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.
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]

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]
Physical wallets can also take the form of metal token coins[102] with a private key accessible under a security hologram in a recess struck on the reverse side.[103]:38 The security hologram self-destructs when removed from the token, showing that the private key has been accessed.[104] Originally, these tokens were struck in brass and other base metals, but later used precious metals as bitcoin grew in value and popularity.[103]:80 Coins with stored face value as high as ₿1000 have been struck in gold.[103]:102–104 The British Museum's coin collection includes four specimens from the earliest series[103]:83 of funded bitcoin tokens; one is currently on display in the museum's money gallery.[105] In 2013, a Utahn manufacturer of these tokens was ordered by the Financial Crimes Enforcement Network (FinCEN) to register as a money services business before producing any more funded bitcoin tokens.[102][103]:80

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.
• 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.

يقصد بتعدين البتكوين هو استخراجه وتنقيبه ولتبسيط المفهوم فالعملية تشبه استخراج الذهب، الذهب لاستخراجه من باطن الأرض يتطلب معدات معينة مخصصة لذلك الغرض وجهد كبير، الأمر مشابه لتعدين البتكوين فهو يتطلب معدات وبرامج مخصصة تقوم بفك الشفرات والعمليات الحسابية المعقدة ، هذه البرامج مجانية على الانترنت تستطيع تعدين البيتكوين الان على جهازك ولكن للاسف جهازك مهما كانت قوته لن يستحمل الضغط الكهربائي الهائل وسيصاب بالتلف أضف إلى ذلك فاتورة الكهرباء التي ستتسبب بها ، احد الحلول يكمن في التعدين السحابي وهذا التعدين السحابي وهو يتمثل ببساطة أن شركات متخصصة في المجال وتسمى بالمسبح (بالانجليزية: Pool) وهو أن يجتمع مجموعة من الأشخاص لهم نفس الهدف كل يدفع نسبة من المال عبارة عن استثمار وعند الربح يأخذ المال على حسب النسبة التي وضعها.

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.
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
It takes a (global) village to raise a blockchain. The live network and the community of open source developers contribute significantly to this effort. They continuously refine and harden the Ethereum platform, helping it get faster at responding to industry demands for the value propositions it offers. These investments of time and resources speak to their faith in Ethereum governance and the value that businesses and developers see in its capabilities. – Joseph Lubin, CEO of Consensys
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]
Bloomberg reported that the largest 17 crypto merchant-processing services handled $69 million in June 2018, down from $411 million in September 2017. Bitcoin is "not actually usable" for retail transactions because of high costs and the inability to process chargebacks, according to Nicholas Weaver, a researcher quoted by Bloomberg. High price volatility and transaction fees make paying for small retail purchases with bitcoin impractical, according to economist Kim Grauer. However, bitcoin continues to be used for large-item purchases on sites such as Overstock.com, and for cross-border payments to freelancers and other vendors.[141]
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]

Lightweight clients consult full clients to send and receive transactions without requiring a local copy of the entire blockchain (see simplified payment verification – SPV). This makes lightweight clients much faster to set up and allows them to be used on low-power, low-bandwidth devices such as smartphones. When using a lightweight wallet, however, the user must trust the server to a certain degree, as it can report faulty values back to the user. Lightweight clients follow the longest blockchain and do not ensure it is valid, requiring trust in miners.[96]
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.

Physical wallets can also take the form of metal token coins[102] with a private key accessible under a security hologram in a recess struck on the reverse side.[103]:38 The security hologram self-destructs when removed from the token, showing that the private key has been accessed.[104] Originally, these tokens were struck in brass and other base metals, but later used precious metals as bitcoin grew in value and popularity.[103]:80 Coins with stored face value as high as ₿1000 have been struck in gold.[103]:102–104 The British Museum's coin collection includes four specimens from the earliest series[103]:83 of funded bitcoin tokens; one is currently on display in the museum's money gallery.[105] In 2013, a Utahn manufacturer of these tokens was ordered by the Financial Crimes Enforcement Network (FinCEN) to register as a money services business before producing any more funded bitcoin tokens.[102][103]:80


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. 

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.
David Golumbia says that the ideas influencing bitcoin advocates emerge from right-wing extremist movements such as the Liberty Lobby and the John Birch Society and their anti-Central Bank rhetoric, or, more recently, Ron Paul and Tea Party-style libertarianism.[132] Steve Bannon, who owns a "good stake" in bitcoin, considers it to be "disruptive populism. It takes control back from central authorities. It's revolutionary."[133]
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]
According to the European Central Bank, the decentralization of money offered by bitcoin has its theoretical roots in the Austrian school of economics, especially with Friedrich von Hayek in his book Denationalisation of Money: The Argument Refined,[127] in which Hayek advocates a complete free market in the production, distribution and management of money to end the monopoly of central banks.[128]:22
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