@tetsu – not sure what you mean. My reading of the sidechains paper is that the worst case scenario is that an attacker manages to “reanimate” Bitcoins on the main blockchain that had been sent to the sidechain… but that would be the attacker stealing the coins from the rightful owner on the sidechain. From Bitcoin’s perspective, the coins were always going to be reanimated…. so the risk is entirely borne by the holder(s) on the sidechain. Am I missing something?
A diferencia con la, hasta ahora, plataforma estrella de smart contracts Ethereum, otra de las diferencias más importantes de Lisk es que, en Lisk, cada aplicación corre sobre su propia sidechain y no sobre una única cadena, cómo es el caso de Ethereum. Por lo tanto, un entorno propio e independiente que podrá exprimir cada desarrollador para cada DAPP desarrollada con un backend en JS/NodeJS y un frontend HTML/CSS/JS.

Transactions are cheaper, since they only need to be verified by a few nodes that can be trusted to have very high processing power, and do not need to be verified by ten thousand laptops. This is a hugely important concern right now, as public blockchains tend to have transaction fees exceeding $0.01 per tx, but it is important to note that it may change in the long term with scalable blockchain technology that promises to bring public-blockchain costs down to within one or two orders of magnitude of an optimally efficient private blockchain system


The Bitcoin White Paper was published by Satoshi Nakamoto in 2008; the first Bitcoin block got mined in 2009. Since the Bitcoin protocol is open source, anyone could take the protocol, fork it (modify the code), and start their own version of P2P money. Many so-called altcoins emerged and tried to be a better, faster or more anonymous than Bitcoin. Soon the code was not only altered to create better cryptocurrencies, but some projects also tried to alter the idea of blockchain beyond the use case of P2P money.
¡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.
Sidechains solve a lot of problems, but at what cost? The introduction of sidechains makes things even more complex and much harder to understand for those who are not actively involved in the blockchain space. This also divides assets, no more “one chain, one asset” adage, which further complicates things. And on a network level there are multiple independent unsynchronised blockchains interacting with each other.
Bitcoin’s block interval is ten minutes so it takes about five ten minutes on average for a new transaction to find its way into a block, even if it pays a high fee. This is too slow for some people so they have experimented with alternative cryptocurrencies, based on the Bitcoin code-base, which employ quicker block intervals   [UPDATED 2014-10-27 to correct my embarrassing misunderstanding of mathematics…]
Private and Public Blockchain occurs when the financial enterprises start to explore the various blocks of the Blockchain technology. These two Blockchains are coming up with business oriented models as to obtain the difference between the two. The private blockchain generates at a lower cost and faster speed than the public blockchain. In the previous years, the blockchain has grown to become an interesting subject globally. It is becoming an integrated part in the financial sectors all over the digital world.
Unfortunately our second option cannot be done yet, because to use these sidechains, main chain (here it is bitcoin) needs to do some upgrade (soft fork). By the way, upgrades in public blockchains are very painful yet. There will be a user activated soft fork (UASF) on August 1. All bitcoin forms’ trend topic is this soft fork which is about a code change for Segregated Witness Adoption.
Segregated Witnesses — The current Bitcoin transaction signature algorithm is complicated and flawed, leading to a problem known as transaction malleability. Segregated witnesses would eliminate that, improving the efficiency of much Bitcoin software considerably … and making much more significant innovations such as the Lightning Network (see below) possible.
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.
Open blockchains are more user-friendly than some traditional ownership records, which, while open to the public, still require physical access to view. Because all early blockchains were permissionless, controversy has arisen over the blockchain definition. An issue in this ongoing debate is whether a private system with verifiers tasked and authorized (permissioned) by a central authority should be considered a blockchain.[36][37][38][39][40] Proponents of permissioned or private chains argue that the term "blockchain" may be applied to any data structure that batches data into time-stamped blocks. These blockchains serve as a distributed version of multiversion concurrency control (MVCC) in databases.[41] Just as MVCC prevents two transactions from concurrently modifying a single object in a database, blockchains prevent two transactions from spending the same single output in a blockchain.[42]:30–31 Opponents say that permissioned systems resemble traditional corporate databases, not supporting decentralized data verification, and that such systems are not hardened against operator tampering and revision.[36][38] Nikolai Hampton of Computerworld said that "many in-house blockchain solutions will be nothing more than cumbersome databases," and "without a clear security model, proprietary blockchains should be eyed with suspicion."[9][43]
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.
Cabe destacar el papel de la gente de Blockstream, una de las compañías centradas en la búsqueda de este objetivo (con un extremeño en sus filas, Jorge Timón). Blockstream está trabajando actualmente en el desarrollo de un protocolo que permita crear sidechains. Son los responsables de uno de los papers más conocidos sobre el tema, publicado en Octubre del 2014:
If one group of nodes continues to use the old software while the other nodes use the new software, a split can occur. For example, Ethereum has hard-forked to "make whole" the investors in The DAO, which had been hacked by exploiting a vulnerability in its code.[31] In this case, the fork resulted in a split creating Ethereum and Ethereum Classic chains. In 2014 the Nxt community was asked to consider a hard fork that would have led to a rollback of the blockchain records to mitigate the effects of a theft of 50 million NXT from a major cryptocurrency exchange. The hard fork proposal was rejected, and some of the funds were recovered after negotiations and ransom payment.[32]

