At 5:22 UTC on October 16, block 4,370,000 was mined and added to the Ethereum blockchain, officially activating the Byzantium hard fork, an upgrade to the Ethereum software. Developers celebrated the highly-anticipated release, but many average users were confused about what exactly Byzantium was and what it accomplished.
In blockchain development, fundamental changes to the software protocol are called “forks”. Soft forks are backward-compatible, enabling the network to stay intact as long as a majority of nodes upgrade to the new software. Hard forks, on the other hand, are not compatible with legacy software versions, so the blockchain will split into two different paths if some node operators do not upgrade to the latest version. This can potentially create a new cryptocurrency, which is what happened in 2016 when a minority group within the Ethereum community refused to follow the hard fork that returned funds stolen during the DAO hack.
What Byzantium Means for Ethereum
Byzantium is the fifth hard fork Ethereum has implemented, and it is designed to increase the network’s privacy, security, and scalability. Specifically, it activates nine ethereum improvement protocols (EIPs), most of which will not be noticeable to the average user.
That said, several EIPs are worthy of note. Some are directed at improving smart contracts by creating a way for developers to program planned contract upgrades, as well as making them more secure against cyber attacks. Others improve the network’s ability to process transactions more efficiently and reduce the block reward for miners.
The most exciting EIP prepares Ethereum for the integration of ZK-Snarks, a cryptographic innovation developed in collaboration with anonymity-centric cryptocurrency Zcash. Once implemented, this technology is expected to allow ethereum users to make transactions that cannot be traced.
What Happens Next
The second phase of Metropolis, Constantinople, is expected to implement an that will reduce the complexity of processing transactions, thus enabling the creation of lighter ethereum clients. Additionally, this fork should make accounts more flexible and customizable, providing users with the freedom to craft their own security models. Unfortunately, Constantinople has not been assigned an official release date, but developers anticipate this hard fork will take place sometime in 2018: