بروتوكول اكتشاف الجيران (NDP) بروتوكول حل العناوين (ARP) بروتوكولات نفقيّة (بروتوكول الأنفاق في الطبقة الثانية) بروتوكول الربط بين نقطتين (PPP) بروتوكول الشجرة المُتفرعة (STP) الواجهة البينية للبيانات الموزعة بالألياف (FDDI) تبديل الأطر الإيثرنت (IEEE 802.3). الشبكات المحليّة اللاسلكيّة (IEEE 802.11) الشبكات الشخصية اللاسلكية (IEEE 802.15) البلوتوث (IEEE 802.15.1) الشبكات الشخصية اللاسلكية منخفضة المعدل (IEEE 802.15.4) مزيد ..

• لا حرج من دفع عمولات تحويل العملات: كما هو شائع بالنسبة للبعض أن دفع العُمولات عبر شبكات الإنترنت مقابل خدمات تحويل أو شراء عُملات البيتكوين يُعد شكل من أشكال الربا غير المسموح بها. لكن إستناداُ إلى ما تم ذكره بحسب الفتوى رقم 259576 أن لا هناك أى حرج على دفع مثل هذه العمولات. حيث إنك تدفع مُقابل حصولك على خدمة معينة بما فيها خدمات تحويل وشراء عُملات البيتكوين الإفتراضية.
Ethereum was announced at the North American Bitcoin Conference in Miami, in January, 2014.[9] During the same time as the conference, a group of people rented a house in Miami Gavin Wood, Charles Hoskinson, and Anthony Di Iorio, a Torontonian who financed the project.[9] Di Iorio invited friend Joseph Lubin, who invited reporter Morgen Peck, to bear witness.[9] Six months later the founders met again in a house in Zug Switzerland, where Buterin told the founders that the project would proceed as a non-profit. Hoskinson left the project at that time.[9]

To be accepted by the rest of the network, a new block must contain a proof-of-work (PoW).[75] The system used is based on Adam Back's 1997 anti-spam scheme, Hashcash.[85][4] The PoW requires miners to find a number called a nonce, such that when the block content is hashed along with the nonce, the result is numerically smaller than the network's difficulty target.[7]:ch. 8 This proof is easy for any node in the network to verify, but extremely time-consuming to generate, as for a secure cryptographic hash, miners must try many different nonce values (usually the sequence of tested values is the ascending natural numbers: 0, 1, 2, 3, ...[7]:ch. 8) before meeting the difficulty target.

The domain name "bitcoin.org" was registered on 18 August 2008.[17] On 31 October 2008, a link to a paper authored by Satoshi Nakamoto titled Bitcoin: A Peer-to-Peer Electronic Cash System[4] was posted to a cryptography mailing list.[18] Nakamoto implemented the bitcoin software as open-source code and released it in January 2009.[19][20][11] Nakamoto's identity remains unknown.[10]


In Charles Stross' 2013 science fiction novel, Neptune's Brood, the universal interstellar payment system is known as "bitcoin" and operates using cryptography.[227] Stross later blogged that the reference was intentional, saying "I wrote Neptune's Brood in 2011. Bitcoin was obscure back then, and I figured had just enough name recognition to be a useful term for an interstellar currency: it'd clue people in that it was a networked digital currency."[228]
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] 

