Shifting and Changing: Ethereum's Casper Code Takes Shape

Ethereum's leading effort to reimagine how nodes in a blockchain system come to agreement is slowly but surely advancing.

At least that was the message front and center at Devcon3, the open-source project's annual technology conference, on Wednesday. The topic of casper – ethereum's much-anticipated version of proof-of-stake consensus – was present during a number of panels at the event.

One of a number of moving parts that need to come together for the project to realize its long-term vision, casper may be among the more important, as it's key to democratizing access to the platform. The perceived necessity of the upgrade was perhaps best put forward by Cornell University researcher Emin Gün Sirer, who argued how proof-of-work – bitcoin's system for keeping its network in sync – has lead to an environment wherein users can no longer participate as envisioned.

Sirer said during the event:

Along these lines, casper is aimed at a more egalitarian approach, differentiating ethereum through the introduction of a new spin on a system called proof-of-stake.

Rather than users buying specialized computers to run the software, the idea is that users would simply set aside funds (which would be locked for a period of time) and perform calculations for approving transactions. Through this action, users could compete for protocol rewards.

In this way, ethereum creator Vitalik Buterin has gone so far as to argue it should be prioritized above all other items on the roadmap. But because proof-of-stake would do away with elements of ethereum's infrastructure, the argument goes, security risks are emerging as a central concern.

On a panel alongside Sirer were ethereum developer Vlad Zamfir; fellow Cornell professor Elaine Shi; and Parity Technologies developer Peter Czaban. The overall feeling among those on the panel: casper needs to happen quickly – at least, as fast as it can within security constraints.

Still, the delicate balance the project needs to strike contrasted with reports about the environment in which the code is being developed.

For example, it was confirmed that the authors of the original proposal – Zamfir and Buterin – are still working on competing versions of the tech, as they were at Devcon2 last year. While Buterin's version claims to be extremely simple, Zamfir's own version promises to constitute a very minimal shift.

Zamfir's presentation demonstrated that he has been quietly working to improve on the earliest version of casper, which included a more complex blockchain structure.

Based on the GHOST protocol, Zamfir's casper boasts faster transaction times through reshaping the rules by which blocks are verified. In this way, the underlying structure looks more like a zig-zag than a linear blockchain – and mirrors other proposals in trying to create a faster protocol.

Buterin's own version of casper, co-authored with fellow developer Virgil Griffith, has pivoted away from these ideas and moved toward a design which he aims to be "as simple as possible, and as simple as to graph onto the existing proof-of-work systems as possible."

Yet at this stage of development, there's still disagreement as to which take on casper achieves true simplicity, with Zamfir pointing to several other data structures that could be deployed to reach this goal.

Image by Rachel Rose O'Leary for CoinDesk