرة لإنفاق أموالهم من خلالها، وهو ما يدفع ببعضهم إلى استبدالها مقابل العملات التقليدية. يتم ذلك عادة عبر منصات خاصة بذلك حيث يتم استبدال البيتكوينات مع مُستخدمين آخرين لها. يبدو أنه وفي حال ما إذا رغبت الحكومات في معرفة هويات أصحاب بعض الحسابات فما عليها سوى أن تقوم بتقنين عمليات التحويل بدل منعها، حيث سيصبح بالإمكان معرفة اسم صاحب كل حساب بُمجرد أن يرغب في استبدال ما بحوزته مقابل عملات تقليدية، وهو ما يُمثل نقطة انطلاق لتتبع الأموال المسروقة.
Ethereum's blockchain uses Merkle trees, for security reasons, to improve scalability, and to optimize transaction hashing.[61] As with any Merkle tree implementation, it allows for storage savings, set membership proofs (called "Merkle proofs"), and light client synchronization. The Ethereum network has at times faced congestion problems, for example, congestion occurred during late 2017 in relation to Cryptokitties.[62]
Ethereum’s core innovation, the Ethereum Virtual Machine (EVM) is a Turing complete software that runs on the Ethereum network. It enables anyone to run any program, regardless of the programming language given enough time and memory. The Ethereum Virtual Machine makes the process of creating blockchain applications much easier and efficient than ever before. Instead of having to build an entirely original blockchain for each new application, Ethereum enables the development of potentially thousands of different applications all on one platform.
In October 2015,[63] a development governance was proposed as Ethereum Improvement Proposal, aka EIP, standardized on EIP-1.[64] The core development group and community were to gain consensus by a process regulated EIP. A few notable decisions were made in the process of EIP, such as EIP-160 (EXP cost increase caused by Spurious Dragon Hardfork)[65] and EIP-20 (ERC-20 Token Standard).[66] In January 2018, the EIP process was finalized and published as EIP-1 status turned "active".[63]
Network nodes can validate transactions, add them to their copy of the ledger, and then broadcast these ledger additions to other nodes. To achieve independent verification of the chain of ownership each network node stores its own copy of the blockchain.[76] About every 10 minutes, a new group of accepted transactions, called a block, is created, added to the blockchain, and quickly published to all nodes, without requiring central oversight. This allows bitcoin software to determine when a particular bitcoin was spent, which is needed to prevent double-spending. A conventional ledger records the transfers of actual bills or promissory notes that exist apart from it, but the blockchain is the only place that bitcoins can be said to exist in the form of unspent outputs of transactions.[7]:ch. 5
تتمتع عملة البيتكوين بقدر عالٍ من السرية. مبدئيا الأمر صحيح، حيث أن كل ما تحتاجه لإرسال بعض البيتكوينات لشخص آخر هو عنوانه فقط. لكن بحكم أنه يتم تسجيل كل عملية تحويل في سجل بيتكوين فإنه بالرغم من عدم معرفتك لهوية مالك أي عُنوان إلا أنه بمقدورك أن تعرف كم عدد البيتكوينات التي في حوزته وما هي العناوين التي أرسلت بيتكوينات إليه. إن قام أحدهم بالإعلان صراحة عن امتلاكه لعناوين بيتكوين مُعينة فإنه سيُصبح بإمكانك معرفة ما هي العناوين التي قامت بإرسال بيتكوينات إليه وما هي العناوين التي أرسل إليها بيتكوينات. الكشف عن عنوان البيتكوين الخاص بك ليس مُستبعدا، حيث أنك ستحتاج إلى إعطائه لغيرك في حال ما إذا احتجت أن يرسلوا لك بعض المال إليه. يُنصح باستخدام عناوين مُختلفة لعمليات تحويل مُختلفة للحفاظ على مُستوى مُعين من المجهولية، رغم ذلك هناك الكثيرون ممن لا يقومون بذلك. من الناحية التقنية يبقى تتبع مصدر بعض العمليات المشبوهة على شبكة بيتكوين مُمكنا، حيث يكفي تتبع عمليات التحويل إلى غاية وصولها إلى عنوان معروفة هوية صاحبه، وحينها يكفي القيام بعمليات تحقيق عكسية إلى غاية الوصول إلى صاحب الحساب المشبوه. صحيح بأن كم البيانات المُتعلقة بجميع عمليات التحويل ضخم، إلا أن قوة الحواسيب في تزايد مُستمر وإمكانية تتبع هذه العمليات واردة جدا، بل ويُمكن الجزم بأنه تتبع عمليات سرقة البيتكوينات أسهل بكثير من تتبع سرقة الأموال على هيئتها الورقية.
