History - early days

2014 - RDF Working Group

• JSON-LD v1.0
• JSON-LD API v1.0

2018-2020 - JSON-LD WG

• JSON-LD v1.1
• JSON-LD API v1.1
• JSON-LD Framing v1.1 (based on JSON-LD CG work)

History - current WG

2020-2023 (extended to 2025) - JSON-LD WG (maintenance mode)

• JSON-LD v1.1
• JSON-LD API v1.1
• JSON-LD Framing v1.1

2025-2027 - Recharter for new work

• JSON-LD, API, Framing v1.1 (maintain)
• JSON-LD, API, Framing v1.2 (new)
• CBOR-LD (new)
• YAML-LD (new)
• Notes
  • Multiple languages in JSON
  • Content hash provision in context URLs

CBOR-LD

Concise Binary Object Representation for Linked Data

Enables small data use cases: QR codes, Web of Things, etc.

• Compression ratios up to 40% better than gzip/zlib.
• Works on any compacted JSON-LD Document.
• Data Integrity signatures do not need to change.
• Extensible registry-based codec model.
• Application-specific codecs.
• "Practical" set of design trade-offs.

CBOR-LD - How?

• Reduce data duplication
• Build compression dictionary using @context (maps terms to numbers)
  • Globally linkable, industry-standard dictionary
  • No need to include the dictionary in the data

CBOR-LD Compression Table

CBOR-LD - Example

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vc-barcodes/v1",
    "https://w3id.org/utopia/v2"
  ],
  "type": [
    "VerifiableCredential",
    "OpticalBarcodeCredential"
  ],
  "credentialSubject": {
    "type": "AamvaDriversLicenseScannableInformation",
    "protectedComponentIndex": "uggAg"
  },
  "issuer": "did:key:...",
  "credentialStatus": {
    "type": "TerseBitstringStatusListEntry",
    "terseStatusListBaseUrl":
      "https://example.com/statuses/abc/status-lists",
    "terseStatusListIndex": 3851559041
  },
  "proof": {
    "type": "DataIntegrityProof",
    "verificationMethod": "did:key:...",
    "cryptosuite": "ecdsa-xi-2023",
    "proofPurpose": "assertionMethod",
    "proofValue": "z4…"
  }
}

1636(
  {
    1: [32768, 32769, 32770],
    157: [118, 164],
    184: {
      156: 166,
      206: 178,
      208: 3851559041
    },
    186: {
      156: 160,
      168: h'...'
    },
    190: 170,
    192: {
      156: 108,
      214: 4,
      224: 230,
      226: h'...',
      228: 172
    }
  }
)

Utopia Driver's License

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vc-barcodes/v1",
    "https://w3id.org/utopia/v2"
  ],
  "type": [
    "VerifiableCredential",
    "OpticalBarcodeCredential"
  ],
  "credentialSubject": {
    "type": "AamvaDriversLicenseScannableInformation",
    "protectedComponentIndex": "uggAg"
  },
  "issuer": "did:key:zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj",
  "credentialStatus": {
    "type": "TerseBitstringStatusListEntry",
    "terseStatusListBaseUrl": "https://sandbox.platform.veres.dev/statuses/z19rJ4oGrbFCqf3cNTVDHSbNd/status-lists",
    "terseStatusListIndex": 3851559041
  },
  "proof": {
    "type": "DataIntegrityProof",
    "verificationMethod": "did:key:zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj#zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj",
    "cryptosuite": "ecdsa-xi-2023",
    "proofPurpose": "assertionMethod",
    "proofValue": "z4g6G3dAZhhtPxPWgFvkiRv7krtCaeJxjokvL46fchAFCXEY3FeX2vn46MDgBaw779g1E1jswZJxxreZDCrtHg2qH"
  }
}

CBOR-LD encoding parameters

registryEntryId: 100
typeTable:
{
  "context":
    {
      "https://www.w3.org/ns/credentials/v2": 32768,
      "https://w3id.org/vc-barcodes/v1": 32769,
      "https://w3id.org/utopia/v2": 32770
    },

  "https://w3id.org/security#cryptosuiteString":
    {
      "ecdsa-rdfc-2019": 1,
      "ecdsa-sd-2023": 2,
      "eddsa-rdfc-2022": 3,
      "ecdsa-xi-2023": 4
    }
}

The term to ID map created by CBOR-LD when compressing a Utopia DL.

