Bitcoin Cash

DEFINITION of 'Bitcoin Cash'

Bitcoin cash is a cryptocurrency created in August 2017, arising from a fork of Bitcoin Classic. Bitcoin Cash increases the size of blocks, allowing more transactions to be processed.

BREAKING DOWN 'Bitcoin Cash'

Since its launch, Bitcoin faced pressure from community members on the topic of scalability. Specifically, that the size of blocks – set at 1 megabyte (MB), or a million bytes, in 2010 – would slow down transaction processing times, thus limiting the currency’s potential, just as it was gaining in popularity. The block size limit was added to the Bitcoin code in order to prevent spam attacks on the network at a time when the value of a Bitcoins was low. By 2015, the value of Bitcoins had increased substantially and average block size had reached 600 bytes, creating a scenario in which transaction times could run into delays as more blocks reached

A number of proposals have been made to deal with transaction processing over the years, often focusing on increasing block size. Because the Bitcoin code is not managed by a central authority, changes to the code require buy-in from developers and miners. This consensus-driven approach can lead to proposals taking a long time to finalize. This has resulted in groups creating separate blockchain ledgers using new standards, called a fork. Several forks, such as Bitcoin XT and Bitcoin Unlimited, failed to be adopted by a wide audience. Bitcoin Cash, launched in August 2017, is another fork from Bitcoin Classic.

Bitcoin Cash differs from Bitcoin Classic in that it increases the block size from 1 MB to 8 MB. It also removes Segregated Witness (SegWit), a proposed code adjustment designed to free up block space by removing certain parts of the transaction. The goal of Bitcoin Cash is to increase the number of transactions that can be processed, and supporters hope that this change will allow Bitcoin Cash to compete with the volume of transactions that PayPal and Visa can handle by increasing the size of blocks.

Because the computer power required to process larger blocks could price out some smaller miners, critics worry that adopting Bitcoin Cash’s approach will lead to power being concentrated in the hands of companies that can afford more and better equipment. Opponents to the fork worry that this will threaten the consensus-driven approach to Bitcoin, as a small number of companies could control Bitcoin and more readily force changes on the community in the future.

A successful hard fork for Bitcoin Cash entails surviving long enough to entice individuals and companies to use and mine the new digital currency if it is able to build substantial interest and reach critical mass. Once this point is reached, however, Bitcoin Cash may find that its success has prompted others to develop their own alternative coins, which would put the same pressure on Bitcoin Cash that it had placed on Bitcoin Classic. Since the issue of scalability tends to be at the forefront of cryptocurrency debates, developers have made increasing block size and improving transaction processing speeds their top focus areas.  

Despite its many vocal advocates, as of July 2018 Bitcoin cash is used in exchanges at a far lower rate than Bitcoin is (with so little traffic that as of yet, the block size increase hasn't been necessary to process transactions more quickly than Bitcoin).