This is a work-in-progress, do not consider anything here to be final.
Telehash began almost 10 years ago and has had two major evolutions in that time, the earlier ones being more focused on a distributed hash table and more recently focusing on the security and end-to-end privacy.
This next evolution continues that tradition by moving the protocol's self-defined primary data structures all to use newer standards instead, JOSE and CBOR. The lightweight nature of v3 has led to adoption in IoT use cases and v4 is embracing constrained environments as a principle architecture.
- All messages will become a JWE
- Handshakes will contain a JWS + ephemeral JWK and establish a single channel (instead of a v3 'link'), multiple channels can exist simultaneously between peers
- All JWE/JWS bodys will be JCOR (CBOR-based JSON)
- Primary/Required JWA is ECC P-256, implementations should support others
- Bindings will be defined for common transports (HTTPS, CoAP, MQTT, XMPP, USB/CDC, UART, etc)
- Reliable channels will not be in v4, messages must be stand-alone or a reliable transport must be used instead
- Communities are being introduced to increase metadata privacy, every endpoint must be part of one or more communities
- Hashnames are unique to each community
- Bindings to OpenID Connect for seamless bootstrap from external identity systems
- a community is defined by a shared JWK
- they are either public or private
- private must be known before joining the community
- public maybe open or password protected
- public has a UTF-8 string name, KDF used to derive the JWK, when password protected it is an additional KDF
- JWE encrypted by the community JWK is used for discovery, can be broadcast on local networks
- JWE contains a JWS+JWK of the joining/announcing peer, JWK is optional on private networks
- when public the community name is available in the JWE headers
- every peer in a community has a unique hashname based on the hash of the thumbprints of the community+peer's JWKs
- advisable to join public communities with a new peer JWK each time so the hashname will change, long-lived identity established at app/higher layer (via OIDC)
- once a peer's joining JWE is validated and associated with a local transport path, E2E channels can be established