Protocols
Waku takes a modular approach, providing a range of protocols that enable applications to control the trade-offs involved in the Anonymity Trilemma. This flexibility empowers applications to make informed choices regarding the desired balance between anonymity, scalability, and latency. Here are the main protocols provided by Waku:
Relay
Relay protocol employs a Pub/Sub architecture to facilitate the sending and receiving of messages among peers. It extends the libp2p GossipSub protocol to create a privacy-focused peer-to-peer messaging protocol that enables secure communication channels, encryption, and protection against censorship. It also scales the Waku Network to accommodate many nodes efficiently.
RLN relay
RLN Relay protocol extends the Relay protocol by using Rate Limit Nullifiers (RLN) to provide efficient and economic spam-prevention. It enforces a rate limit on messages over time for all peers in the network, economically preventing spam, and imposes financial penalties and network removal for spammers. You can find more details in the RLN Relay blog post.
Filter
Filter protocol allows light nodes to selectively subscribe to specific messages relayed by other peers using content topics. It is designed to be a lightweight alternative for accessing the Relay network, particularly tailored for devices with limited bandwidth.
Filter protocol helps optimise bandwidth usage, but it has fewer privacy guarantees as it must disclose the content topic to its peers to retrieve messages.
Store
Store protocol is responsible for storing messages relayed in the network, making it possible to query and retrieve them later. This functionality benefits offline peers by enabling them to retrieve missed messages upon reconnection.
Using Relay and Filter protocols is recommended when a node is online, as Store does not guarantee data availability. The Store protocol is suitable for retrieving messages when connecting to the network, like when a DApp starts.
Light push
Light Push is a Request/Response protocol for nodes with limited bandwidth and short connection windows. It allows a client to receive an acknowledgement when sending messages, indicating that at least one peer has received them. Subsequently, the remote peer forwards these messages to the Relay network.
While the Light Push protocol acknowledges the receipt by the remote peer, it does not guarantee network-wide propagation.
Waku message
Waku Message specifies the structure and format of messages in the Waku Network. It includes the following attributes:
content_topicattribute for content-based filtering.payloadattribute containing the message data payload to be sent.metaattribute for conveying additional details to various protocols for application-specific processing.timestampattribute signifying the time at which the message was generated by its sender.ephemeralattribute specifying whether the network should not store the message.