drip Working Group                                       A. Wiethuechter
Internet-Draft                                                   S. Card
Intended status: Standards Track                      AX Enterprize, LLC
Expires: 31 July 2022                                       R. Moskowitz
                                                          HTT Consulting
                                                                 J. Reid
                                                                RTFM llp
                                                         27 January 2022


                            DRIP Registries
                     draft-ietf-drip-registries-00

Abstract

   This document creates the DRIP DET registration and discovery
   ecosystem.  This includes all components in the ecosystem (e.g., RAA,
   HDA, UA, GCS, USS).  The registration process will use the Extensible
   Provisioning Protocol (EPP) and other protocols.  The discovery
   process will leverage DNS and DNSSEC and related technology.  The
   DETs can be registered with as their "raw public keys" or in X.509
   certificates.

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/.

   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 31 July 2022.

Copyright Notice

   Copyright (c) 2022 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/
   license-info) in effect on the date of publication of this document.



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   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
     2.1.  Required Terminology  . . . . . . . . . . . . . . . . . .   5
     2.2.  Definitions . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  DRIP Attestations & Certificates  . . . . . . . . . . . . . .   5
     3.1.  Attestation Structure . . . . . . . . . . . . . . . . . .   5
       3.1.1.  Attestor Identity Information . . . . . . . . . . . .   6
       3.1.2.  Attestation Data  . . . . . . . . . . . . . . . . . .   7
       3.1.3.  Expiration Timestamp  . . . . . . . . . . . . . . . .   7
       3.1.4.  Signing Timestamp . . . . . . . . . . . . . . . . . .   7
       3.1.5.  Signature . . . . . . . . . . . . . . . . . . . . . .   7
     3.2.  Attestations  . . . . . . . . . . . . . . . . . . . . . .   7
       3.2.1.  Self-Attestation (SA-xx)  . . . . . . . . . . . . . .   7
       3.2.2.  Attestation (A-xy)  . . . . . . . . . . . . . . . . .   8
       3.2.3.  Concise Attestation (CA-xy) . . . . . . . . . . . . .   9
       3.2.4.  Mutual Attestation (MA-xy)  . . . . . . . . . . . . .  10
       3.2.5.  Link Attestation (LA-xy)  . . . . . . . . . . . . . .  11
       3.2.6.  Broadcast Attestation (BA-xy) . . . . . . . . . . . .  12
     3.3.  Certificates  . . . . . . . . . . . . . . . . . . . . . .  14
       3.3.1.  Attestation Certificate (AC-zxy)  . . . . . . . . . .  14
       3.3.2.  Concise Certificate (CC-zxy)  . . . . . . . . . . . .  15
       3.3.3.  Link Certificate (LC-zxy) . . . . . . . . . . . . . .  15
       3.3.4.  Mutual Certificate (MC-zxy) . . . . . . . . . . . . .  16
   4.  Registries  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     4.1.  Classes . . . . . . . . . . . . . . . . . . . . . . . . .  17
       4.1.1.  Root  . . . . . . . . . . . . . . . . . . . . . . . .  18
       4.1.2.  Registered Assigning Authorities  . . . . . . . . . .  18
       4.1.3.  Hierarchial HIT Domain Authorities  . . . . . . . . .  18
     4.2.  Federation  . . . . . . . . . . . . . . . . . . . . . . .  19
   5.  DRIP Fully Qualified Domain Names . . . . . . . . . . . . . .  19
     5.1.  Serial Number . . . . . . . . . . . . . . . . . . . . . .  19
     5.2.  Reverse SN  . . . . . . . . . . . . . . . . . . . . . . .  19
     5.3.  DET . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
     5.4.  Reverse DET . . . . . . . . . . . . . . . . . . . . . . .  20
   6.  Supported DNS Records . . . . . . . . . . . . . . . . . . . .  20
     6.1.  HIP RR  . . . . . . . . . . . . . . . . . . . . . . . . .  20
     6.2.  CERT RR . . . . . . . . . . . . . . . . . . . . . . . . .  20
     6.3.  NS RR . . . . . . . . . . . . . . . . . . . . . . . . . .  20
     6.4.  AAAA RR . . . . . . . . . . . . . . . . . . . . . . . . .  21
     6.5.  SVR RR  . . . . . . . . . . . . . . . . . . . . . . . . .  21



