Kripto Para Platformu tarafından yazılmış tüm yazılar

Blockchain, English

What is a Distributed Ledger?

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Ledgers, the foundation of accounting, are as ancient as writing and money.

Their medium has been clay, wooden tally sticks (that were a fire hazard), stone, papyrus and paper. Once computers became normalized in the 1980s and ’90s, paper records were digitized, often by manual data entry.

These early digital ledgers mimicked the cataloguing and accounting of the paper-based world, and it could be said that digitization has been applied more to the logistics of paper documents rather than their creation. Paper-based institutions remain the backbone of our society: money, seals, written signatures, bills, certificates and the use of double-entry bookkeeping.

Computing power and breakthroughs in cryptography, along with the discovery and use of some new and interesting algorithms, have allowed the creation of distributed ledgers.

In its simplest form, a distributed ledger is a database held and updated independently by each participant (or node) in a large network. The distribution is unique: records are not communicated to various nodes by a central authority, but are instead independently constructed and held by every node. That is, every single node on the network processes every transaction, coming to its own conclusions and then voting on those conclusions to make certain the majority agree with the conclusions.

Once there is this consensus, the distributed ledger has been updated, and all nodes maintain their own identical copy of the ledger. This architecture allows for a new dexterity as a system of record that goes beyond being a simple database.

Distributed Ledgers are a dynamic form of media and have properties and capabilities that go far beyond static paper-based ledgers. For more on this, please read our guide “What Can a Blockchain Do?“ For now, the short version is they enable us to formalize and secure new kinds of relationships in the digital world.

The gist of these new kinds of relationships is that the cost of trust (heretofore provided by notaries, lawyers, banks, regulatory compliance officers, governments, etc…) is avoided by the architecture and qualities of distributed ledgers.

Our Wikipedia analogy in our guide “What is Blockchain Technology?“ hints at the power of these new kinds of relationships.

The invention of distributed ledgers represents a revolution in how information is gathered and communicated. It applies to both static data (a registry), and dynamic data (transactions). Distributed ledgers allow users to move beyond the simple custodianship of a database and divert energy to how we use, manipulate and extract value from databases — less about maintaining a database, more about managing a system of record.

Authored by Nolan Bauerle; images by Maria Kuznetsov

Source: coindesk

Blockchain, English

What Can a Blockchain Do?

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Financial institutions have financed the disruption of countless industries over the last 30 years; they have an idea of what a revolutionary technology can do to static incumbents.

So, to stay ahead of change, banks have been proactive in setting up R&D labs, building test centers and establishing partnerships with blockchain developers to fully understand the revolutionary potential of the technology.

Financial institutions were the first to dip their feet in, but academia, governments and consulting firms have also studied the technology.

All of this work is, of course, in addition to what the entrepreneurs and developers are doing, either by finding new ways to use the bitcoin or ethereum blockchains, or else creating entirely new blockchains.

This has been going on for over three years now, and the results are starting to come in.

While some of the waters are still murky, this is what we know a blockchain can do:

Establish digital identity

As discussed in our guide “How Does Blockchain Technology Work?“, the identity component of blockchain technology is fulfilled through the use of cryptographic keys. Combining a public and private key creates a strong digital identity reference based on possession.

A public key is how you are identified in the crowd (like an email address), a private key is how you express consent to digital interactions. Cryptography is an important force behind the blockchain revolution.

Serve as a system of record

As stated in our guide “What is a Distributed Ledger?”, blockchains are an innovation in information registration and distribution. They are good for recording both static data (a registry) or dynamic data (transactions), making it an evolution in systems of record.

In the case of a registry, data can be stored on blockchains in any combination of three ways:

  • Unencrypted data – can be read by every blockchain participant in the blockchain and is fully transparent.
  • Encrypted data – can be read by participants with a decryption key. The key provides access to the data on the blockchain and can prove who added the data and when it was added.
  • Hashed data – can be presented alongside the function that created it to show the data wasn’t tampered with.

