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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.
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This document was published by the Verifiable Credentials Working Group as a Working Draft using the Recommendation track.
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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 v1.0 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 either the barcode itself or the subject of the barcode. Next, this Verifiable Credential is secured using Data Integrity [VC-DATA-INTEGRITY], and then compressed using CBOR-LD [CBOR-LD].
There are two main mechanisms by which a Verifiable Credential can be used to protect a barcode:
Both use cases achieve authenticity, integrity, and tamper resistance over the data protected by the Verifiable Credential. Additionally, for use cases that require it, these Verifiable Credentials can be revoked or suspended on a per-barcode basis.
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:
The back of the driver's license contains a PDF417 barcode:
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.
{
"@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):
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 a birth certificate as a verifiable credential, which is then expressed as a QR Code on the printed paper document:
The QR Code encodes the following verifiable credential. The details of the encoding are available as separate tabs below:
{
"@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"
}]
}
}
}{
"@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": "2026-07-15T19:08:36Z",
"verificationMethod": "did:key:zDnaeu99ozL26MYFaqaT6iEEjfi9gFvw11NgcPwyJ2gbU1GpE",
"cryptosuite": "ecdsa-rdfc-2019",
"proofPurpose": "assertionMethod",
"proofValue": "zFp9xXE3JE1Aka84rqNNr5RCGp53nfqrH75hDorpS8WM312CdxBKkV2bKH3GvuhefCN7pY925ittuRXYk
kurFtpi"
}
}
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: 1784142516,
338: "ecdsa-rdfc-2019",
348: 354,
350: h'7a0cc6305bbef515f9189690a835753af7681e27637f9998e691adf90a0928e39723e26e3d46dd5018bab
53018cabc5c116006a15593b220928be34ef40f1706fb',
352: [
1025,
h'802403aa943808db3107ad5d75fae858927a8d60fc656a8d9c552b38b066004863e6ff'
]
},
320: 1696073400
}
])}
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
L70CF3Z4BPYMN70W3EJPCHQEOX57VC9OCNF61A6B73.SB*70B73W-BMC8VS8:Y2RKO%2PERND.I1YJCWIQS5.XBV+GSG3X%IMKD0
ZGB20V09KBU4:M9PCS:LE531QP.GKOX9FZ1U:F3WI26J*L1MGF8 FB7319CE73T70/L4*O4IPLY37/VRU/0U BHWV*8B8MFXBC.
CR+HNYAM77C+C 6959TB73U485ZCA%0
{
"@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": "2026-07-15T19:08:36Z",
"verificationMethod": "did:key:zDnaeu99ozL26MYFaqaT6iEEjfi9gFvw11NgcPwyJ2gbU1GpE",
"cryptosuite": "ecdsa-rdfc-2019",
"proofPurpose": "assertionMethod",
"proofValue": "z2NEKCQcfdiaQWaj9QpGJhv8wvs7spCTsbe8FMSLqyAV2nzTSQ6JaGoDkxFyYoeaYMCPqVndY5Xn9sDc3
LkhPKg5p"
}
}}
The following are the design goals of the technology in this specification:
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.
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 MAY, MUST, RECOMMENDED, and REQUIRED 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 type of the credentialSubject of an OpticalBarcodeCredential
identifies the kind of machine-readable data on the physical document that is
secured by the verifiable credential, in addition to the information
expressed in the verifiable credential itself. This specification
defines the general type MachineReadableInformation, which serves as the
superclass for every credentialSubject type used with an
OpticalBarcodeCredential. The main portion of this specification defines
one concrete subclass: MachineReadableZone (see Section
2.1.1 MachineReadableZone), which signifies that the
verifiable credential secures the machine-readable zone on the
physical document. Two further subclasses are defined in the appendices:
AamvaDriversLicenseScannableInformation (see Appendix A. AAMVA Driver License and Identification Documents,
which is normative) and IsoDrivingLicenceMachineReadableInformation (see
Appendix B. ISO-Compliant Driving Licences, which is informative). Other specifications MAY
define additional credentialSubject types
that indicate the credential protects other sorts of machine-readable data, such as
PDF417 barcodes on birth certificates or education certificates.
Every credentialSubject type used with an OpticalBarcodeCredential,
whether defined by this specification or by another, MUST be defined as a
subclass of MachineReadableInformation. The value
MachineReadableInformation MAY be included in the credentialSubject
type array alongside the more specific subclass value; processors that do
not recognize a specific subclass can use the superclass value to determine
that the credentialSubject describes machine-readable data secured by the
verifiable credential.
A new credentialSubject type, whether defined by this specification or by
another, MUST define all of the following in order to be usable with the
algorithms in Section 3. Algorithms:
protectedComponentIndex property, including the length of
its bitstring, the value of any padding bits, and the deterministic list of
components to which its bits refer; and
An example of how such an additional type can be defined to secure a region-specific barcode data model is available in Appendix A. AAMVA Driver License and Identification Documents, which normatively defines how to augment the PDF417 barcode on AAMVA-compliant driver's licenses and identification cards with a Verifiable Credential Barcode.
When the machine-readable data secured by an OpticalBarcodeCredential is
composed of discrete components (such as the individual fields in a PDF417
barcode), and only a subset of those components is digitally signed, the
credentialSubject expresses which components are protected using the
protectedComponentIndex property. The value of protectedComponentIndex is
a multibase-base64url encoded bitstring. Each bit in position i of the
bitstring corresponds to the component at index i of the deterministic list
of components defined for the associated credentialSubject type. If the bit
in position i is 1, the component in position i of the deterministic
list of components is protected by the digital signature; if the bit is 0,
the component is not protected. Any trailing padding bits in the bitstring
that do not correspond to a component MUST be set to 0. For more
information on how protectedComponentIndex is used when generating and
verifying digital signatures, see Section 3.2.4.4 Create opticalDataBytes.
A credentialSubject of type MachineReadableZone signifies that the
verifiable credential secures the machine-readable zone (MRZ)
[ICAO9303-3] on the physical document. MachineReadableZone is a subclass
of MachineReadableInformation. All of the lines of the
machine-readable zone are secured, so the protectedComponentIndex property
is not needed with this type.
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.
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
3.2.3.1 TerseBitstringStatusListEntry to BitstringStatusListEntry 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.
Each credentialSubject type is expected to specify how CBOR-LD encoded
credentials of that type are character-encoded before being placed in a
barcode. The character encoding requirements for MachineReadableZone are
provided in Section 2.1.1 MachineReadableZone; requirements for other types
are provided in the specifications or appendices that define them (e.g.,
Appendix A. AAMVA Driver License and Identification Documents and Appendix B. ISO-Compliant Driving Licences).
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.
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.
45 as targetBase, and
0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./: as the baseAlphabet.
VC1-,
R (the Multibase prefix for base45), and
base45Value.
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.
VC1-R. If it does not an
error MUST be raised.
VC1-R)
removed.
45 as sourceBase, and
0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./: as the baseAlphabet.
This section contains algorithms that are specific to encoding and decoding
verifiable credentials that have a type of OpticalBarcodeCredential, which
typically appears in the use case where existing machine-readable information on
a document is augmented with a verifiable credential.
OpticalBarcodeCredential with
unsignedCredential.issuer set to issuerUrl.
BitstringStatusListEntry
(as defined in the Bitstring Status List v1.0 specification) that the issuer
wishes to add to the OpticalBarcodeCredential.
BitstringStatusListEntry to TerseBitstringStatusListEntry to statusListEntry.
OpticalBarcodeCredential that results from applying
CBOR-LD decompression [CBOR-LD] to cborldBytes, if the payload is
CBOR-LD compressed; otherwise, set credential to the
OpticalBarcodeCredential expressed by cborldBytes.
TerseBitstringStatusListEntry to BitstringStatusListEntry to credential.
The algorithms in this section are used to convert between a
TerseBitstringStatusListEntry and a BitstringStatusListEntry. The
algorithm in Section 3.2.3.2 BitstringStatusListEntry to TerseBitstringStatusListEntry is used when encoding an
OpticalBarcodeCredential, to compress a BitstringStatusListEntry into a
TerseBitstringStatusListEntry before the credential is signed. The
algorithm in Section 3.2.3.1 TerseBitstringStatusListEntry to BitstringStatusListEntry performs the inverse
conversion and 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.
floor() operation).
result can be used as input to the validation algorithm in the Bitstring Status List v1.0 specification.
