Bitcoin Cash brings sound money to the world, fulfilling the original promise of Bitcoin as "Peer-to-Peer Electronic Cash". Merchants and users are empowered with low fees and reliable confirmations. The future shines brightly with unrestricted growth, global adoption, permissionless innovation, and decentralized development.
All Bitcoin holders as of block 478558 are also owners of Bitcoin Cash. All are welcome to join the Bitcoin Cash community as we move forward in creating sound money accessible to the whole world.
Bitcoin Cash (BCH) is a hard forked version of the original Bitcoin. It is similar to bitcoin with regards to its protocol; Proof of Work SHA-256 hashing, 21,000,000 supply, same block times and reward system. However two main differences are the the blocksize limits, as of August 2017 Bitcoin has a 1MB blocksize limit whereas BCH proposes 8MB blocks. Also BCH will adjust the difficulty every 6 blocks as opposed to 2016 blocks as with Bitcoin.
Bitcoin Cash is a proposal from the viaBTC mining pool and the Bitmain mining group to carry out a UAHF (User Activated Hard Fork) on August 1st 12:20 pm UTC. They rejected the agreed consensus (aka BIP-91 or SegWit2x) and have decided to fork the original Bitcoin blockchain and create this new version called “Bitcoin Cash”. Bitcoin Cash can be claimed by BTC owners who have their private keys or store their Bitcoins on a service that will split BCH for the customer.
Bitcoin cash has a set rule as to when it decreases its difficulty. Before we see the rule it is important to understand what Median Time Past (MTP) is. It is the median of the last 11 blocks that have been mined in a blockchain. Basically, line up the last 11 blocks one after another and the time at which the middle block is mined is the median time past of the set. The MTP helps us determine the time at which future blocks can be mined as well. Here is a chart of the MTP of various blocks:
Image courtesy: Jimmy Song Medium article.
On Chain Scalability - Bitcoin Cash follows the Nakamoto roadmap of global adoption with on-chain scaling. As a first step, the blocksize limit has been made adjustable, with an increased default of 8MB. Research is underway to allow massive future increases.
New Transaction Signatures - A new SigHash type provides replay protection, improved hardware wallet security, and elimination of the quadratic hashing problem.
New Difficulty Adjustment Algorithm (DAA) - Responsive Proof-of-Work difficulty adjustment allows miners to migrate from the legacy Bitcoin chain as desired, while providing protection against hashrate fluctuations.
Decentralized Development - With multiple independent teams of developers providing software implementations, the future is secure. Bitcoin Cash is resistant to political and social attacks on protocol development. No single group or project can control it. The bitcoin-ml mailing list is a good venue for making proposals for changes that require coordination across development teams.