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]
Despite bringing a number of benefits, decentralized applications aren’t faultless. Because smart contract code is written by humans, smart contracts are only as good as the people who write them. Code bugs or oversights can lead to unintended adverse actions being taken. If a mistake in the code gets exploited, there is no efficient way in which an attack or exploitation can be stopped other than obtaining a network consensus and rewriting the underlying code. This goes against the essence of the blockchain which is meant to be immutable. Also, any action taken by a central party raises serious questions about the decentralized nature of an application.
On 1 August 2017, a hard fork of bitcoin was created, known as Bitcoin Cash.[111] Bitcoin Cash has a larger block size limit and had an identical blockchain at the time of fork. On 24 October 2017 another hard fork, Bitcoin Gold, was created. Bitcoin Gold changes the proof-of-work algorithm used in mining, as the developers felt that mining had become too specialized.[112]
• لا حرج من دفع عمولات تحويل العملات: كما هو شائع بالنسبة للبعض أن دفع العُمولات عبر شبكات الإنترنت مقابل خدمات تحويل أو شراء عُملات البيتكوين يُعد شكل من أشكال الربا غير المسموح بها. لكن إستناداُ إلى ما تم ذكره بحسب الفتوى رقم 259576 أن لا هناك أى حرج على دفع مثل هذه العمولات. حيث إنك تدفع مُقابل حصولك على خدمة معينة بما فيها خدمات تحويل وشراء عُملات البيتكوين الإفتراضية.
• لا حرج من دفع عمولات تحويل العملات: كما هو شائع بالنسبة للبعض أن دفع العُمولات عبر شبكات الإنترنت مقابل خدمات تحويل أو شراء عُملات البيتكوين يُعد شكل من أشكال الربا غير المسموح بها. لكن إستناداُ إلى ما تم ذكره بحسب الفتوى رقم 259576 أن لا هناك أى حرج على دفع مثل هذه العمولات. حيث إنك تدفع مُقابل حصولك على خدمة معينة بما فيها خدمات تحويل وشراء عُملات البيتكوين الإفتراضية.

Ethereum is also being used as a platform to launch other cryptocurrencies. Because of the ERC20 token standard defined by the Ethereum Foundation, other developers can issue their own versions of this token and raise funds with an initial coin offering (ICO). In this fundraising strategy, the issuers of the token set an amount they want to raise, offer it in a crowdsale, and receive Ether in exchange. Billions of dollars have been raised by ICOs on the Ethereum platform in the last two years, and one of the most valuable cryptocurrencies in the world, EOS, is an ERC20 token.
In 2014, researchers at the University of Kentucky found "robust evidence that computer programming enthusiasts and illegal activity drive interest in bitcoin, and find limited or no support for political and investment motives".[134] Australian researchers have estimated that 25% of all bitcoin users and 44% of all bitcoin transactions are associated with illegal activity as of April 2017. There were an estimated 24 million bitcoin users primarily using bitcoin for illegal activity. They held $8 billion worth of bitcoin, and made 36 million transactions valued at $72 billion.[225][226]

Augur is an open-source prediction & forecasting market platform that allows anyone to forecast events and get rewarded for predicting them correctly. Predictions on future real world events, like who will win the next US election, are carried out by trading virtual shares. If a person buys shares in a winning prediction, they receive monetary rewards. 

Several news outlets have asserted that the popularity of bitcoins hinges on the ability to use them to purchase illegal goods.[135][222] Nobel-prize winning economist Joseph Stiglitz says that bitcoin's anonymity encourages money laundering and other crimes, "If you open up a hole like bitcoin, then all the nefarious activity will go through that hole, and no government can allow that." He's also said that if "you regulate it so you couldn't engage in money laundering and all these other [crimes], there will be no demand for Bitcoin. By regulating the abuses, you are going to regulate it out of existence. It exists because of the abuses."[223][224]


In Ethereum all smart contracts are stored publicly on every node of the blockchain, which has costs.[57] Being a blockchain means it is secure by design and is an example of a distributed computing system with high Byzantine fault tolerance. The downside is that performance issues arise in that every node is calculating all the smart contracts in real time, resulting in lower speeds.[57] As of January 2016, the Ethereum protocol could process about 25 transactions per second.[57] In comparison, the Visa payment platform processes 45,000 payments per second leading some to question the scalability of Ethereum.[58] On 19 December 2016, Ethereum exceeded one million transactions in a single day for the first time.[59]