The algorithm takes a BitstringStatusListEntry (struct
statusListEntry), whose statusListCredential value is expected to be a
URL of the form terseStatusListBaseUrl, '/', statusPurpose, '/',
listIndex, and an integer listLength containing the number of entries in
each BitstringStatusListCredential published by the issuer as
input, and returns a 'TerseBitstringStatusListEntry' object.
A TerseBitstringStatusListEntry does not express the statusPurpose of
the original BitstringStatusListEntry. The statusPurpose is instead
supplied by the verifier as an input to the algorithm in Section
3.2.3.1 TerseBitstringStatusListEntry to BitstringStatusListEntry, which reconstructs the
BitstringStatusListEntry during validation.
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:
The algorithm in this section produces the optical data
(opticalDataBytes) over which a digital signature is generated or
verified. The algorithm is generic to any sort of machine-readable optical
data: the type of the credentialSubject defines how the protected
components of the optical data are extracted (see the type-specific
component extraction sections below), and this algorithm sorts those
components into a deterministic list before canonicalizing and hashing them.
The required inputs to this algorithm are the machine-readable optical data (opticalData) and the credential subject (credentialSubject). A single value representing the hashed canonical form of the protected optical data is produced as output.
protectedComponentIndex if it is defined for
that type. The component extraction rules for MachineReadableZone are
given in Section Component extraction: MachineReadableZone; the rules for other types
are given in the specifications or appendices that define them (e.g.,
Appendix A.2 Component Extraction for the type defined in Appendix
A. AAMVA Driver License and Identification Documents, and Appendix B.2 Component Extraction for the type
described in Appendix B. ISO-Compliant Driving Licences).
For a credentialSubject of type MachineReadableZone, opticalData is
the data in the machine-readable zone, and the protected components are
extracted as follows. The ordering rules for this type are the order in
which the lines appear on the credential.
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:
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.
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.
The following section describes privacy considerations that developers implementing this specification should be aware of in order to avoid violating privacy assumptions.
This appendix defines AamvaDriversLicenseScannableInformation, a
credentialSubject type, defined as a subclass of
MachineReadableInformation, that is used to secure the contents of the PDF417
barcode on driver's licenses and identification cards issued
in accordance with the AAMVA DL/ID Card Design Standard
[aamva-dl-id-card-design-standard]. This type satisfies the requirements for
new credentialSubject types set out in Section 2.1 OpticalBarcodeCredential,
and this appendix also serves as an example of how such a type can be defined for
the documents issued by a particular country or region; other specifications are
encouraged to define similar types for other classes of documents.
A credentialSubject of type AamvaDriversLicenseScannableInformation
signifies that the verifiable credential secures the contents of the
PDF417 barcode on an AAMVA-compliant driver's license or
identification card [aamva-dl-id-card-design-standard].
An AamvaDriversLicenseScannableInformation object has a REQUIRED
protectedComponentIndex property 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). The deterministic list of components associated
with this type is the list of these 22 element IDs sorted according to Unicode
code point order (i.e., ['DAC', 'DAD' ... 'DDG']). 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 are padding bits and MUST be 0. For more
information, see Section 3.2.4.4 Create opticalDataBytes.
It is RECOMMENDED that implementers character-encode CBOR-LD encoded
AamvaDriversLicenseScannableInformation credentials as base64url before
encoding them in a PDF417. A multibase header MAY be prepended to the
base-encoded VCB data. PDF417 field header specifications are expected to
indicate whether a multibase header is present or absent.
{
"@context": [
"https://www.w3.org/ns/credentials/v2",
"https://w3id.org/vc-barcodes/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"
}
}
For a credentialSubject of type
AamvaDriversLicenseScannableInformation, opticalData is the data in the
PDF417 barcode, and the protected components are extracted as follows. The
ordering rules for this type are the default Unicode code point order.
protectedComponentIndex from multibase-base64url to binary.
1 in bitfieldDecoded:
\n, U+000A) to the end,
and append the result to dataToCanonicalize.
This section is non-normative.
This appendix describes IsoDrivingLicenceMachineReadableInformation, a
credentialSubject type, defined as a subclass of
MachineReadableInformation, that can be used to secure the machine-readable
data on an ISO-compliant driving licence (IDL) [ISO18013-2]. It
illustrates how a credentialSubject type satisfying the requirements in
Section 2.1 OpticalBarcodeCredential could be defined for IDLs, and is
expected to be refined by a future revision of this specification, or by
another specification, before use.
