[Docs] [txt|pdf|xml|html] [Tracker] [Email] [Nits]

Versions: 00 01 02 03 04

TMRID                                                    A. Wiethuechter
Internet-Draft                                                   S. Card
Intended status: Standards Track                           AX Enterprize
Expires: April 20, 2020                                     R. Moskowitz
                                                          HTT Consulting
                                                        October 18, 2019


                     TM-RID Authentication Formats
                    draft-wiethuechter-tmrid-auth-00

Abstract

   This document describes how to include HIPv2 into the proposed ASTM
   Remote ID specification defined in WK65041 by the F38 Committee under
   a Broadcast Remote ID (RID) scenario.  It defines a few different
   message schemes that can be used to assure past messages sent by a UA
   and also act as a assurance for UA trustworthiness in the absence of
   Internet connectivity at the receiving node.

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 April 20, 2020.

Copyright Notice

   Copyright (c) 2019 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.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must



Wiethuechter, et al.     Expires April 20, 2020                 [Page 1]


Internet-Draft             TM-RID Auth Formats              October 2019


   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terms and Definitions . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Requirements Terminology  . . . . . . . . . . . . . . . .   3
     2.2.  Definitions . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  UAS Problem Space . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Broadcast RID . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Network RID . . . . . . . . . . . . . . . . . . . . . . .   4
     3.3.  TM-RID Focus Problem Space  . . . . . . . . . . . . . . .   5
   4.  Trustworthy Multi-purpose Remote ID . . . . . . . . . . . . .   5
     4.1.  HIP Benefits for Remote ID  . . . . . . . . . . . . . . .   5
     4.2.  Levels of Trust . . . . . . . . . . . . . . . . . . . . .   6
       4.2.1.  TM-RID Level 1 (Identification) . . . . . . . . . . .   6
       4.2.2.  TM-RID Level 2 (Authentication) . . . . . . . . . . .   7
       4.2.3.  TM-RID Level 3 (Communication)  . . . . . . . . . . .   8
   5.  ASTM Authentication Message . . . . . . . . . . . . . . . . .   8
   6.  HIP Based Extensions to the ASTM Authentication Message . . .   9
     6.1.  Signed Hash Lists . . . . . . . . . . . . . . . . . . . .   9
       6.1.1.  Limitations . . . . . . . . . . . . . . . . . . . . .  12
     6.2.  HIP Based Authentication Wrapper  . . . . . . . . . . . .  13
       6.2.1.  Specific Use Case: Trusted Messages . . . . . . . . .  15
     6.3.  HIP Based Offline Authentication  . . . . . . . . . . . .  15
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  17
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  17
   9.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  17
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  17
     10.2.  Informative References . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  18

1.  Introduction

   The technology space of Unmanned Aircraft (UA) has been expanding
   rapidly on numerous fronts.  This rapid expansion has been noticed by
   various agencies and they are moving to add standards to protect
   individuals and organizations.

   The ASTM has been selected to create a specification for Remote ID
   (RID) classification that various CAAs can cite.  The work presented
   here is an expansion upon their standards to integrate IETF methods
   and work into the space where it is useful.





Wiethuechter, et al.     Expires April 20, 2020                 [Page 2]


Internet-Draft             TM-RID Auth Formats              October 2019


   The current draft standard for Remote ID (RID) does not, in any
   meaningful capacity, address the concerns of trust in the UA space
   with communication in the Broadcast RID environment.  This is a
   requirement that will need to be addressed eventually for various
   different parties that have a stake in the UA industry.

   This document will show how UAS RID can be made trustworthy and can
   enable immediate encrypted communications between mutually
   authenticated parties (typically observer and pilot) by using the
   Host Identity Protocol Version 2 (HIPv2) [RFC7401].

   Further, by leveraging the Hierarchical HIT (HHIT)
   [I-D.moskowitz-hip-hierarchical-hit] RID applications can be enabled
   to have trustworthiness for UA communication in the constrained
   environment of Broadcast RID.

   This solution is called "Trustworthy Multi-purpose Remote ID".

2.  Terms and Definitions

2.1.  Requirements 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

   CAA  Civil Aeronautics Administration.  An example is the Federal
      Aviation Administration; (FAA) in the United States of America.

   C2 Command and Control.

   RID  Remote ID.  Maximum length of 20 bytes.

   HI Host Identity.

   HIT  Host Identity Tag.

   HHIT  Hierarchical Host Identity Tag.

   UA Unmanned Aircraft.

   UAS (Unmanned Aircraft System)  Composed of Unmanned Aircraft and all
      required on-board subsystems, payload, control station, other
      required off-board subsystems, any required launch and recovery



Wiethuechter, et al.     Expires April 20, 2020                 [Page 3]


Internet-Draft             TM-RID Auth Formats              October 2019


      equipment, all required crew members, and command and control (C2)
      links between UA and the control station.

   USS (UAS Service Supplier)  USSs provide UTM services to support the
      UAS community, to connect Operators and other entities to enable
      information flow across the USS network, and to promote shared
      situational awareness among UTM participants.  (From FAA UTM
      ConOps V1, May 2018).

3.  UAS Problem Space

   UA Systems (UAS) are usually in a volatile environment when it comes
   to communication.  UA are generally small with little computational
   (or flying) horsepower to carry standard communication equipment.
   This limits the mediums of communication to few viable options.  The
   ASTM standard focuses on two ways of communicating to a UAS for RID:
   Broadcast and Network.

3.1.  Broadcast RID

   Broadcast RID has three mediums of communication defined by the ASTM.
   These are: Bluetooth 4.X, Bluetooth 5.X Long Range, and Wifi with
   Neighbor Aware Networking (NAN).

   A UA under the ASTM standard is required to support at least one of
   these methods to broadcast messages using the medium's respective
   advertisement framing methods.  Note that when using Bluetooth 5 it
   must be transmitted concurrently with Bluetooth 4.X (which the ASTM
   refers to as Bluetooth Legacy).

   The selection of the Broadcast medium was driven by research into
   what is commonly available on 'ground' units (smartphones and
   tablets) and what was found as prevalent or 'affordable' in UA.
   Further, there must be an API for the UAS receiving application to
   have access to these messages.  It is worth noting that at this time,
   Bluetooth 4.X is readily available but the other two are more for
   future devices.  Thus the focus on working within the 26 byte limit
   of the Bluetooth 4.X "Broadcast Frame" that goes out on the beacon
   channels.

   Finally, the 26 byte limit of the Bluetooth 4.1 "Broadcast Frame"
   strictly enforces the RID maximum length of 20 bytes.

3.2.  Network RID

   Network RID is a much more open space and is enabled when a UA has
   Internet connectivity on board.  This means, in most cases, the




Wiethuechter, et al.     Expires April 20, 2020                 [Page 4]


Internet-Draft             TM-RID Auth Formats              October 2019


   inclusion of a cellular modem on board, but can include WiFi
   communications.  Network RID is the subject of a future document.

3.3.  TM-RID Focus Problem Space

   This document will focus on adding trust to Broadcast RID.  The ASTM
   proposed standard 'used' the limitation put onto the UA by its
   physical design and radio communications to leave one important issue
   un-addressed: Trust.

   Further, the one-way, Adhoc, nature of Broadcast RID precludes any
   stateful security protocol to provide trust which further hampered
   any evaluation of Trust methodologies.

   As currently defined by ASTM, any UA can announce a RID and an
   observer would be seriously challenged to validate the validity in
   the RID and thus any information about the UA.  This is why trust in
   the RID and related trust for all Broadcast messages is considered
   critical in the safe operation of UAs.

4.  Trustworthy Multi-purpose Remote ID

   This document addresses this oversight by using HIP to bring trust
   into UA communication without having to redesign the standard.  The
   Host Identity Tag (HIT) and Host Identity (HI) of HIP are used to
   provide signed statements of Trust of the broadcast messages.  HIP,
   for Broadcast RID, is only used as in HHIT Registries
   [I-D.moskowitz-hip-hhit-registries] to prevent duplicate HHITs and
   provide the Registries with UA information for DNS and other
   inquires.

   The use of HIP is strongly encouraged by the authors to be used in
   Network RID.

4.1.  HIP Benefits for Remote ID

   The Host Identity Tag (HIT) of HIP is unique among structured number
   Identifiers.  It significantly more valuable as an Identifier than
   any other structured number in IETF standards, including [RFC6920]
   option of hash of Public Keys.

      It is a valid IPv6 (non-routable) address.  As such it can be used
      directly as addresses in applications.

      The Suite ID field informs the receiver of the underlying
      cryptographic Identity.





