^ Jump up to: a b c d Bhaskar, Nirupama Devi; Chuen, David Lee Kuo (2015). "3 – Bitcoin Mining Technology". In Cheun, David Lee Kuo. Handbook of Digital Currency: Bitcoin, Innovation, Financial Instruments, and Big Data. Academic Press. pp. 47–51. ISBN 978-0-12-802117-0. Archived from the original on 25 October 2016. Retrieved 2 December 2016 – via ScienceDirect.
By contrast, the Bitcoin blockchain is not Turing complete since it has little to no ability for data manipulation. It has no ability for a user to deploy if else or goto statements. This is a bit of a simplification but anytime you hear someone say something is “Turing complete” you can do a quick check to see if there is functionality for data changes, memory changes and if/else statements. If there is, that’s usually what they mean.
Cohen recently noted that before blockchain is practical in retail, brands have to understand its relevance. NPD said it’s not just about payment methods or sourcing transparency. It also has the potential to touch all areas of a company. Cohen highlights a few areas where blockchain has the ability to impact retail including revolutionizing supply chain management, preventing against counterfeiting, simplifying payments and creating safer data security.
Public blockchains provide a way to protect the users of an application from the developers, establishing that there are certain things that even the developers of an application have no authority to do. From a naive standpoint, it may be hard to understand why an application developer would want to voluntarily give up power and hamstring themselves. However, more advanced economic analysis provides two reasons why, in Thomas Schelling's words, weakness can be a strength. First, if you explicitly make it harder or impossible for yourself to do certain things, then others will be more likely to trust you and engage in interactions with you, as they are confident that those things are less likely to happen to them. Second, if you personally are being coerced or pressured by another entity, then saying "I have no power to do this even if I wanted to" is an important bargaining chip, as it discourages that entity from trying to compel you to do it. A major category of pressure or coercion that application developers are at risk of is that by governments, so "censorship resistance" ties strongly into this kind of argument.
In the context of the two-way peg, the DMMS is represented by the Simplified Payment Verification Proof (SPV Proof), which is a DMMS confirming that a specific action on a PoW blockchain occurred. The SPV Proof functions as the proof of possession in the initial parent chain for its secure transfer to a sidechain. Symmetric two-way pegs are the primary type of two-way peg so we will only be referring specifically to the symmetric (compared to asymmetric) peg in this piece.
The original Litecoin we started out with are now Rootstock Litecoin, which I can use for creating smart contracts and as previously mentioned Sidechains can exist for all types of digital assets with propositions of not only smart contracts but the ability to provide more freedom for experimentation with Beta releases of core software and Altcoins, as well as the taking over of traditional banking instruments such as the issuing and tracking of shares, bonds and other assets.
“Blockchain offers a possible solution to these challenges with its decentralized ledger that can store a history of transactions across a shared database,” Cohen said in the report. “By making the record accessible and verifiable from anywhere in the world, blockchain can enable the authentication of goods and eradicate the criminal element of counterfeit goods in the retail supply chain. By pairing hardware chips with blockchain technology, a product can take on a digital history, going as far back as the raw materials that were used to make the product. This allows retailers and consumers to verify their purchased products are genuine.”

If you’ve been keeping track of developments in the bitcoin industry, you’d know that the blockchain refers to the public ledger of transactions associated with the cryptocurrency. As the bitcoin ecosystem has grown in size and scale throughout the years, the blockchain has also increased considerably in length and storage size, prompting debates on whether or not to increase its block size limit.
Liquid is the world's first federated sidechain that enables rapid, confidential, and secure bitcoin transfers. Participating exchanges and Bitcoin businesses deploy the software and hardware that make up the Liquid network, so that they can peg in and out of the Bitcoin blockchain and offer Liquid’s features to their traders. Liquid provides a more secure and efficient system for exchange-side bitcoin to move across the network.

Blockchains that are private or permissioned work similarly to public blockchains but with access controls that restrict those that can join the network, meaning it operates like a centralised database system of today that limits access to certain users. Private Blockchains have one or multiple entities that control the network, leading to the reliance on third-parties to transact. A well-known example would be Hyperledger.
The first question to answer is “What is public blockchain?” The very name of this type of networks implies that they are open and permissionless. It means that anyone in the world can join the network, add blocks and view the information stored there. Indeed, public blockchains are totally transparent as any of their members can audit them. For this reason, independent participants can easily agree on transactions without middlemen and the fear of deception.
The idea emerged that the Bitcoin blockchain could be in fact used for any kind of value transaction or any kind of agreement such as P2P insurance, P2P energy trading, P2P ride sharing, etc. Colored Coins and Mastercoin tried to solve that problem based on the Bitcoin Blockchain Protocol. The Ethereum project decided to create their own blockchain, with very different properties than Bitcoin, decoupling the smart contract layer from the core blockchain protocol, offering a radical new way to create online markets and programmable transactions known as Smart Contracts.
Send your Bitcoins to a specially formed Bitcoin address. The address is specially designed so that the coins will now be out of your control… and out of the control of anybody else either. They’re completely immobilized and can only be unlocked if somebody can prove they’re no longer being used elsewhere (I’ll explain what I mean by this in a minute).   In other words, you’ve used the core bitcoin transaction rules I described above to lay down a specific condition that the future owner – whoever it ends up being – needs to fulfil in order to take control
Peer-to-peer blockchain networks lack centralized points of vulnerability that computer crackers can exploit; likewise, it has no central point of failure. Blockchain security methods include the use of public-key cryptography.[4]:5 A public key (a long, random-looking string of numbers) is an address on the blockchain. Value tokens sent across the network are recorded as belonging to that address. A private key is like a password that gives its owner access to their digital assets or the means to otherwise interact with the various capabilities that blockchains now support. Data stored on the blockchain is generally considered incorruptible.[1]
A public blockchain is ideal when the network must be truly decentralized, which means that no central entity controls the entry of the members on the network and the consensus mechanism is democratic. A democratic mechanism of consensus means that all members can become a minor and that these miners are in competition to add the blocks to the blockchain (at least when the mechanism of the evidence of the work is used).

The sole distinction between public and private blockchain is related to who is allowed to participate in the network, execute the consensus protocol and maintain the shared ledger. A public blockchain network is completely open and anyone can join and participate in the network. The network typically has an incentivizing mechanism to encourage more participants to join the network. Bitcoin is one of the largest public blockchain networks in production today.
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