^ Mooney, Chris; Mufson, Steven (19 December 2017). "Why the bitcoin craze is using up so much energy". The Washington Post. Archived from the original on 9 January 2018. Retrieved 11 January 2018. several experts told The Washington Post that bitcoin probably uses as much as 1 to 4 gigawatts, or billion watts, of electricity, roughly the output of one to three nuclear reactors.
The price of bitcoins has gone through cycles of appreciation and depreciation referred to by some as bubbles and busts.[159] In 2011, the value of one bitcoin rapidly rose from about US$0.30 to US$32 before returning to US$2.[160] In the latter half of 2012 and during the 2012–13 Cypriot financial crisis, the bitcoin price began to rise,[161] reaching a high of US$266 on 10 April 2013, before crashing to around US$50. On 29 November 2013, the cost of one bitcoin rose to a peak of US$1,242.[162] In 2014, the price fell sharply, and as of April remained depressed at little more than half 2013 prices. As of August 2014 it was under US$600.[163] During their time as bitcoin developers, Gavin Andresen[164] and Mike Hearn[165] warned that bubbles may occur. 

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]

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]


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]
مقارنة بأجزاء أخرى من العالم بدأت الدول العربية في وقت متأخر نسبيا باستخدام بيتكوين حيث أعلن عن قبول هذه العملة لأول مرة في الأردن في بار شاي في العاصمة عمان. وتلى ذلك مطعم بيتزا وصراف آلي في دبي[15] ومن ثم شركة انظمه معلومات في فلسطين[16] كما أصبح سوق السفير من أوئل الاسواق في الكويت و الشرق الأوسط التي تقبل البتكوين في تعاملته [17]. اما بالنسبة للعملة الالكترونية في المشهد الاعلامي العربي فقد بدأت مؤخرا فقرات اخبارية تتحدث عنها ولو بشكل طفيف كما بدأت مواقع متخصصة في اخبار بيتكوين مثل موقع بيتكوين نيوز عربية [18] التابع لمجموعة اعلامية كبيرة،وعلى مستوى الشبكات الاجتماعية يمكن للمستخدمين في الشرق الأوسط وشمال افريقيا التفاعل على موقع askbitcoiner [19] الذي يعتبر أول شبكة اجتماعية للعملة الرقمية في العالم العربي حيث يمكن العثور على الاجوبة للاستفسارات حول العملة الرقمية وتقنية البلوك شاين. وعلى صعيد الشركات اللي توفر خدمات للبيتكون بالوطن العربي فمنهما يلو (بالإنجليزية: Yellow) و بت اويسس (بالإنجليزية: BitOasis) المؤسستان في دبي. بالإضافة إلى بت فلس (بالإنجليزية: BitFils) المؤسسة في الكويت. ويمكن شراء وتداول البيتكوين محليا عن طريق localbitcoins.com .
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.
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
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.
According to The New York Times, libertarians and anarchists were attracted to the idea. Early bitcoin supporter Roger Ver said: "At first, almost everyone who got involved did so for philosophical reasons. We saw bitcoin as a great idea, as a way to separate money from the state."[126] The Economist describes bitcoin as "a techno-anarchist project to create an online version of cash, a way for people to transact without the possibility of interference from malicious governments or banks".[129] 

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.[92]
^ "Crib Sheet: Neptune's Brood – Charlie's Diary". www.antipope.org. Archived from the original on 14 June 2017. Retrieved 5 December 2017. I wrote Neptune's Brood in 2011. Bitcoin was obscure back then, and I figured had just enough name recognition to be a useful term for an interstellar currency: it'd clue people in that it was a networked digital currency.
^ Jump up to: a b c d "Statement of Jennifer Shasky Calvery, Director Financial Crimes Enforcement Network United States Department of the Treasury Before the United States Senate Committee on Banking, Housing, and Urban Affairs Subcommittee on National Security and International Trade and Finance Subcommittee on Economic Policy" (PDF). fincen.gov. Financial Crimes Enforcement Network. 19 November 2013. Archived (PDF) from the original on 9 October 2016. Retrieved 1 June 2014.
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.
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]

In the end, the majority of the Ethereum community voted to perform a hard fork, and retrieve The DAO investors money. But not everyone agreed with this course of action. This resulted in a split where two parallel blockchains now exist. For those members who strongly disagree with any changes to the blockchain even when hacking occurs there is Ethereum classic. For the majority who agreed to rewrite a small part of the blockchain and return the stolen money to their owners, there is Ethereum.  