Wiethuechter, et al.     Expires April 20, 2020                 [Page 5]


Internet-Draft             TM-RID Auth Formats              October 2019


      The hash of the Host Identity public key provides the real proof
      of ownership of the HIT through any private key operation.

   By using HIP a number of benefits to UAs are immediately enabled:

   Unique Identification:  Using the HIP's Host Identity Tag (HIT) a
      unique identifier can be used as a handle for more information
      than just PII.

   Immediate UA Context:  The Hierarchical Host Identity Tag (HHIT)
      provides provable context about the Identity.

   Automatic Connectivity:  When both devices are using HIP the HIT can
      be used, along with standard DNS methods, to quickly create secure
      connections between hosts.  This applies even when both end-points
      are mobile in nature.

4.2.  Levels of Trust

   TM-RID for Broadcast RID there are three levels of trust:

   Level 1 (Identification):  The HHIT is a unique identifier that can
      enable other levels of TM-RID while still fitting within the
      specification of the standard for ID fields.

   Level 2 (Authentication):  When a HHIT is used for an ID of a UA a
      lookup to other information is easy and already has infrastructure
      to do so in place.

   Level 3 (Communication):  After looking up information using a HHIT
      dynamic communication to other parties can be performed that is
      secure and trusted.  (Note that this is for Network RID.)

4.2.1.  TM-RID Level 1 (Identification)

   Level 1 uses HHIT as an ID type in the ASTM standard.  This gives no
   immediate effects of HIP or trust for the UA, but can enable further
   features in other levels.

   Under the current proposed standard (which does not include HIP as a
   valid entry for ID type) the ID type of "4" should be used in the
   Basic ID Message to signal the use of a HHIT as the ID.

   At the time of writing Type 4 in the ASTM standard has yet to used,
   there is no definition for Private used ID types in the standard to
   use.





Wiethuechter, et al.     Expires April 20, 2020                 [Page 6]


Internet-Draft             TM-RID Auth Formats              October 2019


   The RID ONLY is sent in the Basic ID Message.  The standard relies on
   the MAC address to relate all messages from a UA to this RID.

   Level 1 does not provide any trust in the RID.  The Basic ID Message
   is limited to 24 bytes and can only carry the, at maximum 20 byte,
   RID.

   Below is an example of a ASTM Basic ID message format using HHIT as
   the UAS ID type.

    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
   +---------------+---------------+---------------+---------------+
   |  Msg. Header  |                                               |
   +---------------+                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                             HHIT                              |
   |                                                               |
   |                                                               |
   |                                                               |
   |               +-----------------------------------------------|
   |               |                  RESERVED                     |
   +---------------+-----------------------------------------------+

   Msg. Header (1 byte)
           Contains two subfields: ID Type and UA Type (of 4 bits each).
           In the above example the ID Type would be set to "0100".

4.2.2.  TM-RID Level 2 (Authentication)

   With Level 2 it is assumed that the receiving application being used
   by the observer has encountered a HHIT in a Basic ID Message.

   A HHIT can be used to construct a FQDN that can be used in a DNS
   query that will minimally provide the HI for validating signed
   Broadcast Authentication Messages.

   This construction may be through a reverse lookup using the HHIT as
   an IPv6 address.  It may be through an FQDN construction method
   imposed on the receiving application by the receiving application's
   USS.

   A Suite ID of EdDSA [I-D.moskowitz-hip-new-crypto] with the
   EdDSA25519 curve is used as its 64 byte signature will fit in the
   Authentication Messages.




Wiethuechter, et al.     Expires April 20, 2020                 [Page 7]


Internet-Draft             TM-RID Auth Formats              October 2019


   Besides the HI, the most common case will most likely yield a pointer
   of some kind to be used in a controlled access controlled database to
   obtain PII.

4.2.3.  TM-RID Level 3 (Communication)

   Under Level 3 the HHITs, along with Rendezvous Servers (RVS) and
   other HIP aware/enabled infrastructure, would be used as intended to
   connect two hosts securely.

   This will be the subject of the Network RID document(s).

