The testnet launch of ethereum's Istanbul system-wide upgrade has been set.

“For anyone listening in who doesn't know how this works, we pick a block number that we estimate to be around the 2nd of October," Ethereum Foundation community manager Hudson Jameson said Friday on an ethereum core developer call. "However, that might be one or two days behind or forward from that date based on how fast blocks are produced between now and then."

Originally targeted for Sept. 4, the testnet activation was pushed back to Oct. 2 due to the large volume of Ethereum Improvement Proposals (EIPs) that were submitted for review.

Of the roughly 30 EIPs that were deliberated on by developers, only six have been accepted for inclusion in Istanbul with eight other EIPs tentatively planned for a proceeding system-wide upgrade, or hard fork, newly dubbed "Berlin."

With the Istanbul testnet upgrade now a month later than planned, mainnet activation will similarly be postponed till November, after the close of Devcon, ethereum's premier developer conference.

A specific date and block height for mainnet activation was deliberately left unspecified given cautious sentiment from ethereum developers about prematurely committing to new target dates for Istanbul.

"One of the lessons learned in the [previous] Byzantium fork last year is that we shouldn't try to set the testnet and mainnet fork at the same time," E.G. Galano, the chief infrastructure engineer of ethereum startup Infura, said during the meeting. "Let's start with setting the testnet fork and see how that goes and find a period of stability before revisiting when to set the mainnet fork."

Outside of lingering debate over the wording of certain EIPs approved for Istanbul, developers also discussed Friday the results of an initial security audit done by security consulting firm Least Authority over the proposed ProgPoW mining algorithm change.

Having been discussed by developers for close to a year now, ProgPoW is an EIP intended to block specialized mining hardware called ASICs from participating on the network and competing in an estimated $655 million annual market for ethereum's mining rewards.

As summarized by Least Authority CEO Liz Steininger during the meeting:

There is still another audit on ProgPoW pending completion, as noted by Jameson during today's meeting.

"[Bob Rao] is doing a very extensive hardware audit," Jameson said. "Bob's audit should be coming out very soon. It's in final stages [and] is going to answer a lot more of the questions and speculations around ProgPoW."

Barring any significant security concerns raised by these two auditors, developers are expected to proceed with the activation of the mining code change in the following hard fork, Berlin.

Ethereum image via Shutterstock