Bitcoin Cash is a hard fork of Bitcoin with a protocol upgrade to fix on-chain capacity. Bitcoin Cash intends to be a Bitcoin without Segregated Witness (SegWit) as soft fork, where upgrades of the protocol are done mainly through hard forks and without changing the original economic rules of the Bitcoin. Bitcoin Cash (BCH) is released on 1st August 2017 as an upgraded version of the original Bitcoin Core software. The main upgrade is the increase in the block size limit from 1MB to 8MB. This effectively allows miners on the BCH chain to process up to 8 times more payments per second in comparison to Bitcoin. This makes for faster, cheaper transactions and a much smoother user experience. Why was Bitcoin Cash Created? The main objective of Bitcoin Cash is to to bring back the essential qualities of money inherent in the original Bitcoin software. Over the years, these qualities were filtered out of Bitcoin Core and progress was stifled by various people, organizations, and companies involved in Bitcoin protocol development. The result is that Bitcoin Core is currently unusable as money due to increasingly high fees per transactions and transfer times taking hours to complete. This is all because of the 1MB limitation of Bitcoin Core’s block size, causing it unable to accommodate to large number of transactions. Essentially Bitcoin Cash is a community-activated upgrade (otherwise known as a hard fork) of Bitcoin that increased the block size to 8MB, solving the scaling issues that plague Bitcoin Core today. Nov 16th 2018: A hashwar resulted in a split between Bitcoin SV and Bitcoin ABC
Auroracoin is a decentralised, peer-to-peer, and secure cryptocurrency released as an alternative to the Icelandic Króna to bypass governmental restrictions associated with the national fiat currency. It was launched with the aim of becoming the ‘official’ cryptocurrency of Iceland. AUR was a pioneer in the area of country-specific cryptocurrencies. AUR was launched on the 25th of January, 2014, by an anonymous developer who went by the pseudonym of Baldur Friggjar Óðinsson. It was originally based on Litecoin, using the Scrypt algorithm with a Proof of Work mechanism, but was later updated to use a multi-algorithm architecture in 2016, forked from DigiByte. Auroracoin uses the PoW consensus mechanism, which utilises device hashing power to solve a complex mathematical problem in order to authenticate a transaction proposed to be stored in the blockchain. The difficulty of solving the problem ensures that authenticating forged transactions is very difficult unless the attacker owns an impractically large chunk of the network’s total hashing power. AUR is one of the only cryptocurrencies to use a combination of five different hashing algorithms, namely Grøstl, Qubit, scrypt, SHA-256, and Skein. While initially very popular, Auroracoin has seen little to no activity for a while, with poor marketing, and frequent dev team changes. Reasons for little growth have been various, from slow adoption in Iceland, to developers leaving and joining the project midway. However, it is expected to not go lower than the recent low, and might see a rise as AUR plans to launch a more aggressive marketing campaign in Iceland to promote the coin among the masses. Unlike most other altcoins, Auroracoin has made extensive changes to the original codebase. It has introduced security measures such as Automatic checkpointing, and protecting against known flaws present in the BTC blockchain, such as 51% block replacement attacks.