Dan Connolly's tinkering lab notebook

Toward secure distributed computing with Agoric at SFBW '19

After months of indecision, I decided to go to San Francisco Blockchain Week in hopes of syncing up with the Agoric team. I'm glad I did!

#Agoric Team at #CESC Day 1.

I have been working remotely for a few months on SwingSet on xs:

A key to Agoric's smart contract platform is compatibility between widespread understanding of best practices in JavaScript development with object capabilities and fail-stop deterministic execution. Initial development of cosmic-swingset is based on the popular and feature-rich node.js platform, but node.js represents an uncomfortably large amount of code to include in a trusted computing base as well as a substantial risk to deterministic execution. The xs engine in the Moddable SDK is designed for constrained microcontroller environments. It has some limitations, but the supported feature set seems to be an excellent match for the Agoric platform.

SwingSet has about 500 tests across 15 files. Once I got about 200 in 3 files, I started looking for someone to reproduce my work. Switching from my linux desktop to a macbook for this trip meant I could be that someone. In the Agoric office on Wednesday, I found out that some of the kludges I had put in place weren't portable between linux and macOS, so only about 170 tests are working cross-platform. It was great to be able to chat in person with Brian and Michael about this stuff.

Zoe and Offer Safety

Agoric leveled up their platform this week with Zoe, which provides offer safety: when you place an offer, either you'll get what you wanted or you get a refund, regardless of the (mis)behavior of the underlying smart contract.

For example, autoswap is a cool service, but conventional interfaces provide little assurance as to what is going to happen when you send it some tokens in a transaction. In contrast, a wallet working with Zoe presents offers in an intelligible form and guarantees that the offer is either executed as stated or you get a refund.

There are some rough edges in getting these demos running, but I had done the testnet demo the previous week so it only took me a little chatting with JF and co to get them running.

And the Agoric folks are not alone in smoothing out the UI: Dan Finlay built a MetaMask Agoric Plugin at the DeFi hackathon.

I think it would be fun to formally verify the offer safety property. Mark Miller and I chatted about this with Eric McCarthy, who works on the ACL2 Ethereum project. I have some history with ACL2, and in some sense the untyped style of ACL2 goes well with JavaScript, but I wonder if that's a false economy. I'm more facile with ML style propositions-as-types systems (idris, ocaml) lately.

CESC: Ouroboros, Kara from Oasis Labs, ...

At CESC (crypto economics security conference) Monday and Tuesday, some talks were too full of greek letters for me to follow and others were more like TV commercials than academic contributions. Two that stood were:

  • Vassilis Zikas on The Evolution of Ouroboros: From Proof of Work to Proof of Stake. He started with an introduction to bitcoin that seemed a little remedial for this venue but he built on the structure of that intro to make a clear presentation of the rest.

  • Kara from Oasis Labs: privacy-preserving health data analytics. "AI for healthcare is limited by the fact, that the most valuable data is locked in data silos. Kara breaks up these silos and allow researchers to train their models on data that is otherwise hidden from science - extracting value from it, while never exposing the data itself." The talk was a little on the TV commercial side, but the Ekiden on how they mix private compute nodes with the blockchain is pretty convincing. The evaluation includes some machine learning stuff for medical diagnostics.

Epicenter: CasperLabs, Chainlink

I went to the CasperLabs workshop by Michael with Joshy, a fellow rchain expat.

The Chainlink marketplace for connecting smart contracts to real world data sources (oracles) and payment systems looked interesting. I'm a little bummed I missed the chainlink workshop, but I think I made the right call hanging out with the Agoric team instead.