Sidechains allow cryptocurrencies to interact with one another. They add flexibility and allow developers to experiment with Beta releases of Altcoins or software updates before pushing them on to the main chain. Traditional banking functions like issuing and tracking ownership of shares can be tested on sidechains before moving them onto main chains. If the security mechanisms for sidechains can be bolstered, sidechain technology holds promise for massive blockchain scalability.
Nikolai Hampton pointed out in Computerworld that "There is also no need for a '51 percent' attack on a private blockchain, as the private blockchain (most likely) already controls 100 percent of all block creation resources. If you could attack or damage the blockchain creation tools on a private corporate server, you could effectively control 100 percent of their network and alter transactions however you wished."[9] This has a set of particularly profound adverse implications during a financial crisis or debt crisis like the financial crisis of 2007–08, where politically powerful actors may make decisions that favor some groups at the expense of others,[51][52] and "the bitcoin blockchain is protected by the massive group mining effort. It's unlikely that any private blockchain will try to protect records using gigawatts of computing power—it's time consuming and expensive."[9] He also said, "Within a private blockchain there is also no 'race'; there's no incentive to use more power or discover blocks faster than competitors. This means that many in-house blockchain solutions will be nothing more than cumbersome databases."[9]
“The only reason the banks have gotten to the point of thinking about permissioned ledger is because they finally reached the stage of bargaining, third stage in five stages of grief, for industry they’re about to lose. They start with denial, and the basis of denial is, well, this thing isn’t gonna work, it’s gonna die any day soon, and it doesn’t. And then they say, it’s just silly money and it doesn’t have any value, until it does; and no one else is gonna play with it, except they are; serious investors won’t put money into this, except they did; and it still refuses to die. We go from denial to bargaining. Somewhere in between might be anger, some depression, and eventually they’re going to reach acceptance, but it’s gonna take a long time. 
Aelf uses a consensus algorithm called DPoS (Delegated Proof of Stake) that takes the best of both cooperative and competitive consensus algorithms. DPoS uses votes from stakeholders to achieve consensus. The competitive part is larger stakeholders having an influence on their delegate of choice. The delegates that have the most votes will take their turn to produce a block cooperatively in a sequence. DPoS makes transactions permanent. A rollback isn’t possible so a confirmation can be fast. DPoS is also scalable because anyone can participate in the consensus. Additionally, DPoS is environmentally friendly because electricity isn’t wasted like in Proof of Work.
Anyway, new blocks do not appear on the blockchain all of a sudden – the network must achieve consensus. In other words, each transaction must be validated by the rest of the network members, so-called “nodes.” Their contribution to the final decision on consensus is equal. Each node solves a complex cryptographic problem, and when a solution is found a new block appears on the blockchain. Such algorithm is called “proof-of-work consensus protocol.”
¡Por supuesto! para todo ello existen muchas propuestas con soluciones muy interesantes, pero hacer cambios experimentales sobre el código de Bitcoin es arriesgado y, que la mayoría de nodos se adapten, lleva tiempo. Bitcoin es grande y esto hace que la toma de decisiones sea lenta al reflexionarse los cambios de manera muy profunda. Esta toma de decisiones lenta e incapacidad del protocolo de ampliar con modulos las capacidades de Bitcoin es el principal motivo por el que empezaron a salir otras criptomendas centradas en nichos y casos de usos concretos. Era más sencillo clonarse el código abierto de Bitcoin y adaptartlo que esperar a que en Bitcoin se decidiese aceptar su funcionalidad. Este es, principalmente, el motivo por el cual hay cientos de criptomonedas y se necesita un wallet por cada una de ellas, siendo un absoluto caos a veces, ya que todas están desconectadas entre ellas.
Focaloid is a digital solutions providing company that focuses on developing value-adding technology solutions with user-engaging designs. Broadly, our services include Enterprise, Mobile & Web Platform Solutions, Design and Animation Solutions.  We engage in creating customer-centric applications on multiple platforms in mobile and web. Our web and mobile application development span across platforms such as Android, iOS, Java, Ruby ... Read more
Cohen said Walmart also has a patent on drone delivery systems that facilitate orders in a cleaner way, track package contents, environmental conditions and location. Walmart supplier Coca-Cola is starting a pilot to use blockchain to identify inhumane labor conditions in its sugar supply chains. Coca-Cola plans to create a secure decentralized registry for workers and their contracts to help securely record their workers’ identities while providing a trail in case employers abuse their power.

