Sidechains offer a way for new, more radical settings and technologies to be implemented without affecting the main chain. This ensures that the main chain is as secure as possible whilst providing the freedom to explore options which would never be considered for use on the main chain. Sidechains should be quite powerful as they provide cases like anonymity, transparency, confirmation times and turing complete options like rootstock all whilst utilizing bitcoins rather than relying on the hashing power (security) of some far less secure alt coin. That being said… there is quite some controvery regarding blockstream’s funding of most of the core development team and their inflexiblity regarding the max blocksize. This inflexibility has directly contributed to the success of ethereum and it remains to be seen whether the dream of bitcoin maximalism will survive long enough for sidechains with all of the promised functionality to be rolled out. I am skeptical.
The consortium or company running a private blockchain can easily, if desired, change the rules of a blockchain, revert transactions, modify balances, etc. In some cases, eg. national land registries, this functionality is necessary; there is no way a system would be allowed to exist where Dread Pirate Roberts can have legal ownership rights over a plainly visible piece of land, and so an attempt to create a government-uncontrollable land registry would in practice quickly devolve into one that is not recognized by the government itself. Of course, one can argue that one can do this on a public blockchain by giving the government a backdoor key to a contract; the counter-argument to that is that such an approach is essentially a Rube Goldbergian alternative to the more efficient route of having a private blockchain, although there is in turn a partial counter-argument to that that I will describe later.
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”.
Instead, what if the game was played in its own “channel”? Each time a player made a move, the state of the game is signed by each player. After an epic battle where the Protoss player takes out the remaining Zerg forces and forces a gg, the final state of the game (Protoss wins) is sent to a smart contract on the main chain. This neutral smart contract, known as a Judge, waits a while to see if the Zerg player disputes the outcome. If the Zerg player doesn’t, the Protoss player is paid the 1 ETH. </injects>