Network nodes can validate transactions, add them to their copy of the ledger, and then broadcast these ledger additions to other nodes. To achieve independent verification of the chain of ownership each network node stores its own copy of the blockchain.[76] About every 10 minutes, a new group of accepted transactions, called a block, is created, added to the blockchain, and quickly published to all nodes, without requiring central oversight. This allows bitcoin software to determine when a particular bitcoin was spent, which is needed to prevent double-spending. A conventional ledger records the transfers of actual bills or promissory notes that exist apart from it, but the blockchain is the only place that bitcoins can be said to exist in the form of unspent outputs of transactions.[7]:ch. 5
Physical wallets store the credentials necessary to spend bitcoins offline and can be as simple as a paper printout of the private key;[7]:ch. 10 a paper wallet. A paper wallet is created with a keypair generated on a computer with no internet connection; the private key is written or printed onto the paper[g] and then erased from the computer. The paper wallet can then be stored in a safe physical location for later retrieval. Bitcoins stored using a paper wallet are said to be in cold storage.[99]:39 In a 2014 interview, QuadrigaCX founder Gerald Cotten explained that the company stored customer funds on paper wallets in safe deposit boxes: "So we just send money to them, we don’t need to go back to the bank every time we want to put money into it. We just send money from our Bitcoin app directly to those paper wallets, and keep it safe that way."[100]
^ Iansiti, Marco; Lakhani, Karim R. (January 2017). "The Truth About Blockchain". Harvard Business Review. Harvard University. Retrieved 17 January 2017. The technology at the heart of bitcoin and other virtual currencies, blockchain is an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way.
While it’s still early days, Mist, MetaMask and a variety of other browsers look set to make blockchain-based applications accessible to more people than ever before. Even people without a technical background can now potentially build blockchain apps. This is a revolutionary leap for blockchain technology that could bring decentralized applications into the mainstream.
Ethereum addresses are composed of the prefix "0x", a common identifier for hexadecimal, concatenated with the rightmost 20 bytes of the Keccak-256 hash (big endian) of the ECDSA public key (the curve used is the so called secp256k1, the same as Bitcoin). In hexadecimal, 2 digits represents a byte, meaning addresses contain 40 hexadecimal digits. An example of an Ethereum address is 0xb794F5eA0ba39494cE839613fffBA74279579268. Contract addresses are in the same format, however they are determined by sender and creation transaction nonce.[34] User accounts are indistinguishable from contract accounts given only an address for each and no blockchain data. Any valid Keccak-256 hash put into the described format is valid, even if it does not correspond to an account with a private key or a contract. This is unlike Bitcoin, which uses base58check to ensure that addresses are properly typed.
Ethereum is the pioneer for blockchain based smart contracts. When running on the blockchain a smart contract becomes like a self-operating computer program that automatically executes when specific conditions are met. On the blockchain, smart contracts allow for code to be run exactly as programmed without any possibility of downtime, censorship, fraud or third-party interference. It can facilitate the exchange of money, content, property, shares, or anything of value. The Ethereum network went live on July 30th, 2015 with 72 million Ethereum premined.
Despite the fallout from The DAO hack, Ethereum is moving forward and looking to a bright future. By providing a user-friendly platform that enables people to harness the power of blockchain technology, Ethereum is speeding up the decentralization of the world economy. Decentralized applications have the potential to profoundly disrupt hundreds of industries including finance, real estate, academia, insurance, healthcare and the public sector amongst many others.
Mining is a record-keeping service done through the use of computer processing power.[e] Miners keep the blockchain consistent, complete, and unalterable by repeatedly grouping newly broadcast transactions into a block, which is then broadcast to the network and verified by recipient nodes.[75] Each block contains a SHA-256 cryptographic hash of the previous block,[75] thus linking it to the previous block and giving the blockchain its name.[7]:ch. 7[75]
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