Attestto Specifications

Identity standards and open specifications by the Attestto Identity Standards Group

DID Methods

`did:sns` — Full Specification Provisional

Complete DID Method Specification — Living DID architecture, CRUD operations, DID lifecycle, stateless resolution (no DID Log), post-quantum readiness, SAS integration

Assurance Models

IEAL — Identity Evidence Assurance Level Working Draft

Compositional model for classifying identity evidence across three axes (Capture, Algorithm, Storage) with composite levels L0 through L6. Aligned with NIST SP 800-63-4. Carrier-agnostic; embeddable in W3C VCs, COSE, PDF signatures, C2PA manifests.

IEAL — NIST SP 800-63-4 Crosswalk Informative

Axis-by-axis mapping of IEAL to NIST 800-63A, 800-63B, and 800-63C controls. Non-endorsement disclaimer applies — this crosswalk is not endorsed by NIST.

Content Envelopes

VCP — Verifiable Content Provenance Working Draft

Embed-first content envelope. Sign, verify, and carry provenance metadata inside PDF, JPEG, or a sidecar for any file. Ed25519 + JCS RFC 8785. Natural carrier for IEAL claims. Reference implementation: @attestto/vcp.

Resources

did:sns Implementation Report

186 tests across 4 services — W3C DID Core and DID Resolution conformance

VCP Implementation Report

8 tests against @attestto/vcp — sign/verify/inspect across sidecar, PDF, and JPEG carriers; tamper detection; re-sign idempotency; did:key mandatory support