2018 was the year of the bear taking control over the cryptocurrency market. At the surface, we’ve seen many public investors drop out of the market, and to the casual spectator, the whole cryptocurrency sector would appear doomed to fail. But to technology enthusiasts and ideologues, progress in the name of blockchain research and development had never been more active.

Here are the top 5 highlights that rocked the world of Cosmos testnets which occurred over the course of 2018 — a series of events that flew clean under the public radar. Over 20 testnets were launched throughout 2018, where each new one was associated with newly-released software that had added incremental features, optimizations, and bug fixes. We adopted what the Lean Startup coined the “agile” approach, deploying software across multiple iterative feature adds for beta testing rather than releasing a monolith — which would then be broken — all at once.

For context, the Cosmos Hub software daemon is coined gaiad , so our testnet versions start with the name Gaia. For distinction, whenever we refer to ‘Cosmos’, we are referring to the project, and whenever we refer to the ‘Cosmos Hub’ or to ‘Gaia’, we are referring to the application-specific blockchain that runs on Tendermint BFT consensus.

Highlight #5

Gaia-6001: The 1st decentralized start

Summary: One of the earlier testnets, which was launched in June, was the 6000-series. Gaia-6001 was a meaningful testnet because it was launched in a decentralized and asynchronous fashion. This meant that, once the community had picked up a genesis.json file to instantiate the blockchain, individual validators were able to independently come online within a window of time and start making pre-votes and pre-commits (i.e. Tendermint consensus messages) to signal their active status. Once more than 2/3rd of the voting power came online, Gaia-6001 started making blocks.

Why it’s important: Proof-of-Stake is often criticized by Proof-of-Work proponents for being far too centrally-coordinated to be considered a viable censorship-resistant blockchain security model. In Proof-of-Work, a new blockchain is instantiated as soon as a “miner” from anywhere in the world, with just a piece of hardware, spins up a full node to then start grinding through hashes in order to create blocks with no regard for what any other miner does and with no need to coordinate with anyone other than themselves. This property is what makes PoW protocols “permissionless” and “decentralized”. PoS, however, requires significantly more coordination overhead among a group of miners (i.e. validators), in order to instantiate a new blockchain. Lots of times, this coordination must be done over some communication medium, like a chatroom.

Gaia-6001 marked the first of many community-initiated testnet starts without Cosmos core developers providing the training wheels. Cosmos validators have gotten so good at launching decentralized starts that the latest testnets, called the ‘genki’ series, were coordinated entirely independently of Cosmos/Tendermint team members. This is a strong positive signal that this distributed community will launch the Cosmos mainnet in much the same way.

Highlight #4

Gaia-8002: The largest BFT network to have run over the open internet

Summary: With the announcement of Game of Stakes (GoS), an adversarial Cosmos testnet, came a wave of interest and new validators. So, when Gaia-8002 was launched post-GoS announcement, there were almost 200 active validator nodes running the software for the duration of that testnet.

Why it’s important: This has been the largest BFT network to have ever existed over the open internet. In Practical Byzantine Fault Tolerance (PBFT) land, a distributed network usually only occurred over a local area network (LAN), e.g. 4–7 nodes. In 2014, Tendermint broke traditional notions of localized BFT networks by expanding on the number of nodes that could be run over wide area networks (WANs), e.g. hundreds of nodes. So in 2018, to have a network of 200 consensus nodes replicating a blockchain’s changing state while remaining BFT is considered a breakthrough in the world of PBFT.

Highlight #3

Gaia-9001: The Bug Bounty Program in Action

Summary: On Nov 12, a critical bug report found on the Gaia-9001 testnet was publicly disclosed by a white hat by the username ‘Kauchy’ who reported a devastating bug in a core module in the Cosmos-SDK framework. Then, several hours after the bug was reported, this bug was replicated on Gaia-9001, which minted ATOM tokens out of thin air and proceeded to crash the network after printing too much cryptocurrency. Ouch!

Why it’s important: Blockchain networks propped up by Quantitative Easing is a big no-no. Scarce digital resources enabled by cryptography is, if nothing else, the one job that a blockchain should enforce.

While this particular bug was reported outside of the bounds of what’s considered Responsible Disclosure through HackerOne, we’re fortunate to have a vibrant, engaged community who continue to responsibly disclose vulnerabilities such as these to our (ongoing) bug bounty program and for the swift response of Cosmos core developers who had a fix for it within a day. The standard response rate in the broader technology industry averages 90 days, whereas Cosmonauts were able to resolve this issue in less than a week.

Highlight #2

Gaia-9002: The feature-complete testnet

Summary: Gaia-9002 was associatively launched with a very important piece of software for the PoS world. It ran Cosmos-SDK v0.27.0 software, which was the beta version of what was considered feature-complete for the Cosmos Hub mainnet.

Why it’s important: SDK v0.27 contained every feature that is needed for the Cosmos Hub. Those features include all of the staking, slasher, fee distribution, and governance logic that is intended to be used on the mainnet. With those features, we can justify calling Cosmos’ next-generation PoS implementation “Bonded Proof-of-Stake”, or BPoS. BPoS is distinct from first generation PoS algorithms due to slashing both validators and delegators who bond ATOM tokens to validators such that all parties are proportionally penalized for protocol infractions. There are currently no PoS algorithms running in production that slashes both bonded validators and delegators. We believe that by doing this, the highest tier of security can be ensured for the network, as Nothing-at-Stake is a potentially fatal attack vector on any PoS system.

Highlight #1

Gaia-8001: The testnet of over 1 million blocks

Summary: In early November, the longest running testnet, Gaia-8001, was nearing a milestone of hitting one million blocks. The testnet had been running steadily for about 3 months without a single network halt.

Just shortly after Devcon4, when the block height crossed the 1-million-block mark, Cosmos Hub validators around the world independently celebrated the momentous occasion.

Why it’s important: This is a breakthrough in the world of PBFT, as achieving a BFT system in a blockchain context that is both safe (i.e. consistent) and live (i.e. available) is the crux of the challenge that every researcher in Proof-of-Stake is racing to solve. As you probably know, Tendermint is a consistency-favoring protocol, which means that if safety is ever broken at any point in time, the chain that runs it will come to a complete halt. To address this liveness problem, the chain that runs Tendermint should externalize the burden of providing a highly-available network to the operators of the system. These operators are financially incentivized to provide very high uptime in order to stay profitable. Thus, after a full year since the inception of the Validator Working Group, Cosmos validators would run what’s considered a very successful testnet.