The Ethereum Foundation released some additional details, via their core devs meeting, about the upcoming update to the Ethereum network called Metropolis. The Metropolis hard fork is set to be divided into two core releases: Byzantium and Constantinople. Byzantium will be the first of the two releases, and is targeting a late September release that includes updates on transaction anonymity and more predictable gas charges.
Within the initial hard fork, users can expect the following features/upgrades:
Increase anonymity
Zero-knowledge proofs, or zk-SNARKs, are expected which will enable users to perform transactions with more anonymity than what has been afforded in the past. As the Ethereum blockchain is a public chain, there may be some details of a transaction that counter parties may not want to be visible to the public. Using zk-SNARKS allows only intended audiences with the ability to view data that is privy to them. Dr. Christian Reitwiessner, a team lead at Ethereum and creator of Solidity, describes zk-SNARKs as a way:
To verify the correctness of computations without having to execute them and you will not even learn what was executed – just that it was done correctly.
More Predictable Gas Charges
On the Ethereum blockchain, operations performed by a transaction or contract have an associated cost to perform those actions based upon the computational complexity of the operation. Currently developers, or users, must manage the gas limits for their transactions which leads to some unpredictable results. This has become even more problematic during times of high network activity, including during Initial Coin Offerings (ICOs).
With Metropolis, gas charges will be calculated automatically, at the time of the transaction, taking into account the current state of the network. This will increase the predicatability of transactions being processed, especially during higher-volume periods.
Testing
On the Ethereum blog, it cites a new testing language is in development.
Work has started on a testing language which can be used to quickly write and run tests for proof of work, Casper and sharding fork choice rules. This should substantially improve coverage and accelerate testing for both Casper and sharding.
The team of testers on the Ethereum project team has also increased from three people to seven and major clients, including Parity and geth, have implemented most of the Ethereum Investment Proposals (EIPs).
Overall, the Byzantium release is on, or near, schedule. In early September, the test set is expected to take approximately three weeks to complete. Vatalik Buterin, creator of Ethereum, has outlined the following timelines:
The hard fork may occur at block 4.3 million on September 22nd and worst case is block 4.4 million which would take place on October 27th.