High Assurance DIDs with DNS
draft-carter-high-assurance-dids-with-dns-05
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Jesse Carter , Jacques Latour , Mathieu Glaude , Tim Bouma | ||
| Last updated | 2024-07-22 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
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draft-carter-high-assurance-dids-with-dns-05
Network Working Group J. Carter
Internet-Draft J. Latour
Intended status: Informational CIRA
Expires: 23 January 2025 M. Glaude
Northern Block
T. Bouma
Digital Governance Council
22 July 2024
High Assurance DIDs with DNS
draft-carter-high-assurance-dids-with-dns-05
Abstract
This document outlines a method for improving the authenticity,
discoverability, and portability of Decentralized Identifiers (DIDs)
by utilizing the current DNS infrastructure and its technologies.
This method offers a straightforward procedure for a verifier to
cryptographically cross-validate a DID using data stored in the DNS,
separate from the DID document.
About This Document
This note is to be removed before publishing as an RFC.
The latest revision of this draft can be found at
https://ciralabs.github.io/high-assurance-dids-with-dns/draft-carter-
high-assurance-dids-with-dns.html. Status information for this
document may be found at https://datatracker.ietf.org/doc/draft-
carter-high-assurance-dids-with-dns/.
Source for this draft and an issue tracker can be found at
https://github.com/CIRALabs/high-assurance-dids-with-dns.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 23 January 2025.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3
3. Securing a DID using the DNS . . . . . . . . . . . . . . . . 4
3.1. Specifically for did:web . . . . . . . . . . . . . . . . 4
3.2. Consideration for other DID methods . . . . . . . . . . . 4
3.2.1. dnsValidationDomain . . . . . . . . . . . . . . . . . 5
3.3. Mapping DIDs to Domains with URI records . . . . . . . . 5
3.3.1. URI record scoping . . . . . . . . . . . . . . . . . 5
3.3.2. Entity Handles . . . . . . . . . . . . . . . . . . . 5
3.4. Mapping verificationMethods to the DNS with TLSA
records . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.4.1. TLSA Record Scoping, Selector Field . . . . . . . . . 6
3.4.2. Instances of Multiple Key Pairs . . . . . . . . . . . 7
3.4.3. Benefits of Public Keys in the DNS . . . . . . . . . 7
4. Role of DNSSEC for Assurance and Revocation . . . . . . . . . 7
5. Digital Signature and Proof Value of the DID Document . . . . 8
5.1. Use of Alternative Cryptosuites . . . . . . . . . . . . . 9
6. Verification Process . . . . . . . . . . . . . . . . . . . . 9
6.1. Verification Failure . . . . . . . . . . . . . . . . . . 10
7. Control Requirements . . . . . . . . . . . . . . . . . . . . 11
8. Levels of Assurance . . . . . . . . . . . . . . . . . . . . . 13
9. Security Considerations . . . . . . . . . . . . . . . . . . . 14
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
11.1. Normative References . . . . . . . . . . . . . . . . . . 15
11.2. Informative References . . . . . . . . . . . . . . . . . 17
Appendix A. W3C Considerations . . . . . . . . . . . . . . . . . 17
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 17
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Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
In the ever-evolving digital world, the need for secure and
verifiable identities is paramount. DIDs have emerged as a promising
solution, providing a globally unique, persistent identifier that
does not require a centralized registration authority. However, like
any technology, DIDs face challenges in terms of authenticity,
discoverability, and portability.
This is where the Domain Name System (DNS), a well-established and
globally distributed internet directory service, comes into play. By
leveraging the existing DNS infrastructure, we can enhance the
verification process of DIDs. Specifically, we can use Transport
Layer Security Authentication (TLSA) and Uniform Resource Identifier
(URI) DNS records to add an additional layer of verification and
authenticity to DIDs.
TLSA records in DNS allow us to associate a certificate or public key
with the domain name where the record is found, thus providing a form
of certificate pinning. URI records, on the other hand, provide a
way to publish mappings from hostnames to URIs, such as DIDs.