5.  ASTM Authentication Message

   The ASTM Authentication Message format is defined as follows:

   Page 0:
    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
   +---------------+---------------+---------------+---------------+
   |  Msg. Header  |   Page Count  |     Length    |               /
   +---------------+---------------+---------------+---------------+
   /                   Timestamp                   |               |
   +-----------------------------------------------+               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                Authentication Data / Signature                |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   Page 1 - 4:
    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
   +---------------+-----------------------------------------------+
   |  Msg. Header  |                                               |
   +---------------+                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                 Authentication Data / Signature               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |



Wiethuechter, et al.     Expires April 20, 2020                 [Page 8]


Internet-Draft             TM-RID Auth Formats              October 2019


   +---------------------------------------------------------------+

   Msg. Header
           A byte field containing two 4 bit fields.
           Authentication Type and Page Number.

   Page Count
           Only on page 0. Total number of pages this
           authentication message has. Max value of 5.

   Length
           Total length of Authentication Data / Signature
           in bytes. Value of 0 - 109.

   Timestamp
           32 bit Unix timestamp since 00:00:00 01/01/2019.

   Authentication Data / Signature
           Opaque authentication data.


   A few important things to note on this format and its constraints.

   1.  Each page has only 24 bytes based on the Bluetooth 4.X/5.X
       specification.

   2.  The limit on Page Count of 5 is based on being able to fit this
       message as well as 5 other messages (each capped at 25 bytes)
       into a Bluetooth 5 atomic message.  The intention is that this
       message authenticates the whole pack.

6.  HIP Based Extensions to the ASTM Authentication Message

   The following section describes various methods that HIP can help
   enable more trustworthy communication using the Authentication
   Message as the base.  Each diagram will show all 5 pages of the
   format filled out as examples.

6.1.  Signed Hash Lists

   This format is designed to provide provenance to Broadcast RID
   messages sent by a give UAS.

   Page 0:
    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
   +---------------+---------------+---------------+---------------+
   |  Msg. Header  |   Page Count  |     Length    |               /



Wiethuechter, et al.     Expires April 20, 2020                 [Page 9]


Internet-Draft             TM-RID Auth Formats              October 2019


   +---------------+---------------+---------------+---------------+
   /                   Timestamp                   | H-Alg | H-Len |
   +---------------------------------------------------------------+
   |                Hash of Previous Auth. Message                 |
   +---------------------------------------------------------------+
   |                Hash of Current Auth. Message                  |
   +---------------------------------------------------------------+
   |                          Message Hash                         |
   +---------------------------------------------------------------+
   |                          Message Hash                         |
   +---------------------------------------------------------------+

   DataPage 1:
    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
   +---------------+---------------+-------------------------------+
   |  Msg. Header  | H-Alg | H-Len |            RESERVED           |
   +---------------+---------------+-------------------------------+
   |                          Message Hash                         |
   +---------------------------------------------------------------+
   |                          Message Hash                         |
   +---------------------------------------------------------------+
   |                          Message Hash                         |
   +---------------------------------------------------------------+
   |                          Message Hash                         |
   +---------------------------------------------------------------+
   |                          Message Hash                         |
   +---------------------------------------------------------------+

   Page 2:
    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
   +---------------+---------------+-------------------------------+
   |  Msg. Header  |    RESERVED   |       Signature Length        |
   +---------------+---------------+-------------------------------+
   |       Signature Algorithm     |                               |
   +-------------------------------+                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                         HHIT Signature                        |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   Page 3:
    0                   1                   2                   3



Wiethuechter, et al.     Expires April 20, 2020                [Page 10]


Internet-Draft             TM-RID Auth Formats              October 2019


    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
   +---------------+-----------------------------------------------+
   |  Msg. Header  |                                               |
   +---------------+                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                         HHIT Signature                        |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   Page 4:
    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
   +---------------+-----------------------------------------------+
   |  Msg. Header  |                                               |
   +---------------+                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                         HHIT Signature                        |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   H-Alg, H-Len: (4 bits), (4 bits)
       These are fields for relaying information of the Hash
       algorithm used for the messages and the Hash length (in octets).
       For this example of the format a length of 4 bytes is
       used.

   Hash of Previous Auth. Message: (4 bytes)
       A hash of the previous send Authentication message.

   Hash of Current Auth. Message: (4 bytes)
       A hash of the current Authentication message.

   Message Hash: (4 bytes)
       A hash of a previously sent message.

   Signature Length: (2 bytes)



Wiethuechter, et al.     Expires April 20, 2020                [Page 11]


Internet-Draft             TM-RID Auth Formats              October 2019


       Length of signature in octets, excluding Length, and Padding

   Signature Algorithm: (2 bytes)
       Self explanatory.