The use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, law enforcement, and the media.[218] In the United States, the FBI prepared an intelligence assessment,[219] the SEC issued a pointed warning about investment schemes using virtual currencies,[218] and the U.S. Senate held a hearing on virtual currencies in November 2013.[220] The U.S. government claimed that bitcoin was used to facilitate payments related to Russian interference in the 2016 United States elections.[221]
In March 2013 the blockchain temporarily split into two independent chains with different rules due to a bug in version 0.8 of the bitcoin software. The two blockchains operated simultaneously for six hours, each with its own version of the transaction history from the moment of the split. Normal operation was restored when the majority of the network downgraded to version 0.7 of the bitcoin software, selecting the backward compatible version of the blockchain. As a result, this blockchain became the longest chain and could be accepted by all participants, regardless of their bitcoin software version.[38] During the split, the Mt. Gox exchange briefly halted bitcoin deposits and the price dropped by 23% to $37[38][39] before recovering to previous level of approximately $48 in the following hours.[40] The US Financial Crimes Enforcement Network (FinCEN) established regulatory guidelines for "decentralized virtual currencies" such as bitcoin, classifying American bitcoin miners who sell their generated bitcoins as Money Service Businesses (MSBs), that are subject to registration or other legal obligations.[41][42][43] In April, exchanges BitInstant and Mt. Gox experienced processing delays due to insufficient capacity[44] resulting in the bitcoin price dropping from $266 to $76 before returning to $160 within six hours.[45] The bitcoin price rose to $259 on 10 April, but then crashed by 83% to $45 over the next three days.[36] On 15 May 2013, US authorities seized accounts associated with Mt. Gox after discovering it had not registered as a money transmitter with FinCEN in the US.[46][47] On 23 June 2013, the US Drug Enforcement Administration listed ₿11.02 as a seized asset in a United States Department of Justice seizure notice pursuant to 21 U.S.C. § 881.[48][better source needed] This marked the first time a government agency had seized bitcoin.[49] The FBI seized about ₿30,000[50] in October 2013 from the dark web website Silk Road during the arrest of Ross William Ulbricht.[51][52][53] These bitcoins were sold at blind auction by the United States Marshals Service to venture capital investor Tim Draper.[50] Bitcoin's price rose to $755 on 19 November and crashed by 50% to $378 the same day. On 30 November 2013 the price reached $1,163 before starting a long-term crash, declining by 87% to $152 in January 2015.[36] On 5 December 2013, the People's Bank of China prohibited Chinese financial institutions from using bitcoins.[54] After the announcement, the value of bitcoins dropped,[55] and Baidu no longer accepted bitcoins for certain services.[56] Buying real-world goods with any virtual currency had been illegal in China since at least 2009.[57] 

To be accepted by the rest of the network, a new block must contain a proof-of-work (PoW).[75] The system used is based on Adam Back's 1997 anti-spam scheme, Hashcash.[85][4] The PoW requires miners to find a number called a nonce, such that when the block content is hashed along with the nonce, the result is numerically smaller than the network's difficulty target.[7]:ch. 8 This proof is easy for any node in the network to verify, but extremely time-consuming to generate, as for a secure cryptographic hash, miners must try many different nonce values (usually the sequence of tested values is the ascending natural numbers: 0, 1, 2, 3, ...[7]:ch. 8) before meeting the difficulty target.

EthereumPrice.org was developed by Ether0x in March 2016 to allow users to easily track the price of Ethereum both historically and in real-time. The platform has since evolved to include several fiat currencies (EUR, GBP, JPY and others) as well as price data for a number of Ethereum ERC20 tokens and other blockchain currencies. More recently, prediction data from Augur was also added to provide insight into the future price expectations of the Ether market. Price data is currently sourced from multiple exchanges with the weighted average price of these assets being calculated by CryptoCompare.com. For more details on the weighted average calculation, see our FAQ.

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.
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