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     6.6.  TLSA RR . . . . . . . . . . . . . . . . . . . . . . . . .  21
   7.  Registry Operations . . . . . . . . . . . . . . . . . . . . .  21
     7.1.  Registering an RAA  . . . . . . . . . . . . . . . . . . .  21
       7.1.1.  Inputs  . . . . . . . . . . . . . . . . . . . . . . .  21
       7.1.2.  DNS Entries . . . . . . . . . . . . . . . . . . . . .  22
       7.1.3.  Database Entries  . . . . . . . . . . . . . . . . . .  22
       7.1.4.  Outputs . . . . . . . . . . . . . . . . . . . . . . .  22
     7.2.  Registering an IRM  . . . . . . . . . . . . . . . . . . .  22
       7.2.1.  Inputs  . . . . . . . . . . . . . . . . . . . . . . .  22
       7.2.2.  DNS Entries . . . . . . . . . . . . . . . . . . . . .  22
       7.2.3.  Database Entries  . . . . . . . . . . . . . . . . . .  23
       7.2.4.  Outputs . . . . . . . . . . . . . . . . . . . . . . .  23
     7.3.  Registering an HDA  . . . . . . . . . . . . . . . . . . .  23
       7.3.1.  Inputs  . . . . . . . . . . . . . . . . . . . . . . .  23
       7.3.2.  DNS Entries . . . . . . . . . . . . . . . . . . . . .  23
       7.3.3.  Database Entries  . . . . . . . . . . . . . . . . . .  23
       7.3.4.  Outputs . . . . . . . . . . . . . . . . . . . . . . .  23
     7.4.  Registering an MRA  . . . . . . . . . . . . . . . . . . .  23
       7.4.1.  Inputs  . . . . . . . . . . . . . . . . . . . . . . .  24
       7.4.2.  DNS Entries . . . . . . . . . . . . . . . . . . . . .  24
       7.4.3.  Database Entries  . . . . . . . . . . . . . . . . . .  24
       7.4.4.  Outputs . . . . . . . . . . . . . . . . . . . . . . .  24
     7.5.  Registering a Serial Number . . . . . . . . . . . . . . .  24
       7.5.1.  Inputs  . . . . . . . . . . . . . . . . . . . . . . .  24
       7.5.2.  DNS Entries . . . . . . . . . . . . . . . . . . . . .  25
       7.5.3.  Database Entries  . . . . . . . . . . . . . . . . . .  25
       7.5.4.  Outputs . . . . . . . . . . . . . . . . . . . . . . .  25
     7.6.  Registering an Operator . . . . . . . . . . . . . . . . .  25
       7.6.1.  Inputs  . . . . . . . . . . . . . . . . . . . . . . .  25
       7.6.2.  DNS Entries . . . . . . . . . . . . . . . . . . . . .  25
       7.6.3.  Database Entries  . . . . . . . . . . . . . . . . . .  26
       7.6.4.  Outputs . . . . . . . . . . . . . . . . . . . . . . .  26
     7.7.  Registering a Session ID  . . . . . . . . . . . . . . . .  26
       7.7.1.  Inputs  . . . . . . . . . . . . . . . . . . . . . . .  26
       7.7.2.  DNS Entries . . . . . . . . . . . . . . . . . . . . .  26
       7.7.3.  Database Entries  . . . . . . . . . . . . . . . . . .  27
       7.7.4.  Outputs . . . . . . . . . . . . . . . . . . . . . . .  27
   8.  Provisioning  . . . . . . . . . . . . . . . . . . . . . . . .  27
     8.1.  Overview of Transactions  . . . . . . . . . . . . . . . .  27
     8.2.  HHIT Delegation . . . . . . . . . . . . . . . . . . . . .  28
     8.3.  Registry  . . . . . . . . . . . . . . . . . . . . . . . .  29
     8.4.  Manufacturer  . . . . . . . . . . . . . . . . . . . . . .  30
     8.5.  Operator  . . . . . . . . . . . . . . . . . . . . . . . .  30
     8.6.  Aircraft  . . . . . . . . . . . . . . . . . . . . . . . .  31
       8.6.1.  Standard Provisioning . . . . . . . . . . . . . . . .  31
       8.6.2.  Operator Assisted Provisioning  . . . . . . . . . . .  34
       8.6.3.  Initial Provisioning  . . . . . . . . . . . . . . . .  35
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  35



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   10. Security Considerations . . . . . . . . . . . . . . . . . . .  36
   11. Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  36
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  36
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  36
     12.2.  Informative References . . . . . . . . . . . . . . . . .  36
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  37

1.  Introduction

   Registries are fundamental to RID.  Only very limited information can
   be Broadcast, but extended information is sometimes needed.  The most
   essential element of information sent is the UAS ID itself, the
   unique key for lookup of extended information in registries.

   While it is expected that registry functions will be integrated with
   USS, who will provide them is not yet determined in most, and is
   expected to vary between, jurisdictions.  However this evolves, the
   essential registry functions, starting with management of
   identifiers, are expected to remain the same, so are specified
   herein.

   While most data to be sent via Broadcast or Network RID is public,
   much of the extended information in registries will be private.  Thus
   AAA for registries is essential, not just to ensure that access is
   granted only to strongly authenticated, duly authorized parties, but
   also to support subsequent attribution of any leaks, audit of who
   accessed information when and for what purpose, etc.  As specific AAA
   requirements will vary by jurisdictional regulation, provider
   philosophy, customer demand, etc., they are left to specification in
   policies, which should be human readable to facilitate analysis and
   discussion, and machine readable to enable automated enforcement,
   using a language amenable to both, e.g., XACML.

   The intent of the negative and positive access control requirements
   on registries is to ensure that no member of the public would be
   hindered from accessing public information, while only duly
   authorized parties would be enabled to access private information.
   Mitigation of Denial of Service attacks and refusal to allow database
   mass scraping would be based on those behaviors, not on identity or
   role of the party submitting the query per se, but querant identity
   information might be gathered (by security systems protecting DRIP
   implementations) on such misbehavior.

   Registration under DRIP is vital as the worry of collisions in the
   hash portion of the DET.  Forgery of the DET is still possible, but
   including it as a part of a public registration mitigates a lot of
   the risk.  This document creates the DRIP DET registration and
   discovery ecosystem.  This includes all components in the ecosystem



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   (e.g., RAA, HDA, UA, GCS, USS).  The registration process will use
   the Extensible Provisioning Protocol (EPP) and other protocols.  The
   discovery process will leverage DNS and DNSSEC and related
   technology.  The DETs can be registered with as their "raw public
   keys" or in X.509 certificates.

2.  Terminology

2.1.  Required Terminology

   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.

2.2.  Definitions

   See [drip-requirements] for common DRIP terms.

   HDA:  Hierarchial HIT Domain Authority.  The 16 bit field identifying
      the HIT Domain Authority under a RAA.

   HID:  Hierarchy ID.  The 32 bit field providing the HIT Hierarchy ID.

   RAA:  Registered Assigning Authority.  The 16 bit field identifying
      the Hierarchical HIT Assigning Authority.

3.  DRIP Attestations & Certificates

3.1.  Attestation Structure

   All Attestations and Certificates under DRIP share the following
   format:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +---------------+---------------+---------------+---------------+
   |                                                               |
   .                                                               .
   .                 Attestor Identity Information                 .
   .                                                               .
   |                                                               |
   +---------------+---------------+---------------+---------------+
   |                                                               |
   .                                                               .
   .                       Attestation Data                        .
   .                                                               .



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   |                                                               |
   +---------------+---------------+---------------+---------------+
   |               Expiration Timestamp by Attestor                |
   +---------------+---------------+---------------+---------------+
   |                 Signing Timestamp by Attestor                 |
   +---------------+---------------+---------------+---------------+
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                     Signature by Attestor                     |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------+---------------+---------------+---------------+

   Attestor Identity Information: (0, 16-bytes or 120-bytes)
       Field containing Attestor Identity Information in various forms.

   Attestation Data:
       A field of variable length containing the attestation data.

   Expiration Timestamp by Attestor (4 bytes):
       Timestamp denoting recommended time to trust data to.

   Signing Timestamp by Attestor (4 bytes):
       Current time at signing.

   Attestor Signature (64 bytes):
       Signature over preceding fields using the keypair of
       the Attestor.

                      Figure 1: Attestation Structure

3.1.1.  Attestor Identity Information

   This can be any one of the following:

   1.  None




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   2.  Attestor HHIT: 16-bytes

   3.  Attestor SelfAttestation: 120-bytes

   A specific definition of an Attestation or Certificate defines which
   of these are used.

   Two Attestation's remove this field: MutualAttestation Section 3.2.4
   and LinkAttestation Section 3.2.5 as their definition clearly states
   that the signer is the second party with their HHIT or
   SelfAttestation already embedded in the Attestation Data.

3.1.2.  Attestation Data

   The data being attested to.  It can be one of the following forms:

   1.  Claims

   2.  Assertions

   3.  Attestations

   This field is variable length with no limit and specific definitions
   of an Attestation or Certificate indicate the fields, size and
   ordering of any subfields.

3.1.3.  Expiration Timestamp

   A UTC timestamp set some time into the future to indicate a point the
   Attestation Structure should not be trusted.

3.1.4.  Signing Timestamp

   A UTC timestamp set to the time when the Attestation Structure was
   signed.

3.1.5.  Signature

   An EdDSA25519 signature using the signing parties private key over
   the preceding fields in the Attestation Structure.

3.2.  Attestations

3.2.1.  Self-Attestation (SA-xx)

   The only attestation to use a claim (the Host Identity) in the
   Attestation Data with the HHIT acting as the Attestor Identity
   Information.



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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                          Hierarchical                         |
     |                       Host Identity Tag                       |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                          Host Identity                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                         Trust Timestamp                       |
     +---------------+---------------+---------------+---------------+
     |                        Signing Timestamp                      |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                            Signature                          |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 120-bytes

                      Figure 2: DRIP Self-Attestation

3.2.2.  Attestation (A-xy)

   (Editors Note: blurb here?)





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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                             SA-xx                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                             SA-yy                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by X                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by X                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by X                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 312-bytes

                         Figure 3: DRIP Attestation

3.2.3.  Concise Attestation (CA-xy)

   In constrained environments and when there is the guarantee of being
   able to lookup the HHITs to obtain HIs this attestation can be used.






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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                          Hierarchical                         |
     |                    Host Identity Tag of X                     |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                          Hierarchical                         |
     |                    Host Identity Tag of Y                     |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by X                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by X                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by X                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 104-bytes

                     Figure 4: DRIP Concise Attestation

3.2.4.  Mutual Attestation (MA-xy)

   An attestation that perform a sign over an existing Attestation where
   the signer is the second party of the embedded attestation.

   This Attestation is one of two that does not fill in the Attestor
   Identity Information (Section 3.1.1) as the data is already present
   in the Attestation Data (Section 3.1.2) in the form of Y's
   SelfAttestation.



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   The unique size of this attestation (384-bytes) allows for easy
   detection and subsequent decoding without issue.

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                              A-xy                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by Y                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by Y                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by Y                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 384-bytes

                     Figure 5: DRIP Mutual Attestation

3.2.5.  Link Attestation (LA-xy)

   An attestations that perform a sign over an existing
   ConciseAttestation where the signer is the second party of the
   embedded attestation.

   This Attestation is one of two that does not fill in the Attestor
   Identity Information (Section 3.1.1) as the data is already present
   in the Attestation Data (Section 3.1.2) in the form of Y's HHIT.




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   The unique size of this attestation (176-bytes) allows for easy
   detection and subsequent decoding without issue.

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                             CA-xy                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by Y                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by Y                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by Y                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 176-bytes

                      Figure 6: DRIP Link Attestation

3.2.6.  Broadcast Attestation (BA-xy)

   Required by DRIP Authentication Formats for Broadcast RID (Editor
   Note: add link to draft here) to satisfy [drip-requirements] GEN-1
   and GEN-3.








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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                          Hierarchical                         |
     |                    Host Identity Tag of X                     |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                          Hierarchical                         |
     |                    Host Identity Tag of Y                     |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                       Host Identity of Y                      |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by X                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by X                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by X                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 136-bytes

                    Figure 7: DRIP Broadcast Attestation




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3.3.  Certificates

   In DRIP certificates are signed by a third party that has no stake in
   the claims/assertions/attestations being attested to.

   It is analogous to a third party in legal system that signs a
   document as a "witness" and bears no responsibility in the document.

