ICON and Cosmos Hub are two blockchain networks that make interoperability a core value.

Look no further than the network taglines: for ICON, it’s “connecting blockchains,” while for Cosmos, it’s “the Internet of Blockchains.”

Indeed, the similarities between the two networks goes beyond a mere focus on interoperability. Both are fast, low-cost, promote Proof of Stake consensus, and contain growing ecosystems, including DeFi, NFTs and games.

Nevertheless, there are some key differences in how ICON and Cosmos Hub go about their business. In this post, we’ll take a look at those differences and what they might mean for users and builders.

ICON vs Cosmos Hub

The most dramatic difference between ICON and Cosmos Hub is how the two networks function at their most fundamental level.

Cosmos Hub is built using Cosmos. Cosmos is a “layer 0” platform, much like Polkadot. This means Cosmos functions mostly as infrastructure to connect separate blockchains built upon it. Unlike “layer 1” platforms, like Ethereum, the layer 0 runs no smart contracts, nor does it support DApps or other services.

Instead, that work is performed by the blockchains built on top of them, with the underlying layer 0 serving to enable interoperability between those blockchains.

There are advantages to doing things this way, mostly related to the limitations layer 1 platforms have faced.

When you build all your services on top of the layer 1 chain, they have to compete for resources, slowing down transaction speeds, though this is a bigger problem in some networks than others. Moreover, layer 1 platforms tend to be designed for the average use case, presenting difficulties to service providers who would prefer a more optimized environment. Finally, building on the layer 1 means your service is dependent on the governance of that specific network.

Layer 0 networks resolve these issues by allowing services to build their own blockchains, complete with their own governance and tokenomics.

The Cosmos Network is essentially a network of heterogeneous blockchains that consists of “zones” (application-specific blockchains) connected to one another through a router, or “hub,” including Cosmos Hub.

In fact, Cosmos Hub was the first layer 1 blockchain built using Cosmos. Its core mission is to serve as a router for compatible blockchains (i.e., mostly blockchains in the Cosmos ecosystem) by establishing connections for Cosmos IBC, the network’s interoperability solution (see below). However, going forward, Cosmos will be playing a more prominent role in protecting the security of the Cosmos Network and promoting an interchain economy. It also issues ATOM, which serves — more or less — as the network’s reserve currency.

ICON, meanwhile, functions as a more traditional layer 1 platform, meaning developers can build their applications and services right on ICON itself. In theory, this could present developers with some of the limitations mentioned above. On the plus side, though, you don’t have to build your own blockchain (or choose from what is a universe of sidechains) to deploy an application, or be responsible for your own security (which had been the case with Cosmos, though this is set to change as the network upgrades).

Moreover, building on ICON opens the door to the network’s innovative interoperability solution, the Blockchain Transmission Protocol (BTP), which we are about to address.

Cosmos IBC versus BTP

As we said earlier, both Cosmos and ICON make interoperability a top priority. Additionally, both use (or in ICON’s case, will use) trustless interoperability solutions that use light clients — essentially, mini-blockchains that let users sync chains without the massive resources you’d need to sync full-sized chains.

To integrate into ICON’s BTP, however, blockchains should simply implement a few smart contracts. This makes it easier for completely heterogeneous blockchains to integrate into the BTP ecosystem. Indeed, when you look at the current list of BTP partners — Algorand, NEAR Protocol, BNB Smart Chain,etc. — almost none related to ICON. Only the ICE Network, ICON’s Polkadot parachain, is an ICON expansion network.

To implement Cosmos IBC, however, you should implement a module via Cosmos SDK, the network’s toolkit for building blockchain networks. Essentially, this means to use Cosmos IBC, you should build your blockchain using Cosmos architecture. This is more in line with the hub-and-spoke concept of interoperability favored by Cosmos and Polkadot. 

Cosmos SDK versus ICON SDK

Both Cosmos and ICON have their own software development kits, or SDKs.

Both Cosmos SDK and ICON SDK contain all the elements and tools developers need to build blockchains of their own, including blockchain engines, wallets, trackers and the like. They allow you to build fully functional blockchain networks without having to build everything from scratch.

But where Cosmos SDK is mostly designed to build independent blockchains that are meant to fit into the Cosmos ecosystem, ICON SDK produces mainnets that are completely independent of ICON, albeit interoperable with ICON through BTP, which is included in the kit. A perfect example is ICON SDK’s first use case, the HAVAH interchain NFT platform, which is an independent blockchain, but one connected to ICON through BTP.

Of course, some of this comparison is theoretical. While Cosmos IBC and Cosmos SDK are very much in current use, BTP and ICON SDK are still works in progress. Still, should both solutions live up to their promise — and there is no reason to believe they won’t — they should offer users and developers an intriguing alternative to existing solutions, including Cosmos.