By storing crucial information about a DID, such as the DID itself
and its Public Key Infrastructure (PKI) in these DNS records, we can
provide a verifier with a simple yet effective method to cross-
validate and authenticate a DID. This not only ensures the
authenticity of the DID document but also allows for interaction with
material signed by the DID without access to the DID document itself.
In essence, the integration of DIDs with DNS, specifically through
the use of TLSA and URI records, provides a robust solution to some
of the challenges faced by DIDs, paving the way for a more secure and
trustworthy digital identity landscape.
2. Conventions and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" 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.
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3. Securing a DID using the DNS
Much like presenting two pieces of ID to provide a higher level of
assurance when proving your identity or age, replicating important
information about a DID into a different domain (like the DNS)
enables a similar form of cross validation. This enhances the
initial trust establishment between the user and the DID document, as
the key information can be compared and verified across two
segregated sets of infrastructure. This also acts as a form of
ownership verification in a similar way to 2FA, as the implementer
must have control over both the DNS zone and the DID document to
properly duplicate the relevant information.
+----------------+ +----------------+
| | | |
| DNS Server | | Web Server |
| | | |
| +-------+ | | +-------+ |
| | DID |<---+-----+-->| DID | |
| +-------+ | | +-------+ |
| +-------+ | | +-------+ |
| | PKI |<---+-----+-->| PKI | |
| +-------+ | | +-------+ |
| | | |
+----------------+ +----------------+
The diagram above illustrates how a web server storing the DID
document, and the DNS server storing the URI and TLSA records shares
and links the key information about the DID across two independent
sets of infrastructure.
3.1. Specifically for did:web
With did:web, there’s an inherent link between the DNS needed to
resolve the associated DID document and the domain where the relevant
supporting DNS records are located. This means that the domain
specified by the did:web identifier (for example,
did:web:*example.ca*) is also the location where you can find the
supporting DNS records.
3.2. Consideration for other DID methods
In the case of other DID methods, the association between a DID and a
DNS domain is still possible although less inherent than with the
aforementioned did:web. As such, it provides much of the same
benefits as the [wellKnownDidConfiguration], but the method in which
it accomplishes this is slightly different. Specifically, the
integrity of the DID document is secured by including a
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dataIntegrityProof inside the DID document itself rather than in a
seperate resource, and the key material used to verify this proof is
explicitly duplicated in the DNS, rather than only being referenced
back to the DID document which is being verified.
3.2.1. dnsValidationDomain
To faciliate the linking of a non did:web to the DNS, we propose the
inclusion of an optional property "dnsValidationDomain" to the DID
document.
{"dnsValidationDomain": "example.ca"}
In the case of non did:webs that wish to use DNS for increased
assurance, the verification process is identical to the one used for
did:web but instead of referencing the domain in the identifier, the
verifier MUST use the domain referenced by the "dnsValidationDomain"
property instead.
3.3. Mapping DIDs to Domains with URI records
The association to a domain stemming only from the did is
unidirectional. By leveraging URI records as outlined in
[DID-in-the-DNS], we can create a bidirectional relationship,
allowing a domain to publish their associated DID in the DNS.
*_Ex: _did.example-issuer.ca IN URI 1 0 “did:web:XXXXXX”_*
This relationship enhances security, as an entity would require
control over both the DID and the domain’s DNS server to create this
bidirectional association, reducing the likelihood of malicious
impersonation.
3.3.1. URI record scoping
* The records MUST be scoped by setting the global underscore name
of the URI RRset to __did_ (0x5F 0x64 0x69 0x64).
3.3.2. Entity Handles
An implementer may have multiple sub entities operating and issuing
credentials on their behalf, like the different deparments in a
university issuing diplomas or publishing research. For this reason,
the introduction of an entity handle, represented as a subdomain in
the resource record name, provides a simple way to facilitate the
distinction of DIDs, their public keys, and credentials they issue in
their relationship to another entity or root authority.