Thus Tradle set out to build a meta-protocol that saves the data in the overlay network, and only puts minimal referencing data on the blockchain. There is a general grumpy consensus among bitcoin core devs and mining pool operators on allowing one small data chunk, a hash, per transaction. Many devs say it is not possible to secure this second overlay network. I agree, unless we use the blockchain to help with the task. We have a partial solution working, and are preparing a new design to improve it (partial, as it can not yet handle all known attacks). We are actively sharing the designs at various meetups (and on the github) and are inviting devs to find attack vectors and propose solutions. Tradle’s protocol not only relieves the pressure on bitcoin’s blockchain but is also able to handle larger transaction sizes than Counterparty and Mastercoin, so it can be used for complex identity, supply chain management and many other applications. It is also capable of handling attachment files, needed in the healthcare and financial industries.


You cannot be a crypto investor or entrepreneur without having a real understanding of the differences between these types of blockchains as well as their implications. Even if they are based on similar principles, their operation is, in fact, different to all levels. So the tokens issued by these blockchains will not be assessed in the same manner.
“Such brazen theft would indicate [1] that Bitcoin would be (in the near future) without sidechains of any kind, and [2] that Bitcoin itself may be in danger from the miners (and we may need to consider using an alternate proof-of-work hash function),” he explained the impact of this setup in his original post on the topic. Like SPV sidechains, drivechains require a soft-forking change to Bitcoin.
This construction is achieved by composing smart contracts on the main blockchain using fraud proofs whereby state transitions can be enforced on a parent blockchain. We compose blockchains into a tree hierarchy, and treat each as an individual branch blockchain with enforced blockchain history and MapReducable computation committed into merkle proofs. By framing one’s ledger entry into a child blockchain which is enforced by the parent chain, one can enable incredible scale with minimized trust (presuming root blockchain availability and correctness).
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.
In order to spend them, you have to prove you’re entitled to do so. And you do that by providing the solution to a challenge that was laid down when they were sent to you in the first place. This challenge is usually just: “prove to the world that you know the public key that corresponds to a particular Bitcoin address and are in possession of the corresponding private key”. But it can be more sophisticated than that.
Bitdeal is a bitcoin cryptocurrency exchange software & Blockchain development company. The main focus of the firm is to reduce the risks in bitcoin trading and to encourage new bitcoin exchange startups by providing a well-developed bitcoin exchange script or a cryptocurrency exchange software.  Being a cryptocurrency exchange software solution, bitdeal has covered around 50+ countries around the world, and have collected more than 200+ ... Read more
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).
2. Ardor’s Blockchain as a service platform for business: Ardor uses the Proof of Stake consensus mechanism. Ardor calls its sidechains ‘childchains’, and they are tightly integrated into the main chain. Security is enhanced because all transactions are processed and secured by parent chain forgers. Most transactions are pushed down to the childchain level, as the parent mainchain retains minimal features. Global entities such as assets and currencies across chains can be accessed through childchains.