3.3.1.  Attestation Certificate (AC-zxy)

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                             SA-zz                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                              A-xy                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by Z                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by Z                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by Z                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 504-bytes



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                   Figure 8: DRIP Attestation Certificate

3.3.2.  Concise Certificate (CC-zxy)

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                          Hierarchical                         |
     |                    Host Identity Tag of Z                     |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                             CA-xy                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by Z                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by Z                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by Z                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 192-bytes

                     Figure 9: DRIP Concise Certificate

3.3.3.  Link Certificate (LC-zxy)






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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                          Hierarchical                         |
     |                    Host Identity Tag of Z                     |
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                             LA-xy                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by Z                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by Z                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by Z                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 300-bytes

                      Figure 10: DRIP Link Certificate

3.3.4.  Mutual Certificate (MC-zxy)










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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                             SA-zz                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     .                                                               .
     .                             MA-xy                             .
     .                                                               .
     |                                                               |
     +---------------+---------------+---------------+---------------+
     |                      Trust Timestamp by Z                     |
     +---------------+---------------+---------------+---------------+
     |                     Signing Timestamp by Z                    |
     +---------------+---------------+---------------+---------------+
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                         Signature by Z                        |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     |                                                               |
     +---------------+---------------+---------------+---------------+

     Length = 576-bytes

                     Figure 11: DRIP Mutual Certificate

4.  Registries

4.1.  Classes

   Under DRIP there 3 classes of registries, with specific variants in
   each.




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4.1.1.  Root

   This is a special registry holding the RAA value of 0 and HDA value
   of 0.  It delegates out RAA values only to registries that wish to
   act as an RAA.

   (Editors Note: we contemplate this is ICAO running this server or
   federation of them)

4.1.2.  Registered Assigning Authorities

   RAA's are the upper hierarchy in DRIP.  Most are contemplated to be
   Civil Aviation Authorities (CAAs) then delegate HDAs to manage their
   NAS.  This is does not preclude other entities to operate an RAA if
   the Root server allows it.

   All RAA's use an HDA value of 0 and have their RAA value delegated to
   them by the Root.

4.1.2.1.  ICAO Registry of Manufacturer's (IRM)

   A special RAA that hands out HDA values to participating
   Manufacturer's that hold an ICAO Manufacturer Code used in ANSI
   CTA2063-A Serial Numbers.

   It is holds the RAA value of 1 and HDA value of 0.

   (Editors Note: we contemplate this is ICAO running this server or
   federation of them)

4.1.3.  Hierarchial HIT Domain Authorities

4.1.3.1.  Manufacturer's Registry of Aircraft (MRA)

   A registry (HDA) run by a manufacturer of UAS systems that
   participate in Remote ID.  Stores UAS Serial Numbers under a specific
   ICAO Manufacturer Code (assigned to the manufacturer by ICAO).

   A DET can be encoded into a Serial Number (Editor Note: link to -uas-
   rid) and when done so this registry would hold a mapping from the
   Serial Number to the DET and its artifacts.

   Hold RAA value of 1 and HDA values of 1+.








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4.1.3.2.  Remote ID Registries (RIDR)

   Registry that holds the binding between a UAS Session ID (for DRIP
   the DET) and the UA Serial Number.  The Serial Number MUST have its
   access protected to allow only authorized parties to obtain.  The
   Serial Number SHOULD be encrypted in a way only the authorized party
   can decrypt.

   As part of the UTM system they also hold a binding between a UAS ID
   (Serial Number or Session ID) and an Operational Intent.

   (Editors Note: these are contemplated to be part of a USS as a
   function or a standalone SDSP in the UTM system)

   Hold RAA values of 2+ and HDA values of 1+.

4.2.  Federation

   (Editors Note: Due to nature of HHIT we could have multiple
   registries with same RAA/HDA pairings running and being federated
   together.  How do we handle this?)

5.  DRIP Fully Qualified Domain Names

   Under DRIP there are a number of FQDN forms used to allow lookups to
   take place.

   (Editor Note: copy in DET Section 5 here)

5.1.  Serial Number

   Serial Number: 8653FZ2T7B8RA85D19LX
   ICAO Mfr Code: 8653
   Length Code: F
   ID: FZ2T7B8RA85D19LX
   FQDN: Z2T7B8RA85D19LX.F.8653.mfr.uas.icao.int

5.2.  Reverse SN

   (Editors Note: convert SN to DET format then perform reverse DET?)

5.3.  DET









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   DET: 2001:0030:00a0:0145:a3ad:1952:0ad0:a69e
   ID: a3ad:1952:0ad0:a69e
   OGA: 5
   HDA: 0014 = 20
   RAA: 000a = 10
   Prefix: 20010030
   FQDN: a3ad19520ad0a69e.5.20.10.20010030.det.uas.icao.int

   When building a DET FQDN the following two things must be done:

   1.  The RAA and HDA values MUST be converted from hexadecimal to
       decimal form

   2.  The FQDN must be built using the expanded form of the IPv6
       address

   The prefix is included in the FQDN form to support other potential
   prefixes being used.

5.4.  Reverse DET

   $ORIGIN  5.4.1.0.0.a.0.0.0.3.0.0.1.0.0.2.ip6.arpa.
   e.9.6.a.0.d.a.0.2.5.9.1.d.a.3.a    IN   PTR

6.  Supported DNS Records

   DRIP requires a number of resource records, some specific to certain
   registries to function.

6.1.  HIP RR

   All registries will have their own DET associated with them and their
   respective DNS server will hold a HIP RR that is pointed to by their
   DET FQDN.

   MRA and RIDR servers will also have HIP RRs for their registered
   parties (aircraft and operators).

6.2.  CERT RR

   Most attestations can be placed into DNS.  An exception to this is
   the AttestationCertificate made during Session ID registration.

6.3.  NS RR

   Along with their associated "glue" record (A/AAAA) supports the
   traversal in DNS across the tree.