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*_Ex: _did.diplomas.example-issuer.ca IN URI 1 0
“did:web:diplomas.example-issuer.ca”_*
*_Ex: _did.certificates.example-issuer.ca IN URI 1 0
“did:web:certificates.example-issuer.ca”_*
3.4. Mapping verificationMethods to the DNS with TLSA records
The DID to DNS mapping illustrated in section 3.2 provides a way of
expressing the association between a DID and a domain, but no way of
verifying that relationship. By hosting the public keys of that DID
in its associated domain’s zone, we can provide a cryptographic
linkage to bolster this relationship while also providing access to
the DID’s public keys outside of the infrastructure where the DID
document itself resides, facilitating interoperability and increasing
availability.
TLSA records [RFC6698] provide a simple way of hosting cryptographic
information in the DNS. Key material or full x509 certificates can
be represented in TLSA records either hashed or unhashed depending on
the requirements and use case of the implementer.
It is important to note that as key sizes increase in respect to the
needs of post-quantum cryptography, TLSA records can support these
keys via the hashed representation, making this implementation post-
quantum compatible.
3.4.1. TLSA Record Scoping, Selector Field
When public keys related to DIDs are published in the DNS as TLSA
records:
* The records MUST be scoped by setting the global underscore name
of the TLSA RRset to __did_ (0x5F 0x64 0x69 0x64).
* The Selector Field of the TLSA record must be set to 1,
SubjectPublicKeyInfo: DER-encoded binary structure as defined in
[RFC5280].
When x509 certificates related to DIDs are published in the DNS as
TLSA records:
* The records MUST be scoped by setting the global underscore name
of the TLSA RRset to __did_ (0x5F 0x64 0x69 0x64).
* The Selector Field of the TLSA record must be set to 0, full
certificate: the Certificate binary structure as defined in
[RFC5280].
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3.4.2. Instances of Multiple Key Pairs
Depending on the needs of the implementer, it is possible they may
use multiple keypairs associated with a single DID to sign and issue
credentials or enable other PKI related interactions. In this case,
a TLSA record will be created per [verificationMethod] and then be
bundled into the corresponding TLSA RRset. A resolver can then parse
the returned records and match the key content to the
verificationMethod they wish to interact with or verify.
*_Ex: _did.example-issuer.ca IN TLSA 3 1 0
"4e18ac22c00fb9...b96270a7b4"_*
*_Ex: _did.example-issuer.ca IN TLSA 3 1 0
"5f29bd33d11gc1...b96270a7b5"_*
3.4.2.1. Security Consideration
It is RECOMMENDED implementers limit the total number of TLSA records
for a given domain to 255 to mitigate DoS style attacks, such as
creating a problematic number of TLSA records to then be resolved and
parsed by the verifier.
If total number of TLSA records returned to a verifier exceeds this
threshold, it is RECOMMENDED the verifier abort the verification
process and deem the target DID insecure.
3.4.3. Benefits of Public Keys in the DNS
Hosting the public keys in TLSA records provides a stronger mechanism
for the verifier to verify a did and its associated entity with, as
they are able to perform a cryptographic challenge against the DID
using the corresponding TLSA records, or against the domain using the
corresponding [verificationMethod] in the DID document. The
accessibility of the public keys is also beneficial, as the verifier
does not need to resolve the DID document to accesss its associated
key material, enhancing interoperability.
4. Role of DNSSEC for Assurance and Revocation
It is RECOMMENDED that all the participants in this digital identity
ecosystem enable DNSSEC signing for the DNS instances they operate.
See [RFC9364].
DNSSEC provides cryptographic assurance that the DNS records returned
in response to a query are authentic and have not been tampered with.
This assurance within the context of the __did_ URI and __did_ TLSA
records greatly strengthens the mechanism to ensure the integrity of
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the DID and its public keys. DNSSEC vastly reduces the possible
attack vectors in which the repudiated DID information in the DNS can
be tampered with.
