Verifiable Credential Barcodes v1.0

Abstract

This specification describes a mechanism to protect optical barcodes, such as those found on driver's licenses (PDF417) and travel documents (MRZ), using Verifiable Credentials [ VC-DATA-MODEL-2.0 ]. The Verifiable Credential representations are compact enough such that they fit in under 150 bytes and can thus be integrated with traditional two-dimensional barcodes that are printed on physical cards using standard printing processes.

Physical credentials, such as driver's licenses, passports, and travel credentials often include machine-readable data that can be used to quickly read the information from the document. This information is encoded in formats such as PDF417 [ ISO15438-2015 ], machine-readable zone (MRZ) [ ICAO9303-3 ], and other optically scannable codes that are formatted in one-dimensional or two-dimensional "bars"; thus the term "barcode". This information is often not protected from tampering and the readily available barcode generation and scanning libraries mean that it is fairly trivial for anyone to generate these barcodes.

It is, therefore, useful for an issuer of these barcodes to protect the information contained within the barcode as well as the entity that generated the barcode.

The Verifiable Credentials Data Model v2.0 specification provides a global standard for expressing credential information, such as those in a driver's license or travel document. The Verifiable Credential Data Integrity 1.0 specification provides a global standard for securing credential information. These two specifications, when combined, provide a means of protecting credentials from tampering, expressing authorship of the credential, and providing the current status of a credential in a privacy-protecting manner. These data formats, however, tend to be too large to express in an optical barcode.

The Compact Binary Object Representation for Linked Data v0.7 specification provides a means of compressing secured verifiable credentials to the point at which it becomes feasible to express the information as an optical barcode, or embedded within an optical barcode.

This specification describes a mechanism to protect optical barcodes, such as those found on driver's licenses (PDF417) and travel documents (MRZ), by using a verifiable credential [ VC-DATA-MODEL-2.0 ] to express information about the barcode, which is then secured using Data Integrity [ VC-DATA-INTEGRITY ], and then compressed using CBOR-LD [ CBOR-LD ]. The resulting verifiable credential representations are compact enough such that they fit in under 140 bytes and can thus be integrated with traditional two-dimensional barcodes that are printed on physical cards using standard printing processes. This adds tamper resistance to the barcode while optionally enhancing the barcode to provide information related to whether or not the physical document has been revoked or suspended by the issuer .

The following sections provide a few introductory examples of the ways this specification can be used to enhance existing physical credentials with digital signatures via verifiable credentials .

This section provides an example on how the technology in this specification can be utilized to secure the optical barcode on a driver's license that uses a PDF417 barcode. We start off with an example driver's license:

Picture of the front of a driver's license issued by the state of Utopia which contains a picture of the individual that is the subject of the driver's license along with their attributes, such as name, address, height, weight, eye color, and driving privileges. — Figure 1 The front of a driver's license issued by the state of Utopia.

The back of the driver's license contains a PDF417 barcode:

Picture of the back of a driver's license issued by the state of Utopia, containing usage rules as well as a PDF417 barcode that encodes much of the information displayed on the front of the card. — Figure 2 A back of a driver's license issued by the state of Utopia.

The PDF417 data contains information that is secured using the algorithms described in this specification. Namely, the PDF417 barcode contains a verifiable credential of the following form.

Example 1 : Verifiable Credential embedded in the PDF417 barcode

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vdl/v2",
    "https://w3id.org/vdl/utopia/v1"
  ],
  "type": [
    "VerifiableCredential",
    "OpticalBarcodeCredential"
  ],
  // the issuer value below is defined as a URL in the 'utopia/v1' context above
  "issuer": "did:web:dmv.utopia.example",
  "credentialStatus": {
    "type": "TerseBitstringStatusListEntry",
    "terseStatusListBaseUrl": "https://dmv.utopia.gov/statuses/12345/status-lists"
    "terseStatusListIndex": 123567890
  },
  "credentialSubject": {
    "type": "AamvaDriversLicenseScannableInformation",
    "protectedComponentIndex": "uP_BA"
  },
  "proof": {
    "type": "DataIntegrity",
    "cryptosuite": "ecdsa-xi-2023",
    // the public key below is defined as a URL in the 'utopia/v1' context above
    "verificationMethod": "did:web:dmv.utopia.example#key-1",
    "proofPurpose": "assertionMethod",
    "proofValue": "z4peo48uwK2EF4Fta8P...HzQMDYJ34r9gL"
  }
}

The verifiable credential above is then compressed using [ CBOR-LD ] to the following output (in CBOR Diagnostic Notation):

Example 2 : CBOR-LD compressed Verifiable Credential (145 bytes)

1281{
  1 => [ 32768, 32769, 32770],                           // @context
  155 => [ 116, 164 ],                                   // type
  192 => 174,                                            // issuer
  186 => { 154 => 166, 206 => 178, 208 => 1234567890 },  // credentialStatus
  188 => { 154 => 172, 180 => h'753FF040 },              // credentialSubject
  194 => {                                               // proof
    154 => 108,                                          // type
    214 => 4,                                            // cryptosuite
    224 => 230                                           // verificationMethod
    228 => 176,                                          // proofPurpose
    210 => Uint8Array(65) [ ... ],                       // proofValue
  }
}

This section provides an example on how the technology in this specification can be utilized to secure the machine-readable zone on an employment authorization document that uses a machine-readable zone (MRZ) on the back of the card. We start off with an example employment authorization document:

Picture of the front of an employment authorization document issued by the state of Utopia which contains a picture of the individual that is the subject of the document along with their attributes, such as name, address, height, weight, eye color, and employment privileges. — Figure 3 The front of an employment authorization document issued by the state of Utopia.

The back of the employment authorization document contains a machine-readable zone (MRZ) containing information designed to be read through optical character recognition:

Picture of the back of a employment authorization document issued by the state of Utopia, containing usage rules as well as machine-readable zone data that encodes much of the information displayed on the front of the card. — Figure 4 A back of an employment authorization document issued by the state of Utopia.

The MRZ data contains information that is secured using the algorithms described in this specification. Namely, the QR Code on the front of the card contains a verifiable credential of the following form, which secures the information on the back of the card.

Example 3 : Verifiable Credential expressed as a QR Code on the front of the card

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/citizenship/v2",
    "https://w3id.org/citizenship/utopia/v1"
  ],
  "type": [
    "VerifiableCredential",
    "OpticalBarcodeCredential"
  ],
  // the value below is defined as a URL in the 'utopia/v1' context above
  "issuer": "did:web:immigration.utopia.example",
  "credentialSubject": {
    "type": "MachineReadableZone",
  },
  "proof": {
    "type": "DataIntegrity",
    "cryptosuite": "ecdsa-xi-2023",
    // the value below is defined as a URL in the 'utopia/v1' context above
    "verificationMethod": "did:web:immigration.utopia.example#key-4"
    "proofPurpose": "assertionMethod",
    "proofValue": "z4peo48uwK2EF4Fta8P...HzQMDYJ34r9gL"
  }
}

Note : credentialStatus is optional

Readers might note that the credential above does not contain the optional credentialStatus property. Not every optical barcode credential issuer will have the requirement to have revocable optical barcode credentials.