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   1.  <mfr.remoteid.aero> on Root points to specific DET FQDN of IRM

   2.  <icao_mfr_code>.mfr.remoteid.aero on IRM points to specific DET
       FQDN of MRA

   3.  <raa_value>.det.remoteid.aero on Root pointing to DET FQDN of
       matching RAA

   4.  <hda_value>.<raa_value>.det.remoteid.aero on RAA Registry
       pointing to DET FQDN of matching HDA

6.4.  AAAA RR

   DRIP requires the use of IPv6.

6.5.  SVR RR

   TODO - points to server for RDAP stuff

6.6.  TLSA RR

   Raw key format here; for DTLS support.  RFC6698

7.  Registry Operations

   (Editors Note: General processing instructions here?)

   As a general rule the following processing performed for any
   registration operation:

   1.  Verify SelfAttestation of registering party

   2.  Populate DNS with required/optional records

   3.  Populate Database with PII and other info

   4.  Generate and return required/optional Attestations

7.1.  Registering an RAA

   Specifically handled by the Root Registry (Section 4.1.1).

7.1.1.  Inputs

   Required:

   1.  SelfAttestation of RAA




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   2.  IP Address of RAA

7.1.2.  DNS Entries

   Required on Root:

   NS RR = <raa_value>.det.remoteid.aero NS <raa_det_fqdn>

   AAAA RR = <raa_det_fqdn> AAAA ...

   CERT RR = ???

   Required on RAA:

   HIP RR = <raa_det_fqdn> HIP ...

   CERT RR = ???

7.1.3.  Database Entries

7.1.4.  Outputs

7.2.  Registering an IRM

   Specifically handled by the Root Registry (Section 4.1.1).

7.2.1.  Inputs

   Required:

   1.  Self-Attestation of IRM

   2.  IP Address of IRM

7.2.2.  DNS Entries

   Required on Root:

   NS RR = mfr.remoteid.aero NS <irm_det_fqdn>

   NS RR = 1.det.remoteid.aero NS <irm_det_fqdn>

   AAAA RR = <irm_det_fqdn> AAAA ...

   CERT RR = ???

   Required on IRM:




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   HIP RR = <irm_det_fqdn> HIP ...

   CERT RR = ???

7.2.3.  Database Entries

7.2.4.  Outputs

   Required:

   1.  Attestation: Root on IRM

7.3.  Registering an HDA

   Specifically handled by an RAA (Section 4.1.2).

7.3.1.  Inputs

   Required:

   1.  Self-Attestation of HDA

   2.  IP Address of HDA

7.3.2.  DNS Entries

   Required on RAA:

   NS RR = <hda_value>.<raa_value>.det.remoteid.aero NS <hda_det_fqdn>

   AAAA RR = <hda_det_fqdn> AAAA ...

   CERT RR = ???

   Required on HDA:

   HIP RR = <hda_det_fqdn> HIP ...

7.3.3.  Database Entries

7.3.4.  Outputs

7.4.  Registering an MRA

   Specifically handled by the IRM Registry (Section 4.1.2.1).






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7.4.1.  Inputs

   Required:

   1.  ICAO Manufacturer Code

   2.  Self-Attestation of MRA

   3.  IP Address of MRA

7.4.2.  DNS Entries

   Required on IRM:

   NS RR = <icao_mfr_code>.mfr.remoteid.aero NS <mra_det_fqdn>

   NS RR = <hda_value>.1.det.remoteid.aero NS <mra_det_fqdn>

   AAAA RR = <mra_det_fqdn> AAAA ...

   CERT RR = ???

   Required on MRA:

   HIP RR = <mra_det_fqdn> HIP ...

   CERT RR = ???

7.4.3.  Database Entries

   (HDA value, MRA Details)

7.4.4.  Outputs

   Required:

   1.  Attestation: IRM on MRA

7.5.  Registering a Serial Number

   Specifically handled by a MRA (Section 4.1.3.1).

7.5.1.  Inputs

   Required:

   1.  Serial Number




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   2.  Aircraft Metadata

   Optional:

   1.  SelfAttestation: Aircraft on Aircraft (if DET encoded)

7.5.2.  DNS Entries

   Required on MRA:

   A/AAAA with Serial Number FQDN (Section 5.1)

   Optional on MRA:

   HIP RR of Aircraft with DET FQDN (Section 5.3) (<sn_det_fqdn> HIP
   ...)

   CERT RRs of SelfAttestation and BroadcastAttestation

7.5.3.  Database Entries

   (Serial Number, [DET], Metadata, [SelfAttestation])

7.5.4.  Outputs

   Optional:

   1.  BroadcastAttestation: Mfr on Aircraft

7.6.  Registering an Operator

   Specifically handled by a RIDR (Section 4.1.3.2).

7.6.1.  Inputs

   Required:

   1.  SelfAttestation: Operator on Operator

   2.  Operator PII

   Optional: TODO

7.6.2.  DNS Entries

   Optional on RIDR:

   HIP RR of Operator



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   CERT RRs SelfAttestation of Operator, A-ro

7.6.3.  Database Entries

   TODO

7.6.4.  Outputs

   Required:

   1.  Attestation (A-ro) - using SA-rr and SA-oo

   Optional:

   1.  ConciseAttestation (CA-ro) - using SA-oo

   2.  BroadcastAttestation (BA-ro) - using SA-oo

7.7.  Registering a Session ID

   Specifically handled by a RIDR (Section 4.1.3.2).

7.7.1.  Inputs

   Required:

   1.  Attestation: Registry on Operator

   2.  Attestation: Operator on Aircraft

   3.  UAS Serial Number

   Optional:

   1.  ConciseAttestation: Operator on Aircraft

   2.  MutualAttestation: Operator on Aircraft

   3.  LinkAttestation: Operator on Aircraft

   4.  Operational Intent ID (GUFI)

7.7.2.  DNS Entries

   Required on RIDR:

   HIP RR of Aircraft with DET FQDN (Section 5.3) (<session_det_fqdn>
   HIP ...)