Map(97) {
  '@context' => 0,
  '@type' => 2,
  '@id' => 4,
  '@value' => 6,
  '@direction' => 8,
  '@graph' => 10,
  '@included' => 12,
  '@index' => 14,
  '@json' => 16,
  '@language' => 18,
  '@list' => 20,
  '@nest' => 22,
  '@reverse' => 24,
  '@base' => 26,
  '@container' => 28,
  '@default' => 30,
  '@embed' => 32,
  '@explicit' => 34,
  '@none' => 36,
  '@omitDefault' => 38,
  '@prefix' => 40,
  '@preserve' => 42,
  '@protected' => 44,
  '@requireAll' => 46,
  '@set' => 48,
  '@version' => 50,
  '@vocab' => 52,
  '...' => 100,
  'BitstringStatusList' => 102,
  'BitstringStatusListCredential' => 104,
  'BitstringStatusListEntry' => 106,
  'DataIntegrityProof' => 108,
  'EnvelopedVerifiableCredential' => 110,
  'EnvelopedVerifiablePresentation' => 112,
  'JsonSchema' => 114,
  'JsonSchemaCredential' => 116,
  'VerifiableCredential' => 118,
  'VerifiablePresentation' => 120,
  '_sd' => 122,
  '_sd_alg' => 124,
  'aud' => 126,
  'cnf' => 128,
  'description' => 130,
  'digestMultibase' => 132,
  'digestSRI' => 134,
  'exp' => 136,
  'iat' => 138,
  'id' => 140,
  'iss' => 142,
  'jku' => 144,
  'kid' => 146,
  'mediaType' => 148,
  'name' => 150,
  'nbf' => 152,
  'sub' => 154,
  'type' => 156,
  'x5u' => 158,
  'AamvaDriversLicenseScannableInformation' => 160,
  'MachineReadableZone' => 162,
  'OpticalBarcodeCredential' => 164,
  'TerseBitstringStatusListEntry' => 166,
  'protectedComponentIndex' => 168,
  'did:key:zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj' => 170,
  'did:key:zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj#zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj' => 172,
  'did:key:zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj' => 174,
  'did:key:zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj#zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj' => 176,
  'https://sandbox.platform.veres.dev/statuses/z19rJ4oGrbFCqf3cNTVDHSbNd/status-lists' => 178,
  'confidenceMethod' => 180,
  'credentialSchema' => 182,
  'credentialStatus' => 184,
  'credentialSubject' => 186,
  'evidence' => 188,
  'issuer' => 190,
  'proof' => 192,
  'refreshService' => 194,
  'relatedResource' => 196,
  'renderMethod' => 198,
  'termsOfUse' => 200,
  'validFrom' => 202,
  'validUntil' => 204,
  'terseStatusListBaseUrl' => 206,
  'terseStatusListIndex' => 208,
  'challenge' => 210,
  'created' => 212,
  'cryptosuite' => 214,
  'domain' => 216,
  'expires' => 218,
  'nonce' => 220,
  'previousProof' => 222,
  'proofPurpose' => 224,
  'proofValue' => 226,
  'verificationMethod' => 228,
  'assertionMethod' => 230,
  'authentication' => 232,
  'capabilityDelegation' => 234,
  'capabilityInvocation' => 236,
  'keyAgreement' => 238
}

A CBOR-LD compressed Utopia Driver's License VC

d90664a60183198000198001198002189d82187618a418b8a3189c18a618ce18b218d01ae592208118baa2189c18a018a8447582002018be18aa18c0a5189c186c18d60418e018e618e258417ab7c2e56b49e2cce62184ce26818e15a8b173164401b5d3bb93ffd6d2b5eb8f6ac0971502ae3dd49d17ec66528164034c912685b8111bc04cdc9ec13dbadd91cc18e418ac

diagnostic:
1636(
  {
    1: [32768, 32769, 32770],
    157: [118, 164],
    184: {156: 166, 206: 178, 208: 3851559041},
    186: {156: 160, 168: h'75820020'},
    190: 170,
    192: {
      156: 108,
      214: 4,
      224: 230,
      226: h'7AB7C2E56B49E2CCE62184CE26818E15A8B173164401B5D3BB93FFD6D2B5EB8F6AC0971502AE3DD49D17EC66528164034C912685B8111BC04CDC9EC13DBADD91CC',
      228: 172
    }
  }
)

A Verifiable Ccredential Barcode (a PDF417) of the Utopia driver's license.

CBOR-LD - Road Ahead

• Added to charter
• CBOR-LD 1.0 Working Draft
• Incorporate other work
  • CBOR-LD 1.0 - primary input from JSON-LD CG report
  • JSON-LD in CBOR - alternate approach previously explored
  • CBL: Compact Encoding of JSON-LD Data using CBOR and Bitmaps for Web of Things - community paper exploring alternative approaches
• Gather WG feedback/contribution/changes

YAML-LD

• Enable human-friendly Linked Data
  • Stay compatible with JSON-LD for easy transformation
• CCG developed spec
• Stable, but needs implementers
• WG picking up to formalize and build test suite

Multiple languages in JSON

• JSON-LD's Value Object pattern expressed "alone"
• encourage implementations of Value Objects
• encourage use in JSON documents that lack `@context`
• create a referenceable spec/note for other specs

Content hash fragment for context URLs

• #hash=
• optionally used by document loaders to verify equality of contexts
• not strictly about HTTP