Blockchain hashes are generally done in combination with the original data stored off-chain. Digital ‘fingerprints’, for example, are often hashed into the blockchain, while the main body of information can be stored offline.

Such a shared system of record can change the way disparate organizations work together.

Currently, with data siloed in private servers, there is an enormous cost for inter-company transactions involving processes, procedures and cross-checking of records.

Prove immutability

A feature of a blockchain database is that is has a history of itself. Because of this, they are often called immutable. In other words, it would be a huge effort to change an entry in the database, because it would require changing all of the data that comes afterwards, on every single node. In this way, it is more a system of record than a database.

Serve as a platform

Cryptocurrencies were the first platform developed using blockchain technology. Now, people have moved from the idea of a platform to exchange cryptocurrencies to a platform for smart contracts.

The term ‘smart contracts’ has become somewhat of a catch-all phrase, but the idea can actually be divided into several categories:

There are the ‘vending machine’ smart contracts coined in the 1990s by Nick Szabo. This is where machines engage after receiving an external input (a cryptocurrency), or else send a signal that triggers a blockchain activity.

There are also smart legal contracts, or Ricardian contracts. Much of this application is based on the idea that a contract is a meeting of the minds, and that it is the result of whatever the consenting parties to the contract agree to. So, a contract can be a mix of a verbal agreement, a written agreement, and now also some of the useful aspects of blockchains like timestamps, tokens, auditing, document coordination or business logic.

Finally, there are the ethereum smart contracts. These are programs which control blockchain assets, executed over interactions on the ethereum blockchain. Ethereum itself is a platform for smart contract code.

Blockchains are not built from a new technology. They are built from a unique orchestration of three existing technologies.

Authored by Nolan Bauerle; images by Maria Kuznetsov

Source: coindesk

Blockchain, English

How Does Blockchain Technology Work?

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As stated in our guide “What is Blockchain Technology?“, there are three principal technologies that combine to create a blockchain. None of them are new. Rather, it is their orchestration and application that is new.

These technologies are: 1) private key cryptography, 2) a distributed network with a shared ledger and 3) an incentive to service the network’s transactions, record-keeping and security.

The following is an explanation of how these technologies work together to secure digital relationships.

Cryptographic keys

Two people wish to transact over the internet.

Each of them holds a private key and a public key.

The main purpose of this component of blockchain technology is to create a secure digital identity reference. Identity is based on possession of a combination of private and public cryptographic keys.

The combination of these keys can be seen as a dexterous form of consent, creating an extremely useful digital signature.

In turn, this digital signature provides strong control of ownership.

Identity

But strong control of ownership is not enough to secure digital relationships. While authentication is solved, it must be combined with a means of approving transactions and permissions (authorisation).

For blockchains, this begins with a distributed network.

A Distributed Network

The benefit and need for a distributed network can be understood by the ‘if a tree falls in the forest’ thought experiment.

If a tree falls in a forest, with cameras to record its fall, we can be pretty certain that the tree fell. We have visual evidence, even if the particulars (why or how) may be unclear.

Much of the value of the bitcoin blockchain is that it is a large network where validators, like the cameras in the analogy, reach a consensus that they witnessed the same thing at the same time. Instead of cameras, they use mathematical verification.

In short, the size of the network is important to secure the network.

That is one of the bitcoin blockchain’s most attractive qualities — it is so large and has amassed so much computing power. At time of writing, bitcoin is secured by 3,500,000 TH/s, more than the 10,000 largest banks in the world combined. Ethereum, which is still more immature, is secured by about 12.5 TH/s, more than Google and it is only two years old and still basically in test mode.

System of record

When cryptographic keys are combined with this network, a super useful form of digital interactions emerges. The process begins with A taking their private key, making an announcement of some sort — in the case of bitcoin, that you are sending a sum of the cryptocurrency — and attach it to B’s public key.