Setting up an environment to test and research blockchain requires an ecosystem with multiple systems to be able to develop research and test. The big players in the cloud industry like Amazon(AWS), Microsoft(Azure), IBM(BlueMix) have seen the potential benefits of offering blockchain services in the cloud and started providing some level of BaaS to their customers. Users will benefit from not having to face the problem of configuring and setting up a working blockchain. Hardware investments won’t be needed as well. Microsoft has partnered with ConsenSys to offer Ethereum Blockchain as a Service (EBaaS) on Microsoft Azure. IBM(BueMix) has partnered with Hyperledger to offer BaaS to its customers. Amazon announced they would be offering the service in collaboration with the Digital Currency Group. Developers will have a single-click cloud-based blockchain developer environment, that will allow for rapid development of smart contracts.


AppTrait Solutions, are not just a mobile app development company but a full-fledged network in itself that is well-versed with the latest market trends and technological advancements. We are also a home to skilled techs that connect with customers and their businesses like you to make change happen. We offer all latest solutions in terms of mobile application development. Our team is well-versed in iOS and Android operating systems and ... Read more

Our services are designed to take your business to the next level, reducing the gap between you and the heights of success you wish to achieve. Empowered by 12+ years of experience in the field of IT, CIS has the right expertise to help you with all your technology needs. We have consistently delivered optimal solutions for our wide-ranging global client base. Leverage our rich experience for your unique IT requirements. CIS has established ... Read more
Smart contracts are immutable pieces of code and their outcomes are irreversible. Hence, formal verification of their code is very important before deploying them. It’s very hard to verify smart contracts in the Ethereum Virtual Machine (EVM). A business can’t afford to deploy faulty but immutable smart contracts and suffer the consequences of their irreversible outcome. This article details the challanges: “Fundamental challenges with public blockchains”.
A public blockchain has absolutely no access restrictions. Anyone with an internet connection can send transactions[disambiguation needed] to it as well as become a validator (i.e., participate in the execution of a consensus protocol).[84][self-published source?] Usually, such networks offer economic incentives for those who secure them and utilize some type of a Proof of Stake or Proof of Work algorithm.
“Such a move could allow retailers to lower prices and incentivize consumers to shop at one retailer over a competitor,” Cohen noted. “This idea is not as ludicrous as it might seem. Amazon recently registered three cryptocurrency-related domain names, suggesting a potential move into the cryptocurrency space. If large companies like Amazon, Walmart or Starbucks issued digital coins that inspired public trust, blockchain-based cryptocurrencies might gain acceptance by the public and other retail giants.”

A consortium blockchain is often said to be semi-decentralized. It, too, is permissioned but instead of a single organization controlling it, a number of companies might each operate a node on such a network. The administrators of a consortium chain restrict users' reading rights as they see fit and only allow a limited set of trusted nodes to execute a consensus protocol.
NPD said the next step for retailers is to develop their own cryptocurrency to prevent customers from having to use credit cards when shopping online. NPD said the practice makes sense for the retailer, because if the customer could send the payment transfer via blockchain, it would avoid third-party clearing house fees retailers pay for processing card payments.
Performance at scale: It is not uncommon for large businesses to process 100,000’s of transactions per second (TPS). Therefore, enterprise blockchains need to scale so that they can deliver performance accordingly. To achieve this, they can compartmentalize processes using containers or similar approaches. Read more about this requirement in this article “Enterprise blockchain ready to go live”.