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   CERT RRs for SelfAttestation of Aircraft, BroadcastAttestation

7.7.3.  Database Entries

   (Session ID, Serial Number, GUFI, A-oa, BA-ra, AC-roa)

7.7.4.  Outputs

   Required:

   1.  BroadcastAttestation (BA-ra) - generated using the embedded SA-aa
       from A-oa

   2.  AttestationCertificate (AC-roa) - using A-oa

   Optional:

   1.  MutualCertificate (MC-roa) - using MA-oa

   2.  ConciseCertificate (CC-roa) - using CA-oa

   3.  LinkCertificate (LC-roa) - using LA-oa

   4.  BroadcastAttestation's of parent Registries in chain

8.  Provisioning

   Under DRIP UAS RID a special provisioning procedure is required to
   properly generate and distribute the certificates and attestations to
   all parties in the USS/UTM ecosystem using DRIP RID.

   Keypairs are expected to be generated on the device hardware it will
   be used on.  Due to hardware limitations (see Section 10) and
   connectivity it is acceptable under DRIP RID to generate keypairs for
   the Aircraft on Operator devices and later securely inject them into
   the Aircraft (as defined in Section 8.6.2).  The methods to securely
   inject and store keypair information in a "secure element" of the
   Aircraft is out of scope of this document.

8.1.  Overview of Transactions

   In DRIP, each Operator MUST generate a Host Identity of the Operator
   (HIo) and derived Hierarchical HIT of the Operator (HHITo).  These
   are registered with a Private Information Registry along with
   whatever Operator data (inc.  PII) is required by the cognizant CAA
   and the registry.  In response, the Operator will obtain an
   attestation from the Registry, Attestation: Registry on Operator
   (A-ro), signed with the Host Identity of the Registry private key



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   (HIr(priv)) proving such registration.

   An Operator may now claim one or more UA.

   *  An Operator MUST generate a Host Identity of the Aircraft (HIa)
      and derived Hierarchical HIT of the Aircraft (HHITa)

   *  Create an attestation from the Operator on the Aircraft (A-oa)
      signed with the Host Identity of the Operator private key
      (HIo(priv)) to associate the UA with its Operator

   *  Register them with a Private Information Registry along with
      whatever UAS data is required by the cognizant CAA and Registry

   *  Obtain an attestation from the Registry on the Operator and
      Aircraft ("AC-roa") signed with the HIr(priv) proving such
      registration

   *  And obtain a broadcast attestation from the Registry on the
      Aircraft (BA-ra) signed with HIr(priv) proving UA registration in
      that specific registry while preserving Operator privacy.

   The operator then MUST provision the UA with HIa, HIa(priv), HHITa
   and B-Ara.

   *  UA engaging in Broadcast RID MUST use HIa(priv) to sign
      Authentication Messages and MUST periodically broadcast BA-ra.

   *  UAS engaging in Network RID MUST use HIa(priv) to sign
      Authentication Messages.

   *  Observers MUST use HIa from received BA-ra to verify received
      Broadcast RID Authentication messages.

   *  Observers without Internet connectivity MAY use BA-ra to identify
      the trust class of the UAS based on known registry vetting.

   *  Observers with Internet connectivity MAY use HHITa to perform
      lookups in the Public Information Registry and MAY then query the
      Private Information Registry which MUST enforce AAA policy on
      Operator PII and other sensitive information

8.2.  HHIT Delegation

   Under the FAA [NPRM], it is expecting that IDs for UAS are assigned
   by the UTM and are generally one-time use.  The methods for this
   however are unspecified leaving two options.




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   1  The entity generates its own HHIT, discovering and using thr RAA
      and HDA for the target Registry.  The method for discovering a
      Registry's RAA and HDA is out of scope here.  This allows for the
      device to generate an HHIT to send to the Registry to be accepted
      (thus generating the required Host Identity Claim) or denied.

   2  The entity sends to the Registry its HI for it to be hashed and
      result in the HHIT.  The Registry would then either accept
      (returning the HHIT to the device) or deny this pairing.

   In either case the Registry must decide on if the HI/HHIT pairing is
   valid.  This in its simplest form is checking the current Registry
   for a collision on the HHIT.

   Upon accepting a HI/HHIT pair the Registry MUST populate the required
   the DNS serving the HDA with the HIP RR and other relevant RR types
   (such as TXT and CERT).  The Registry MUST also generate the
   appropriate Attestation for the given operation.

   If the Registry denied the HI/HHIT pair, because there was a HHIT
   collision or any other reason, the Registry MUST signal back to the
   device being provisioned that a new HI needs to be generated.

8.3.  Registry

   (Editor Note: this should break down the individual registrations
   between Root/RAA, RAA/HDA and their special variants).

   TODO

   DRIP UAS RID defines two levels of hierarchy maintained by the
   Registration Assigning Authority (RAA) and HHIT Domain Authority
   (HDA).  The authors anticipate that an RAA is owned and operated by a
   regional CAA (or a delegated party by an CAA in a specific airspace
   region) with HDAs being contracted out.  As such a chain of trust for
   registries is required to ensure trustworthiness is not compromised.
   More information on the registries can be found in [hhit-registries].

   Both the RAA and HDA generate their own keypairs and self-signed
   attestations (SelfAttestation: RAA on RAA and SelfAttestation: HDA on
   HDA respectively).  The HDA sends to the RAA its self-signed
   attestation to be added into the RAA DNS.

   The RAA confirms the attestation received is valid and that no HHIT
   collisions occur before added a HIP RR to its DNS for the new HDA.
   An Attestation: RAA on HDA (A-rh) is sent as a confirmation that
   provisioning was successful.




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   The HDA is now a valid "Registry" and uses its keypair and
   SelfAttestation: HDA on HDA (SA-hh) with all provisioning requests
   from downstream.

