Zfort Group is a Full Service IT provider. We offer comprehensive and cost-effective web & mobile solutions: from consulting and website planning to application launch and support, serving businesses across the globe since 2000. Our highly motivated team includes 196 specialists in the following areas: PHP, ASP.NET, JavaScript, UI/UX Design, HTML/CSS, Quality Assurance, iOS and Android development.

Ethereum is an open-source blockchain platform that allows anyone to build and use decentralized applications running on blockchain technology. Ethereum is a programmable blockchain - it allows users to create their own operations. These operations, coded as Smart Contracts, are deployed and executed by the Ethereum Virtual Machine (EVM) running inside every node.
@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.
Nodes can be trusted to be very well-connected, and faults can quickly be fixed by manual intervention, allowing the use of consensus algorithms which offer finality after much shorter block times. Improvements in public blockchain technology, such as Ethereum 1.0's uncle concept and later proof of stake, can bring public blockchains much closer to the "instant confirmation" ideal (eg. offering total finality after 15 seconds, rather than 99.9999% finality after two hours as does Bitcoin), but even still private blockchains will always be faster and the latency difference will never disappear as unfortunately the speed of light does not increase by 2x every two years by Moore's law.
At Iryo, we consider databases and blockchains that are not opened to the public to be insecure they, can easily be altered by the business running it, at their discretion and it goes against the ethos of the open and transparent cryptocurrency space. Designed to keep public out and introducing “trusted” middlemen, private chains forget that trusted third parties are security holes.
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.
Byzantine fault tolerance (BFT) is what keeps the blockchain fundamentally secure. For simplicity, let’s say there were 100 nodes in a blockchain network (there are currently about 10,500 full Bitcoin nodes in the world). What happens when one node wants to tamper with the latest block and say other Bitcoin users sent him a whole bunch of Bitcoin when they really didn’t?
People believe that permissioned means that only a select group of people can access the data and that’s the security feature. But it’s not. Since there is no real user data on the blockchain, (you) as a member of the public, can’t verify the actual content of it. This means that data resides in a location where corruption can stay undetected and data can be easily modified. So why does it even exist? Mainly because of the phenomena known as “hype surfing”; essentially reusing old technology and strapping a blockchain sticker on it gets IBM salesmen a foot in the door to institutions who can’t evaluate the technology accurately in the first place. Unfortunately, even some teams doing public token offerings started to sell this deeply flawed approach to the public.

Function Transactions executed between the locks and unlocks of the main chain tokens don't bloat the main chain. As the technology of a side chain is connected to its main chain, it can be used to build on the developments of the main chain and introduce new features to the market. Child chains serve as the transactional chains of the parent-child architecture, as the parent chain retains minimal features.

Now, making experimental or rapid changes to Bitcoin is very risky and so change happens slowly. So if the one-size-fits-all architecture of Bitcoin doesn’t suit a particular use-case, you have a problem. You either have to use an entirely different cryptocurrency (or build one!). Or you have to use (or build) a centralized service, which brings new risks.
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.
Sometimes separate blocks can be produced concurrently, creating a temporary fork. In addition to a secure hash-based history, any blockchain has a specified algorithm for scoring different versions of the history so that one with a higher value can be selected over others. Blocks not selected for inclusion in the chain are called orphan blocks.[22] Peers supporting the database have different versions of the history from time to time. They keep only the highest-scoring version of the database known to them. Whenever a peer receives a higher-scoring version (usually the old version with a single new block added) they extend or overwrite their own database and retransmit the improvement to their peers. There is never an absolute guarantee that any particular entry will remain in the best version of the history forever. Because blockchains are typically built to add the score of new blocks onto old blocks and because there are incentives to work only on extending with new blocks rather than overwriting old blocks, the probability of an entry becoming superseded goes down exponentially[23] as more blocks are built on top of it, eventually becoming very low.[1][24]:ch. 08[25] For example, in a blockchain using the proof-of-work system, the chain with the most cumulative proof-of-work is always considered the valid one by the network. There are a number of methods that can be used to demonstrate a sufficient level of computation. Within a blockchain the computation is carried out redundantly rather than in the traditional segregated and parallel manner.[26]
Sidechains interactuando con blockchain. Blockstream explica en su paper como, a las sidechains, se les añade una nueva pieza llamada two-way peg. Two-way peg es “el conector” entre ambas cadenas y se encarga de hacer la “magia” para que los bitcoins “salten” a la otra cadena. Juntando ambas cosas obtenemos las pegged sidechain: cadenas laterales conectadas en todo momento. En la imagen puedes observar como, incluso, las sidechain pueden interactuar entre ellas. ¿Llegaremos a un escenario de blockchains interactuando con aspecto fractal?
Our Proof of Work tutorial talks about it in depth, but the best explanation might come from Satoshi Nakamoto himself. If the camps above start receiving messages that don’t agree, they rely on executing a Proof of Work. The Proof of Work is sufficiently complicated and requires significant computing power. Once one camp solves the Proof of Work, it broadcasts the results to the other camps. This message is now accepted in a chain of messages and the competing messages are dropped by the other camps.

Ethereum, a provider of decentralized platform and programming language that helps running smart contracts and allows developers to publish distributed applications. Factom, a provider of records management, record business process for business and governments. Blockstream, a provider of sidechain technology, focused on extending capabilities of Bitcoin. The company has started experimenting on providing accounting (considered a function to be done on private blockchain) with the use of public blockchain technology.
Necessity is the answer to that question, well for the short term anyway. Currently public & private blockchains still have a lot of challenging technological problems that need to be sorted out, with privacy and scalability being foremost. Gallactic’s blockchain can certainly help with scalability due to its multi-chain architecture that allows for massive scaling to rival and in most cases surpass other blockchains in the market with transactions at 300 per second on mainchain with the ability to scale up to hundreds of thousands per second when the multi-chain model is configured for speed.