The verifiable credential above is then compressed using [ CBOR-LD ] to the following output (in CBOR Diagnostic Notation):

Example 4 : CBOR-LD compressed Verifiable Credential (120 bytes)

{
  1 => [ 32768, 32769, 32770],           // @context
  155 => [ 116, 176 ],                   // type
  208 => 194,                          // issuer
  204 => { 154 => 192 },                 // credentialSubject
  210 => {                               // proof
    154 => 108,                          // type
    226 => 4,                        // cryptosuite
    236 => 242                         // verificationMethod
    240 => 196,                          // proofPurpose
    210 => Uint8Array(65) [ ... ],       // proofValue
  }
}

This section provides an example on how the technology in this specification can be utilized to secure a birth certificate as a verifiable credential , which is then expressed as a QR Code on the printed paper document:

A picture of the front of a birth certificate containing information such as the newborn's name, parent's names, information about the hospital, attendees, and person responsible for the registration. — Figure 5 The front of a birth certificate issued by a hospital in the state of Utopia.

The QR Code encodes the following verifiable credential . The details of the encoding are available as separate tabs below:

Example 5 : A verifiable credential expressing a short-form birth certificate

Credential
Binary
QR Code

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vital-records/v1rc1"
  ],
  "type": [
    "VerifiableCredential",
    "BirthCertificateCredential"
  ],
  "issuer": "https://hospital.example/issuer",
  "validFrom": "2023-09-30T11:30:00Z",
  "credentialSubject": {
    "type": "BirthCertificate",
    "certificationDate": "2023-09-30T13:44:52Z",
    "newborn": {
      "type": "Newborn",
      "name": "Tim Doe",
      "gender": "Male",
      "birthDate": "2023-10-05T14:29:00Z",
      "birthPlace": {
        "type": "PostalAddress",
        "streetAddress": "123 Hospital Rd",
        "addressLocality": "Utopia Town",
        "addressRegion": "Utopolis",
        "postalCode": "12345",
        "addressCountry": "Utopia"
      },
      "parent": [{
        "type": "Mother",
        "name": "Jane Doe",
        "namePriorToMarriage": "Jane Smith"
      }, {
        "type": "Father",
        "name": "John Doe"
      }]
    }
  }
}

application/vc+cborld

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

JSON-LD size: ~~1036~~ 1037 bytes
CBOR-LD size: 484 bytes
Compression : 53%

application/vc

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vital-records/v1rc1"
  ],
  "type": [
    "VerifiableCredential",
    "BirthCertificateCredential"
  ],
  "issuer": "https://hospital.example/issuer",
  "validFrom": "2023-09-30T11:30:00Z",
  "credentialSubject": {
    "type": "BirthCertificate",
    "certificationDate": "2023-09-30T13:44:52Z",
    "newborn": {
      "type": "Newborn",
      "name": "Tim Doe",
      "gender": "Male",
      "birthDate": "2023-10-05T14:29:00Z",
      "birthPlace": {
        "type": "PostalAddress",
        "streetAddress": "123 Hospital Rd",
        "addressLocality": "Utopia Town",
        "addressRegion": "Utopolis",
        "postalCode": "12345",
        "addressCountry": "Utopia"
      },
      "parent": [
        {
          "type": "Mother",
          "name": "Jane Doe",
          "namePriorToMarriage": "Jane Smith"
        },
        {
          "type": "Father",
          "name": "John Doe"
        }
      ]
    }
  },
  "proof": {
    "type": "DataIntegrityProof",
    "created": "2026-04-10T16:33:15Z",
    "verificationMethod": "did:key:zDnaeS3nL9GyPpdr3YoCg8Hpb3U5F8S8XZhrYnZYbvttqGGdR",

    "verificationMethod": "did:key:zDnaehu9u1f4ChH2UdYySo3WtoKAQoPjhawCALsXDLjfmEhGj",

    "cryptosuite": "ecdsa-rdfc-2019",
    "proofPurpose": "assertionMethod",
    "proofValue": "zZXD7UAPW17m1VhfRwQwtiFEXyiZaUmKMgbS6LHtHRmfWk4Tbv4vvEdLfGpPuSpKVYJ6X2bjHqxUaGJyG
B4yCzBs"

    "proofValue": "z5ZqGwTGwddp3bD1aN3TfN6mMJBYoyqbc8zQehd2yikrCbRBvoSRXJh6Yw7hKh3H6HDAbpfnRiZEFS6Sr
4oRwXzhw"

  }
}

CBOR-LD Diagnostic Mode

51997(
  [
    1,
    {
      1: [
        "https://www.w3.org/ns/credentials/v2",
        "https://w3id.org/vital-records/v1rc1"
      ],
      157: [
        118,
        164
      ],
      304: {
        156: 162,
        204: "2023-09-30T13:44:52Z",
        260: {
          150: "Tim Doe",
          156: 174,
          188: "2023-10-05T14:29:00Z",
          196: {
            156: 178,
            324: "Utopia",
            326: "Utopia Town",
            328: "Utopolis",
            330: "12345",
            332: "123 Hospital Rd"
          },
          226: "Male",
          267: [
            {
              150: "Jane Doe",
              156: 172,
              258: "Jane Smith"
            },
            {
              150: "John Doe",
              156: 170
            }
          ]
        }
      },
      308: [
        2,
        "hospital.example/issuer"
      ],
      310: {
        156: 108,
        336: 1775838795,
        338: "ecdsa-rdfc-2019",
        348: 354,
        350: h'7a1c0b740b366f2477618e6b832eb73abd1fb8a9ac36efe5409a1b2ca4a55d99a3fae2ac8b428f785d99b
4081c06135a44d77f36d3375f6d89f79fc5e03de2cd92',

        350: h'7ae4619fbdbbb3ab3250ba1e88b84ceac109dc3d209eab986e5ce5356c21bf2017a0e7cec9bca4c1f0599
70dcb0bd04860019b01b0c518347f117e28a3ba91055a',

        352: [
          1025,
          h'80240218087aee9640b1ac1450c98e076cd4837879517ee5dbecdb3b2386fc31f1c2d4'

          h'802403038da1191710cbd2ff13d5566a456b912f9638cedb5275d6df9a1da1154cafb8'

        ]
      },
      320: 1696073400
    }
  ])}

image/png

Verifiable Credential QR Code

QR Code version: 15
Error correction: Low

QR Code Content (text)

VC1-R0OR*W3H90Q80L8FA9DIWENPEJ/5S4F03F53F7*5$KE$:5CPEXPC  C1$CBWEAECCPEI.EL8FA9DIWENPEJ/553FPED7*5$K
E006-EDAECOX5Z C04EKVC006DB6DOC1534KG$-EOXKY60$RK0XJ6MK5%PNF6QF63W5CA79L6/SAJL6:Q66G7KG6B73KQ0*43$2D
YEDP34W3E053I53W531VE8466L6$963W5HX6-963G7PA7646OHBW%O053M53B735T86 A/3EMEDB73R+86 A/3EMED-3454EF-DD
70O8DHWES9EXVDZOEF70UZCQF60R6B73$T9*96%K6379WQE-EDAEC*34JTC-RS9Z9TVDB73LK1$RKT0J6I91/DP34W3E053G53B7
3XD06I91/D+34J$DAWE6MKT0JKI949DP34W3E053E53B73WS61E059DWQE-EDAEC.%5$9FQ$DTVDW:5ZQE%$E4JE+60+:K0XJ/TD
L70BF3FKRAM9N70W3EJPCHQEOX57VC9OCNF61A6B73.SB*70B73W-BMC80XE.YVB.GSWCJIIB0GNPVFYFY9U2K1DC4:L0:S3N2KC
LO5E5W8GPQ29M7E50ABG-OHCDMGUCQNOKI1M93/ H/XJXMADTQ0BNB7319CE73T70/L4%O4W13FOFY:IYKMPP2SLPA.0/%QGAFRD
AS2TK.TJL7-2H5E6GSOB73U485ZCA%0

