The first half of the Ethereum Metropolis hard fork, nicknamed Byzantium, is happening on Monday at some point between 12:00 and 13:00 UTC. The fork is scheduled to take place at block number 4,370,000. For those interested in watching the fork take place live, a countdown clock can be found here.
The much anticipated hard fork contains a number of updates to the Ethereum chain including an addition of ‘REVERT’ opcode, which permits error handling without consuming all gas, support for big integer modular exponentiation, support for variable length return values, and changes to the difficulty adjustment formula to take uncles into account.
However, perhaps the most discussed upgrades include the successful addition of fully anonymous zero knowledge proofs (ZK-Snarks), and the delay of the difficulty bomb (nicknamed ice age) by a full year, as well as a reduction of block creation reward from five to three ether. Some have argued that the anonymity of the ZK Snark upgrade will create newfound adoption on Wall Street.
What’s a user to do?
Users who do not upgrade will have clients sync to the pre-fork chain without replay protection. Users are advised to download the latest version of Ethereum client - Ethereum Wallet/Mist, geth client (v 1.7.2), Parity client (v 1.7.6), Harmony client (v 2.1.0).
Users who are using mobile or Internet-based wallets should be certain to check if their wallet provider is requiring any actions from users. Generally, mobile and Internet providers are running their own client infrastructure, and users should not have to take any action. However, as always it is recommended that users contact their individual providers to be certain.
Source：Read the official page