drip A. Wiethuechter Internet-Draft Independent Obsoletes: 7343 (if approved) R. Moskowitz Updates: 7401, 9374 (if approved) HTT Consulting Intended status: Standards Track 12 October 2026 Expires: 15 April 2027 Overlay Routable Crytographic Hash IDentifiers Version 3 draft-atwrgm-drip-orchid-v3-00 Abstract Over time improvements and implementation considerations have been accumulating around Overlay Routable Cryptographic Hash Identifiers (ORCHIDs) for the Host Identity Protocol (HIP) and the Drone Remote Identification Protocol (DRIP). Such improvements like the addition of hierarchy in RFC9374, or the development of using ORCHIDs in other frameworks are scattered across resources. This document serves to combine lessons learned and minor corrections into a single specification that obsolete RFC7343 and updates RFC7401 and RFC9374 to maintain interoperability of ORCHID-aware implementations. About This Document This note is to be removed before publishing as an RFC. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-atwrgm-drip-orchid-v3/. Discussion of this document takes place on the drip Working Group mailing list (mailto:tm-rid@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/tm-rid/. Subscribe at https://www.ietf.org/mailman/listinfo/tm-rid/. Source for this draft and an issue tracker can be found at https://github.com/atw-ietf/draft-orchid-v3. 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/. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 1] Internet-Draft orchid-v3 October 2026 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 15 April 2027. Copyright Notice Copyright (c) 2026 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 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 . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Purpose . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Background . . . . . . . . . . . . . . . . . . . . . . . 4 1.3. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. Additional Definitions & Abbreviations . . . . . . . . . 5 3. Architecture . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Fields & Construction . . . . . . . . . . . . . . . . . . 5 3.1.1. OGA ID & Suite ID . . . . . . . . . . . . . . . . . . 6 3.1.2. Hash Function Guidelines . . . . . . . . . . . . . . 7 3.2. Class Definitions . . . . . . . . . . . . . . . . . . . . 7 3.3. Guidelines for Internet Frameworks & Infrastructure . . . 8 3.3.1. COSE & JOSE . . . . . . . . . . . . . . . . . . . . . 8 3.3.2. Public Key Infrastructure . . . . . . . . . . . . . . 9 3.3.3. Domain Name System . . . . . . . . . . . . . . . . . 9 3.4. Considerations . . . . . . . . . . . . . . . . . . . . . 9 4. Host Identity Protocol . . . . . . . . . . . . . . . . . . . 10 4.1. Host Identity Tag . . . . . . . . . . . . . . . . . . . . 10 4.2. Payload Format . . . . . . . . . . . . . . . . . . . . . 10 4.2.1. HIP Controls . . . . . . . . . . . . . . . . . . . . 10 4.3. HIP Parameters . . . . . . . . . . . . . . . . . . . . . 10 4.3.1. HOST_ID . . . . . . . . . . . . . . . . . . . . . . . 10 4.3.2. HIT_SUITE_LIST . . . . . . . . . . . . . . . . . . . 12 4.3.3. HIP_PREFIX_LIST . . . . . . . . . . . . . . . . . . . 14 4.3.4. NOTIFICATION . . . . . . . . . . . . . . . . . . . . 15 Wiethuechter & Moskowitz Expires 15 April 2027 [Page 2] Internet-Draft orchid-v3 October 2026 4.4. HIP Packets . . . . . . . . . . . . . . . . . . . . . . . 15 4.4.1. HIP Initiator (I1) . . . . . . . . . . . . . . . . . 15 4.4.2. HIP Responder (R1) . . . . . . . . . . . . . . . . . 15 5. Drone Remote ID Protocol . . . . . . . . . . . . . . . . . . 15 5.1. DRIP Entity Tag . . . . . . . . . . . . . . . . . . . . . 15 5.2. Addition to HI Algorithms . . . . . . . . . . . . . . . . 16 5.3. Addition to HIP Prefix ID . . . . . . . . . . . . . . . . 16 5.4. Additions to HIP Suite ID . . . . . . . . . . . . . . . . 16 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 7. Security Considerations . . . . . . . . . . . . . . . . . . . 17 7.1. Hash Input . . . . . . . . . . . . . . . . . . . . . . . 17 7.2. Hash Size vs Collisions . . . . . . . . . . . . . . . . . 17 8. Privacy & Transparency Considerations . . . . . . . . . . . . 18 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 9.1. Normative References . . . . . . . . . . . . . . . . . . 18 9.2. Informative References . . . . . . . . . . . . . . . . . 18 Appendix A. OGA ID Encodings & Enumerations . . . . . . . . . . 21 A.1. Basic OGA ID . . . . . . . . . . . . . . . . . . . . . . 21 A.2. Extended OGA ID . . . . . . . . . . . . . . . . . . . . . 22 A.3. Flex OGA ID . . . . . . . . . . . . . . . . . . . . . . . 24 Appendix B. Host Identities . . . . . . . . . . . . . . . . . . 25 B.1. RSA . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 B.2. DSA . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 B.3. ECDSA & ECDSA_LOW . . . . . . . . . . . . . . . . . . . . 26 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27 1. Introduction 1.1. Purpose This document provides clarifications and corrections around the use of Overlay Routable Cryptographic Hash Identifiers (ORCHIDs) for the Host Identity Protocol (HIP, [RFC9063]) and the Drone Remote Identification Protocol (DRIP, [RFC9434]). Over time the construction and expected uses of an ORCHID have changed, most recently in the series of documents from the DRIP Working Group. This has resulted in a confusing set of requirements and options with minor errors and missing considerations across a number of documents. Simplifying the context and knowledge required to produce a cross- domain implementation using ORCHIDs is paramount for interoperability and is the goal of this document. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 3] Internet-Draft orchid-v3 October 2026 1.2. Background An ORCHID is the result of a process, originally defined in [RFC7343], that hashes information down to a "tag" in the form of valid IPv6 address out of special-use address space. Anything can be the input for this process for example the Host Identity Tag (HIT) and later the DRIP Entity Tag (DET, [RFC9374]) use a public key of an asymmetric key-pair. .---------------. +---+ ORCHID Class A +-------+----------+---------------------+ | '---------------' | | | | prefix | oga ID | hash | +---o------------------------+-----o----+----------o----------+ | | | | | | | .---------------------. | | +---o---+ Unicast IPv6 Address +---o------+--------o----------+ | '------------+--------' | | | network ID | subnet ID | interface ID | +-----------o--------+---------------o----+----------o--------+ | | | | | | | | | +-----------o------------------+-----o----+----------o--------+ | prefix & information | oga ID | hash | | .---------------------. | | | +---+ ORCHID Class B, C, D +---+----------+-------------------+ '---------------------' Figure 1: Comparison of ORCHID Classes to Unicast IPv6 Address The HIT is an identifier that is built around the use of HIP and the Base Exchange (BEX). DRIP improved the HIT by introducing the concept of a Hierarchial HIT (HHIT) and developing the DET as a session identifier for UAS RID. Being under a broadcast centric domain, DRIP users are in most cases is not expected to or cannot perform the HIP BEX. During the development of DETs, it was broadly attempted to keep backwards compatibility with the existing HIP specifications. Recent developments have found this goal has fallen short, with various elements of HIP not being interoperable with DETs. One example is the Suite ID definition of DRIP and the original HIP parameter to share them. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 4] Internet-Draft orchid-v3 October 2026 1.3. Scope This document obsoletes [RFC7343], such that the construction of ORCHIDs for [RFC7401], [RFC9374], and other classes (Figure 1) are clearly defined in a single document. It also updates [RFC7401] to enable the interoperability of ORCHIDs in general rather specifically the HIT. Guidelines for using of ORCHIDs in other applications such as Object Signing & Encryption, Public Key Infrastructure and the Domain Name System (DNS) is also specified or referenced. 2. 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. 2.1. Additional Definitions & Abbreviations This document uses the Concise Data Definition Language (CDDL, [RFC8610]). TBD 3. Architecture Author TBD: small blurb on arch. w/ high-level changes from RFC7343? 3.1. Fields & Construction The general construction of an ORCHID is adapted from [RFC7343] and [RFC9374] and is shown below in Figure 2. Prefix := IPv6 Prefix Context ID := CGA Extension Type Tag bitstring Info := Additional information bitstring OGA ID := Orchid Generation Algorithm (OGA) ID Input := any bitstring Hash := Hash Function( Input ) ORCHID := Prefix | Info | OGA ID | Hash Figure 2: ORCHID Format & Construction *_Prefix_*: IANA assigned IPv6 Prefix from the Special Use block. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 5] Internet-Draft orchid-v3 October 2026 Size P_SIZE in bits. *_Context ID_* A randomly generated bitstring value defining the expected usage context for the particular ORCHID by _Prefix_ and _OGA ID_ to be used as part of the _Input_ bitstring or _Hash Function_ parameter. These values MUST be enumerated in the [IANA.CGA.Tags] namespace. *_Info_*: OPTIONAL bitstring of additional information. MUST be 0 <= I_SIZE <= 60 where I_SIZE % 4 == 0, determined by _Prefix_. *_OGA ID_*: Enumeration for _Input_ and _Hash Function_. O_SIZE in bits determined by _Prefix_. See Section 3.1.1. *_Input_*: Input bitstring for _Hash Function_. Contents determined by _Prefix_ and _OGA ID_. See Section 7.1 for security considerations. *_Hash Function_*: Selection and usage (parameters, truncation, etc.) determined by _Prefix_ and _OGA ID_. See Section 3.1.2. *_Hash_*: Output of _Hash Function_ that MUST be H_SIZE = 128 - P_SIZE - I_SIZE - O_SIZE bits. It is RECOMMENDED to keep H_SIZE >= 64 && H_SIZE % 4 == 0 bits for hash collision security (see Section 7.2) and to align with the "interface ID" portion of an IPv6 address. *_ORCHID_*: The resulting IPv6 address known as an ORCHID. The sum size of components MUST be P_SIZE + I_SIZE + O_SIZE + H_SIZE == 128. Construction is limited to the IPv6 unicast and anycast address format with construction as a multicast IPv6 address is out of scope. The placement of _OGA ID_ to be directly before the _Hash_ portion is analogous to the "subnet ID" portion of an IPv6 address. The combination of _Prefix_, _Info_ and _OGA ID_ is relative to the "network prefix" terminology of IPv6. 3.1.1. OGA ID & Suite ID The OGA ID is a field that allows enumeration of an _Input_ and _Hash Algorithm_ to be used to form an ORCHID. The exact specification of what consists of an _Input_ and what _Hash Algorithm_ to use is decided by a domain/protocol/application that obtains a _Prefix_ (see Section 3.4). Wiethuechter & Moskowitz Expires 15 April 2027 [Page 6] Internet-Draft orchid-v3 October 2026 A "Suite ID" is an application specific enumeration table to be used as the _OGA ID_ in the creation of an ORCHID. Enumerations for a Suite ID are set by the _Prefix_ owner. The Suite ID SHOULD encompasses any parameters that are required for processing the ORCHID by a receiver. For some applications this MAY include details that become unavailable while disconnected from the Internet such as if the recipient is not expected or unable to perform a HIP Base Exchanged (BEX) or DNS lookup. 3.1.2. Hash Function Guidelines 3.1.2.1. Context ID Inclusion Inclusion of _Context ID_ as part of the hash function is determined by the _Prefix_ owner. Currently for both the [RFC7401] and [RFC9374] _Prefix_ the _Context ID_ MUST be prepended to the _Input_ for the SHA family of hash algorithms. For cSHAKE [RFC9374], the _Context ID_ MUST be set in the "custom string" parameter. 3.1.2.2. Fixed Hash Output Some hash function families, such as SHA, that have a fixed length output which exceeds the _Hash_ field length. For security purposes truncation SHOULD NOT be used to shorten the hash to the length needed for an ORCHID. Instead the generalized function of Figure 3 MUST be used to select a middle portion of the output for use. DEF extract (input, input_size, output, output_size) TBD Figure 3: TBD 3.2. Class Definitions .--------. +---------------+---+---------------------------+ Class A +-----+ | |OGA| '--------' | | Prefix |ID | Hash | +---------------+---+-------------------------------------------+ Figure 4: TBD *Class A: Simple*: Class where _Info_ MUST NOT be present. The exemplar of this class is the HIT for use in [RFC7401]. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 7] Internet-Draft orchid-v3 October 2026 .--------------. +---------------+-----------+---+---------+ Class B, C, D +-----+ | | |OGA| '--------------' | | Prefix | Info |ID | Hash | +---------------+-----------+---+-------------------------------+ Figure 5: TBD *Class B: Hierarchical (Static)*: Class where _Info_ MUST be present and MUST contain hierarchy information, forming a Hierarchy ID (HID), that has fixed sized fields. The exemplar case is the HHIT and the use-case instance of a DET from [RFC9374]. *Class C: Opaque*: Class where _Info_ MUST be present and MUST contain non-hierarchical opaque domain/application information. There is currently no example of such an ORCHID, thus is out of scope for this document. A potential case for such is a closed off network of computational agents. *Class D: Hierarchical (Dynamic)*: Similar to Class B, but instead of a hierarchy of fixed sized fields Classless Inter-Domain Routing (CIDR, [BCP122]) is used for _Info_. The exact specification is out of scope for this document. 3.3. Guidelines for Internet Frameworks & Infrastructure This section only applies for ORCHID use cases that included a cryptographic key as part of _Input_. 3.3.1. COSE & JOSE CBOR Object Signing & Encryption (COSE; [STD96]) and JSON Object Signing & Encryption (JOSE; [RFC7515], [RFC7516] & [RFC7517]) are common envelope models that are used in modern applications to interchange data signing and/or encrypted. An ORCHID MAY be used as a Key ID as part of COSE or JOSE when applicable. An ORCHID COSE Key ID MUST be set using Section 3.2 of [RFC9164]. A JOSE Key ID MUST follow Section 2.2 of [RFC4291]. It is RECOMMENDED that ORCHID applications use JSON Web Key (JWK, [RFC7517]) or COSE Key (Section 7 of [RFC9052]) to store and exchange public and/or private keys. The Key ID parameter MUST be set as the ORCHID for these structures. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 8] Internet-Draft orchid-v3 October 2026 3.3.2. Public Key Infrastructure Support of ORCHIDs in X.509 Public Key Infrastructure ([RFC5280], PKIX) MUST follow [RFC8002]. This uses the extensions "Subject Alternative Name: IP6" and "Issuer Alternative Name: IP6" to carry the ORCHID. Use of other extensions are defined by policy as needed. If required multiple ORCHIDs can be part of the Issuer or Subject Alternative Name to cover interoperability considerations between ORCHID classes. 