L70BF3FKRAM9N70W3EJPCHQEOX57VC9OCNF61A6B73.SB*70B73W-BMC8RRRKRAY4KH21QYO*8TSIT2%Q0IBHGQ0:2VWGY1GG/4H
3U:UH5XNS+D%ID7JT3JB352R%R::KZJ5U+K7TFI2M4S9/WEU:MM%GB7319CE73T70/L4*O49K0LGK9-2NYP4BWT/QPJD.QDW0678
7VWRG+E2CSPX37V2T9MB73U485ZCA%0

JSON-LD Diagnostic Mode

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vital-records/v1rc1"
  ],
  "type": [
    "VerifiableCredential",
    "BirthCertificateCredential"
  ],
  "issuer": "https://hospital.example/issuer",
  "validFrom": "2023-09-30T11:30:00Z",
  "credentialSubject": {
    "type": "BirthCertificate",
    "certificationDate": "2023-09-30T13:44:52Z",
    "newborn": {
      "type": "Newborn",
      "name": "Tim Doe",
      "gender": "Male",
      "birthDate": "2023-10-05T14:29:00Z",
      "birthPlace": {
        "type": "PostalAddress",
        "streetAddress": "123 Hospital Rd",
        "addressLocality": "Utopia Town",
        "addressRegion": "Utopolis",
        "postalCode": "12345",
        "addressCountry": "Utopia"
      },
      "parent": [
        {
          "type": "Mother",
          "name": "Jane Doe",
          "namePriorToMarriage": "Jane Smith"
        },
        {
          "type": "Father",
          "name": "John Doe"
        }
      ]
    }
  },
  "proof": {
    "type": "DataIntegrityProof",
    "created": "2026-04-10T16:33:15Z",
    "verificationMethod": "did:key:zDnaeS3nL9GyPpdr3YoCg8Hpb3U5F8S8XZhrYnZYbvttqGGdR",

    "verificationMethod": "did:key:zDnaehu9u1f4ChH2UdYySo3WtoKAQoPjhawCALsXDLjfmEhGj",

    "cryptosuite": "ecdsa-rdfc-2019",
    "proofPurpose": "assertionMethod",
    "proofValue": "z3L9c3EVdcbEkrcR58jhCHa8wpDpmLHrxrJDRmfxUnxrL6AHSVZvj4yT1iKXDjAezN3XKPQt1aPZWbheU
gSCEycff"

    "proofValue": "z5NHn9KPGCveNgXSNcfvaHK7mbMQUa1cToARUebEGU5KoDtRH6VeThqcGiA2vzsr3MadnUUss1mteDYn1
XVfojJMy"

  }
}}

The following are the design goals of the technology in this specification:

Authenticity : a Verifiable Credential Barcode that successfully verifies is guaranteed to have originated from the claimed issuing authority.
Integrity : data on a document with a Verifiable Credential Barcode that successfully verifies is guaranteed to not have been modified as long as that data is secured by the barcode.
Real-time Status : verification of a Verifiable Credential Barcode proves that the document has not been revoked or suspended, and this is done without a privacy-invasive "phone home" to a source-of-truth database.
Simplicity : Verifiable Credential Barcodes reuse existing optical barcodes on documents (e.g., PDF417s on the back of AAMVA compliant Driver's Licenses) or add a new barcode in an easily consumable form (e.g., a QR code).
Conformance : the Verifiable Credential Barcodes technology stack is aligned with global standards and standards-track technologies.

Terminology used throughout this document is defined in the Terminology section of the Verifiable Credentials Data Model v2.0 specification as well as the Verifiable Credential Data Integrity 1.0 specification.

Unicode code point order: This refers to determining the order of two Unicode strings ( A and B ), using Unicode Codepoint Collation , as defined in [ XPATH-FUNCTIONS ], which defines a total ordering of strings comparing code points. Note that for UTF-8 encoded strings, comparing the byte sequences gives the same result as code point order .

As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.

The key words MUST , RECOMMENDED , REQUIRED , and SHOULD in this document are to be interpreted as described in BCP 14 [ RFC2119 ] [ RFC8174 ] when, and only when, they appear in all capitals, as shown here.

A conforming document is any concrete expression of the data model that complies with the normative statements in this specification. Specifically, all relevant normative statements in Sections 2. Data Model and 3. Algorithms of this document MUST be enforced.

A conforming processor is any algorithm realized as software and/or hardware that generates or consumes a conforming document . Conforming processors MUST produce errors when non-conforming documents are consumed.

This document contains examples of JSON and JSON-LD data. Some of these examples are invalid JSON, as they include features such as inline comments ( // ) explaining certain portions and ellipses ( ... ) indicating the omission of information that is irrelevant to the example. Such parts need to be removed if implementers want to treat the examples as valid JSON or JSON-LD.

The following sections outline the data model that is used by this specification to express verifiable credentials that secure optically printed information such as barcodes and machine-readable zones on travel documents.

An OpticalBarcodeCredential is used to secure the contents of an optical barcode in a way that provides 1) authorship information , 2) tamper resistance, and 3) optionally, revocation and suspension status. In other words, the credential can tell you who issued the optical barcode, if the optical barcode has been tampered with since it was first issued, and whether or not the issuer of the optical barcode still warrants that the document is still valid or not. These features provide significant anti-fraud protections for physical documents.

The credentialSubject of an OpticalBarcodeCredential is either of type AamvaDriversLicenseScannableInformation or a MachineReadableZone. A AamvaDriversLicenseScannableInformation signifies that the verifiable credential secures the PDF417 barcode on the physical document as well as the information expressed in the verifiable credential . A MachineReadableZone signifies that the verifiable credential secures the machine-readable zone on the physical document as well as the information expressed in the verifiable credential .

If an OpticalBarcodeCredential is of type AamvaDriversLicenseScannableInformation, there is a REQUIRED additional field protectedComponentIndex that contains information about which fields in the PDF417 are digitally signed. protectedComponentIndex MUST be a three byte/24 bit value that is multibase-base64url encoded for a total of 5 characters in the JSON-LD credential. There are 22 mandatory fields in an AAMVA compliant driver's license PDF417 [ aamva-dl-id-card-design-standard ], and the first 22 bits of the protectedComponentIndex value correspond to these fields. Each AAMVA mandatory field begins with a three character element ID (e.g., DBA for document expiration date). To construct a mapping between bits in the protectedComponentIndex value and these fields, sort these element IDs according to Unicode code point order. Then, if a bit in position i of protectedComponentIndex is 1, the AAMVA mandatory field in position i of the sorted element IDs is protected by the digital signature. The last two bits in protectedComponentIndex MUST be 0. For more information, see Section 3.2.4.4 Create opticalDataBytes .

In order to achieve as much compression as possible, it is RECOMMENDED that the issuer and verificationMethod fields utilize terms from a JSON-LD Context, which can then be compressed down to a few bytes due to CBOR-LD's semantic compression mechanism.

An example of an optical barcode credential that utilizes the properties specified in this section is provided below:

Example 6 : An OpticalBarcodeCredential utilizing a TerseBitstringStatusListEntry

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vdl/v2",
    "https://w3id.org/vdl/utopia/v1"
  ],
  "type": [
    "VerifiableCredential",
    "OpticalBarcodeCredential"
  ],
  "issuer": "did:web:dmv.utopia.example",
  "credentialStatus": {
    "type": "TerseBitstringStatusListEntry",
    "terseStatusListBaseUrl": "dmv.utopia.gov/statuses/12345/status-lists"
    "terseStatusListIndex": 123567890
  },
  "credentialSubject": {
    "type": "AamvaDriversLicenseScannableInformation",
    "protectedComponentIndex": "uP_BA"
  }
}

A TerseBitstringStatusListEntry is a compact representation of a BitstringStatusListEntry as defined in the Bitstring Status List v1.0 specification.

