Post-quantum document signing

Smart documents with
cryptographic trust

Structure contracts into sections and clauses, route them through configurable approval workflows, and sign them with hybrid ECDSA-P256 + ML-DSA-65 signatures that remain verifiable beyond 2035.

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Open format · No vendor lock-in · Self-hostable

Product hub

Use the product, not just read about it

Launch documents, route reviews, enforce permissions, and sign open files — all from one unified product experience.

Create structured documents

Draft contracts with sections, clauses, and role-aware visibility rules instead of flat pages.

Open Create

Review & approve workflows

Move documents through configurable states and capture every decision in an audit trail.

Open Review

Sign, export, inspect

Apply hybrid signatures, export open `.smdx` packages, and verify every version independently.

Open Sign,

Better than PDF

A smart document platform, not a static file

Unlike PDFs, `.smdx` documents are structured, versioned, auditable, and cryptographically verifiable.

Flat PDF documents

• Fixed layout with no structured metadata
• No built-in workflow or role-aware access
• Hard to compare versions and prove authenticity
• Proprietary or locked format for review and audit

`.smdx` smart documents

• Structured sections, clauses, permissions, and workflow
• Hybrid cryptographic signatures and open audit trail
• Versioned, inspectable, and exportable as an open archive
• Role-based review and gated approvals built into the product

How it works

From draft to executed in three steps

Create & Draft

Structure your document into sections and clauses. Set visibility rules per clause — some roles see everything, others only what they need.

Review & Approve

Move the document through configurable workflow states. Admins and editors approve transitions; every state change is recorded in the audit log.

Sign & Execute

Apply hybrid ECDSA-P256 + ML-DSA-65 signatures to the content hash. The signed document is packaged as a portable, inspectable .smdx file.

Features

Everything a smart document needs

Built for legal teams, compliance workflows, and anyone who needs documents that are structured, auditable, and cryptographically verifiable.

Structured Clauses

Organise documents into sections and numbered clauses. Each clause carries its own content type, visibility rules, and effective version.

Role-based Permissions

Fine-grained access control per section. Assign view and edit rights by role — different parties see different parts of the same document.

Workflow Automation

Define custom state machines: draft → review → legal review → executed. Transitions require specific roles and optionally a cryptographic signature.

Post-quantum Signatures

Every signing event produces both an ECDSA-P256 and an ML-DSA-65 signature over the SHA-256 content hash. Verifiable well beyond 2035.

Immutable Audit Trail

Every create, update, status change, and signing event is appended to a tamper-evident audit log tied to the document.

Version History

Every save creates a new immutable version. Compare hashes, restore previous content, and mark specific versions as legally authoritative.

AI Clause Drafting

Describe what a clause should say and let the AI generate it in the correct format, with full awareness of the document type and section context.

Open .smdx Format

Documents are packaged as a standard ZIP archive containing JSON files. No vendor lock-in — open, inspect, and verify with any tool.

Security

Built for a post-quantum world

NIST IR 8547 prohibits classical cryptography after 2035. Every signature smdx produces includes both a classical ECDSA-P256 component and a post-quantum ML-DSA-65 (FIPS 204) component — so your documents remain verifiable regardless of which threat materialises first.

Hybrid post-quantum cryptography

ECDSA-P256 provides classical security today. ML-DSA-65 (FIPS 204) ensures signatures remain valid when quantum computers arrive.

Content-addressed integrity

Every document version carries a SHA-256 hash of its canonical serialisation. Signatures are over the hash — any tampering breaks verification.

Append-only audit log

Audit entries are never updated or deleted. The log records every actor, timestamp, and IP address for every significant event.

signature.sig

{
  "version": 3,
  "signer_id": "usr_...",
  "signed_at": "2026-03-07T14:00:00Z",
  "document_hash": "a3f9c2...",
  "algorithms": [
    "ECDSA-P256",
    "ML-DSA-65"
  ],
  "ecdsa_signature": "MEUC...",
  "ml_dsa_signature": "3082..."
}

The .smdx format is an open ZIP archive

Rename any .smdx file to .zip and open it with any archive tool. Inside you'll find manifest.json, content.json, permissions.json, workflow.json, per-version signature files, and an append-only audit.jsonl. No proprietary binary formats, no lock-in.

Try it free

Ready to create your first smart document?

Structured clauses, configurable workflows, hybrid post-quantum signatures, and an open portable format — all in one place.

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Smart documents with cryptographic trust