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.
Izabella Kaminska, the editor of FT Alphaville, has pointed out that criminals are using Ethereum to run Ponzi schemes and other forms of investment fraud.[67] The article was based on a paper from the University of Cagliari, which placed the number of Ethereum smart contracts which facilitate Ponzi schemes at nearly 10% of 1384 smart contracts examined. However, it also estimated that only 0.05% of the transactions on the network were related to such contracts.[68]
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.
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].
On 3 January 2009, the bitcoin network was created when Nakamoto mined the first block of the chain, known as the genesis block.[21][22] Embedded in the coinbase of this block was the text "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks".[11] This note references a headline published by The Times and has been interpreted as both a timestamp and a comment on the instability caused by fractional-reserve banking.[23]:18
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. 

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.[87] As new blocks are mined all the time, the difficulty of modifying a block increases as time passes and the number of subsequent blocks (also called confirmations of the given block) increases.[75]
In the blockchain, bitcoins are registered to bitcoin addresses. Creating a bitcoin address requires nothing more than picking a random valid private key and computing the corresponding bitcoin address. This computation can be done in a split second. But the reverse, computing the private key of a given bitcoin address, is mathematically unfeasible. Users can tell others or make public a bitcoin address without compromising its corresponding private key. Moreover, the number of valid private keys is so vast that it is extremely unlikely someone will compute a key-pair that is already in use and has funds. The vast number of valid private keys makes it unfeasible that brute force could be used to compromise a private key. To be able to spend their bitcoins, the owner must know the corresponding private key and digitally sign the transaction. The network verifies the signature using the public key; the private key is never revealed.[7]:ch. 5
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.
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]
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.
Though transaction fees are optional, miners can choose which transactions to process and prioritize those that pay higher fees.[77] Miners may choose transactions based on the fee paid relative to their storage size, not the absolute amount of money paid as a fee. These fees are generally measured in satoshis per byte (sat/b). The size of transactions is dependent on the number of inputs used to create the transaction, and the number of outputs.[7]:ch. 8
^ 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.
The bitcoin blockchain is a public ledger that records bitcoin transactions.[75] It is implemented as a chain of blocks, each block containing a hash of the previous block up to the genesis block[c] of the chain. A network of communicating nodes running bitcoin software maintains the blockchain.[32]:215–219 Transactions of the form payer X sends Y bitcoins to payee Z are broadcast to this network using readily available software applications.
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'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]

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.
This dramatic volatility attracted global attention with the mainstream media running near-daily reports on the price of Ether. The publicity generated has been a major boon for the ecosystem, attracting thousands of new developers and business ventures alike. In 2018 the amount raised through Ethereum-enabled ICOs reached almost $8bn, increasing from just $90m in 2016. While the price of Ethereum has faced extreme volatility over the years, it is this volatility which has driven interest. After every boom and bust cycle, Ethereum comes out the other side with a fundamentally stronger platform and a broader developer community backing it. These fundamental improvements would suggest a positive long-term outlook on the price of Ethereum.
Bitcoin is a digital currency, sometimes referred to as a cryptocurrency, best known as the world's first truly decentralized digital currency. Bitcoin is traded on a peer-to-peer basis with a distributed ledger called the Blockchain, and the Bitcoin exchange rate to the US Dollar and other major currencies is determined by supply and demand as with other global exchange rates. The traded value of Bitcoin has proven volatile through various booms and busts in demand. Ultimately, however, many see Bitcoin as a store of value against government-backed fiat currencies.
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]
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]
بيتكوين ليست العملة الافتراضية الوحيدة المتواجدة حاليًا في الأسواق الافتراضية. فقد برزت بفضل نجاحات ال بيتكوين ، مجموعة متنوعة من ما يسمى ب "altcoins" أو العملات الافتراضية البديلة ذات قيمة جيدة في الأسواق. أهم الفروقات بين البيتكوين وهذه العملات البديلة هي: البتكوين الأصعب في التعدين والأكثر غلاءً بينما العملات البديلة يمكن الحصول عليها عادةً بطريقة أسهل وأرخص، ويمكن أن يكون سعرها أكثر ثباتًا من سعر البتكوين ذات السعر المتقلب، كما أنّ الكثير من هذه العملات تم إنشاؤها لتلافي المشاكل الحاصلة في نظام بتكوين.[20] هذه لائحة بست عملات رقمية بديلة :
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]

^ Beikverdi, A.; Song, J. (June 2015). Trend of centralization in Bitcoin's distributed network. 2015 IEEE/ACIS 16th International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing (SNPD). pp. 1–6. doi:10.1109/SNPD.2015.7176229. ISBN 978-1-4799-8676-7. Archived from the original on 26 January 2018.


Izabella Kaminska, the editor of FT Alphaville, has pointed out that criminals are using Ethereum to run Ponzi schemes and other forms of investment fraud.[67] The article was based on a paper from the University of Cagliari, which placed the number of Ethereum smart contracts which facilitate Ponzi schemes at nearly 10% of 1384 smart contracts examined. However, it also estimated that only 0.05% of the transactions on the network were related to such contracts.[68]


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]
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.

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.
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