An object of type TerseBitstringStatusListEntry MUST have two additional properties:

terseStatusListBaseUrl, which identifies the location of the status lists associated with this credential. terseStatusListBaseUrl MUST be a URL [ URL ].
terseStatusListIndex, which specifies an individual status at the above URL. terseStatusListIndex MUST be representable as a 32 bit unsigned integer.

To process a TerseBitstringStatusListEntry, apply the algorithm in Section 3.2.3 Convert Status List Entries to convert it to a BitstringStatusListEntry, then process it as in Bitstring Status List v1.0 .

Implementers need to set a value listLength for the length of an individual status list. This then yields a number of status lists listCount = 2^32 / listLength for a 32-bit terseStatusListIndex. listLength is needed to convert from a TerseBitstringStatusListEntry to a BitstringStatusListEntry. Noting that some values of listLength will harm the privacy-preserving properties of these status lists, implementations MUST use listLength = 2^26 and listCount = 2^6.

While the credentials in this specification use CBOR-LD to efficiently encode verifiable credentials in a binary format, binary data is often inefficient or incompatible to turn into standard barcode image formats directly. To that end, we provide requirements here for implementations.

It is RECOMMENDED that implementers character-encode CBOR-LD encoded AamvaDriversLicenseScannableInformation credentials as base64url before encoding them in a PDF417.

It is REQUIRED that implementers re-encode CBOR-LD encoded MachineReadableZone credentials as base45-multibase with the string 'VC1-' prepended before encoding them in a QR code.

The following section describes algorithms for adding and verifying digital proofs that protect optical information, such as barcodes and machine-readable zones, on physical media, such as driver's licenses and travel documents.

This section contains algorithms that are general to encoding and decoding verifiable credentials .

This specification requires that an application-specific compression table is provided to a CBOR-LD processor when encoding and decoding verifiable credentials . A registry for all context URLs for various issuers is provided as a comma-separated value file and can be updated and modified via change requests to the file on an append-only and first-come-first-served basis. Implementations SHOULD retrieve and utilize the latest file on a monthly basis to ensure that compression and decompression supports the latest values.

The following algorithm specifies how to encode a verifiable credential into a text string that can be expressed in a QR Code. Required inputs are a verifiable credential ( map inputDocument ), and a set of options ( map options ). The output is an encoded verifiable credential ( string ) or an error. Whenever this algorithm encodes strings, it MUST use UTF-8 encoding.

Let typeTable be the value of options. typeTable.
Let registryEntryId be the value of options. registryEntryId.
Let cborldDocument be the result of the JSON-LD to CBOR-LD Compression Algorithm , passing inputDocument, typeTable, and registryEntryId as inputs. If an encoding error occurs, an error MUST be raised.
Let base45Value be the result of the Base Encoding algorithm, passing cborldDocument as bytes, the integer 45 as targetBase, and 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./: as the baseAlphabet.
Let qrCodeText be the result of concatenating the following values: VC1-, R (the Multibase prefix for base45), and base45Value.
Return qrCodeText as the encoded verifiable credential , which can then be provided to any QR Code library as text to be encoded as a QR Code image.

The following algorithm specifies how to decode a verifiable credential that has been encoded into a QR Code. Required inputs are a text string ( string inputDocument ), and a set of options ( map options ). The output is a verifiable credential ( map ) or an error. Whenever this algorithm encodes strings, it MUST use UTF-8 encoding.

Ensure that the inputDocument starts with the text VC1-R. If it does not an error MUST be raised.
Let base45Value be inputDocument with the first five characters ( VC1-R ) removed.
Let cborldDocument be the result of the Base Decoding algorithm, passing base45Value as sourceEncoding, the integer 45 as sourceBase, and 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./: as the baseAlphabet.
Let jsonldDocument be the result of CBOR-LD to JSON-LD Decompression Algorithm , passing cborldDocument as the input. If a decoding error occurs, an error MUST be raised.
Return jsonldDocument as the decoded verifiable credential .

This section contains algorithms that are specific to encoding and decoding verifiable credentials that have a type of OpticalBarcodeCredential.

Set opticalData to the data in the optical barcode to be secured.
Set statusListEntryVerbose to the BitstringStatusListCredential (as defined in the Bitstring Status List v1.0 specification) that the issuer wishes to add to the OpticalBarcodeCredential.
Let statusListEntryTerse be an empty map . Set statusListEntryTerse. type to TerseBitstringStatusListEntry and statusListEntryTerse. index to the integer representation of statusListEntryVerbose. statusListIndex.
Set issuerUrl to the URL the issuer wishes to use for credential verification.
Set unsignedStatus to an OpticalBarcodeCredential with unsignedStatus. issuer set to issuerUrl and unsignedStatus. credentialStatus set to statusListEntryTerse.
Set signedStatusVc to the result of using the algorithm in 3.2.4.1 Add Proof (ecdsa-xi-2023) to sign opticalData and unsignedStatus.
Encode signedStatusVc using CBOR-LD [ CBOR-LD ] and add it to the designated area of the opticalData.
Generate the machine-readable credential (MRZ or PDF417).

Set securedDocument to the data in the PDF417 or MRZ.
Set verificationResult to the result of applying the algorithm in Section 3.2.4.2 Verify Proof (ecdsa-xi-2023) to securedDocument.
Set credential to the OpticalBarcodeCredential in securedDocument.
Set statusListEntry to the result of applying the algorithm in Section 3.2.3 Convert Status List Entries to credential.
Set statusResult to the result of applying the algorithm in Bitstring Status List v1.0: Validate Algorithm to statusListEntry.
Return ( validationResult, statusResult ).

The algorithm in this section is used to convert the TerseBitstringStatusListEntry to a BitstringStatusListEntry, which is used after verification has been performed on the verifiable credential , during the validation process.

After verifiable credential verification has been performed, the algorithm takes an OpticalBarcodeCredential verifiable credential ( struct vc ), an integer listLength containing the number of entries in the BitstringStatusListCredential associated with vc, and a string statusPurpose (e.g., 'revocation', 'suspension'...) as input and returns a 'BitstringStatusListEntry' object.

Set result to be an empty map .
Set listIndex to vc. credentialStatus. terseStatusListIndex / listLength rounded down to the next lowest integer (i.e., apply the floor() operation).
Set statusListIndex to vc. credentialStatus. terseStatusListIndex % listLength.
Set result. statusListCredential to the concatenation of the following values: vc. credentialStatus. terseStatusListBaseUrl, '/', statusPurpose, '/', listIndex.
Set result. type to 'BitstringStatusListEntry'.
Set result. statusListIndex to statusListIndex.
Set result. statusPurpose to statusPurpose.
Return result.

result can be used as input to the validation algorithm in the Bitstring Status List v1.0 specification.

Note : Status lists are optional

Implementers are advised that not all issuers will publish status list information for their verifiable credentials . Some issuers might require authorization before allowing a verifier to access a status list credential.

The ecdsa-xi-2023 cryptosuite is effectively the ecdsa-rdfc-2019 algorithm [ VC-DI-ECDSA ] with an added step that takes some "extra information" (xi) as input, such as the original optical barcode data, and includes that data in the information that is protected by the digital signature. The algorithms in this section detail how such a signature is created and verified.

To generate a proof, the algorithm in Section 4.1: Add Proof in the Data Integrity [ VC-DATA-INTEGRITY ] specification MUST be executed. For that algorithm, the cryptographic suite specific transformation algorithm is defined in the Transformation (ecdsa-rdfc-2019) section of the Data Integrity ECDSA Cryptosuites v1.0 , the hashing algorithm is defined in Section 3.2.4.3 Hashing (ecdsa-xi-2023) , and the proof serialization algorithm is defined in the Proof Serialization (ecdsa-rdfc-2019) section of the Data Integrity ECDSA Cryptosuites v1.0 .

