Ethereum developers are aiming to unleash the blockchain’s latest upgrade, the Istanbul hard fork, on December 4. Istanbul promises to make the network more secure and efficient. However, plans that would make Ethereum ASIC-resistant are on hold until nearly next year.

The date for Istanbul was tentatively set during the core developer call on Oct 25 and was firmed up by core developer Peter Szilágyi, via Twitter on Thursday.

He tweeted that Geth v1.9.7, which will enable the Istanbul hardfork on Ethereum’s main client had been released.

Istanbul is the latest hard fork in the network’s eventual transition to Ethereum 2.0, which begins to roll out in stages from early 2020.

The update, which delivers major fixes and upgrades to the world’s second-largest blockchain network, will be implemented in two parts. The first update, Istanbul, will take place later this year, and the second, dubbed Berlin, sometime in the first quarter of 2020.

Improvements due to role out on December 4 are intended to optimize and lower gas costs, increase compatibility with Zcash, address scalability, as well as allowing contracts to introduce more creative functions.

The most controversial change, Ethereum Improvement Proposal 1884, will increase the cost of recalling data on the Ethereum blockchain for application developers.

As the size of the blockchain has increased, these operations have threatened to overload the network. Ethereum core developers have agreed that increased fees will better safeguard the platform from potential denial-of-service, or spam, attacks, but not all community members are convinced.

In September, leaders from governance platform Aragon, voiced concerns that the code changes would break around 680 smart contracts, which manage the governance of decentralized applications (dapps) running on the Ethereum blockchain. The group claimed forced upgrades would now be needed to ensure that decentralized autonomous organizations (DAOs,) built on the Aragon platform, continue to function smoothly.

Less controversially, Istanbul will also enforce new fork upgrades to avoid people getting left using older versions of the blockchain.

Ethereum’s last system-wide upgrade, Constantinople, needed to be delayed due to the discovery of a critical code vulnerability just 48 hours before the scheduled roll-out. So, with Istanbul, developers have planned for this eventuality with pre-determined backstop dates in the event of any unforeseen circumstances.

The second part of Istanbul will launch early next year, and is currently set to include the controversial ProgPow (Programmatic Proof of Work) improvement proposal, that would make Ethereum ASIC-resistant.

In essence, some experts believe that this could jeopardize the network’s security given that fewer miners would support it, but others welcome it, claiming that it will attract more GPU miners.