Within this use-case, DNSSEC also provides revocation checks for both
DIDs and their public keys. In particular, a DNS query for a
specific __did_ URI record or __did_ TLSA record can return an
NXDOMAIN [RFC8020] response if the DID or public key has been
revoked. This approach can simplify the process of verifying the
current validity of DIDs and public keys by reducing the need for
complex revocation mechanisms or implementation specific
technologies.
5. Digital Signature and Proof Value of the DID Document
Digital signatures ensure the integrity of the DID Document, and by
extent the public keys, authentication protocols, and service
endpoints necessary for initiating trustworthy interactions with the
identified entity. The use of digital signatures in this context
provides a robust mechanism for verifying that the DID Document has
not been tampered with and indeed originates from the correct entity.
In accordance with W3C specifications, we propose including a data
integrity proof such as those outlined in [dataIntegrityProofECDSA]
and [dataIntegrityProofEdDSA], with the mandatory inclusions of the
"created" and "expires" fields. The inclusion of which acts as a
lifespan for the document, similar to the TTL for a DNS record.
Depending on the use case and security requirements, a longer or
shorter expiry period would be used as necessary.
"proof": {
"type": "DataIntegrityProof",
"cryptosuite": "ecdsa-jfc-2019",
"created": "2023-10-11T15:27:27Z",
"expires": "2099-10-11T15:27:27Z",
"proofPurpose": "assertionMethod",
"verificationMethod": "did:web:trustregistry.ca#key-1",
}
The data integrity proof SHOULD be signed using a verificationMethod
that has an associated TLSA record to allow for the verification of
the data integrity proof using pki material contained outside of the
DID document. This provides an added layer of authenticity, as the
PKI information contained in the DID document would need to be
repudiated across 2 different domains, the resource hosting the DID
document and its associated DNS domain.
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5.1. Use of Alternative Cryptosuites
While [dataIntegrityProofECDSA] and [dataIntegrityProofEdDSA] are the
cryptosuites we have chosen to highlight in this specification, it is
important to note that this implementation for a high assurance did
using dns is cryptosuite agnostic. It is interoperable with any new
and existing cryptosuites and associated key types as required by the
implementers and verifiers.
6. Verification Process
Using the new DNS records and proof object in the DID document, we
enable a more secure and higher assurance verification process for
the DID. It is important to note that while not strictly necessary,
DNSSEC verification SHOULD be performed each time a DNS record is
resolved to ensure their authenticity.
The process below outlines the general steps required to complete the
higher assurance did verification process;
1. *Verification of the DID:* The user verifies the DID is
represented as a URI record in the associated domain.
1. In the case of did:web, the domain and record name to be
queried is indicated by the last segment of the did. In
example, *did:web:example.ca* would translate to a URI record
with the name *_did.example.ca*.
2. In the case of other did methods, the domain and record name
to be queried is indicated by the "dnsValidationDomain"
property. In example, *{"dnsValidationDomain":
"example.ca"}* would translate to a URI record with the name
*_did.example.ca*.
2. *Verification of the PKI:* The user verifies the
verificationMethod/s in the DID document are represented as TLSA
record/s in the associated domain.
1. The domain and record name for the TLSA record to be queried
is determined identically to steps 1.a or 1.b.
1. Note: The matching of the TLSA record content and
verificationMethod may require some conversion, as TLSA
records store key material as hex encoded DER format, and
this representation is not supported by
[verificationMethod]. However, there are many well
supported cryptography libraries in a variety of
languages that facilitate the conversion process.
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3. *Verification of the DID document's integrity:* The user verifies
the "proof" object to ensure the integrity of the DID document.
1. This can be accomplished by using either the
[verificationMethod] directly from the DID document, or using
the key material stored in the TLSA record. Using the TLSA
record would provide a higher level of assurance as this
confirms the key material is being accurately represented
across 2 different domains, both at the DID document level
and the DNS level.