To verify a proof, the algorithm in Section 4.2: Verify Proof in the Data Integrity [ VC-DATA-INTEGRITY ] specification MUST be executed. For that algorithm, the cryptographic suite specific transformation algorithm is defined in the Transformation (ecdsa-rdfc-2019) section of the Data Integrity ECDSA Cryptosuites v1.0 , the hashing algorithm is defined in Section 3.2.4.3 Hashing (ecdsa-xi-2023) , and the proof verification algorithm is defined in the Proof Verification (ecdsa-rdfc-2019) section of the Data Integrity ECDSA Cryptosuites v1.0 .

The hashing algorithm is what is defined in the Hashing (ecdsa-rdfc-2019) section of the Data Integrity ECDSA Cryptosuites v1.0 specification with the addition of the hashing of the optical data, as described below. It is presumed that the implementation makes the machine-readable optical data (PDF417 or MRZ data) available to this hashing algorithm.

The required inputs to this algorithm are a transformed data document ( transformedDocument ), a canonical proof configuration ( canonicalProofConfig ), and the optical data ( opticalDataBytes ). A single hash data value represented as series of bytes is produced as output.

The hashing algorithm is what is defined in the Hashing (ecdsa-rdfc-2019) section of the Data Integrity ECDSA Cryptosuites v1.0 with step 3 replaced with the following two steps:

Let opticalDataHash be the result of applying the same hash algorithm that was applied to hashData to the opticalDataBytes value.
Let hashData be the result of joining proofConfigHash (the first hash), transformedDocumentHash (the second hash), and opticalDataHash (the third hash).

Set dataToCanonicalize to an empty array.
Set bitfieldDecoded to be first 22 bits of the length 24 bitstring resulting from decoding credentialSubject.protectedComponentIndex from multibase-base64url to binary.
Set fieldsAlphabetized to be an array containing the 22 AAMVA mandatory PDF417 Element IDs [ aamva-dl-id-card-design-standard ] sorted in Unicode code point order (i.e., ['DAC', 'DAD' ... 'DDG']).
For each bit with value 1 in bitfieldDecoded:
1. Set the string fieldName to fieldsAlphabetized [ i ], where i is the index of the bit in bitfieldDecoded.
2. Set the string fieldData to the data that will be in the PDF417 associated with that field name.
3. Concatenate fieldData to the end of fieldName, concatenate a newline character ( \n, U+000A ) to the end, and append the result to dataToCanonicalize.
Set canonicalizedData to the result of sorting dataToCanonicalize in Unicode code point order and then applying a join operation to create a single string from the array.
Hash canonicalizedData and return the result.

Set dataToCanonicalize to an empty array.
For each line in the Machine Readable Zone on the credential:
1. Set mrzLine to a string containing the data in that line.
2. Append a newline character to the end of mrzLine and append mrzLine to dataToCanonicalize.
Set canonicalizedData to the result of ordering the elements of dataToCanonicalize to match the order they appear on the credential and then applying a join operation to create a single string from the array.
Hash canonicalizedData and return the result.

The proof configuration algorithm is what is defined in the Proof Configuration (ecdsa-rdfc-2019) section of the Data Integrity ECDSA Cryptosuites v1.0 with step 4 replaced with the following step:

If options. type is not set to DataIntegrityProof and proofConfig. cryptosuite is not set to ecdsa-xi-2023, an INVALID_PROOF_CONFIGURATION error MUST be raised.

This section is non-normative.

Before reading this section, readers are urged to familiarize themselves with general security advice provided in the Security Considerations section of the Data Integrity specification as well as the specific security advice provided in the Security Considerations section of the ECDSA Cryptosuites specification .

In the following sections, we review these important points and direct the reader to additional information.

One attack vector against OpticalBarcodeCredentials involves duplicating an optical barcode containing a digital signature for use on a fraudulent document. While a duplicated barcode will pass signature validation like the original, this attack is mitigated by the document verifier checking the following three things: the signed data matches the data visible on the document, the signed data matches the physical attributes of the user, and the visible data matches the physical attributes of the user. When these three are all equivalent, the only way the OpticalBarcodeCredential could be a duplicate is if the fraudulent document creator had access to a real OpticalBarcodeCredential where the signed physical attributes fully overlapped with those of the user of the fraudulent document. The low likelihood of an undetected stolen OpticalBarcodeCredential existing that completely matches the appearance of an arbitrary person makes this attack unlikely to succeed.

It is possible that in some cases the digital signature cannot be created over the entirety of the existing optical data. For example, consider a case where a serial number is injected by a physical credential manufacturer such that it is not known to the issuer at signature time. In this case, the verifier will assume that any data not digitally signed could have been changed in the optical barcode without impacting the OpticalBarcodeCredential's ability to successfully validate.

When checking that data from the optical barcode matches the data visible on the document as well as the characteristics of the document holder, implementers are advised to only use the fields that are digitally signed. Verifiers are advised to only use fields protected by the digital signature, no matter how commonly the other fields are used for fraud detection on unsigned documents. For example, if eye color and hair color are protected by the signature, but the holder 's portrait is not, verifiers are advised to emphasize the eye color and hair color when attempting to detect fraud over the portrait.

Implementers of software used by verifiers are advised to only display card data that has been secured via digital signature during the verification process. Displaying unsigned data, which could have been tampered with, could interfere with fraud detection.

Verifiers are advised to always use trusted programs and interfaces to check the validity of the OpticalBarcodeCredential. Use of untrusted software to verify a document could result in a fraudulent credential being accepted, or a genuine credential being stolen.

This section is non-normative.

This section contains examples of Verifiable Credential Barcodes as well as step-by-step processes for how they are generated and how they are verified.

In this section we will analyze two running examples: a VCB securing the MRZ of a Utopia Employment Authorization Document, and a VCB securing the PDF417 of a Utopia Driver's License.

We start with the data that will be signed by the VCB (i.e., mandatory AAMVA fields from a PDF417):

Example 7 : Fields from a PDF417 that might appear on a Utopia Driver's License

DACJOHN
DADNONE
DAG123 MAIN ST
DAIANYVILLE
DAJUTO
DAKF87P20000
DAQF987654321
DAU069 IN
DAYBRO
DBA04192030
DBB04191988
DBC1
DBD01012024
DCAC
DCBNONE
DCDNONE
DCFUTODOCDISCRIM
DCGUTO
DCSSMITH
DDEN
DDFN
DDGN

Assume for simplicity that the only data in the PDF417 that you want to sign is first name ( DAC ), last name ( DCS ), and license number ( DAQ ). The bitstring value for use in protectedComponentIndex is then 100000100000000000100000, and the value of protectedComponentIndex is "uggAg". Applying 3.2.4.4 Create opticalDataBytes , we get

Example 8 : Data from the canonicalization of a Utopia Driver's License

canonicalizedData = 'DACJOHN\nDAQ987654321\nDCSSMITH\n'
opticalDataBytes:
  [188,  38, 200, 146, 227, 213,  90, 250,
  50,  18, 126, 254,  47, 177,  91,  23,
  64, 129, 104, 223, 136,  81, 116,  67,
136,
125,
137,
165,
117,
63,
152,
207]

We can now use this hash value with 3.2.4.3 Hashing (ecdsa-xi-2023) to sign the VC. Executing 3.2.1 Encode OpticalBarcodeCredential with a BitstringStatusListCredential, we get the following JSON-LD VC:

Example 9 : A JSON-LD VC for a Utopia Driver's License VCB

{
  "@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"
  }
}

We can now apply CBOR-LD compression to this VC. Here, we use the newest version of CBOR-LD; however, at the end of the section, we provide VCBs encoded using older versions of CBOR-LD for interoperability testing with CBOR-LD implementations that are not up to date.

