Relayers

Entity that relays transactions and messages between different blockchains to enable crosschain communication.

The main functions performed by relayers are:

• Watching activity on multiple chains and detecting relevant transactions or state changes that need to be relayed across chains.

• Validating that the transactions/messages follow the expected formatting and protocols of the source and destination chains. This ensures security and smooth relaying.

• Relaying or reproducing the transactions on the destination chain in a manner recognizable and valid on that chain. May involve reformatting transactions or creating proxy contracts.

• Providing proof of the original transaction from the source chain to the destination chain so it can be verified. For example, passing cryptographic proofs.

• Maintaining operational reliability to relay transactions in a timely and predictable manner between chains.

• In some cases, providing various incentives to decentralized relayers for reliable message relaying services.

The relationship between relayers and bridges in the context of blockchain interoperability is as follows:

• Bridges are the overall infrastructure and architecture that enables interoperability between two or more chains.

• Relayers are components within a bridge that perform the actual relaying of transactions and messages between the chains.

• Bridges establish the network connections, protocols, mechanisms like hash-locking, data formats etc. to facilitate crosschain communication.

• Relayers operate on this bridge infrastructure to monitor chains, detect relevant transactions, validate formatting, and relay information between chains.

• A single bridge may employ one or more relayers operating in parallel for load balancing, redundancy etc.

• Relayers provide a pluggable component within bridges for upgrading relaying algorithms, incentives, APIs etc.

So in summary:

• Bridges provide the overall infrastructure.

• Relayers are modular components within bridges that execute transaction and message relaying.

• Bridges establish the facilities for interoperability.

• Relayers do the actual information relaying on this infrastructure.

Therefore, relayers provide an operational component within the overall bridge architecture for interoperability.