   HHIT Signature: (64 bytes)
           EdDSA25519 signature using an EdDSA25519-based HHIT from HIP.
           Spread across 3 pages of a given DataPage.

   This specific format has various different ways to be added into the
   Authentication Message structure - the general concept is the same
   regardless.

   By hashing previously sent messages and signing them we gain trust in
   the UAS's previous reports.  An observer who has been listening for
   any length of time can hash received messages and cross check against
   listed hashes.  The signature is signed across the list of hashes.

   Two special hashes are included; a previous authentication hash,
   which links to the previous signed hash list message, as well as a
   current hash.  This gives a pseudo-blockchain provenance to the
   authentication message that could be traced back if the observer was
   present for extended periods of time.

   In regards to the creation and use of the current authentication hash
   field:

   First during creation and signing of this message format this field
   MUST be set to 0.  So the signature will be based on this field being
   0, as well as its own hash.  It is an open question of if we compute
   the hash, then sign or sign then compute.

   There a few different ways to cycle this message.  We can "roll up"
   the hash of 'current' to 'previous' when needed or to completely
   recompute the hash.  This mostly depends on the previous note.

6.1.1.  Limitations

   With the current format defined by ASTM only 7 messages can be hashed
   reasonably in the above format.

   Another option is to places hashes into the Authentication Wrapper
   format (also defined in this document).  This only gives five total
   hashes - excluding the pseudo-blockchain linking hashes entirely.

   To address this problem the authors feel that the Authentication
   Messages needs to have a max bound of 10 pages, instead of 5.  This
   argument is discussed later in this document.



Wiethuechter, et al.     Expires April 20, 2020                [Page 12]


Internet-Draft             TM-RID Auth Formats              October 2019


6.2.  HIP Based Authentication Wrapper

   This format is a way to authenticate a given UA using the first 2
   levels of TM-RID for UAS.

   Page 0:
    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
   +---------------+---------------+---------------+---------------+
   |  Msg. Header  |   Page Count  |     Length    |               /
   +---------------+---------------+---------------+---------------+
   /                   Timestamp                   |    RESERVED   |
   +-----------------------------------------------+---------------+
   |                                                               |
   |                                                               |
   |                                                               |
   |                             HHIT                              |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   Page 1:
    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
   +---------------+-----------------------------------------------+
   |  Msg. Header  |                 Trust Timestamp               /
   +---------------+---------------+-------------------------------+
   /               |    RESERVED   |                               |
   +---------------+---------------+                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                         HHIT Signature                        |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   Page 2:
    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
   +---------------+-----------------------------------------------+
   |  Msg. Header  |                                               |
   +---------------+                                               |
   |                                                               |
   |                                                               |
   |                                                               |



Wiethuechter, et al.     Expires April 20, 2020                [Page 13]


Internet-Draft             TM-RID Auth Formats              October 2019


   |                                                               |
   |                         HHIT Signature                        |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   Page 3:
    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
   +---------------+-----------------------------------------------+
   |  Msg. Header  |                                               |
   +---------------+                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                         HHIT Signature                        |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   Page 4:
    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
   +---------------+-----------------------------------------------+
   |  Msg. Header  |                                               |
   +---------------+                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                            Payload                            |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   +---------------------------------------------------------------+

   HHIT
           16 byte HHIT of EdDSA25519 HI.

   Trust Timestamp
           4 byte message trust until timestamp.




Wiethuechter, et al.     Expires April 20, 2020                [Page 14]


Internet-Draft             TM-RID Auth Formats              October 2019


   HHIT signature
           64 byte Signature of whole message.

   Payload
           0 to n bytes of payload. Max of n is 23.

   In this format the Payload could be anything that fits within the 23
   bytes.  A further two btyes could be used for payload (by removing)
   the RESERVED sections allowing for 25 bytes of payload.

6.2.1.  Specific Use Case: Trusted Messages

   This document suggests the creation of a "Trusted Message".

   One specific use case that is useful in the RID space is the creation
   of a "Trusted Vector Message".  By placing a previous [or new] vector
   message into the Payload section of the Authentication Message a
   verifiable broadcast can be created.

   Due to being signed this creates an authentic vector that is hard to
   spoof, which can confirm flight paths in real time.

   This model can be applied to any of the Broadcast RID messages in the
   ASTM standard as they all fit within the max of 25 bytes.