1. Note: Unlike with matching the verificationMethod and
TLSA record in step 2, DER is a widely supported encoding
format for key material enabling a verifier to directly
use the TLSA record content to verify the signature
without having to convert the key back to its
representation in the verificationMethod.
_Note_: The order of the steps presented does not specify a required
order for verification. As a general rule (and depending on the use
case) the 3 verification steps outlined above may be performed in any
order as best fits the verifier's needs. In example, a verifier may
arrive at the DID document during a credential verification process,
in which case it makes sense to peform step 3 before steps 1 and 2.
Alternatively, a verifier may arrive at the DID document after
exploring an organization's domain, in which case it may make more
sense to perform steps 1 and 2 prior to step 3. So long as the 3
steps are performed together, the same level of assurance is achieved
irrespective of their order.
6.1. Verification Failure
If at any given step verification fails, the DID document should be
deemed INSECURE. Whether it is due to the DID and DNS being out of
sync with recent updates, or the resource hosting the DID document or
DNS zone themselves being compromised, a failed verification MAY
indicate malicious activity. It is then up to the verifier to
determine, according to their requirements and use case, the
appropriate course of action regarding interactions with the target
DID until successful verification is restored.
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7. Control Requirements
This section defines a simple framework to define a set of technical
controls that can be implemented and mapped into levels of assurance
for did:web identifiers. To assist in decision-making and
implementation, The controls are ordered in increasing level of
security assurance and are grouped into levels of assurance from
*LOW-* to *HIGH+* - *Issuing Authority* is the entity accountable for
the did:web identifier. - *Issuing Service* is the entity responsible
for operating the did:web identifier infrastructure. In many cases
the *Issuing Authority* may delegate elements of providing a high
assurance did:web identifier to an *Issuing Service* that may be a
commercial provider. In the simplest case, the *Issuing Authority*
can be regarded as the same as the *Issuing Service*. Note that
Controls 9, 10, and 11 CANNOT BE DELEGATED to an *Issuing Service*
11 technical controls are defined. These controls would be
implemented in order of precedence for an increasing level of
security assurance. (e.g., Control No. N would need to be
implemented before implementing Control No. N+1)
+=========+============+==========================================+
| Control | Control | Description |
| No. | Name | |
+=========+============+==========================================+
| 1 | DID | The Issuing Service MUST control the |
| | Resource | resource that generates the DID |
| | Control | document. (i.e., website) |
+---------+------------+------------------------------------------+
| 2 | DID | The Issuing Service MUST have the |
| | Document | ability to do CRUD operations on the DID |
| | Management | document. |
+---------+------------+------------------------------------------+
| 3 | DID | The Issuing Service MUST ensure the data |
| | Document | integrity of the DID document by |
| | Data | cryptographic means, typically a digital |
| | Integrity | signature or other means. The use of |
| | | approved or established cryptographic |
| | | algorithms is HIGHLY RECOMMENDED |
+---------+------------+------------------------------------------+
| 4 | DID | The Issuing Service MUST control the |
| | Document | keys required to sign the DID document. |
| | Key | |
| | Control | |
+---------+------------+------------------------------------------+
| 5 | DID | With proper delegation from the Issuing |
| | Document | Authority, the DID Document signing key |
| | Key | MAY be generated by the Issuing Service. |
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| | Generation | Otherwise, the signing key must be |
| | | generated by the Issuing Authority. |
+---------+------------+------------------------------------------+
| 6 | Domain | The Issuing Service MUST have control of |
| | Zone | the domain zone (or subdomain zone).If |
| | Control | direct control of the domain is not |
| | | feasible, the use of an accredited DNS |
| | | provider is HIGHLY RECOMMENDED |
+---------+------------+------------------------------------------+
| 7 | Domain | There MUST be domain zone records that |