8.4.  Manufacturer

                +--------------+    SA-a0a0 +-----------------+
                | Manufacturer | <--------> | Manufacturer CA |
                +--------------+ A-ma0      +-----------------+
                    ^    |
                    |    |
                    |    |
            SA-a0a0 |    |   A-ma0
                    |    |
                    |    v
                +----------+
                | Aircraft |
                +----------+

                     Figure 12: Manufacturer Provision

   During the initial configuration and production at the factory the
   Aircraft MUST be configured to have a serial number.  ASTM defines
   this to be an ANSI/CTA-2063A.  Under DRIP a HHIT can be encoded as
   such to be able to convert back and forth between them.  This is out
   of scope for this document.  TODO: link from UAS RID document.

   Under DRIP the Manufacturer SHOULD be using HHITs and have their own
   keypair and SA-mm (SelfAttestation: Manufacturer on Manufacturer).
   (Ed.  Note: some words on aircraft keypair and certs here?).

   SelfAttestation: Aircraft 0 on Aircraft 0 (SA-a0a0) is extracted by
   the manufacturer and sent to their Certificate Authority (CA) to be
   verified and added.  A resulting attestation (Attestation:
   Manufacturer on Aircraft 0 [A-ma0]) SHOULD be a DRIP Attestation -
   however this could be a X.509 certificate binding the serial number
   to the manufacturer.

8.5.  Operator












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                    +----------+            +---------+
                    | Registry | ---------> | HDA DNS |
                    +----------+  [HIP RR]  +---------+
                        ^   |
                        |   |
                        |   |
                    Coo |   | Aro
                        |   |
                        |   v
                    +----------+
                    | Operator |
                    +----------+

                       Figure 13: Operator Provision

   The Operator generates a keypair and HHIT as specified in DRIP UAS
   RID.  A self-signed attestation (Attestation: Operator on Operator
   [SA-oo]) is generated and sent to the desired Registry (HDA).  Other
   relevant information and possibly personally identifiable information
   needed may also be required to be sent to the Registry (all over a
   secure channel - the method of which is out of scope for this
   document).

   The Registry cross checks any personally identifiable information as
   required.  Certificate: Operator on Operator is verified (both using
   the expiration timestamp and signature).  The HHIT is searched in the
   Registries database to confirm that no collision occurs.  A new
   attestation is generated (Attestation: Registry on Operator) and sent
   securely back to the Operator.  Optionally the HHIT/HI pairing can be
   added to the Registries DNS in to form of a HIP Resource Record (RR).
   Other RRs, such as CERT and TXT, may also be used to hold public
   information.

   With the receipt of Attestation: Registry on Operator (A-ro) the
   provisioning of an Operator is complete.

8.6.  Aircraft

8.6.1.  Standard Provisioning

   Under standard provisioning the Aircraft has its own connectivity to
   the Registry, the method which is out of scope for this document.









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             +----------+
             | Registry |
             +----------+
                 ^
                 |
                 |
                 |  A-ro, A-oaN
                 |
                 |
             +----------+                        +----------+
             | Operator | <--------------------- | Aircraft |
             +----------+        A-a0aN          +----------+

                   Figure 14: Standard Provision: Step 1

   Through mechanisms not specified in this document the Aircraft should
   have methods to instruct the Aircraft onboard systems to generate a
   keypair and certificate.  This certificate is chained to the factory
   provisioned certificate (SelfAttestation: Aircraft 0 on Aircraft 0
   [SA-a0a0]).  This new attestation (Attestation: Aircraft 0 on
   Aircraft N [A-a0aN]) is securely extracted by the Operator.

   With A-a0aN the sub-attestation (SelfAttestation: Aircraft N on
   Aircraft N [SA-aNaN]) is used by the Operator to generate
   Attestation: Operator on Aircraft N (A-oaN).  This along with
   Attestation: Registry on Operator (A-ro) is sent to the Registry.

             +----------+
             | Registry |
             +----------+
                 |
                 |
                 |
                 |  Token
                 |
                 v
             +----------+                        +----------+
             | Operator | ---------------------> | Aircraft |
             +----------+        Token           +----------+

                   Figure 15: Standard Provision: Step 2

   On the Registry, A-ro is verified and used as confirmation that the
   Operator is already registered.  A-oaN also undergoes a validation
   check and used to generate a token to return to the Operator to
   continue provisioning.





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   Upon receipt of this token, the Operator injects it into the Aircraft
   and its used to form a secure connection to the Registry.  The
   Aircraft then sends Attestation: Manufacturer on Aircraft 0 (A-ma0)
   and Attestation: Aircraft 0 to Aircraft N (A-a0aN).

        +---------+
        | HDA DNS |
        +---------+
            ^
            |
            | HIP RR
            |
            |
            |
        +----------+ <----------------------------+
        | Registry |                              |
        +----------+ ------------------------+    |
            |                                |    |
            |                                |    |  Token,
            |  AC-roaN               BA-raN  |    |  A-ma0, A-a0aN
            |                                |    |
            |                                |    |
            v                                v    |
        +----------+                      +----------+
        | Operator |                      | Aircraft |
        +----------+                      +----------+

                   Figure 16: Standard Provision: Step 3

   The Registry uses Attestation: Manufacturer on Aircraft 0 (with an
   external database if supported) to confirm the validity of the
   Aircraft.  Attestation: Aircraft 0 on Aircraft N is correlated with
   Attestation: Operator on Aircraft N and Attestation: Manufacturer on
   Aircraft 0 to see the chain of ownership.  The new HHIT tied to
   Aircraft N is then checked for collisions in the HDA.  With the
   information the Registry generates two items: AttestationCertificate:
   Registry on Operator on Aircraft N (AC-roaN) and
   BroadcastAttestation: Registry on Aircraft N (BA-raN).  A HIP RR (and
   other RR types as needed) are generated and inserted into the HDA.

