COSMOS Hub validators participate in consensus by broadcasting cryptographic signatures, or votes, to commit blocks. Tendermint requires a fixed known set of validators, where each validator is identified by their public key. Validators attempt to come to consensus one block at a time, where a block is a list of transactions. 


ATOMs are the native and only staking token of the COSMOS Hub. ATOMs represent the right to participate in consensus (vote, validate or delegate) for the Hub and earn inflationary ATOM block rewards and transaction fees in exchange.


COSMOS is deploying a multi-token model in which the ATOM is used primarily for staking and the Photon can be used primarily for transaction payments.The proposed ‘photons’ would be awarded as block rewards to the COSMOS Hub validators. Photons can be used to pay ‘gas’ fees on Ethermint zones as well as pay fees for any zone in the COSMOS ecosystem that accepts it as a fee token.

Tendermint Core

Tendermint Core combines the Tendermint consensus algorithm along with a p2p gossip protocol. So, when you put it all together in the software stack, you get the Tendermint Core along with the COSMOS-SDK application layer.


The COSMOS SDK is a modular framework that simplifies the process of building secure blockchain applications. 


The Tendermint Core engine is connected to the application by a socket protocol called the Application Blockchain Interface (ABCI). This protocol can be wrapped in any programming language, making it possible for developers to choose a language that fits their needs.


BFT stands for Byzantine Fault-Tolerance. Byzantine faults within distributed systems are some of the most difficult to deal with. A Byzantine Fault-Tolerant consensus algorithm is a consensus algorithm that guarantees safety for up to a third of Byzantine, or malicious, actors.


IBC is the inter blockchain communication protocol which can be thought of as the TCP/IP for blockchains. It allows fast-finality blockchains to exchange value and data with each other in a decentralized way.