لضمان صحّة عمليات التحويل، يقوم نظام البيتكوين بالاحتفاظ بسجل حسابات تُسجل فيه جميع الإجراءات التي تتم على الشبكة يُطلق عليه اسم سلسلة الكُتل (بالإنجليزية: block chain). تتشارك جميع العُقد المتواجدة على شبكة البيتكوين هذا السجل عبر نظام يعتمد على بروتوكول بِتكُيِن. تحتوي سلسلة الكُتل على جميع الإجراءات التي تمت باستخدام بِتكُيِن، وهو ما يُمكن من معرفة الرصيد الذي يملكه كل عنوان على هذه الشبكة. يُطلق على هذا المفهوم وصف السلسلة للترابط المتواجد ما بين الكُتل، حيث تحتوي كل كُتلة على هاش الكُتلة التي تسبقها ويتواصل الأمر إلى غاية الوصول إلى الكُتلة الأولى التي يُطلق عليها اسم "كتلة التكوين" (بالإنجليزية: genesis block) . تكوين السلسلة بهذه الطريقة يجعل من مهمة تغيير أي كُتلة بعد مرور مُدة مُعينة على إنشائها في غاية الصعوبة، حيث أن تغيير أي كُتلة يتطلب تغيير كل الكُتل التي تليها بسبب الحاجة إلى إعادة حساب هاش كل كُتلة لتحديث قيمة هاش الكُتلة السابقة فيها. هذه الخاصية هي ما يجعل من مُشكل الإنفاق المُتكرر لنفس العُملات في غاية الصعوبة على بِتكُيِن، بل ويُمكن اعتبار سلسلة الكُتل العمود الفقري الذي لا يُمكن لعُملة بِتكُيِن الوقوف من دونه[10].
Any services that are centralized can be decentralized using Ethereum. Think about all the intermediary services that exist across hundreds of different industries. From obvious services like loans provided by banks to intermediary services rarely thought about by most people like title registries, voting systems, regulatory compliance and much more.
Ethereum enables developers to build and deploy decentralized applications. A decentralized application or Dapp serve some particular purpose to its users. Bitcoin, for example, is a Dapp that provides its users with a peer to peer electronic cash system that enables online Bitcoin payments. Because decentralized applications are made up of code that runs on a blockchain network, they are not controlled by any individual or central entity.
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.
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.[123] For example, in 2012, Mt. Gox froze accounts of users who deposited bitcoins that were known to have just been stolen.[124]
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]
لنفرض بأن أغلب المُنقبين يستخدمون أجهزة تقارب في كفاءتها Radeon 5870 video card والتي يتم اعتبارها كإحدى أعلى البطاقات مردودية على هذا الموقع. بإمكان بطاقة Radeon 5870 أن تُنفذ 402 ميجا هاش في الثانية وتُكلف حوالي 1.2 دولار لليوم الواحد إن تم استخدامها على جهاز يحتوي بطاقتين من نفس النوع في الولايات المُتحدة أين يُمكن القول بأن سعر الكهرباء رخيص نسبيا. للوصول إلى النتيجة آنفة الذكر نحتاج إلى استخدام 14,164,898 جهاز بتكلفة $16,997,877 وهو ما يُمثل خسارة تُقدر بـ $13,072,014 يوميا للمُنقبين.
Nigel Dodd argues in The Social Life of Bitcoin that the essence of the bitcoin ideology is to remove money from social, as well as governmental, control.[131] Dodd quotes a YouTube video, with Roger Ver, Jeff Berwick, Charlie Shrem, Andreas Antonopoulos, Gavin Wood, Trace Meyer and other proponents of bitcoin reading The Declaration of Bitcoin's Independence. The declaration includes a message of crypto-anarchism with the words: "Bitcoin is inherently anti-establishment, anti-system, and anti-state. Bitcoin undermines governments and disrupts institutions because bitcoin is fundamentally humanitarian."[131][130]
Another type of physical wallet called a hardware wallet keeps credentials offline while facilitating transactions.[106] The hardware wallet acts as a computer peripheral and signs transactions as requested by the user, who must press a button on the wallet to confirm that they intended to make the transaction. Hardware wallets never expose their private keys, keeping bitcoins in cold storage even when used with computers that may be compromised by malware.[99]:42–45 

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

البيتكوين عملة رقمية ذات مجهولية، حيث أن عملية التحويل عبرها يتطلب فقط معرفة رقم محفظة الشخص المحول إليه ويتم تخزين عملية التحويل في سلسلة الكتل برقم تسلسلي خاص ولا يتضمن هذا اسم المرسل او المتلقي او اي بيانات اخرى خاصة بهما، مما يجعل منها فكرة رائجة لدى كل من المدافعين عن الخصوصية، أو بائعي البضائع غير المشروعة (مثل المخدرات) عبر الإنترنت على حد سواء.[9]


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]
Any services that are centralized can be decentralized using Ethereum. Think about all the intermediary services that exist across hundreds of different industries. From obvious services like loans provided by banks to intermediary services rarely thought about by most people like title registries, voting systems, regulatory compliance and much more. 

البيتكوين عملة رقمية ذات مجهولية، حيث أن عملية التحويل عبرها يتطلب فقط معرفة رقم محفظة الشخص المحول إليه ويتم تخزين عملية التحويل في سلسلة الكتل برقم تسلسلي خاص ولا يتضمن هذا اسم المرسل او المتلقي او اي بيانات اخرى خاصة بهما، مما يجعل منها فكرة رائجة لدى كل من المدافعين عن الخصوصية، أو بائعي البضائع غير المشروعة (مثل المخدرات) عبر الإنترنت على حد سواء.[9]
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.g., transactions that spend coins from multiple inputs indicate that the inputs may have a common owner) and corroborating public transaction data with known information on owners of certain addresses.[120] Additionally, bitcoin exchanges, where bitcoins are traded for traditional currencies, may be required by law to collect personal information.[121] To heighten financial privacy, a new bitcoin address can be generated for each transaction.[122]

طرح شخص أطلق على نفسه الاسم الرمزي ساتوشي ناكاموتو فكرة بيتكوين للمرة الأولى في ورقة بحثية في عام 2008،[2] ووصفها بأنها نظام نقدي إلكتروني يعتمد في التعاملات المالية على مبدأ الند للند (بالإنجليزية: Peer-to-Peer) ، وهو مصطلح تقني يعني التعامل المباشر بين مستخدم وآخر دون وجود وسيط (كالتورنت). يقول القائمون على بيتكوين إن الهدف من هذه العملة التي طرحت للتداول للمرة الأولى سنة 2009 [3] هو تغيير الاقتصاد العالمي بنفس الطريقة التي غيرت بها الويب أساليب النشر.[4] وفي عام 2016 أعلن رجل الأعمال الأسترالي كريغ رايت أنه هو ساتوشي ناكاموتو مقدما دليلا تقنيا على ذلك ولكن تم كشف زيف أدلّته بسهولة.[5]

Ethereum-based customized software and networks, independent from the public Ethereum chain, are being tested by enterprise software companies.[48] Interested parties include Microsoft, IBM, JPMorgan Chase,[33][49] Deloitte,[50] R3,[51] Innovate UK (cross-border payments prototype).[52] Barclays, UBS and Credit Suisse are experimenting with Ethereum blockchain to automate Markets in Financial Instruments Directive (MiFID) II requirements.


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.


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.
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.g., transactions that spend coins from multiple inputs indicate that the inputs may have a common owner) and corroborating public transaction data with known information on owners of certain addresses.[120] Additionally, bitcoin exchanges, where bitcoins are traded for traditional currencies, may be required by law to collect personal information.[121] To heighten financial privacy, a new bitcoin address can be generated for each transaction.[122]
^ 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.
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] 

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]
تُعتبر بيتكوين عُملة معمّاة (بالإنجليزية: cryptocurrency) ويُقصد بذلك أنها تعتمد بشكل أساسي على مبادئ التشفير في جميع جوانبها، كما أنها تُعتبر أيضا العُملة الأولى من نوعها والأكثر شهرة وانتشارًا لكن رغم ذلك ليست العُملة التشفيرية الوحيدة الموجودة على شبكة الإنترنت حاليًا. حيث يتوفر ما يزيد عن 60 عُملة تشفيرية مُختلفة[6] منها 6 عُملات يُمكن وصفها بالرئيسية [7] وذلك اعتمادًا على عدد المُستخدمين وبنية كل شبكة، إضافة إلى الأماكن التي يُمكن استبدال وشراء هذه العُملات التشفيرية مُقابل عُملات أخرى. جميع العُملات التشفيرية الحالية مبنية على مبدأ عمل عُملة بيتكوين نفسها باستثناء عُملة Ripple [8]، وبما أن عُملة بيتكوين مفتوحة المصدر فإنه من المُمكن استنساخها وإدخال بعض التعديلات عليها ومن ثم إطلاق عُملة جديدة.