3.3.3. Domain Name System The inclusion of ORCHIDs in DNS depends on specific use-case goals. There are currently three resource record types (RRType) that ORCHID can be used. CERT: A domain name associated using one or more CERT RRType that contains an X.509 certificate following Section 3.3.2. HIP: A domain name associated using one or more HIP RRType of [RFC8005] to an ORCHID, Public Key and any Rendezvous Servers used as part of [RFC8004]. HHIT: A domain name associated using one or more HHIT RRType of Section 5.1 of [RFC9886]. Use of DNSSEC is RECOMMENDED for any of the above methods to strengthen an authoritative server claim. [RFC9886] details, and readily demonstrates its deployment with DETs, using the existing ip6.arpa domain hierarchy to allow clean delegation and standardized lookup of ORCHIDs. It is RECOMMENDED as it is applicable for all ORCHID classes but MAY, at the loss of global interoperability, be augmented or replaced in isolated LANs. When using DNS for ORCHID Class B, C or D the internal structures of _Info_ SHOULD be evenly divisible by four (4) to ensure that fields in _Info_ stay on clean nibble boundaries for delegation. Author TBD: do we enable a DNS lookup of Suite IDs for a given prefix+info? 3.4. Considerations The declaration of an ORCHID requires the selection of an ORCHID Class (Section 3.2) along with the following items: Wiethuechter & Moskowitz Expires 15 April 2027 [Page 9] Internet-Draft orchid-v3 October 2026 1. If Class B & C: size in bits and definition of fields encoded into _Info_ 2. Selection of _OGA ID_ encoding size and appropriate Suite ID (see Appendix A for definitions and Suite ID templates) 3. Size of _Hash_ in bits Author TBD: something about hash function selection here and input parameters? 4. Host Identity Protocol Author TBD: small blurb on HIP here? 4.1. Host Identity Tag HITs are a Class A ORCHID defined as as shown in Figure 6. Prefix := 2001:20::/28 (28-bits) Context ID := 0xF0EF F02F BFF4 3D0F E793 0C3C 6E61 74EA Info := None (0-bits) OGA ID := Basic OGA ID (4-bits) Input := Host Identity Figure 6: Construction of HIT Note: The _Context ID_ for HITs is defined as part of [RFC7401] and is constant for all _OGA ID_'s. The _Host Identity_ is described in Section 4.3.1.2. The _Basic OGA ID_ uses Section 4.3.2.1 as the source of values. 4.2. Payload Format Author TBD: update to be Sender's ORCHID and Receiver's ORCHID 4.2.1. HIP Controls Author TBD: Add HIP Controls for optional HIP_PREFIX_LIST to I1/R1 and updated HIT_SUITE_LIST behavior? 4.3. HIP Parameters 4.3.1. HOST_ID Wiethuechter & Moskowitz Expires 15 April 2027 [Page 10] Internet-Draft orchid-v3 October 2026 4.3.1.1. Algorithm The HI Algorithm registry provides an enumeration of "profiles" that are used as part of the HOST_ID parameter (Section 5.2.9 of [RFC7401]). This document modifies this registry to add a new column (see Table 1) to indicate the encoding of a given public key to be used in Section 4.3.1.2. +=======+==============+========================+ | Value | HI Algorithm | Public Key Encoding | +=======+==============+========================+ | 3 | DSA | Section 2 of [RFC2536] | +-------+--------------+------------------------+ | 6 | RSA | Section 2 of [RFC3110] | +-------+--------------+------------------------+ | 7 | ECDSA | Section 6 of [RFC6090] | +-------+--------------+------------------------+ | 9 | ECDSA_LOW | Section 6 of [RFC6090] | +-------+--------------+------------------------+ Table 1: New HI Algorithm Registry Note: this document deprecates the use of Section 4.2 of [RFC6090] for the encoding of ECDSA and ECDSA_LOW Host Identities. The support of RSA, DSA and ECDSA_LOW is for legacy applications that use HIP. Newer implementations SHOULD NOT allow the creation of an ORCHID with these HI Algorithms. 4.3.1.2. Host Identity The "Host Identity" is a field as part of the HOST_ID parameter (Section 5.2.9 of [RFC7401]). The content is selected using the HI Algorithm ("Algorithm" field) and its "Public Key Encoding". This field MUST be used as part of HIT generation. Implementation Note: in [RFC7401] it was unclear exactly what was used as _Input_ for HIT generation without careful mapping of multiple references. For clarity all current HI Algorithm's "Host Identity" field contents are specified in Appendix B. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 11] Internet-Draft orchid-v3 October 2026 4.3.2. HIT_SUITE_LIST When using the HIT_SUITE_LIST parameter (Section 5.2.10 of [RFC7401]), the ID's, sourced from Section 4.3.2.1 MUST be encoded as a full octet to maintain backwards compatibility. This specification removes the requirement for senders to set the lower nibble to zero (0), along with removing the error state for receipt of a lower nibble of non-zero, enabling support of Suite IDs using an _Extended OGA ID_. Note: the more accurate name of this parameter after the changes is HIP_SUITE_LIST. 4.3.2.1. HIP Suite ID The updated HIT Suite ID registry shown in Table 2 (renamed to "HIP Suite ID"). It maintains an 8-bit enumeration but can either be used with a 4-bit or 8-bit encoding. Author TBD: should this be more specific? Columns for HI Algorithm, and a new table for Hash Algorithms to use and reference? Columns: Value(dec)/HI Alg/Hash Alg/Label? +===========+==============+=================+============+ | Value | Basic OGA ID | Extended OGA ID | HIP Suite | | (Decimal) | (4-bit, Hex) | (8-bit, Hex) | ID | +===========+==============+=================+============+ | 0 | 0x0 | 0x00 | Reserved | +-----------+--------------+-----------------+------------+ | 1 - 15 | - | 0x01 - 0x0F | Unassigned | +-----------+--------------+-----------------+------------+ | 16 | 0x1 | 0x10 | RSA,DSA/ | | | | | SHA-256 | +-----------+--------------+-----------------+------------+ | 17 - 31 | - | 0x11 - 0x1F | Unassigned | +-----------+--------------+-----------------+------------+ | 32 | 0x2 | 0x20 | ECDSA/ | | | | | SHA-384 | +-----------+--------------+-----------------+------------+ | 33 - 47 | - | 0x21 - 0x2F | Unassigned | +-----------+--------------+-----------------+------------+ | 48 | 0x3 | 0x30 | ECDSA_LOW/ | | | | | SHA-1 | +-----------+--------------+-----------------+------------+ | 49 - 63 | - | 0x31 - 0x3F | Unassigned | +-----------+--------------+-----------------+------------+ | 64 | 0x4 | 0x40 | Unassigned | +-----------+--------------+-----------------+------------+ Wiethuechter & Moskowitz Expires 15 April 2027 [Page 12] Internet-Draft orchid-v3 October 2026 | 65 - 79 | - | 0x41 - 0x4F | Unassigned | +-----------+--------------+-----------------+------------+ | 80 | 0x5 | 0x50 | Unassigned | +-----------+--------------+-----------------+------------+ | 81 - 95 | - | 0x51 - 0x5F | Unassigned | +-----------+--------------+-----------------+------------+ | 96 | 0x6 | 0x60 | Unassigned | +-----------+--------------+-----------------+------------+ | 97 - 111 | - | 0x61 - 0x6F | Unassigned | +-----------+--------------+-----------------+------------+ | 112 | 0x7 | 0x70 | Unassigned | +-----------+--------------+-----------------+------------+ | 113 - 127 | - | 0x71 - 0x7F | Unassigned | +-----------+--------------+-----------------+------------+ | 128 | 0x8 | 0x80 | Unassigned | +-----------+--------------+-----------------+------------+ | 129 - 143 | - | 0x81 - 0x8F | Unassigned | +-----------+--------------+-----------------+------------+ | 144 | 0x9 | 0x90 | Unassigned | +-----------+--------------+-----------------+------------+ | 145 - 159 | - | 0x91 - 0x9F | Unassigned | +-----------+--------------+-----------------+------------+ | 160 | 0xA | 0xA0 | Unassigned | +-----------+--------------+-----------------+------------+ | 161 - 175 | - | 0xA1 - 0xAF | Unassigned | +-----------+--------------+-----------------+------------+ | 176 | 0xB | 0xB0 | Unassigned | +-----------+--------------+-----------------+------------+ | 177 - 191 | - | 0xB1 - 0xBF | Unassigned | +-----------+--------------+-----------------+------------+ | 192 | 0xC | 0xC0 | Unassigned | +-----------+--------------+-----------------+------------+ | 193 - 207 | - | 0xC1 - 0xCF | Unassigned | +-----------+--------------+-----------------+------------+ | 208 | 0xD | 0xD0 | Unassigned | +-----------+--------------+-----------------+------------+ | 209 - 223 | - | 0xD1 - 0xDF | Unassigned | +-----------+--------------+-----------------+------------+ | 224 | 0xE | 0xE0 | Unassigned | +-----------+--------------+-----------------+------------+ | 225 - 239 | - | 0xE1 - 0xEF | Unassigned | +-----------+--------------+-----------------+------------+ | 240 | 0xF | 0xF0 | Unassigned | +-----------+--------------+-----------------+------------+ | 241 - 255 | - | 0xF1 - 0xFF | Unassigned | +-----------+--------------+-----------------+------------+ Table 2: Extended OGA ID Registry Template Wiethuechter & Moskowitz Expires 15 April 2027 [Page 13] Internet-Draft orchid-v3 October 2026 Note: HITs MUST only use the values indicated by the "Basic OGA ID (4-bit, Hex)" column. 4.3.3. HIP_PREFIX_LIST A new parameter titled HIP_PREFIX_LIST (Figure 7) that contains enumerated prefixes from Table 3 that a HIP client supports. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix #1 | Prefix #2 | Prefix #N | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: HIP_PREFIX_LIST _Type_: TBD _Length_: length in octets, excluding Type, Length, and Padding _Prefix_: identifies a HIP Prefix ID supported by the host. The list of prefixes is ordered by preference of the host. Each HIP Prefix ID is one octet long. 4.3.3.1. HIP Prefix ID +=====+==============+====+=====+====+=====+============+=========+ |Value| Prefix |Info|OGA |Hash|Class| HIP Prefix |Reference| | | | |ID | | | ID | | +=====+==============+====+=====+====+=====+============+=========+ |0 | - |- |- |- |- | Reserved |- | +-----+--------------+----+-----+----+-----+------------+---------+ |1 | 2001:20::/28 |0 |Basic|96 |A | Host |Section | | | | | | | | Identity |4.1 | | | | | | | | Tag (HIT) | | +-----+--------------+----+-----+----+-----+------------+---------+ |2 - | - |- |- |- |- | Unassigned |- | |255 | | | | | | | | +-----+--------------+----+-----+----+-----+------------+---------+ Table 3: HIP Prefix ID Registry _Prefix_: IANA assigned IPv6 prefix in CIDR notation. _Info_: Size of _Info_ in bits. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 14] Internet-Draft orchid-v3 October 2026 _OGA ID_: Encoding format for _OGA ID_: Basic, Extended, or Flex. _Hash_: Size of _Hash_ in bits. _Class_: ORCHID Class: A, B, C, or D. 4.3.4. NOTIFICATION Author TBD: add UNSUPPORTED_PREFIX to Error enumeration, data contains supported HIP Prefix IDs 4.4. HIP Packets 4.4.1. HIP Initiator (I1) Author TBD: Add optional HIP_PREFIX_LIST to I1 packet 4.4.2. HIP Responder (R1) Author TBD: Add optional HIP_PREFIX_LIST to R1 packet 5. Drone Remote ID Protocol Author TBD: small blurb on DRIP here? 5.1. DRIP Entity Tag DETs are a Class B ORCHID defined as as shown in Figure 8. Prefix := 2001:30::/28 (28-bits) Context ID := 0x00B5 A69C 795D F5D5 F008 7F56 843F 2C40 RAA := Registered Assigning Authority (14-bits) HDA := Hierarchical HIT (HHIT) Domain Authority (14-bits) Info := RAA | HDA (28-bits) OGA ID := Extended OGA ID (8-bits) Input := Prefix | Info | OGA ID | Host Identity Figure 8: Construction of DET Note: The _Context ID_ for DETs is defined in [RFC9374] and is constant for all _OGA ID_'s. The _Host Identity_ as part of _Input_ is described in Section 4.3.1.2. The _Extended OGA ID_ uses the HIP Suite ID registry (Section 4.3.2.1) as the source of values. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 15] Internet-Draft orchid-v3 October 2026 5.2. Addition to HI Algorithms The following HI Algorithm was originally added by [RFC9374] and is updated to reflect the changes of Section 4.3.1.1. +=======+==============+=====================+ | Value | HI Algorithm | Public Key Encoding | +=======+==============+=====================+ | 13 | EdDSA | [RFC8032] | +-------+--------------+---------------------+ Table 4: Addition to HI Algorithm Registry The EdDSA HI Algorithm uses the same "Host Identity" as ECDSA/ ECDSA_LOW (Figure 12). A separate curve registry (EdDSA Curve Label) is defined by [RFC9374]. 5.3. Addition to HIP Prefix ID +=====+==============+====+==========+====+=====+======+===========+ |Value| Prefix |Info| OGA ID |Hash|Class|HIP | Reference | | | | | | | |Prefix| | | | | | | | |ID | | +=====+==============+====+==========+====+=====+======+===========+ |2 | 2001:30::/28 |28 | Extended |64 |B |DRIP | Section | | | | | | | |Entity| 5.1 | | | | | | | |Tag | | | | | | | | |(DET) | | +-----+--------------+----+----------+----+-----+------+-----------+ Table 5: Addition to HIP Prefix ID Registry 5.4. Additions to HIP Suite ID The Suite IDs that were allocated during DRIP did not contain enough information for scenarios where the DET recipient had no intention of performing a HIP BEX ([RFC7401]) or ability to access Internet resources (such as [RFC9886] to get access to an X.509 certificate which would convey such information). This issue was concealed by [RFC9575] constraining the selection of the EdDSA curve to Ed25519 due to media size limits. This requires receivers to rely on the specifications narrow scope to avoid interoperability issues. Thus this document defines new HIP Suite ID specific values encoding HI Algorithm parameters such as curve to resolve the issue. The allocation of HIP Suite ID value 5 is to avoid existing implementation changes from the old HHIT Suite ID allocations. The HHIT Suite ID defined in [RFC9374] is deprecated. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 16] Internet-Draft orchid-v3 October 2026 +===========+==============+=================+================+ | Value | Basic OGA ID | Extended OGA ID | HIP Suite ID | | (Decimal) | (4-bit, Hex) | (8-bit, Hex) | | +===========+==============+=================+================+ | 5 | - | 0x05 | EdDSA-25519/ | | | | | cSHAKE128 | +-----------+--------------+-----------------+----------------+ | 33 | - | 0x21 | ECDSA-P256/ | | | | | SHA-384 | +-----------+--------------+-----------------+----------------+ | 34 | - | 0x22 | ECDSA-P384/ | | | | | SHA-384 | +-----------+--------------+-----------------+----------------+ | 80 | 0x5 | 0x50 | EdDSA/ | | | | | cSHAKE128 | +-----------+--------------+-----------------+----------------+ | 81 | - | 0x51 | EdDSA-25519ph/ | | | | | cSHAKE128 | +-----------+--------------+-----------------+----------------+ | 82 | - | 0x52 | EdDSA-448/ | | | | | cSHAKE256 | +-----------+--------------+-----------------+----------------+ | 83 | - | 0x53 | EdDSA-448ph/ | | | | | cSHAKE256 | +-----------+--------------+-----------------+----------------+ | 254 | - | 0xFE | DET HDA | | | | | Private Use | +-----------+--------------+-----------------+----------------+ | 255 | - | 0xFF | DET HDA | | | | | Private Use | +-----------+--------------+-----------------+----------------+ Table 6: Additions to HIP Suite ID Registry 6. IANA Considerations TBD 7. Security Considerations 7.1. Hash Input TBD 7.2. Hash Size vs Collisions TBD Wiethuechter & Moskowitz Expires 15 April 2027 [Page 17] Internet-Draft orchid-v3 October 2026 8. Privacy & Transparency Considerations TBD 9. References 9.1. 