   AC-roaN is sent via a secure channel back to the Operator to be
   stored.  ABA-raN is sent to the Aircraft to be used in Broadcast RID
   as specified in (Editors Note: add link to -auth-formats).








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8.6.2.  Operator Assisted Provisioning

   This provisioning scheme is for when the Aircraft is unable to
   connect to the Registry itself or does not have the hardware required
   to generate keypairs and certificates.

             +----------+
             | Registry |
             +----------+






             +----------+                        +----------+
             | Operator | ---------------------> | Aircraft |
             +----------+     aN, SA-aNaN        +----------+

               Figure 17: Operator Assisted Provision: Step 1

   To start the Operator generates on behalf of the Aircraft a new
   keypair and Attestation: Aircraft N on Aircraft N (SA-aNaN).  This
   keypair and certificate are injected into the Aircraft for it to
   generate Attestation: Aircraft 0 on Aircraft N (A-a0aN).  After
   injecting the keypair and certificate, the Operator MUST destroy all
   copies of the keypair.

             +----------+
             | Registry |
             +----------+
                 ^
                 |
                 |
                 |  A-ro, A-ma0, A-a0aN, A-oaN
                 |
                 |
             +----------+                        +----------+
             | Operator | <--------------------- | Aircraft |
             +----------+      A-ma0, A-a0aN     +----------+

               Figure 18: Operator Assisted Provision: Step 2









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   Attestation: Manufacturer on Aircraft 0 (A-ma0) and Attestation:
   Aircraft 0 on Aircraft N (A-a0aN) is extracted by the Operator and
   the following data items are sent to the Registry; Attestation:
   Registry on Operator (A-ro), Attestation: Manufacturer on Aircraft 0
   (A-ma0), Attestation: Aircraft 0 on Aircraft N (A-a0aN), Attestation:
   Operator on Aircraft N (A-oaN).

             +----------+            +---------+
             | Registry | ---------> | HDA DNS |
             +----------+   HIP RR   +---------+
                 |
                 |
                 |
                 |  AC-roaN, BA-raN
                 |
                 v
             +----------+                        +----------+
             | Operator | ---------------------> | Aircraft |
             +----------+        BA-raN          +----------+

               Figure 19: Operator Assisted Provision: Step 3

   On the Registry validation checks are done on all attestations as per
   the previous sections.  Once complete then the Registry checks for a
   HHIT collision, adding to the HDA if clear and generates
   AttestationCertificate: Registry on Operator on Aircraft N (AC-roaN)
   and BroadcastAttestation: Registry on Aircraft N (BA-raN).  Both are
   sent back to the Operator.

   The Operator securely inject BA-raN and securely stores AC-roaN of
   Aircraft N.

8.6.3.  Initial Provisioning

   A special form of provisioning is used when the Aircraft is first
   sold to an Operator.  Instead of generating a new keypair, the built
   in keypair and certificate done by the Manufacturer is used to
   provision and register the aircraft to the owner.

   For this either Standard or Operator Assisted methods can be used.

9.  IANA Considerations

   (Editor Note: EPP/RDAP adds to existing registries, CERT RR update,
   HIP RR update)






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10.  Security Considerations

   TODO

11.  Contributors

   *  Scott Hollenbeck for his guidance with EPP/RDAP

   *  Andrei Gurtov for his insights as a pilot

12.  References

12.1.  Normative References

   [F3411-19] "Standard Specification for Remote ID and Tracking",
              February 2020.

   [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/info/rfc2119>.

   [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/info/rfc8174>.

12.2.  Informative References

   [drip-requirements]
              Card, S. W., Wiethuechter, A., Moskowitz, R., and A.
              Gurtov, "Drone Remote Identification Protocol (DRIP)
              Requirements", Work in Progress, Internet-Draft, draft-
              ietf-drip-reqs-18, 8 September 2021,
              <https://www.ietf.org/archive/id/draft-ietf-drip-reqs-
              18.txt>.

   [drip-rid] Moskowitz, R., Card, S. W., Wiethuechter, A., and A.
              Gurtov, "UAS Remote ID", Work in Progress, Internet-Draft,
              draft-ietf-drip-uas-rid-01, 9 September 2020,
              <https://www.ietf.org/archive/id/draft-ietf-drip-uas-rid-
              01.txt>.

   [hhit-registries]
              Moskowitz, R., Card, S. W., and A. Wiethuechter,
              "Hierarchical HIT Registries", Work in Progress, Internet-
              Draft, draft-moskowitz-hip-hhit-registries-02, 9 March
              2020, <https://www.ietf.org/archive/id/draft-moskowitz-
              hip-hhit-registries-02.txt>.



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   [NPRM]     "Notice of Proposed Rule Making on Remote Identification
              of Unmanned Aircraft Systems", December 2019.

   [RFC7519]  Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
              (JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
              <https://www.rfc-editor.org/info/rfc7519>.

   [RFC8392]  Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
              "CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392,
              May 2018, <https://www.rfc-editor.org/info/rfc8392>.

Authors' Addresses

   Adam Wiethuechter
   AX Enterprize, LLC
   4947 Commercial Drive
   Yorkville, NY 13495
   United States of America

   Email: adam.wiethuechter@axenterprize.com


   Stuart Card
   AX Enterprize, LLC
   4947 Commercial Drive
   Yorkville, NY 13495
   United States of America

   Email: stu.card@axenterprize.com


   Robert Moskowitz
   HTT Consulting
   Oak Park, MI 48237
   United States of America

   Email: rgm@labs.htt-consult.com


   Jim Reid
   RTFM llp
   St Andrews House
   382 Hillington Road

   Email: jim@rfc1035.com






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