In 2016 a decentralized autonomous organization called The DAO, a set of smart contracts developed on the platform, raised a record US$150 million in a crowdsale to fund the project.[25] The DAO was exploited in June when US$50 million in ether were taken by an unknown hacker.[26][27] The event sparked a debate in the crypto-community about whether Ethereum should perform a contentious "hard fork" to reappropriate the affected funds.[28] As a result of the dispute, the network split in two. Ethereum (the subject of this article) continued on the forked blockchain, while Ethereum Classic continued on the original blockchain.[29] The hard fork created a rivalry between the two networks.
As the industry continues to investigate blockchain platforms, it’s apparent that Ethereum is becoming a de facto leader. For example, a few days ago JPMorgan publicly open-sourced its Quorum platform, architected and developed around the Go Ethereum client by Jeff Wilcke and his team. Several other major banks are using Ethereum, and Microsoft is anchoring its Bletchley platform on it as the foundational blockchain element. Industry, both publicly and confidentially, continues to contribute to Ethereum and work with us and others to help our promising, toddler-age codebase reach maturity. Stay tuned for news on this front.
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”.

The overwhelming majority of bitcoin transactions take place on a cryptocurrency exchange, rather than being used in transactions with merchants.[138] Delays processing payments through the blockchain of about ten minutes make bitcoin use very difficult in a retail setting. Prices are not usually quoted in units of bitcoin and many trades involve one, or sometimes two, conversions into conventional currencies.[32] Merchants that do accept bitcoin payments may use payment service providers to perform the conversions.[139]


Bitcoin (BTC) is known as the first open-source, peer-to-peer, digital cryptocurrency that was developed and released by a group of unknown independent programmers named Satoshi Nakamoto in 2008. Cryptocoin doesn’t have any centralized server used for its issuing, transactions and storing, as it uses a distributed network public database technology named blockchain, which requires an electronic signature and is supported by a proof-of-work protocol to provide the security and legitimacy of money transactions. The issuing of Bitcoin is done by users with mining capabilities and is limited to 21 million coins. Currently, Bitcoin’s market cap surpasses $138 billion and this is the most popular kind of digital currency. Buying and selling cryptocurrency is available through special Bitcoin exchange platforms or ATMs.

نيمكوين : مليون هو مجموع عملة ال نيمكوين وهذا يعني أن ال نيمكوين ستكون نادرة نسبيا، بالضبط نفس مستوى ندرة ال بيتكوين . هذا وتساعد ال نيمكوين على إنشاء الإنترنت الغير خاضعة للرقابة، وتنكر السيطرة الحكومية. وهي منصة متعددة الاستخدامات يمكن استخدامها لنظام أسماء النطاقات الغير مركزي والغير منظم، نوع من الإنترنت الخاصة بها. ويمكن أيضا أن تستخدم لإرسال الرسائل، والتصويت، ونظام تسجيل الدخول.
The Bank for International Settlements summarized several criticisms of bitcoin in Chapter V of their 2018 annual report. The criticisms include the lack of stability in bitcoin's price, the high energy consumption, high and variable transactions costs, the poor security and fraud at cryptocurrency exchanges, vulnerability to debasement (from forking), and the influence of miners.[189][190][191]
لنفرض بأن أغلب المُنقبين يستخدمون أجهزة تقارب في كفاءتها Radeon 5870 video card والتي يتم اعتبارها كإحدى أعلى البطاقات مردودية على هذا الموقع. بإمكان بطاقة Radeon 5870 أن تُنفذ 402 ميجا هاش في الثانية وتُكلف حوالي 1.2 دولار لليوم الواحد إن تم استخدامها على جهاز يحتوي بطاقتين من نفس النوع في الولايات المُتحدة أين يُمكن القول بأن سعر الكهرباء رخيص نسبيا. للوصول إلى النتيجة آنفة الذكر نحتاج إلى استخدام 14,164,898 جهاز بتكلفة $16,997,877 وهو ما يُمثل خسارة تُقدر بـ $13,072,014 يوميا للمُنقبين.
While another less aggressive soft fork solution was put forth, the Ethereum community and its founders were placed in a perilous position. If they didn’t retrieve the stolen investor money, confidence in Ethereum could be lost. On the other hand, recovering investor money required actions that went against the core ideas of decentralization and set a dangerous precedent.
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J. P. Morgan Chase is developing JPM Coin on a permissioned-variant of Ethereum blockchain dubbed "Quorum".[53] It's designed to toe the line between private and public in the realm of shuffling derivatives and payments. The idea is to satisfy regulators who need seamless access to financial goings-on, while protecting the privacy of parties that don't wish to reveal their identities nor the details of their transactions to the general public.[54]

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.  

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.
Ethereum enables developers to build and deploy decentralized applications. A decentralized application or Dapp serve some particular purpose to its users. Bitcoin, for example, is a Dapp that provides its users with a peer to peer electronic cash system that enables online Bitcoin payments. Because decentralized applications are made up of code that runs on a blockchain network, they are not controlled by any individual or central entity.
^ 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. 
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