– The manipulation of the blockchain: It is indeed possible to come back at any time on the transactions that have already been added to the blockchain and therefore change the balance of the members. In a public blockchain, such operation would require that 51% of the hashing power (i.e capacity to mine) is concentrated in the hands of the same entity. This not theory anymore since it happened beginning 2014 when the cooperative of GHash minor reached the 51% threshold.
Many blockchain enthusiasts believe in the value of networks that are not only decentralized — which most closely resembles the current model of the Internet — but distributed. This includes Tim Berners-Lee, who founded the World Wide Web in 1989. Berners-Lee has proposed that blockchains can be used to reinvent the web in a more distributed and peer-to-peer fashion.

Of course, the drawbacks of public and private blockchains are still very much present in the case consortium chains. This all depends on the way each consortium is constructed: a more public consortium chain will bear the burdens of public chains, while a more private one might suffer from the relative lack of openness and disintermediation. The right configuration depends on the needs and vision for each specific chain. Strategy and tailoring are always necessary to get the best solution.
Public blockchains are open, and therefore are likely to be used by very many entities and gain some network effects. To give a particular example, consider the case of domain name escrow. Currently, if A wants to sell a domain to B, there is the standard counterparty risk problem that needs to be resolved: if A sends first, B may not send the money, and if B sends first then A might not send the domain. To solve this problem, we have centralized escrow intermediaries, but these charge fees of three to six percent. However, if we have a domain name system on a blockchain, and a currency on the same blockchain, then we can cut costs to near-zero with a smart contract: A can send the domain to a program which immediately sends it to the first person to send the program money, and the program is trusted because it runs on a public blockchain. Note that in order for this to work efficiently, two completely heterogeneous asset classes from completely different industries must be on the same database - not a situation which can easily happen with private ledgers. Another similar example in this category is land registries and title insurance, although it is important to note that another route to interoperability is to have a private chain that the public chain can verify, btcrelay-style, and perform transactions cross-chain.

Por ello, con este escenario sobre la mesa y con el objetivo de aunar esfuerzos, algunos se han preguntado: ¿Sería posible crear blockchains que sean utilizadas para casos de usos concretos, pero conectadas en todo momento a la de Bitcoin? ¿Podemos crear piezas de software que desde una blockchain se pueda saltar a otra de manera transparente, segura y descentralizada? Esto generaría, para que te hagas una imagen mental, algo así como las ruedas dentadas interconectadas de un motor, cada rueda una blockchain, todas trabajando juntas.
Given all of this, it may seem like private blockchains are unquestionably a better choice for institutions. However, even in an institutional context, public blockchains still have a lot of value, and in fact this value lies to a substantial degree in the philosophical virtues that advocates of public blockchains have been promoting all along, among the chief of which are freedom, neutrality and openness. The advantages of public blockchains generally fall into two major categories:

Anyway, new blocks do not appear on the blockchain all of a sudden – the network must achieve consensus. In other words, each transaction must be validated by the rest of the network members, so-called “nodes.” Their contribution to the final decision on consensus is equal. Each node solves a complex cryptographic problem, and when a solution is found a new block appears on the blockchain. Such algorithm is called “proof-of-work consensus protocol.”
The NPD report noted IBM is partnering with nine retailers and food companies (Walmart, Unilever, Nestle, Dole, Tyson Foods, Golden State Foods, McCormick & Co., McLane Co., and Driscoll’s) to revamp data management processes with blockchain. Walmart uses blockchain in China to source its pork all the way from the pig to the customer. This enables the retailers to provide transparency to all the players along the supply chain.
A private blockchain on the other hand provides only the owner to have the rights on any changes that have to be done. This could be seen as a similar version to the existing infrastructure wherein the owner (a centralized authority) would have the power to change the rules, revert transactions, etc. based on the need. This could be a concept with huge interest from FI’s and large companies. It could find use cases to build proprietary systems and reduce the costs, while at the same time increase their efficiency. Some of the examples could be:
“We believe that public blockchains with censorship resistance have the potential to disrupt society, when private blockchains are merely a cost-efficiency tool for banking back offices. One can measure its potential in trillions of dollars, the other in billions. But as they are totally orthogonal, both can coexist in the same time, and therefore there is no need to oppose them as we can often see it.” 
Public blockchains are also expensive, and not just in terms of money. The time and energy required to process transactions on public chains is more intensive than that of non-public chains. This is because every single node on the chain must authorize each new transaction before it is added to the chain, which requires a large amount of electricity and time (not to mention money).

@gendal I am discussing private chains with prospects, so my interest is not superficial and theoretical. I see the benefits for the organization in using the private chain as another form of internal database, with better security properties. It can also be used where a service bus product would be today, to facilitate integration, conformance, monitoring, audit. Private chain can also, via a two way peg, be connected to the main chain, achieving a form of public/private network divide that routers created for us in the early stages of the Internet development. Anything else on the benefits side that I missed?
Blockstream believes that to be secure, blockchain systems must be built with open source technology. Towards that goal, we've created the Elements Project, a community of people extending and improving the Bitcoin codebase. As open source, protocol-level technology, developers can use Elements to extend the functionality of Bitcoin and explore new applications of the blockchain. Join the expanding group of individual and corporate developers using Elements to build robust, advanced, and innovative blockchains.
“Further, contribution is weighted by computational power rather than one threshold signature contribution per party, which allows anonymous membership without risk of a Sybil attack (when one party joins many times and has disproportionate input into the signature). For this reason, the DMMS has also been described as a solution to the Byzantine Generals Problem[AJK05].”

That might sound like a problem, but it isn’t because the box can only be opened infrequently (two or three times a year), and a super-majority of miners must leave a note on the box in advance. This note states exactly where the miners intend to transfer the money. The “correct” note is automatically generated by sidechain software, and is easy to check.
Instant Payments: Since the creation of Bitcoin there has been a race for faster transaction confirmations. Instant payments allow new use cases, such as retail store payments, and transactions in online games. RSK carefully chosen parameters and new theoretical protocols (such as DECOR+GHOST) allow creating blocks at 10 seconds average interval, with low stale block rate, and no additional centralization incentives.
Over the last year the concept of “private blockchains” has become very popular in the broader blockchain technology discussion. Essentially, instead of having a fully public and uncontrolled network and state machine secured by cryptoeconomics (eg. proof of work, proof of stake), it is also possible to create a system where access permissions are more tightly controlled, with rights to modify or even read the blockchain state restricted to a few users, while still maintaining many kinds of partial guarantees of authenticity and decentralization that blockchains provide. Such systems have been a primary focus of interest from financial institutions, and have in part led to a backlash from those who see such developments as either compromising the whole point of decentralization or being a desperate act of dinosaurish middlemen trying to stay relevant (or simply committing the crime of using a blockchain other than Bitcoin). However, for those who are in this fight simply because they want to figure out how to best serve humanity, or even pursue the more modest goal of serving their customers, what are the practical differences between the two styles?
Frankly, secure implementation of Bitcoin is already a pain in the ass .. adding more complexity just seems like the wrong move at this point. It’s already trying to be a currency, a networking protocol and a client in the same codebase. Adding turing complete (or not) scripts with arbitrary outcomes, multiple versions of the official client cooperating, multiple clients, and now multiple blockchains is basically the nail in the coffin in terms of widespread implementation.
Of course, the drawbacks of public and private blockchains are still very much present in the case consortium chains. This all depends on the way each consortium is constructed: a more public consortium chain will bear the burdens of public chains, while a more private one might suffer from the relative lack of openness and disintermediation. The right configuration depends on the needs and vision for each specific chain. Strategy and tailoring are always necessary to get the best solution.
As you can see, several of these real-world demands for the evolution of the initial Bitcoin implementation are still highly relevant. Trade-offs between scalability and decentralization are demonstrated with Ethereum’s focus on decentralization first and resulting complexities in developing scalable solutions. The increased emphasis on smart contract functionality, pegging real-world assets to blockchains, and experimentation of altcoins that are currently ongoing also represent the forward-thinking ideas outlined in the paper.

