Getting Started

General Information

The Liccium APIs facilitate the declaration of metadata and rights using cryptographic methods. This section provides an overview of key processes required for making API calls.

Overview

Liccium uses a combination of cryptographic signatures and structured metadata to ensure the integrity and authenticity of content declarations. Understanding these fundamental concepts is essential for successful API integration.

Key Concepts

Cryptographic Validation

All Liccium declarations use cryptographic signatures to ensure:

• Authenticity: Proof that the declaration comes from the claimed source
• Integrity: Assurance that the data hasn't been tampered with
• Non-repudiation: The ability to prove that a declaration was made by a specific entity

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Metadata Collection

To make a proper API call, a structured metadata object must be included in the HTTP request body.

Metadata Structure

The metadata object contains essential information required for a declaration, including:

• Internal Identifiers: Such as declarerId, iscc, and cid
• Cryptographic Signatures: For validation, namely signature and tsaSignature
• Declaration Metadata: The declarationMetadata section stores publicMetadata

Example Metadata Object

Code(json)
 
{
  "declarerId": "did:web:example.com",
  "iscc": "ISCC:KACYPXW445FNGZZ2",
  "cid": "QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG",
  "signature": "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9...",
  "tsaSignature": "base64-encoded-tsa-signature",
  "declarationMetadata": {
    "publicMetadata": {
      "title": "Example Content",
      "creator": "John Doe",
      "description": "Sample content description",
      "contentType": "text/plain",
      "license": "CC-BY-4.0"
    }
  }
}

Metadata Validation Process

1. Structure Validation

   The API validates that all required fields are present and properly formatted.

2. Signature Verification

   The cryptographic signature is verified against the declared identity using the associated cryptographic keypair.

3. Timestamp Validation

   The TSA signature is validated to ensure the declaration was made at the claimed time.

Best Practices

Next Steps

Now that you understand the basics of metadata collection, you can proceed to:

• Set up X.509 certification for cryptographic authentication
• Learn about certificate signatures for metadata validation
• Explore the Declaration API for making your first declaration