tyr

Our own eID — locked down, mega small, binary, fast from embedded up.

tyr (Old Norse Týr, god of law and oaths — the one who bound the wolf Fenrir with his own hand as the pledge) is Nordisk's own electronic-identity protocol. Where frida buys EU interoperability with heavyweight envelopes (JOSE/COSE, SD-JWT, mdoc), tyr makes the opposite trade: a tight binary wire protocol for constrained hardware and very high throughput.

Lesson behind it: an XML-era identity protocol, re-done as a binary protocol, cost ~100× less CPU/space. tyr starts binary.

Goals

• Compact binary wire format — no XML/JSON; fixed/TLV framing, versioned, minimal allocations.
• Embedded-friendly — a no_std-capable core codec; runs on constrained devices.
• Fast + scalable — cheap to parse, cheap to serve; scales from a microcontroller to a fleet.
• Locked down — small attack surface, modern crypto only, hardware-bound keys.
• auth + sign — deliberately minimal capability set (no issuance/wallet sprawl).

Holders

• Device key — hardware-backed key in a mobile / embedded secure element.
• Card reader — smartcard over PKCS#11.

Who uses it

Vetra's heimdal integrates tyr as a provider (heimdal-tyr) behind its IdentityProvider trait, alongside Freja, BankID, and frida.

Persistence & deployment — no relational database, ever

Same Store trait as frida (lives in edda, following nornir-warehouse-trait); never an RDBMS.

• Single server (the common case for tyr) — embedded redb / rocksdb; often the whole deployment on constrained hardware.
• Multi-server — scaled via Kubernetes; an append-only event log with per-event ACK is the source of truth, with skade (Iceberg lakehouse) as the sink for large transactional / audit volume.
• Networking — WireGuard node-to-node (natural via Cilium transparent WireGuard). Cilium guarantees the network (connectivity, policy, encryption), not application ACK — delivery/ACK is the event log's job.

Repo layout (planned)

spec/                the binary wire format + crypto suite (the product)
crates/
  tyr-proto/           no_std wire codec (frames, TLV, versioning)
  tyr-crypto/          signature/attestation suite (Ed25519 / ECDSA)
  tyr-server/          high-speed server
  tyr-client/          client (used by heimdal-tyr)
  tyr-embedded/        constrained-device profile

Crypto / credential primitives shared with frida are expected to live in edda/ rather than being duplicated.

Status

Design. No protocol code yet — see docs/PROTOCOL.md.

License

0BSD (Zero-Clause BSD) — maximally permissive, no attribution required. See LICENSE.