Bitcoin blockchain design has been done for a specific purpose, and this is a money (crypto currency) transfer. But what will we do, if we want to change or add some functions of the bitcoin blockchain? What if we want to transfer other assets rather than money, what if we want to do transactions automatically when pre-determined events occurred. Or what if we don't want other people see our transactions, or track our transactions' history. You can ask countless of what if questions and every answer to these questions drive you to a different blockchain or configurations


The term “sidechains” was first described in the paper “Enabling Blockchain Innovations with Pegged Sidechains”, circa 2014 by Adam Back et al. The paper describes “two-way pegged sidechains”, a mechanism where by proving that you had “locked” some coins that were previously in your posession, you were allowed to move some other coins within a sidechain.
– we provide no uniqueness of names, unlike the domain registrars, social networks, namecoin, onename.io, etc. There is no uniqueness of names in real life either. Instead the identity is just a hash of a [json] object that contains a public key. Identity object can not be modified directly, but a new version of it can be created, pointing to a previous version. The owner of the identity object can optionally connect it with the real life credentials, e.g. the social account, internet domain, email, etc. by proving the proof of ownership of that account the way onetime.io does it, the way Google Analytics does it, etc. This allows a spectrum of identities from fully anonymous to fully disclosed and verified. This also allows a person to have multiple identities, for work, for social, for gaming, for interest-specific forums. To simulate OAUTH2, a new site-specific identity can be created and signed with person’s other identity.
When you send Bitcoins somewhere, you lay down the challenge for the next owner. Usually, you’ll simply specify that they need to know the public and private keypair that correspond to the Bitcoin address the coins were sent to. But it can be more complicated than that. In the general case, you don’t even know who the next owner is… it’s just whoever can satisfy the condition.

As we’ve talked about, writing to the blockchain is slow and expensive. This is because every node in the entire network needs to verify and slurp in the whole blockchain and all the data it contains. Executing a large smart contract on a blockchain can be prohibitively expensive, and doing things like storing images on blockchains is economically infeasible.
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.
We are a reputed software development agency that believes in delivering efficient and reliable digital solutions to all kind of businesses. If you're having a creative startup idea with a great vision, we will offer you the wings to fly really high in the practical world. If you're an already well-established enterprise, we will help you to win the kings crown and maintain its shine. We Design, Architect and Develop digital solutions ... Read more
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.    
Private institutions like banks realized that they could use the core idea of blockchain as a distributed ledger technology (DLT), and create a permissioned blockchain (private or federated), where the validator is a member of a consortium or separate legal entities of the same organization. The term blockchain in the context of permissioned private ledger is highly controversial and disputed. This is why the term distributed ledger technologies emerged as a more general term.
A blockchain is a decentralized, distributed and public digital ledger that is used to record transactions across many computers so that the record cannot be altered retroactively without the alteration of all subsequent blocks and the consensus of the network.[1][18] This allows the participants to verify and audit transactions inexpensively.[19] A blockchain database is managed autonomously using a peer-to-peer network and a distributed timestamping server. They are authenticated by mass collaboration powered by collective self-interests.[20] The result is a robust workflow where participants' uncertainty regarding data security is marginal. The use of a blockchain removes the characteristic of infinite reproducibility from a digital asset. It confirms that each unit of value was transferred only once, solving the long-standing problem of double spending. Blockchains have been described as a value-exchange protocol.[13] This blockchain-based exchange of value can be completed quicker, safer and cheaper than with traditional systems.[21] A blockchain can assign title rights because, when properly set up to detail the exchange agreement, it provides a record that compels offer and acceptance.
Blockchain-based smart contracts are proposed contracts that could be partially or fully executed or enforced without human interaction.[55] One of the main objectives of a smart contract is automated escrow. An IMF staff discussion reported that smart contracts based on blockchain technology might reduce moral hazards and optimize the use of contracts in general. But "no viable smart contract systems have yet emerged." Due to the lack of widespread use their legal status is unclear.[56]
×