A federation is a group that serves as the intermediary between a parent chain and its corresponding sidechain. It is an additional layer in the protocol but serves a key function and is what Blockstream’s Liquid sidechain uses. Due to the lack of expressiveness of Bitcoin’s scripting language, an externally implemented and mutually distrusting set of members form a federated peg.
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:
Always there is a balance in nature, even in blockchains. If you want to have extra features, you need to make a sacrifice from your current features. For example to have high speed and volume; you need to give some from your security & immutability by doing consensus with smaller groups or you need to use different methods in consensus like POS / PBFT. (Proof of Stake / Practical Byzantine Fault Tolerance)
RSK is the first open-source smart contract platform with a 2-way peg to Bitcoin that also rewards the Bitcoin miners via merge-mining, allowing them to actively participate in the Smart Contract revolution. RSK goal is to add value and functionality to the Bitcoin ecosystem by enabling smart-contracts, near instant payments and higher-scalability.
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).
A federation is a group of servers that act as an in-between point between the main chain and a sidechain. The Federation decides when the user’s coins are locked as well as when they are released. The developers of the sidechains can choose the members of the federation. The downside to using federations is that they add another layer between the sidechains and the parent chain.
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).[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.
Sidechain is a blockchain that runs parallel to the main blockchain. It extends the functionality of interplorable blockchain networks. Interpolable blockchain networks signifies the ability to share data between different computer systems on different machines. It means that data can be sent and received between interconnected networks eliminating the possibility of negative impact to the networks. Sidechain enables this to be done in a decentralised manner to transfer and synchronise tokens between two chains.
They rely on a technology called SPV (simplified payment verification) proofs, which work like this: in order to send money to a sidechain and back to the main bitcoin network again, users need to attach a proof that they really have the funds. Without these proofs, when users or miners move their money back to the main chain, under certain conditions, they could take more money than they really have.
It doesn’t matter if you’re moving $1bn or 0.01c across the Bitcoin network, you get the same security guarantees. And you pay for this in fees and time. What if you were prepared to trade safety for speed? Today, your only real option is to send the coins to a centralized wallet provider, whom you must trust not to lose or steal your coins. You can then do all the transactions you like on their books, with their other customers and you never need touch the Bitcoin blockchain. But now you lose all the benefits of a decentralized value-transfer network.
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.
Sidechains, just like any other Blockchain, need their own miners to help protect them from nefarious actors and attacks which people would like to leverage against the network. However, since wealth isn't actually created on the Sidechain there is far less incentive for miners to actually work on it and help protect it. Because of this, transaction fees are the basic reward that is offered to miners. However, these often equate to mere pennies.
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. 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.
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.
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.