| | Zone | map the necessary URI, TLSA, CERT and/or |
| | Mapping | TXT records to the specified did:web |
| | | identifier. |
+---------+------------+------------------------------------------+
| 8 | Domain | The domain zone records MUST be signed |
| | Zone | according to DNSSEC. (RRSIG) |
| | Signing | |
+---------+------------+------------------------------------------+
| 9 | Domain | The Issuing Authority MUST have control |
| | Zone | over the domain zone keys used for |
| | Signing | signing and delegation. (KSK and ZSK) |
| | Key | |
| | Control | |
+---------+------------+------------------------------------------+
| 10 | Domain | The domain zone signing key MUST be |
| | Zone | generated under the control of the |
| | Signing | Issuing Authority. |
| | Key | |
| | Generation | |
+---------+------------+------------------------------------------+
| 11 | Hardware | A FIPS 140-2 compliant hardware security |
| | Security | module must be under the control of the |
| | Module | Issuing Authority. |
+---------+------------+------------------------------------------+
Table 1
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In addition to the technical controls specified in the table it is
advisable to add in DANE (DNS-based Authentication of Named Entities)
[RFC6698] to secure TLS communications. TLS uses certificates to
bind keys to names, which are published by public "Certification
Authorities" (CAs). It is important to realize that the public CA
model is fundamentally vulnerable because it allows any CA to issue a
certificate for any domain name. Thus, a compromised CA can issue a
fake replacement certificate which could be used to subvert TLS-
protected websites. DANE offers the option to use the DNSSEC
infrastructure to store and sign keys and certificates that are used
by a TLS-protected website. The keys are bound to names in the
Domain Name System (DNS), instead of relying on arbitrary keys and
names issued in a potentially compromised certificate.
8. Levels of Assurance
Many trust frameworks specify levels of assurance to assist in
determining which controls must be implemented.
The following table is not a definitive mapping to trust framework
levels of assurance. It is intended to assist in determining
mappings by grouping the controls within a range from *LOW-* to
*HIGH+* relating to the appropriate risk level. Note that controls
are additive in nature. (i.e.,, controls of the preceding level must
be fulfilled).
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+===========+==========+=====================================+
| Level of | Controls | Description |
| Assurance | | |
+===========+==========+=====================================+
| *LOW-* | Control | SHOULD only be used for low risk |
| | 1 | transactions where attribution to |
| | | originator is desirable. |
+-----------+----------+-------------------------------------+
| *LOW* | Control | SHOULD only be used for lower risk |
| | 2 | transactions where establishing the |
| | | accountability of the originator is |
| | | desirable. |
+-----------+----------+-------------------------------------+
| *MEDIUM* | Controls | MAY be used for medium risk |
| | 3, 4 and | commercial transactions, such as |
| | 5 | correspondence, proposals, etc. |
+-----------+----------+-------------------------------------+
| *MEDIUM+* | Controls | MAY be used for higher risk |
| | 6 and 7 | transactions, such as signing and |
| | | verifying invoices, contracts, or |
| | | official/legal documentation |
+-----------+----------+-------------------------------------+
| *HIGH* | Controls | MUST be high risk transactions, |
| | 8, 9 and | such as government transactions for |
| | 10 | signing and verifying licenses, |
| | | certifications or identification |
+-----------+----------+-------------------------------------+
| *HIGH+* | Control | MUST be used for extremely high |
| | 11 | risk transactions where there may |
| | | be systemic or national security |
| | | implications |
+-----------+----------+-------------------------------------+
Table 2
9. Security Considerations
TODO Security
10. IANA Considerations
Per [RFC8552], IANA is requested to add the following entries to the
"Underscored and Globally Scoped DNS Node Names" registry:
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+---------+------------+-------------------------------------------+
| RR Type | _NODE NAME | Reference |
+---------+------------+-------------------------------------------+
| TLSA | _did | [draft-ietf-high-assurance-dids-with-dns] |
| URI | _did | [draft-mayrhofer-did-dns-01] |
+---------+------------+------------------------------------------+.
