Sigil Protocol — Cryptographic Agreement Documentation

Overview

Cryptographic Integrity.

Sigil is a protocol that anchors human agreements into the Git Directed Acyclic Graph (DAG). It ensures that once a contract is signed, it cannot be altered without breaking the cryptographic chain.

Sigil is not a blockchain. It uses existing, proven technologies (Git and GPG) to provide absolute proof of content and consent at zero cost.

Features

Sovereign Proof.

Immutable

SHA-256 content hashing creates a permanent link between the document and its signatures.

GPG-Verified

Signatures are applied via your local GPG keychain, ensuring absolute proof of identity.

Platform Agnostic

Agreements are stored in Git. Sync via GitHub, GitLab, or your own private server.

Workflow

How it Works.

The Sigil lifecycle is designed for simplicity and cryptographic rigor.

Initialization

Choose a template and define the parties. Sigil generates a unique agreement dossier with a SHA-256 anchor.

$ sigil init --template freelance

Content Sealing

Once the content is finalized, it is hashed. This hash becomes the 'dossier ID' that all parties will sign.

Cryptographic Signing

Each party applies their GPG signature to the dossier ID. Sigil verifies the signature against the party's public key.

$ sigil sign a3f9c12e

Verification

At any point, any party can verify the integrity of the agreement and all signatures in milliseconds.

$ sigil verify a3f9c12e

CLI Reference

Command Line Interface.

sigil init Initialize a new agreement from a template

sigil sign Apply GPG signature to a specific dossier

sigil verify Validate hashes and signatures of a dossier

sigil list Show all agreements in the current registry

sigil help Display help information

Templates

Agreement Registry.

Sigil includes production-ready templates for the most common collaborative scenarios.

Freelance

Service delivery terms, IP transfer, and payment milestones.

CLA

Contributor License Agreements for open-source maintenance.

SLA

Standard service level agreements with response targets.

Public Registry

The Global Index.

A centralized index of decentralized agreements. Publicly verifiable, yet privately owned.

The public registry provides a way to timestamp and announce agreements to the world without revealing private details, using hashes as public pointers.

Comparison

The Protocol Advantage.

Metric	DocuSign / SaaS	Blockchain	Sigil Protocol
Unit Cost	$10 - $40 / mo	Variable Gas	$0.00
Infrastructure	Centralized Cloud	Global Nodes	Local Git / GPG
Offline Access	None	None	Native (Full)
Setup Time	Minutes	Hours / Days	30 Seconds

Specifications

Technical Reference.

SIGIL_V1_SPEC:
  HASH: SHA-256
  SIGN: OpenPGP (RSA-4096 / EdDSA)
  ARCH: Git Merkle Tree

INTEGRITY_CHECK:
  1. Calculate H(content)
  2. For each party P in Parties:
     Verify GPG_Sign(P.Sig, H(content)) == P.PubKey

Your signature,sealed in history.