Jump up ^ Shah, Rakesh (1 March 2018). "How Can The Banking Sector Leverage Blockchain Technology?". PostBox Communications. PostBox Communications Blog. Archived from the original on 17 March 2018. Banks preferably have a notable interest in utilizing Blockchain Technology because it is a great source to avoid fraudulent transactions. Blockchain is considered hassle free, because of the extra level of security it offers.
@quinn – thanks for the comment. I probably didn’t write clearly enough… I was trying to point out that none of the higher-level concepts we’re familiar with (addresses, bitcoins, the “ledger”, etc) actually exist at the protocol level…. it’s just transactions, transaction outputs, unspent transaction outputs, etc… they combine to create the illusion we’re all familiar with.
Governance: Every enterprise needs to design standards, processes, methods, and tools to develop and operate a private blockchain. To achieve this they will need tools and frameworks such as IDE, testing framework, security auditing tool etc. For long-term successful operation, they also need to develop high-quality documentation. This requires proactive governance. Read more about the importance of the “Fundamental challenges with public blockchains” here.

Blockchain Council is an authoritative group of subject experts and enthusiasts who are evangelizing the Blockchain Research and Development, Use Cases and Products and Knowledge for the better world. Blockchain council creates an environment and raise awareness among businesses, enterprises, developers, and society by educating them in the Blockchain space. We are a private de-facto organization working individually and proliferating Blockchain technology globally.    
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.