11. References
11.1. Normative References
[alsoKnownAs]
"Decentralized Identifiers (DIDs) v1.0", n.d.,
<https://www.w3.org/TR/did-core/#also-known-as>.
[dataIntegrityProofECDSA]
"Data Integrity ECDSA Cryptosuites v1.0", n.d.,
<https://www.w3.org/TR/vc-di-ecdsa/#proof-
representations>.
[dataIntegrityProofEdDSA]
"Data Integrity ECDSA Cryptosuites v1.0", n.d.,
<https://www.w3.org/TR/vc-di-eddsa/#proof-
representations>.
[DID-in-the-DNS]
"The Decentralized Identifier (DID) in the DNS", n.d.,
<https://datatracker.ietf.org/doc/html/draft-mayrhofer-
did-dns-05#section-2>.
[DID-Specification-Registries]
"DID Specification Registries", n.d.,
<https://www.w3.org/TR/did-spec-registries/#did-methods>.
[didSpecRegistries]
"Did Specification Registries", n.d.,
<https://w3c.github.io/did-spec-registries>.
[issuer] "Verifiable Credentials Data Model v2.0", n.d.,
<https://www.w3.org/TR/vc-data-model-2.0/#issuer>.
[LinkedDomains]
"Well Known DID Configuration", n.d.,
<https://identity.foundation/.well-known/resources/did-
configuration/#linked-domain-service-endpoint>.
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<https://www.rfc-editor.org/rfc/rfc5280>.
[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
of Named Entities (DANE) Transport Layer Security (TLS)
Protocol: TLSA", RFC 6698, DOI 10.17487/RFC6698, August
2012, <https://www.rfc-editor.org/rfc/rfc6698>.
[RFC8020] Bortzmeyer, S. and S. Huque, "NXDOMAIN: There Really Is
Nothing Underneath", RFC 8020, DOI 10.17487/RFC8020,
November 2016, <https://www.rfc-editor.org/rfc/rfc8020>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8552] Crocker, D., "Scoped Interpretation of DNS Resource
Records through "Underscored" Naming of Attribute Leaves",
BCP 222, RFC 8552, DOI 10.17487/RFC8552, March 2019,
<https://www.rfc-editor.org/rfc/rfc8552>.
[RFC9364] Hoffman, P., "DNS Security Extensions (DNSSEC)", BCP 237,
RFC 9364, DOI 10.17487/RFC9364, February 2023,
<https://www.rfc-editor.org/rfc/rfc9364>.
[services] "Decentralized Identifiers (DIDs) v1.0", n.d.,
<https://www.w3.org/TR/did-core/#services>.
[verificationMethod]
"Decentralized Identifiers (DIDs) v1.0", n.d.,
<https://www.w3.org/TR/did-core/#verification-methods>.
[W3C-VC-Data-Model]
"Verifiable Credentials Data Model v1.1", n.d.,
<https://www.w3.org/TR/vc-data-model/>.
[wellKnownDidConfiguration]
"Well Known DID Configuration", n.d.,
<https://identity.foundation/.well-known/resources/did-
configuration/>.
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11.2. Informative References
[Self-Sovereign-Identity]
Reed, D. and A. Preukschat, "Self-Sovereign Identity",
ISBN 9781617296598, 2021.
Appendix A. W3C Considerations
1. We propose the inclusion of an optional data integrity proof for
the DID document, as outlined in [dataIntegrityProofECDSA] and
[dataIntegrityProofEdDSA].
2. We propose the inclusion of the optional "dnsValidationDomain"
property to the [didSpecRegistries] as outlined in section 3.2.
Acknowledgments
TODO acknowledge.
Authors' Addresses
Jesse Carter
CIRA
Email: jesse.carter@cira.ca
Jacques Latour
CIRA
Email: jacques.latour@cira.ca
Mathieu Glaude
Northern Block
Email: mathieu@northernblock.ca
Tim Bouma
Digital Governance Council
Email: tim.bouma@dgc-cgn.org
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