The rapidly growing Bitcoin Cash network has undergone a hard fork designed to tackle issues with the blockchain's DAA (difficulty adjustment algorithm). This change is meant to ensure a consistent block time of around 10 minutes and improve the network's response time to sudden hashrate changes, allowing it to adjust its difficulty more rapidly. The upgrade was published by Bitcoin ABC, with their lead developer Amaury Sechet providing the new DAA.
Why was the change necessary? Bitcoin Cash's EDA (emergency difficulty adjustment) algorithm was designed to prevent chain stagnation caused by BCH competing for the same hash power with BTC. It reduced difficulty by 20% if miners needed more than 12 hours to mine six blocks, causing wild fluctuations in hashrate, as miners would mine BTC and switch to BCH once the difficulty dropped. This in turn interfered with confirmations for users and the coin issuance schedule.
This change should drastically improve the stability of Bitcoin Cash, and is currently enjoying widespread approval from the user base, but it is yet to be seen how mining activity will adjust to the new algorithms in the long term.