Jed McCaleb Talks Stellar's New Protocol for Consensus

The Stellar Foundation has released details about the new consensus protocol it hopes to deploy on the Stellar network as early as this summer.

Founded on a concept called federated Byzantine agreement, the Stellar Consensus Protocol is intended to replace Stellar's existing consensus protocol, itself is based on the system used by competitor Ripple Labs. The Stellar team said in December that it was working to replace its existing protocol following network issues last September.

The Stellar Foundation, the organization that oversees the development of the Stellar network, published the code for the protocol alongside a white paper by Stanford University researcher and Stellar Foundation chief scientist Professor David Mazieres.

Founder Jed McCaleb said in an interview that the protocol and associated white paper have been in development for months. The goal of the release, he said, was to both provide analytical backing for the new protocol as well as give less technology inclined individuals the means to understand the new technology.

McCaleb explained that work on the new protocol was based on the intention to build a scalable, decentralized system, noting:

“From the beginning, we were trying to design it to be able to reach hundreds of millions of accounts, thousands of transactions. So we’ve stress tested to 100 million accounts and a few hundred transactions per second, and its holding up under those loads."

The formal announcement coincided with the release of an introductory guide and the first chapter of a “graphic novel” that takes place in a fictional galaxy occupied by aliens seeking a new way to conduct interplanetary payments.

The general's problem

Byzantine agreement refers to the Byzantine General's Problem, which compares the issue nodes face when seeking to discern whether to trust one another to a group of military leaders receiving potentially false information from messengers during the siege of a city.

Byzantine agreement frameworks establish methods by which nodes can come to agreement on the veracity of the information they received.

The Stellar Consensus Protocol white paper outlines the principles of federated Byzantine agreement, by which nodes in a network agree to accept information from a group of trusted nodes, known as quorums or slices.

Consensus in the network spreads as these slices form collective agreement on the information.

"Every node has a list of other people," McCaleb said. "It doesn't necessarily trust [those nodes], it just needs to think they won't collude with each other.

Work underway

Since December, the network has been relying on a single verifying node until the protocol is ready to be deployed. According to McCaleb, testing is well underway to see how far the system can be pushed.

"Right now what we have is a small test network of a few nodes just talking to each other and people can kind of play around with it, but it's not production ready by any means," he said.

McCaleb added the team is now focused on scaling the new protocol, with a goal of creating significant transaction capacity alongside the ability to meet heavy user activity.

"Part of the process from now until when we switch over the network is increasing those metrics, squeezing more performance out of it," he said.

McCaleb added that Stellar's partner organizations are waiting for the launch of the new system before integrating.

The last mile of money

Overall, McCaleb said that the Stellar Foundation hopes to use the new consensus protocol as a mechanism by which the unbanked and underbanked can achieve greater access to global payment channels.

He speculated that systems like Stellar stand a good chance of capturing the same kind of developmental momentum experienced by payment systems like Kenya's M-Pesa, which has provided a means by which people can store value without having to use a traditional bank account.

McCaleb said he envisions a framework by which Stellar exists as a foundation for the creation of value transfer services that use the network to communicate.

“We kind of want to be the bedrock layer that people can build on top of so you can easily build an M-Pesa like thing in whatever your country is," he said. "And the cool thing is, these things will now all be able to talk to each other."

Images via Stellar