▪️Relayer nodes

Relayer nodes maintain the bridge by retrieving data from the source chain and submitting it to the target chain. These nodes provide input for the Relay contract, which verifies the provided input and stores it only if it passes certain checks. In most cases, the data that Relayers provides is the block header of the source blockchain.

Anyone can become a Relayer in TeleportDAO by running the Relayer script. This decentralizes the TeleportDAO protocol. The script is lightweight and can be run on a small server. Relayers who provide valid source chain data faster for the Relay contract would be rewarded.

How many honest Relayer should be there?

Relayers provide the necessary input for the Relay contract. Without Relayers, the bridge cannot remain synchronized with the source blockchain. In fact, only one honest Relayer is needed for a safe and operational bridge, making this requirement minimal. Other bridging protocols typically require many honest nodes, often with a considerable amount of collateral locked. Here, we only need one honest node, which doesn’t even need to lock any collateral.

Liveness

For the relay to be live, we need at least one honest Relayer to submit the latest data from the source chain to the relay. As the network of Relayers is decentralized and anyone can become a Relayer by running the Relayer script, we expect that at any time, at least one honest Relayer exists. We recommend applications using the relay to run their own Relayer node to increase system reliability.

Safety

Relayers submit data from the source chain to the relay contract. The relay contract then verifies the validity of the submitted data against the consensus rules of the source chain and only accepts valid data. If a Relayer submits invalid data, it would be rejected by the contract, and the Relayer loses funds. Therefore, no one can submit the wrong data to the relay. However, if there is no honest Relayer in the system, a malicious Relayer can generate some source chain data that follows the consensus rules but is not included in the source chain. To avoid this scenario, there is a need for at least one honest Relayer to submit the latest data from the source chain within a reasonable time frame. The protocol can manage a slight delay in Relayer operation, as it is not easy for malicious Relayers to generate valid source chain data that is not part of the source chain.