Files
fips/docs/design
Johnathan Corgan 507086e39d docs: refresh tutorials, how-to, design, reference, and examples for v0.4.0
Pre-cut documentation pass for the 0.4.0 release, verified against current source.

Corrections:
- fipsctl: stale 'show identities'/'show node' -> 'show status'
  (host-a-service, run-as-unprivileged-user)
- mesh address derivation: first 16 bytes of SHA-256(pubkey) with the leading
  byte set to 0xfd, not a fixed fd97: prefix (reach-mesh-services,
  ipv6-adapter-walkthrough)
- gateway control socket mode 0660 -> 0770 (troubleshoot-gateway)
- Tor example: add advertised_port: 8443 so the published port matches the
  prose (enable-nostr-discovery)
- bloom mesh-size estimate rewritten to the OR-union-of-peer-filters algorithm;
  plus mtu deep-link, gateway pool wording, and a NAT failure-mode line
- examples: delete orphaned nostr-rs-relay config, accept inbound to the local
  8443 TCP listener, fix fd::/8 -> fd00::/8 typos, dotless wireguard alias

Additions:
- new Nym mixnet transport section (fips-transport-layer) and the architecture
  transport list
- new LAN/mDNS discovery section (fips-nostr-discovery)
- reference docs: Nym transport, LAN discovery, and new control/stats surfaces;
  drop ble from the connect transport list
2026-06-14 15:14:05 +00:00
..
2026-06-07 23:30:35 +00:00

FIPS Design

Architectural and protocol-level explanations for FIPS — the why and the how behind the wire and the system. For wire formats and configuration keys, see reference/. For task recipes, see how-to/. For end-to-end lessons, see tutorials/.

Reading Order

Start with fips-concepts.md for the novice-friendly framing of what FIPS is and why, then move to fips-architecture.md for the protocol stack, identity model, and two-layer encryption walkthrough. From there, follow the protocol stack from bottom to top. After the stack, fips-mesh-operation.md explains how the pieces work together at runtime. Cross-cutting and supporting documents cover specific subsystems in detail.

Foundations

Document Description
fips-concepts.md What FIPS is, why it exists, mental model
fips-architecture.md Protocol stack, identity, two-layer encryption
fips-prior-work.md Designs and protocols FIPS builds on

Protocol Stack

Document Description
fips-transport-layer.md Transport layer: datagram delivery over arbitrary media
fips-mesh-layer.md FIPS Mesh Protocol (FMP): peer authentication, link encryption, forwarding
fips-session-layer.md FIPS Session Protocol (FSP): end-to-end encryption, sessions
fips-ipv6-adapter.md IPv6 adaptation: TUN interface, DNS, MTU enforcement

Cross-Cutting

Document Description
fips-mmp.md Metrics Measurement Protocol (link + session)
fips-mtu.md Path MTU model, encapsulation overhead, PMTUD
fips-security.md fips0 interface threat model and default-deny baseline

Mesh Behavior

Document Description
fips-mesh-operation.md How the mesh operates: routing, discovery, error recovery
fips-nostr-discovery.md Optional Nostr-mediated peer discovery and UDP NAT hole-punch
port-advertisement-and-nat-traversal.md Nostr-signaled port advertisement and UDP NAT-traversal protocol; generic, with FIPS as an example implementation

Deeper Dives

Document Description
fips-spanning-tree.md Spanning tree algorithms: root discovery, parent selection, coordinates
fips-bloom-filters.md Bloom filter properties: FPR analysis, size classes, split-horizon
spanning-tree-dynamics.md Spanning tree walkthroughs: convergence scenarios, worked examples

Adjacent Components

Document Description
fips-gateway.md fips-gateway service: outbound (LAN-to-mesh) DNS-proxy + virtual-IP NAT and inbound (mesh-to-LAN) port-forwarding, sharing one nftables table