What Is Blockchain?

blockchain

ˈblɒktʃeɪn/

noun
noun: blockchain; plural noun: blockchains; noun: block-chain; plural noun: block-chains
a digital ledger in which transactions made in bitcoin or another cryptocurrency are recorded chronologically and publicly.
"we can actually have a look at the blockchain and see evidence of what's going on"

Origin
early 21st century: from block and chain.


Welcome to the brave new world of blockchain. Some say it’s the future lifeblood of the internet and commerce. It will provide the foundation of the most robust information security system ever created. It will allow access to economic tools currently unavailable to billions. You may have seen many articles on blockchain recently. Maybe you’ve never heard of blockchain. Or maybe all you’ve heard about it is the hype.

But what’s a blockchain? The short explanation: It’s a network-based tool for storing information securely and permanently. The information in a blockchain can be authenticated by members of the public, but the information can be accessed only by those who have permission.

Blockchains can take any information—from simple ledgers to complex contracts—and store it in online containers called “blocks.” These blocks are then encrypted, meaning that the information is translated into a unique series of letters and numbers called the “hash.” The hash is created using a special encryption key. Only users who have the key can read the information.

The blocks are then linked together. Each block’s information includes the hash of the previous block in the chain, along with a time stamp. For example, a hash might look like this: 00002fg5d5500aae9046ff80cccefa. The tools that create hashes use sophisticated cryptographic calculations so that each hash in a particular chain will start with a set of standard characters, such as 0000.

How does this keep information secure?  The blocks are “decentralized,” meaning that different blocks are stored on different computers, creating a distributed network of information. This network is public, so members of the public can see the chain and read the hashes.

Changing the information in any block changes its hash. This change then moves up the chain, changing their hashes as well. The hashes in blocks that are further up the chain will no longer start with the standard characters. For example, they won’t start with 0000 and the time stamp will have changed. That means anyone can now see that data in the chain has been compromised.Some blockchains are single chains, but many blockchains work by distributing copies of the whole chain in the decentralized network. If the copies don’t agree with one another, the blockchain’s users will elect to accept only those chains that match, and will discard any compromised chains.

Read more :http://blogs.kentlaw.iit.edu/islat/2017/10/30/blockchain-3-0-web-3-no/

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Blockchain is a technology that seems to be a leap change in the business models of the  “digital relationship” as we’re witnessing now. But it is much more than an optimisation of the online interactions in the context of new technologies. It is a proof of evolution of our society, from a centralised system thinking towards a distributed one and the benefits of the change can go beyond imagination. The Next Web explains that the businesses or institutions will keep a role in the constitution of the distributed system, but the system itself is autonomous by definition and powered by its own members [1].

Bitcoin is a digital currency that exists (only) on a specialised blockchain. It is not the only one. See in Business Insider a comparison between todays important cryptocurrencies [2].

Concept & implicationsThe online interaction let aside, this is not a new concept: it was discovered in remote places, applied locally, in small isolated communities (see video below – [3]), being in place for hundreds of years. The concept is about authority belonging to an entire community instead of its concentration into one entity (a person, a company, an institution – as we know it now).

Because of this, there are consequences

– at the level of trust, as we don’t have to look for credentials of only one person or institution. We reach a zone of comfort with trusting an entire community and, the greater the community, the more secure will be any transaction inside that community, the higher the trust.

– on the freedom of information: the knowledge becomes available to everyone in community, at the same time, in a public community/network ledger.

There are already many applications. If you’ll search online, you’ll get already businesses specialised in data storage like MaidSafe or Filecoin, hubs like Blockchain Hub, social platforms Akasha, search engines BitClave that operate on the blockchain technology, as well as applications or experiments of universities, like Blockcerts, from MIT.

source https://librarytrends.weblog.tudelft.nl/tag/blockchain-technology/

Further reading…

Blockchain technologyThere are in fact three technologies that made the blockchain possible. None of them are new, but their combination is [8]. These technologies are:

1. the private/public key cryptography,
2. a P2P network with a shared ledger and
3. a protocol (that requires the existence of an incentive “to service the network’s transactions, record-keeping and security“). 

The key cryptography takes care of the identification of an individual with a private and a public key.

Any transactions made between two persons is recorded in a data block containing the digital signature, the time and the information related to the transaction. A chain of transactions recorded at different times is at the origin of the name of this technology: a blockchain (see figures below).

from https://www.coindesk.com/information/how-does-blockchain-technology-work/

The transactions range from simple to complex, like contracts that execute themselves – known as “smart contracts”. “Smart contracts help you exchange money, property, shares, or anything of value in a transparent, conflict-free way while avoiding the services of a middleman.” [9].

These transactions are recorded by the entire network at the same time, so every node in the network receives the same reliable information.

The reliability comes from the network protocol, that takes care of the authorisation of a transaction. That happens by the execution of a mathematical problem that is called “proof of work” [4]. This proof of work is a code that runs simultaneously on more computers, doing what it’s known as “mining” a new block. The one computer that solves first the problem, authorises a new block in the chain and gets an incentive: a bitcoin (BTC – in the bitcoin network) or an ethereum (ETH – in the Ethereum network) or any other coin in any other network where such a technology functions.

For a better understanding, follow this 17 minutes demo of MIT experts on how blockchain works.

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Is blockchain technology the new internet?

The blockchain is an undeniably ingenious invention – the brainchild of a person or group of people known by the pseudonym,  Satoshi Nakamoto. But since then, it has evolved into something greater, and the main question every single person is asking is: What is Blockchain?

By allowing digital information to be distributed but not copied, blockchain technology created the backbone of a new type of internet. Originally devised for the digital currency, Bitcoin,  (Buy Bitcoin) the tech community is now finding other potential uses for the technology.

Bitcoin has been called “digital gold,” and for a good reason. To date, the total value of the currency is close to $9 billion US. And blockchains can make other types of digital value. Like the internet (or your car), you don’t need to know how the blockchain works to use it. However, having a basic knowledge of this new technology shows why it’s considered revolutionary. So, we hope you enjoy this, what is Blockchain guide.

Read more 

Credit 

http://www.libraryblockchain.org/2018/05/blockchain-for-information-science.html

https://ischoolblogs.sjsu.edu/blockchains/blog/

http://www.ala.org/tools/future/trends/blockchain

https://lifehacker.com/what-is-blockchain-1822094625

http://blogs.edweek.org/edweek/on_innovation/2017/12/how_blockchain_will_transform_credentialing_and_education.html?cmp=eml-enl-dd-news2-rm&M=%%MESSAGE_ID%%&U=%%CF_ICNACCOUNTNUMBER%%&print=1