A credentialSubject of type
IsoDrivingLicenceMachineReadableInformation signifies that the
verifiable credential secures the compact-encoded machine-readable
data, as defined in [ISO18013-2], on an ISO-compliant driving licence
(IDL), such as the contents of a PDF417 barcode on the
licence. The machine-readable IDL data is organized into data groups
(DG1 through DG11) as defined by the logical data structure in
[ISO18013-2]; these data groups are the components of the optical data
for the purposes of this specification.
IsoDrivingLicenceMachineReadableInformation is a subclass of
MachineReadableInformation.
An IsoDrivingLicenceMachineReadableInformation object has a required
protectedComponentIndex property that contains information about which
data groups are digitally signed. protectedComponentIndex is a
two byte/16 bit value that is multibase-base64url encoded for a total of
4 characters in the JSON-LD credential. The deterministic list of components
associated with this type is the list of data groups defined in [ISO18013-2],
sorted in ascending order of data group number (i.e.,
['DG1', 'DG2' ... 'DG11']), and the first 11 bits of the
protectedComponentIndex value correspond to these data groups. If a bit
in position i of protectedComponentIndex is 1, the data group in
position i of the deterministic list of components is protected by the
digital signature. The remaining bits in protectedComponentIndex are
padding bits and are set to 0. For more information, see Section
3.2.4.4 Create opticalDataBytes.
Implementers are expected to character-encode CBOR-LD encoded
IsoDrivingLicenceMachineReadableInformation credentials as base64url
before encoding them in a PDF417. A multibase header can be prepended to
the base-encoded VCB data. The encoded VCB is expected to be placed
in Data Group 11, for optional and jurisdiction-specific data. If the VCB
is placed into one of the 11 Data Groups, the corresponding element of
protectedComponentIndex is set to 0.
For a credentialSubject of type
IsoDrivingLicenceMachineReadableInformation, opticalData is the
compact-encoded machine-readable data [ISO18013-2] on the licence, and
the protected components are extracted as follows. The ordering rules for
this type are ascending order of data group number.
protectedComponentIndex from multibase-base64url to
binary.
['DG1', 'DG2' ... 'DG11']).
1 in bitfieldDecoded:
\n, U+000A) to the end, and append the result to
dataToCanonicalize.
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):
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
canonicalizedData = 'DACJOHN\nDAQF987654321\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:
{
"@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:
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:
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 C.3 Implementation Notes.
This results in the following encoded credential:
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:
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:
We now apply the reverse process to verify.
We first read the data from the PDF417:
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)
We extract the data in field 'ZZA' in subfile 'ZZ', undoing the base encoding:
D9CB1D821864A60183198000198001198002189D82187618A418B8A3189C18A618CE18B218D01AE592208118BAA2189C18A018A8447582002018BE18AA18C0A5189C186C18D60418E018E618E258417AB7C2E56B49E2CCE62184CE26818E15A8B173164401B5D3BB93FFD6D2B5EB8F6AC0971502AE3DD49D17EC66528164034C912685B8111BC04CDC9EC13DBADD91CC18E418AC
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.
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.
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 C.3 Implementation Notes.
Decompression then yields the following credential:
{
"@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.
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 3.2.3.1 TerseBitstringStatusListEntry to BitstringStatusListEntry
to convert the TerseBitstringStatusListEntry into a BitstringStatusListEntry.
Here we check two status types, 'revocation' and 'suspension', passing those
strings as values of statusPurpose.
{
type: 'BitstringStatusListEntry',
statusListCredential: 'https://sandbox.platform.veres.dev/statuses/z19rJ4oGrbFCqf3cNTVDHSbNd/status-lists/revocation/29385',
statusListIndex: 8321,
statusPurpose: 'revocation'
}
{
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.
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.
appContextMap: [['https://www.w3.org/ns/credentials/v2', 32768], ['https://w3id.org/vc-barcodes/v1', 32769], ['https://w3id.org/utopia/v2', 32770]]
This section is non-normative.
This section contains the substantive changes that have been made to this specification over time.
The content for this specification will be filled in after the standards-track process has been started.