Appendix C. Glossary

Work in progress — not audited

Definitions are normative for interpreting P1–P8 unless a chapter defines a term more specifically.

Term	Definition
Application PDU	JSON object on a WebRTC data channel with required type field (P4).
Broker	PeerJS-compatible signaling server over WSS; relays SDP/ICE only in v0 profile.
Cascade	Ordered stack MLS → Signal → ML-KEM → AES applied by CascadingCipherManager (P5).
cascadedPayload	Object inside encryptedMessage holding finalCiphertext and layer metadata.
encryptionReady	Implementation flag: local crypto handshake complete for a peer; required before E2EE message PDUs (P3).
encryptedConnections	Set of remote Peer IDs allowed on encrypt path (P7).
encryptedMessage	Wrapper object carrying ciphertext (cascade or MLS-only).
Fast file profile	Bulk transfer that MAY bypass cascade; DTLS-only protection (P6.6).
Handshake PDU	Control type values in P3 establishing crypto state.
Initiator / Responder	WebRTC roles for outbound connect vs inbound accept (P2).
MLS	Messaging Layer Security (RFC 9420).
Peer ID	Opaque broker address string; not a global cryptographic identity (P2.5).
PDU	Protocol data unit; here, one JSON object on the data channel.
Profile	Named configuration EnkryptedChat-Profile-v0 (P1).
Signaling	WSS broker traffic for WebRTC setup, distinct from application PDUs.
TOFU	Trust on first use — accept Peer ID and in-band keys without prior out-of-band verification.
TURN	Relay for ICE when direct UDP fails; sees traffic metadata (ch. 3).