For this specification, we have reserved the CBOR-LD registry entry with value 100 (i.e., these payloads will begin with tag 0x0664 ). The parameters to encode using CBOR-LD, which can be found in the registry in the CBOR-LD specification, are then as follows:

Example 10 : 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 mapping that should result from processing the contexts and assigning integer values to context terms is as follows:

Example 11 : 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
}

For more information on the above, see 6.3 Implementation Notes .

This results in the following encoded credential:

Example 12 : A CBOR-LD compressed Utopia Driver's License VC

D9CB1D821864A60183198000198001198002189D82187618A418B8A3189C18A618CE18B218D01AE592208118BAA2189C18A018A8447582002018BE18AA18C0A5189C186C18D60418E018E618E258417AB7C2E56B49E2CCE62184CE26818E15A8B173164401B5D3BB93FFD6D2B5EB8F6AC0971502AE3DD49D17EC66528164034C912685B8111BC04CDC9EC13DBADD91CC18E418AC
diagnostic:
51997([
  100,
  {
    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
    }
  }
])

Encoding the Driver's License CBOR-LD as base64url and inserting the result into the PDF417 bytes in the 'ZZA' field in the 'ZZ' subfile:

Example 13 : Bytes from a PDF417 including an encoded Utopia Driver's License VCB

bytes(@\n\x1e\rANSI
000000090002DL00410234ZZ02750202DLDAQF987654321\nDCSSMITH\nDDEN\nDACJOHN\nDDFN\nDADNONE\nDDGN\nDCAC\nDCBNONE\nDCDNONE\nDBD01012024\nDBB04191988\nDBA04192030\nDBC1\nDAU069
IN\nDAYBRO\nDAG123
MAIN
ST\nDAIANYVILLE\nDAJUTO\nDAKF87P20000
\nDCFUTODOCDISCRIM\nDCGUTO\nDAW158\nDCK1234567890\nDDAN\rZZZZA2csdghhkpgGDGYAAGYABGYACGJ2CGHYYpBi4oxicGKYYzhiyGNAa5ZIggRi6ohicGKAYqER1ggAgGL4YqhjApRicGGwY1gQY4BjmGOJYQXq3wuVrSeLM5iGEziaBjhWosXMWRAG107uT/9bSteuPasCXFQKuPdSdF+xmUoFkA0yRJoW4ERvATNyewT263ZHMGOQYrA==\r)

The above can now be turned into a barcode:

Figure 6 A VCB from a Utopia driver's license.

We start with the data that will be signed by the VCB (i.e an MRZ):

Example 14 : A Machine-Readable Zone that might appear on a Utopia EAD

IAUTO0000007010SRC0000000701<<
8804192M2601058NOT<<<<<<<<<<<5
SMITH<<JOHN<<<<<<<<<<<<<<<<<<<

For the EAD, we apply 3.2.4.4 Create opticalDataBytes :

Example 15 : Data from the canonicalization of a Utopia EAD MRZ

canonicalizedData =
  'IAUTO0000007010SRC0000000701<<\n' +
  '8804192M2601058NOT<<<<<<<<<<<5\n' +
  'SMITH<<JOHN<<<<<<<<<<<<<<<<<<<\n'
opticalDataBytes:
[8, 198, 126, 183,  25, 160, 166, 112,
254, 184, 189,  47, 225, 211, 125, 210,
132, 137, 45,  86, 169,  28,  57, 165,
46,
253,
9,
137,
145,
42,
192,
113]

We can now use this hash value with 3.2.4.3 Hashing (ecdsa-xi-2023) to sign the VC. Executing 3.2.1 Encode OpticalBarcodeCredential without adding status, we get the following JSON-LD VC:

Example 16 : A JSON-LD VC for a Utopia EAD VCB

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vc-barcodes/v1",
    "https://w3id.org/utopia/v2"
  ],
  "type": [
    "VerifiableCredential",
    "OpticalBarcodeCredential"
  ],
  "credentialSubject": {
    "type": "MachineReadableZone"
  },
  "issuer": "did:key:zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj",
  "proof": {
    "type": "DataIntegrityProof",
    "verificationMethod": "did:key:zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj#zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj",
    "cryptosuite": "ecdsa-xi-2023",
    "proofPurpose": "assertionMethod",
    "proofValue": "z4B8AQgjwgsEdcPEZkrkK2mTVKn7qufoDgDkv9Qitf9tjxQPMoJaGdXwDrThjp7LUdvzsDJ7UwYu6Xpm9fjbo6QnJ"
  }
}

We can now apply CBOR-LD compression to this VC. Here we use the newest version of CBOR-LD, however at the end of the section we provide VCBs encoded using older versions of CBOR-LD for interoperability testing with CBOR-LD implementations that are not up to date.

For this specficiation, we have reserved the CBOR-LD registry entry with value 100 (i.e., these payloads will begin with tag 0x0664 ). The parameters to encode using CBOR-LD, which can be found in the registry in the CBOR-LD specification, are then as follows:

Example 17 : 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 mapping that should result from processing the contexts and assigning integer values to context terms is as follows:

Example 18 : The term-to-ID map created by CBOR-LD when compressing a Utopia EAD

Map(95) {
  '@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,
  'challenge' => 206,
  'created' => 208,
  'cryptosuite' => 210,
  'domain' => 212,
  'expires' => 214,
  'nonce' => 216,
  'previousProof' => 218,
  'proofPurpose' => 220,
  'proofValue' => 222,
  'verificationMethod' => 224,
  'assertionMethod' => 226,
  'authentication' => 228,
  'capabilityDelegation' => 230,
  'capabilityInvocation' => 232,
  'keyAgreement' => 234
}

For more information on the above, see 6.3 Implementation Notes .

Compression then results in the following encoded credential:

Example 19 : A CBOR-LD compressed Utopia EAD VC

D9CB1D821864A50183198000198001198002189D82187618A418BAA1189C18A218BE18AE18C0A5189C186C18D20418DC18E218DE58417A9EC7F688F60CAA8C757592250B3F6D6E18419941F186E1ED4245770E687502D51D01CD2C2295E4338178A51A35C2F044A85598E15DB9AEF00261BC5C95A744E718E018B0
diagnostic:
51997([
  100,
  {
    1: [32768, 32769, 32770],
    157: [118, 164],
    186: {156: 162},
    190: 174,
    192: {
      156: 108,
      210: 4,
      220: 226,
      222: h'7A9EC7F688F60CAA8C757592250B3F6D6E18419941F186E1ED4245770E687502D51D01CD2C2295E4338178A51A35C2F044A85598E15DB9AEF00261BC5C95A744E7',
      224: 176
    }
  }
])

Encoding the EAD CBOR-LD as base45-multibase and prepending 'VC1-':

Example 20 : An encoded Utopia EAD VCB

VC1-R0OR*W3Y33V%K
PG88G3A3B60A8G1534KG$-ENXKWQN053653Y53I53
539*K0XJ.TDYOQJ63P63L6337BPMFPCP7EH2R12YH%%EXU4$08E-D8D86F8E2HX:T8Z8/
1TZEH.QBA03Q5W.I0N6FBF4E3:SOQU8.
A3MSELNHFU0GCVVBP6LU9T%ES-3

The above can now be turned into a QR code:

For use with the following MRZ:

Figure 8 An MRZ on a Utopia Employment Authorization Document.