Protocol

A block – containing a digital signature, timestamp and relevant information – is then broadcast to all nodes in the network.

Network servicing protocol

A realist might challenge the tree falling in the forest thought experiment with the following question: Why would there be a million computers with cameras waiting to record whether a tree fell? In other words, how do you attract computing power to service the network to make it secure?

For open, public blockchains, this involves mining. Mining is built off a unique approach to an ancient question of economics — the tragedy of the commons.

With blockchains, by offering your computer processing power to service the network, there is a reward available for one of the computers. A person’s self-interest is being used to help service the public need.

With bitcoin, the goal of the protocol is to eliminate the possibility that the same bitcoin is used in separate transactions at the same time, in such a way that this would be difficult to detect.

This is how bitcoin seeks to act as gold, as property. Bitcoins and their base units (satoshis) must be unique to be owned and have value. To achieve this, the nodes serving the network create and maintain a history of transactions for each bitcoin by working to solve proof-of-work mathematical problems.

They basically vote with their CPU power, expressing their agreement about new blocks or rejecting invalid blocks. When a majority of the miners arrive at the same solution, they add a new block to the chain. This block is timestamped, and can also contain data or messages.

Here’s a chain of blocks:

The type, amount and verification can be different for each blockchain. It is a matter of the blockchain’s protocol – or rules for what is and is not a valid transaction, or a valid creation of a new block. The process of verification can be tailored for each blockchain. Any needed rules and incentives can be created when enough nodes arrive at a consensus on how transactions ought to be verified.

It’s a taster’s choice situation, and people are only starting to experiment.

We are currently in a period of blockchain development where many such experiments are being run. The only conclusions drawn so far are that we are yet to fully understand the dexterity of blockchain protocols.

Authored by Nolan Bauerle; images by Maria Kuznetsov

Source: coindesk

Blockchain, English

What is Blockchain Technology?

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“The practical consequence […is…] for the first time, a way for one Internet user to transfer a unique piece of digital property to another Internet user, such that the transfer is guaranteed to be safe and secure, everyone knows that the transfer has taken place, and nobody can challenge the legitimacy of the transfer. The consequences of this breakthrough are hard to overstate.”

– Marc Andreessen

From a cruising altitude, a blockchain might not look that different from things you’re familiar with, say Wikipedia.

With a blockchain, many people can write entries into a record of information, and a community of users can control how the record of information is amended and updated. Likewise, Wikipedia entries are not the product of a single publisher. No one person controls the information.

Descending to ground level, however, the differences that make blockchain technology unique become more clear. While both run on distributed networks (the internet), Wikipedia is built into the World Wide Web (WWW) using a client-server network model.

A user (client) with permissions associated with its account is able to change Wikipedia entries stored on a centralized server.

Whenever a user accesses the Wikipedia page, they will get the updated version of the ‘master copy’ of the Wikipedia entry. Control of the database remains with Wikipedia administrators allowing for access and permissions to be maintained by a central authority.

Wikipedia’s digital backbone is similar to the highly protected and centralized databases that governments or banks or insurance companies keep today. Control of centralized databases rests with their owners, including the management of updates, access and protecting against cyber-threats.

The distributed database created by blockchain technology has a fundamentally different digital backbone. This is also the most distinct and important feature of blockchain technology.

Wikipedia’s ‘master copy’ is edited on a server and all users see the new version. In the case of a blockchain, every node in the network is coming to the same conclusion, each updating the record independently, with the most popular record becoming the de-facto official record in lieu of there being a master copy.

Transactions are broadcast, and every node is creating their own updated version of events.

It is this difference that makes blockchain technology so useful – It represents an innovation in information registration and distribution that eliminates the need for a trusted party to facilitate digital relationships.

Yet, blockchain technology, for all its merits, is not a new technology.

Rather, it is a combination of proven technologies applied in a new way. It was the particular orchestration of three technologies (the Internet, private key cryptography and a protocol governing incentivization) that made bitcoin creator Satoshi Nakamoto’s idea so useful.