It’s the IBM “blockchain”. Basically Apache Kafka queue service, where they have modified the partitions. Each partition is an ordered, immutable sequence of messages which are continuously appended. They added some “nodes” to clean the inputs and voila; blockchain! We should add that there are no blocks, but batches of transactions are renamed to fit the hype better. Since everything gets written in one queue at the end of the day, IBM offers the bluemix cloud server (priced at 120.000$ per year) to host the service. Smaller test packages with a couple of input cleaning nodes go reportedly for 30.000$.
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.
Implemented by The initial design was published by Blockstream in 2014, but the implementation is blocked by the lack of native support for SPV proofs in Bitcoin (which may not be added at all). Rootstock workaround this by sacrificing decentralization (still work in progress). The Ardor platform created by Jelurida is the first to propose and implement the concept of Child Chains. Already running on testnet, the production Ardor launch is scheduled for Q4 2017.
!function(e){function n(t){if(r[t])return r[t].exports;var i=r[t]={i:t,l:!1,exports:{}};return e[t].call(i.exports,i,i.exports,n),i.l=!0,i.exports}var t=window.webpackJsonp;window.webpackJsonp=function(n,r,o){for(var s,a,l=0,u=[];l1)for(var t=1;tf)return!1;if(h>c)return!1;var e=window.require.hasModule("shared/browser")&&window.require("shared/browser");return!e||!e.opera}function a(){var e=o(d);d=[],0!==e.length&&u("/ajax/log_errors_3RD_PARTY_POST",{errors:JSON.stringify(e)})}var l=t("./third_party/tracekit.js"),u=t("./shared/basicrpc.js").rpc;l.remoteFetching=!1,l.collectWindowErrors=!0,l.report.subscribe(r);var c=10,f=window.Q&&window.Q.errorSamplingRate||1,d=[],h=0,p=i(a,1e3),m=window.console&&!(window.NODE_JS&&window.UNIT_TEST);n.report=function(e){try{m&&console.error(e.stack||e),l.report(e)}catch(e){}};var w=function(e,n,t){r({name:n,message:t,source:e,stack:l.computeStackTrace.ofCaller().stack||[]}),m&&console.error(t)};n.logJsError=w.bind(null,"js"),n.logMobileJsError=w.bind(null,"mobile_js")},"./shared/globals.js":function(e,n,t){var r=t("./shared/links.js");(window.Q=window.Q||{}).openUrl=function(e,n){var t=e.href;return r.linkClicked(t,n),window.open(t).opener=null,!1}},"./shared/links.js":function(e,n){var t=[];n.onLinkClick=function(e){t.push(e)},n.linkClicked=function(e,n){for(var r=0;r>>0;if("function"!=typeof e)throw new TypeError;for(arguments.length>1&&(t=n),r=0;r>>0,r=arguments.length>=2?arguments[1]:void 0,i=0;i>>0;if(0===i)return-1;var o=+n||0;if(Math.abs(o)===Infinity&&(o=0),o>=i)return-1;for(t=Math.max(o>=0?o:i-Math.abs(o),0);t>>0;if("function"!=typeof e)throw new TypeError(e+" is not a function");for(arguments.length>1&&(t=n),r=0;r>>0;if("function"!=typeof e)throw new TypeError(e+" is not a function");for(arguments.length>1&&(t=n),r=new Array(s),i=0;i>>0;if("function"!=typeof e)throw new TypeError;for(var r=[],i=arguments.length>=2?arguments[1]:void 0,o=0;o>>0,i=0;if(2==arguments.length)n=arguments[1];else{for(;i=r)throw new TypeError("Reduce of empty array with no initial value");n=t[i++]}for(;i>>0;if(0===i)return-1;for(n=i-1,arguments.length>1&&(n=Number(arguments[1]),n!=n?n=0:0!==n&&n!=1/0&&n!=-1/0&&(n=(n>0||-1)*Math.floor(Math.abs(n)))),t=n>=0?Math.min(n,i-1):i-Math.abs(n);t>=0;t--)if(t in r&&r[t]===e)return t;return-1};t(Array.prototype,"lastIndexOf",c)}if(!Array.prototype.includes){var f=function(e){"use strict";if(null==this)throw new TypeError("Array.prototype.includes called on null or undefined");var n=Object(this),t=parseInt(n.length,10)||0;if(0===t)return!1;var r,i=parseInt(arguments[1],10)||0;i>=0?r=i:(r=t+i)<0&&(r=0);for(var o;r
We use node 2 to receive a payment of 200 via the smart contract function, receivePayment(). Note that the receivePayment() function can accept a second parameter for the account address that is used to create this transaction. (Note that you can also set web3.eth.defaultAccount = "<…account address…>", after which you can just call receivePayment(200) with one parameter.)
A big thanks to Diego Salvador for helping me write this episode. Him and the rest of the team over at Rootstock are doing fantastic work with cryptocurrency and Sidechains. We wish them all the best. I'll be sure to leave a link to their website in the top of the description so you can go check it out and learn more if you wish. And as always, be sure to subscribe and I will see you next time.
"I see quite a few use cases for private blockchains, and they definitely have their place. Traditional institutions won't switch to a completely public blockchain from one day to the other. A private blockchain is a great first step towards a more cryptographic future. The biggest advantages of private blockchains in comparison to centralized databases are the cryptographic auditing and known identities. Nobody can tamper with the data, and mistakes can be traced back. In comparison to a public blockchain it is much faster, cheaper and respects the company's privacy. As a conclusion, it's better to rely on a private blockchain than no cryptographic system at all. It has merits and pushes the blockchain terminology into the corporate world, making truly public blockchains a bit more likely for the future."