We now apply the reverse process to verify.

We first read the data from the PDF417:

Example 21 : Bytes from a PDF417 including an encoded Utopia Driver's License VCB

bytes(@\n\x1e\rANSI
000000090002DL00410234ZZ02750202DLDAQF987654321\nDCSSMITH\nDDEN\nDACJOHN\nDDFN\nDADNONE\nDDGN\nDCAC\nDCBNONE\nDCDNONE\nDBD01012024\nDBB04191988\nDBA04192030\nDBC1\nDAU069
IN\nDAYBRO\nDAG123
MAIN
ST\nDAIANYVILLE\nDAJUTO\nDAKF87P20000
\nDCFUTODOCDISCRIM\nDCGUTO\nDAW158\nDCK1234567890\nDDAN\rZZZZA2QZkpgGDGYAAGYABGYACGJ2CGHYYpBi4oxicGKYYzhiyGNAa5ZIggRi6ohicGKAYqER1ggAgGL4YqhjApRicGGwY1gQY4BjmGOJYQXq3wuVrSeLM5iGEziaBjhWosXMWRAG107uT_9bSteuPasCXFQKuPdSdF-xmUoFkA0yRJoW4ERvATNyewT263ZHMGOQYrA==\r)

We extract the data in field 'ZZA' in subfile 'ZZ', undoing the base encoding:

Example 22 : A Utopia Driver's License VC compressed with CBOR-LD

d90664a60183198000198001198002189d82187618a418b8a3189c18a618ce18b218d01ae592208118baa2189c18a018a8447582002018be18aa18c0a5189c186c18d60418e018e618e258417ab7c2e56b49e2cce62184ce26818e15a8b173164401b5d3bb93ffd6d2b5eb8f6ac0971502ae3dd49d17ec66528164034c912685b8111bc04cdc9ec13dbadd91cc18e418ac

We now decompress with CBOR-LD to get the original JSON-LD VC to be verified. Again, the parameters are associated with CBOR-LD registry entry 100.

Example 23 : CBOR-LD decoding parameters

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 ID-to-term mapping that should result from processing the contexts and assigning integer values to context terms is as follows. Note that this is the inverse of the map constructed during compression.

Example 24 : The ID-to-term map created by CBOR-LD when decompressing a Utopia DL

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

For more information on the above, see 6.3 Implementation Notes .

Decompression then yields the following credential:

Example 25 : A JSON-LD VC for a Utopia Driver's License VCB

{
  "@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"
  }
}

We apply 3.2.4.4 Create opticalDataBytes to create the opticalDataBytes that ecdsa-xi-2023 requires, using the scanned PDF417 and protectedComponentIndex as input.

Example 26 : A canonicalization of a Utopia Driver's License PDF417

canonicalizedData = 'DACJOHN\nDAQ987654321\nDCSSMITH\n'
opticalDataBytes:
  [188,  38, 200, 146, 227, 213,  90, 250,
  50,  18, 126, 254,  47, 177,  91,  23,
  64, 129, 104, 223, 136,  81, 116,  67,
136,
125,
137,
165,
117,
63,
152,
207]

We then apply 3.2.4.3 Hashing (ecdsa-xi-2023) and 3.2.4.2 Verify Proof (ecdsa-xi-2023) to verify the credential.

The last step is to check the status information on the Driver's License credential. We apply 3.2.3 Convert Status List Entries to convert the TerseBitstringStatusListEntry into a BitstringStatusListEntry. Here we check two status types, 'revocation' and 'suspension', passing those strings as values of statusPurpose.

Example 27 : A BitstringStatusListEntry for status purpose: revocation

{
  type: 'BitstringStatusListEntry',
  statusListCredential: 'https://sandbox.platform.veres.dev/statuses/z19rJ4oGrbFCqf3cNTVDHSbNd/status-lists/revocation/29385',
  statusListIndex: 8321,
  statusPurpose: 'revocation'
}

Example 28 : A BitstringStatusListEntry for status purpose: suspension

{
  type: 'BitstringStatusListEntry',
  statusListCredential: 'https://sandbox.platform.veres.dev/statuses/z19rJ4oGrbFCqf3cNTVDHSbNd/status-lists/suspension/29385',
  statusListIndex: 8321,
  statusPurpose: 'suspension'
}

These can then be validated as in the Bitstring Status List v1.0: Validate Algorithm .

We first read the data from the QR code:

Example 29 : An encoded Utopia Driver's License EAD

VC1-RSJRPWCR803A3P0098G3A3-B02-J743853U53KGK0XJ6MKJ1OI0M.FO053.33963DN04$RAQS+4SMC8C3KM7VX4VAPL9%EILI:I1O$D:23%GJ0OUCPS0H8D2FB9D5G00U39.PXG49%SOGGB*K$Z6%GUSCLWEJ8%B95MOD0P
NG-I:V8N63K53

We extract the data after 'VC1-' undoing the base encoding:

Example 30 : A CBOR-LD compressed Utopia EAD VC

d90664a50183198000198001198002189d82187618a418baa1189c18a218be18ae18c0a5189c186c18d20418dc18e218de58417a9ec7f688f60caa8c757592250b3f6d6e18419941f186e1ed4245770e687502d51d01cd2c2295e4338178a51a35c2f044a85598e15db9aef00261bc5c95a744e718e018b0

We now decompress with CBOR-LD to get the original JSON-LD VC to be verified. Again, the parameters are associated with CBOR-LD registry entry 100.

Example 31 : CBOR-LD decoding parameters

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
    }
}

Example 32 : The ID-to-term map created by CBOR-LD when decompressing a Utopia EAD

Map(95) {
  0 => '@context',
  2 => '@type',
  4 => '@id',
  6 => '@value',
  8 => '@direction',
  10 => '@graph',
  12 => '@included',
  14 => '@index',
  16 => '@json',
  18 => '@language',
  20 => '@list',
  22 => '@nest',
  24 => '@reverse',
  26 => '@base',
  28 => '@container',
  30 => '@default',
  32 => '@embed',
  34 => '@explicit',
  36 => '@none',
  38 => '@omitDefault',
  40 => '@prefix',
  42 => '@preserve',
  44 => '@protected',
  46 => '@requireAll',
  48 => '@set',
  50 => '@version',
  52 => '@vocab',
  100 => '...',
  102 => 'BitstringStatusList',
  104 => 'BitstringStatusListCredential',
  106 => 'BitstringStatusListEntry',
  108 => 'DataIntegrityProof',
  110 => 'EnvelopedVerifiableCredential',
  112 => 'EnvelopedVerifiablePresentation',
  114 => 'JsonSchema',
  116 => 'JsonSchemaCredential',
  118 => 'VerifiableCredential',
  120 => 'VerifiablePresentation',
  122 => '_sd',
  124 => '_sd_alg',
  126 => 'aud',
  128 => 'cnf',
  130 => 'description',
  132 => 'digestMultibase',
  134 => 'digestSRI',
  136 => 'exp',
  138 => 'iat',
  140 => 'id',
  142 => 'iss',
  144 => 'jku',
  146 => 'kid',
  148 => 'mediaType',
  150 => 'name',
  152 => 'nbf',
  154 => 'sub',
  156 => 'type',
  158 => 'x5u',
  160 => 'AamvaDriversLicenseScannableInformation',
  162 => 'MachineReadableZone',
  164 => 'OpticalBarcodeCredential',
  166 => 'TerseBitstringStatusListEntry',
  168 => 'protectedComponentIndex',
  170 => 'did:key:zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj',
  172 => 'did:key:zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj#zDnaeWjKfs1ob9QcgasjYSPEMkwq31hmvSAWPVAgnrt1e9GKj',
  174 => 'did:key:zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj',
  176 => 'did:key:zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj#zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj',
  178 => 'https://sandbox.platform.veres.dev/statuses/z19rJ4oGrbFCqf3cNTVDHSbNd/status-lists',
  180 => 'confidenceMethod',
  182 => 'credentialSchema',
  184 => 'credentialStatus',
  186 => 'credentialSubject',
  188 => 'evidence',
  190 => 'issuer',
  192 => 'proof',
  194 => 'refreshService',
  196 => 'relatedResource',
  198 => 'renderMethod',
  200 => 'termsOfUse',
  202 => 'validFrom',
  204 => 'validUntil',
  206 => 'challenge',
  208 => 'created',
  210 => 'cryptosuite',
  212 => 'domain',
  214 => 'expires',
  216 => 'nonce',
  218 => 'previousProof',
  220 => 'proofPurpose',
  222 => 'proofValue',
  224 => 'verificationMethod',
  226 => 'assertionMethod',
  228 => 'authentication',
  230 => 'capabilityDelegation',
  232 => 'capabilityInvocation',
  234 => 'keyAgreement'
}