The result is a system for digital interactions that does not need a trusted third party. The work of securing digital relationships is implicit — supplied by the elegant, simple, yet robust network architecture of blockchain technology itself.

Defining digital trust

Trust is a risk judgement between different parties, and in the digital world, determining trust often boils down to proving identity (authentication) and proving permissions (authorization).

Put more simply, we want to know, ‘Are you who you say you are?’ and ‘Should you be able to do what you are trying to do?’

In the case of blockchain technology, private key cryptography provides a powerful ownership tool that fulfills authentication requirements. Possession of a private key is ownership. It also spares a person from having to share more personal information than they would need to for an exchange, leaving them exposed to hackers.

Authentication is not enough. Authorization – having enough money, broadcasting the correct transaction type, etc – needs a distributed, peer-to-peer network as a starting point. A distributed network reduces the risk of centralized corruption or failure.

This distributed network must also be committed to the transaction network’s recordkeeping and security. Authorizing transactions is a result of the entire network applying the rules upon which it was designed (the blockchain’s protocol).

Authentication and authorization supplied in this way allow for interactions in the digital world without relying on (expensive) trust. Today, entrepreneurs in industries around the world have woken up to the implications of this development – unimagined, new and powerful digital relationshionships are possible. Blockchain technology is often described as the backbone for a transaction layer for the Internet, the foundation of the Internet of Value.

In fact, the idea that cryptographic keys and shared ledgers can incentivize users to secure and formalize digital relationships has imaginations running wild. Everyone from governments to IT firms to banks is seeking to build this transaction layer.

Authentication and authorization, vital to digital transactions, are established as a result of the configuration of blockchain technology.

The idea can be applied to any need for a trustworthy system of record.

Authored by Nolan Bauerle; images by Maria Kuznetsov

Source: coindesk

Altcoin, Bitcoin, Ethereum, Haberler, Ripple

Kripto Para Piyasasında Son Durum Nedir?

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Aralık ayından günümüze kadar çok ciddi dalgalanmaların olduğu kripto para piyasasında sular yavaş yavaş durulmaya başlıyor diyebiliriz. Gelen olumlu kripto para haberleri üzerine Bitcoin 10 bin dolar üzerinde tutunmaya çalışıyor. Son üç gündür 11 bin doları geçmiş durumda ve bu değer üzerinde tutunabilmesi halinde kripto para piyasasında ciddi artışlar beklenebilir.

04.03.2018 tarihli Coinmarketcap verilerine göre piyasada şuan; 1536 kripto para bulunmakta. Bugün itibariyle kripto paraların toplam piyasa değeri 456 Milyar $ değerine ulaşmış durumda. Bitcoin ise 190 Milyar $ değer ile toplam piyasanın %41 ‘lik hacmini oluşturmakta. 83 Milyar $ işlem hacmi ile %18 ‘lik bir paya sahip olan Ethereum ise ikinciliğini korumaya devam ediyor. Üçüncü sırada ise 35 Milyar $ değer ile Ripple bulunmakta.

Kripto para piyasasında son 24 saatte 15 Milyar $ değerinde işlem hacmi oluşmakla beraber 1. sırada 6 Milyar $ işlem hacmi ile Bitcoin, 2. sırada 2,2 Milyar $ işlem hacmi ile Tether bulunmakta.

Bitcoin‘de Son Durum Nedir?

Bitcoin – Günlük Mum Grafiği – 04.03.2018

6 Şubat tarihinde 6.000 ‘li değerlere düşen Bitcoin son bir haftadır 9.300 $ üzerinde işlem görmekte. 20 şubatta 11.768 $ değerine ulaşan Bitcoin şuan ki saatlerde ise 11.200 $ değerinde işlem görmeye devam ediyor. Bitcoin’in yükseliş rekoru ise 17 aralık 2017 tarihinde 19.850 $ olduğunu hatırlatmakta fayda var.