6.3.  HIP Based Offline Authentication

   This specific format does not currently fit within the ASTM
   specification.  Requiring a minimum of 200 bytes, this would require
   the Authentication Message to have 10 pages, instead of the current 5
   page limit.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   |                            DEV HHIT                           |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            TIMESTAMP                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   |                            DEV HHIT                           |
   |                              SIG                              |
   .                                                               .
   .                                                               .
   .                                                               .



Wiethuechter, et al.     Expires April 20, 2020                [Page 15]


Internet-Draft             TM-RID Auth Formats              October 2019


   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   |                              DEV HI                           |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         AUTH TIMESTAMP                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   |                           AUTH HHIT                           |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   |                            AUTH                               |
   |                              SIG                              |
   .                                                               .
   .                                                               .
   .                                                               .
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   /                            PAYLOAD                            /
   /                                                               /
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   DEV HHIT       16 byte Dev HHIT of EdDSA25519 HI
   TIMESTAMP      4 byte packet trust until timestamp
   DEV HHIT SIG   64 byte Signature of whole packet
   DEV HI         32 byte Device HI of EdDSA25519 HI
   AUTH TIMESTAMP 4 byte Dev HHIT trust until timestamp
   AUTH HHIT      16 byte Authorizer's HHIT of EdDSA25519 HI
   AUTH SIG       64 byte Signature of Device HHIT-HI
   PAYLOAD        0 to n bytes of payload
   Length             200 + n bytes

   What this will grant, if attainable in future revisions of the ASTM
   specification, is the ability to authenticate UA information when the
   receiving device of the observer (e.g. a smartphone with a dedicated
   RID application) has no Internet service (e.g.  LTE signal).

   By including the device HI along with a signature from the registry
   the UA is under, we can assert trust of a given drone without
   requiring the need for immediate reverse lookups online.



Wiethuechter, et al.     Expires April 20, 2020                [Page 16]


Internet-Draft             TM-RID Auth Formats              October 2019


7.  IANA Considerations

   TBD

8.  Security Considerations

   TBD

9.  Acknowledgments

   TBD

10.  References

10.1.  Normative References

   [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>.

10.2.  Informative References

   [I-D.moskowitz-hip-hhit-registries]
              Moskowitz, R., Card, S., and A. Wiethuechter,
              "Hierarchical HIT Registries", draft-moskowitz-hip-hhit-
              registries-01 (work in progress), October 2019.

   [I-D.moskowitz-hip-hierarchical-hit]
              Moskowitz, R., Card, S., and A. Wiethuechter,
              "Hierarchical HITs for HIPv2", draft-moskowitz-hip-
              hierarchical-hit-01 (work in progress), October 2019.

   [I-D.moskowitz-hip-new-crypto]
              Moskowitz, R., Card, S., and A. Wiethuechter, "New
              Cryptographic Algorithms for HIP", draft-moskowitz-hip-
              new-crypto-02 (work in progress), October 2019.

   [RFC6920]  Farrell, S., Kutscher, D., Dannewitz, C., Ohlman, B.,
              Keranen, A., and P. Hallam-Baker, "Naming Things with
              Hashes", RFC 6920, DOI 10.17487/RFC6920, April 2013,
              <https://www.rfc-editor.org/info/rfc6920>.





Wiethuechter, et al.     Expires April 20, 2020                [Page 17]


Internet-Draft             TM-RID Auth Formats              October 2019


   [RFC7401]  Moskowitz, R., Ed., Heer, T., Jokela, P., and T.
              Henderson, "Host Identity Protocol Version 2 (HIPv2)",
              RFC 7401, DOI 10.17487/RFC7401, April 2015,
              <https://www.rfc-editor.org/info/rfc7401>.

Authors' Addresses

   Adam Wiethuechter
   AX Enterprize
   4947 Commercial Drive
   Yorkville, NY  13495
   USA

   Email: adam.wiethuechter@axenterprize.com


   Stuart W. Card
   AX Enterprize
   4947 Commercial Drive
   Yorkville, NY  13495
   USA

   Email: stu.card@axenterprize.com


   Robert Moskowitz
   HTT Consulting
   Oak Park, MI  48237
   USA

   Email: rgm@labs.htt-consult.com




















Wiethuechter, et al.     Expires April 20, 2020                [Page 18]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/