For more information on the above, see 6.3 Implementation Notes .

Decompression then yields the following credential:

Example 33 : A JSON-LD VC for a Utopia EAD VCB

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://w3id.org/vc-barcodes/v1",
    "https://w3id.org/utopia/v2"
  ],
  "type": [
    "VerifiableCredential",
    "OpticalBarcodeCredential"
  ],
  "credentialSubject": {
    "type": "MachineReadableZone"
  },
  "issuer": "did:key:zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj",
  "proof": {
    "type": "DataIntegrityProof",
    "verificationMethod": "did:key:zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj#zDnaeZSD9XcuULaS8qmgDUa6TMg2QjF9xABnZK42awDH3BEzj",
    "cryptosuite": "ecdsa-xi-2023",
    "proofPurpose": "assertionMethod",
    "proofValue": "z4B8AQgjwgsEdcPEZkrkK2mTVKn7qufoDgDkv9Qitf9tjxQPMoJaGdXwDrThjp7LUdvzsDJ7UwYu6Xpm9fjbo6QnJ"
  }
}

We apply 3.2.4.4 Create opticalDataBytes to create the opticalDataBytes that ecdsa-xi-2023 requires,using the MRZ on the EAD as input for the EAD:

Example 34 : A canonicalization of a Utopia EAD MRZ

canonicalizedData =
  'IAUTO0000007010SRC0000000701<<\n' +
  '8804192M2601058NOT<<<<<<<<<<<5\n' +
  'SMITH<<JOHN<<<<<<<<<<<<<<<<<<<\n'
opticalDataBytes:
[8, 198, 126, 183,  25, 160, 166, 112,
254, 184, 189,  47, 225, 211, 125, 210,
132, 137, 45,  86, 169,  28,  57, 165,
46,
253,
9,
137,
145,
42,
192,
113]

We then apply 3.2.4.3 Hashing (ecdsa-xi-2023) and 3.2.4.2 Verify Proof (ecdsa-xi-2023) to verify the credential.

When building maps from context terms to CBOR-LD integers, note that some contexts include other contexts inside of them, nested under particular types of objects. These nested contexts are called "type-scoped contexts" and they only become active when the associated type is used in the data. This is important for term ID assignment because the terms in a context are only assigned IDs once that context becomes active. In these test vectors, this is why the maps created for the Driver's License and the Employment Authorization Document are different even though the two credentials use identical contexts.

In addition, note that odd numbers are used in CBOR-LD to express terms when the associated value is plural. For example, in the CBOR-LD term-to-ID and ID-to-term maps above, "type" is mapped to 156, but in places where multiple types are expressed in a VC, 157 is used instead.

This process is used to test whether a CBOR-LD implementation that is not fully up to date has been used.

The process remains the same, with the exception of the CBOR-LD decoding step, for which the following appContextMap should be used:

Example 35 : A BitstringStatusListEntry for status purpose: suspension

appContextMap:
[['https://www.w3.org/ns/credentials/v2', 32768],
['https://w3id.org/vc-barcodes/v1', 32769],
['https://w3id.org/utopia/v2',
32770]]

Figure 9 A VCB from a Utopia driver's license encoded with legacy CBOR-LD.

Figure 10 A VCB from a Utopia EAD encoded with legacy CBOR-LD.

For use with the following MRZ:

Verifiable Credential Barcodes v1.0

Embedding Verifiable Credentials in optical barcodes

Abstract

Status of This Document

1. Introduction

1.1 Introductory Examples

1.1.1 Driver's License

1.1.2 Employment Authorization

1.1.3 Birth Certificate

1.2 Design Goals

1.3 Terminology

1.4 Conformance

2. Data Model

2.1 OpticalBarcodeCredential

2.2 TerseBitstringStatusListEntry

2.3 Encoding to and from barcodes

3. Algorithms

3.1 General Algorithms

3.1.1 CBOR-LD Compression Tables

3.1.2 Encode VC to QR Code

3.1.3 Decode QR Code to VC

3.2 OpticalBarcodeCredential Algorithms

3.2.1 Encode OpticalBarcodeCredential

3.2.2 Decode OpticalBarcodeCredential

3.2.3 Convert Status List Entries

3.2.4 ecdsa-xi-2023

3.2.4.1 Add Proof (ecdsa-xi-2023)

3.2.4.2 Verify Proof (ecdsa-xi-2023)

3.2.4.3 Hashing (ecdsa-xi-2023)

3.2.4.4 Create opticalDataBytes

AamvaDriversLicenseScannableInformation Credentials

MachineReadableZone Credentials

3.2.4.5 Proof Configuration (ecdsa-xi-2023)

4. Security Considerations

4.1 Optical Data Duplication

4.2 Partially Signed Optical Data

4.3 Safe Verification

5. Privacy Considerations

6. Test Vectors

6.1 Creating VCBs

6.1.1 Utopia Driver's License

6.1.1.1 Creating opticalDataBytes

6.1.1.2 Example VC

6.1.1.3 CBOR-LD Compression and Encoding

6.1.2 Utopia Employment Authorization Document

6.1.2.1 Creating opticalDataBytes

6.1.2.2 Example VC

6.1.2.3 CBOR-LD Compression and Encoding

6.1.2.4 Employment Authorization Document

6.2 Verifying VCBs

6.2.1 Utopia Driver's License

6.2.1.1 Decoding and Decompressing

6.2.1.2 Verifying

6.2.1.3 Status Checking

6.2.2 Utopia Employment Authorization Document

6.2.2.1 Decoding and Decompressing

6.2.2.2 Verifying

6.3 Implementation Notes

6.3.1 CBOR-LD

6.4 Legacy CBOR-LD encoded credentials

6.4.1 CBOR-LD Version 6.X

6.4.1.1 Utopia Driver's License

6.4.1.2 Utopia Employment Authorization Document

6.4.2 CBOR-LD Version 7.X

6.4.2.1 Utopia Driver's License

6.4.2.2 Utopia Employment Authorization Document

7. Revision History

A. References

A.1 Normative references

3.2 `OpticalBarcodeCredential` Algorithms

3.2.1 Encode `OpticalBarcodeCredential`

3.2.2 Decode `OpticalBarcodeCredential`

`AamvaDriversLicenseScannableInformation` Credentials

`MachineReadableZone` Credentials

6.1.1.1 Creating `opticalDataBytes`

6.1.2.1 Creating `opticalDataBytes`