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, . [RFC7343] Laganier, J. and F. Dupont, "An IPv6 Prefix for Overlay Routable Cryptographic Hash Identifiers Version 2 (ORCHIDv2)", RFC 7343, DOI 10.17487/RFC7343, September 2014, . [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, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC9374] Moskowitz, R., Card, S., Wiethuechter, A., and A. Gurtov, "DRIP Entity Tag (DET) for Unmanned Aircraft System Remote ID (UAS RID)", RFC 9374, DOI 10.17487/RFC9374, March 2023, . 9.2. Informative References [BCP122] Best Current Practice 122, . At the time of writing, this BCP comprises the following: Fuller, V. and T. Li, "Classless Inter-domain Routing (CIDR): The Internet Address Assignment and Aggregation Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August 2006, . [IANA.CGA.Tags] IANA, "CGA Extension Type Tags", September 2026, . Wiethuechter & Moskowitz Expires 15 April 2027 [Page 18] Internet-Draft orchid-v3 October 2026 [RFC2536] Eastlake 3rd, D., "DSA KEYs and SIGs in the Domain Name System (DNS)", RFC 2536, DOI 10.17487/RFC2536, March 1999, . [RFC3110] Eastlake 3rd, D., "RSA/SHA-1 SIGs and RSA KEYs in the Domain Name System (DNS)", RFC 3110, DOI 10.17487/RFC3110, May 2001, . [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, DOI 10.17487/RFC4291, February 2006, . [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008, . [RFC6090] McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic Curve Cryptography Algorithms", RFC 6090, DOI 10.17487/RFC6090, February 2011, . [RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May 2015, . [RFC7516] Jones, M. and J. Hildebrand, "JSON Web Encryption (JWE)", RFC 7516, DOI 10.17487/RFC7516, May 2015, . [RFC7517] Jones, M., "JSON Web Key (JWK)", RFC 7517, DOI 10.17487/RFC7517, May 2015, . [RFC8002] Heer, T. and S. Varjonen, "Host Identity Protocol Certificates", RFC 8002, DOI 10.17487/RFC8002, October 2016, . [RFC8004] Laganier, J. and L. Eggert, "Host Identity Protocol (HIP) Rendezvous Extension", RFC 8004, DOI 10.17487/RFC8004, October 2016, . [RFC8005] Laganier, J., "Host Identity Protocol (HIP) Domain Name System (DNS) Extension", RFC 8005, DOI 10.17487/RFC8005, October 2016, . Wiethuechter & Moskowitz Expires 15 April 2027 [Page 19] Internet-Draft orchid-v3 October 2026 [RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital Signature Algorithm (EdDSA)", RFC 8032, DOI 10.17487/RFC8032, January 2017, . [RFC8610] Birkholz, H., Vigano, C., and C. Bormann, "Concise Data Definition Language (CDDL): A Notational Convention to Express Concise Binary Object Representation (CBOR) and JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610, June 2019, . [RFC9063] Moskowitz, R., Ed. and M. Komu, "Host Identity Protocol Architecture", RFC 9063, DOI 10.17487/RFC9063, July 2021, . [RFC9164] Richardson, M. and C. Bormann, "Concise Binary Object Representation (CBOR) Tags for IPv4 and IPv6 Addresses and Prefixes", RFC 9164, DOI 10.17487/RFC9164, December 2021, . [RFC9434] Card, S., Wiethuechter, A., Moskowitz, R., Zhao, S., Ed., and A. Gurtov, "Drone Remote Identification Protocol (DRIP) Architecture", RFC 9434, DOI 10.17487/RFC9434, July 2023, . [RFC9575] Wiethuechter, A., Ed., Card, S., and R. Moskowitz, "DRIP Entity Tag (DET) Authentication Formats and Protocols for Broadcast Remote Identification (RID)", RFC 9575, DOI 10.17487/RFC9575, June 2024, . [RFC9886] Wiethuechter, A., Ed. and J. Reid, "DRIP Entity Tags (DETs) in the Domain Name System", RFC 9886, DOI 10.17487/RFC9886, December 2025, . [STD96] Internet Standard 96, . At the time of writing, this STD comprises the following: Schaad, J., "CBOR Object Signing and Encryption (COSE): Structures and Process", STD 96, RFC 9052, DOI 10.17487/RFC9052, August 2022, . Wiethuechter & Moskowitz Expires 15 April 2027 [Page 20] Internet-Draft orchid-v3 October 2026 Schaad, J., "CBOR Object Signing and Encryption (COSE): Countersignatures", STD 96, RFC 9338, DOI 10.17487/RFC9338, December 2022, . Appendix A. OGA ID Encodings & Enumerations The _OGA ID_ of an ORCHID has three supported encodings of which a _Prefix_ selects one for use. A.1. Basic OGA ID The _Basic OGA ID_ is a simple 4-bit encoding and enumeration as shown in Table 7. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 21] Internet-Draft orchid-v3 October 2026 +===========+==============+ | Value | Basic OGA ID | | (Decimal) | (4-bit, Hex) | +===========+==============+ | 0 | 0x0 | +-----------+--------------+ | 1 | 0x1 | +-----------+--------------+ | 2 | 0x2 | +-----------+--------------+ | 3 | 0x3 | +-----------+--------------+ | 4 | 0x4 | +-----------+--------------+ | 5 | 0x5 | +-----------+--------------+ | 6 | 0x6 | +-----------+--------------+ | 7 | 0x7 | +-----------+--------------+ | 8 | 0x8 | +-----------+--------------+ | 9 | 0x9 | +-----------+--------------+ | 10 | 0xA | +-----------+--------------+ | 11 | 0xB | +-----------+--------------+ | 12 | 0xC | +-----------+--------------+ | 13 | 0xD | +-----------+--------------+ | 14 | 0xE | +-----------+--------------+ | 15 | 0xF | +-----------+--------------+ Table 7: Basic OGA ID Registry Template A.2. Extended OGA ID A RECOMMENDED mapping of _Basic OGA ID_ values into to _Extended OGA ID_ registry using the upper nibble as shown in Table 8. A given ORCHID declaration with a newly defined Suite ID MAY choose to ignore this recommendation and use a one-to-one mapping between encoding and enumeration. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 22] Internet-Draft orchid-v3 October 2026 +===========+==============+=================+ | Value | Basic OGA ID | Extended OGA ID | | (Decimal) | (4-bit, Hex) | (8-bit, Hex) | +===========+==============+=================+ | 0 | 0x0 | 0x00 | +-----------+--------------+-----------------+ | 1 - 15 | - | 0x01 - 0x0F | +-----------+--------------+-----------------+ | 16 | 0x1 | 0x10 | +-----------+--------------+-----------------+ | 17 - 31 | - | 0x11 - 0x1F | +-----------+--------------+-----------------+ | 32 | 0x2 | 0x20 | +-----------+--------------+-----------------+ | 33 - 47 | - | 0x21 - 0x2F | +-----------+--------------+-----------------+ | 48 | 0x3 | 0x30 | +-----------+--------------+-----------------+ | 49 - 63 | - | 0x31 - 0x3F | +-----------+--------------+-----------------+ | 64 | 0x4 | 0x40 | +-----------+--------------+-----------------+ | 65 - 79 | - | 0x41 - 0x4F | +-----------+--------------+-----------------+ | 80 | 0x5 | 0x50 | +-----------+--------------+-----------------+ | 81 - 95 | - | 0x51 - 0x5F | +-----------+--------------+-----------------+ | 96 | 0x6 | 0x60 | +-----------+--------------+-----------------+ | 97 - 111 | - | 0x61 - 0x6F | +-----------+--------------+-----------------+ | 112 | 0x7 | 0x70 | +-----------+--------------+-----------------+ | 113 - 127 | - | 0x71 - 0x7F | +-----------+--------------+-----------------+ | 128 | 0x8 | 0x80 | +-----------+--------------+-----------------+ | 129 - 143 | - | 0x81 - 0x8F | +-----------+--------------+-----------------+ | 144 | 0x9 | 0x90 | +-----------+--------------+-----------------+ | 145 - 159 | - | 0x91 - 0x9F | +-----------+--------------+-----------------+ | 160 | 0xA | 0xA0 | +-----------+--------------+-----------------+ | 161 - 175 | - | 0xA1 - 0xAF | +-----------+--------------+-----------------+ Wiethuechter & Moskowitz Expires 15 April 2027 [Page 23] Internet-Draft orchid-v3 October 2026 | 176 | 0xB | 0xB0 | +-----------+--------------+-----------------+ | 177 - 191 | - | 0xB1 - 0xBF | +-----------+--------------+-----------------+ | 192 | 0xC | 0xC0 | +-----------+--------------+-----------------+ | 193 - 207 | - | 0xC1 - 0xCF | +-----------+--------------+-----------------+ | 208 | 0xD | 0xD0 | +-----------+--------------+-----------------+ | 209 - 223 | - | 0xD1 - 0xDF | +-----------+--------------+-----------------+ | 224 | 0xE | 0xE0 | +-----------+--------------+-----------------+ | 225 - 239 | - | 0xE1 - 0xEF | +-----------+--------------+-----------------+ | 240 | 0xF | 0xF0 | +-----------+--------------+-----------------+ | 241 - 255 | - | 0xF1 - 0xFF | +-----------+--------------+-----------------+ Table 8: Extended OGA ID Registry Template A.3. Flex OGA ID To support a dynamic _OGA ID_ sizing as part of an ORCHID the most significant bit of the _OGA ID_ is a flag (FX in Figure 9) indicating a total length of 4-bits or 8-bits. The _Basic OGA ID_ is a 4-bit encoding with a 3-bit enumeration (0b0xxx, values 0 to 7) and _Extended OGA ID_ is an 8-bit encoding with a 7-bit enumeration (0b1xxx xxxx, values 0 to 127). 7 6 5 4 3 2 1 0 +-----+-----+-----+-----+-----+-----+-----+-----+ | F | Basic & | Extended | | X | Extended | Only | +-----+-----+-----+-----+-----+-----+-----+-----+ Figure 9: TBD Author TBD: move FX bit from MSb to LSb? An _Extended OGA ID_ has seven (7) values shared between the encodings due to three shared bits (4, 5 & 6). A registry template is provided as Table 9. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 24] Internet-Draft orchid-v3 October 2026 +===========+==============+=================+ | Value | Basic OGA ID | Extended OGA ID | | (Decimal) | (4-bit, Hex) | (8-bit Hex) | +===========+==============+=================+ | 0 | 0x0 | 0x80 | +-----------+--------------+-----------------+ | 1 - 15 | - | 0x81 - 0x8F | +-----------+--------------+-----------------+ | 16 | 0x1 | 0x90 | +-----------+--------------+-----------------+ | 17 - 31 | - | 0x91 - 0x9F | +-----------+--------------+-----------------+ | 32 | 0x2 | 0xA0 | +-----------+--------------+-----------------+ | 33 - 47 | - | 0xA1 - 0xAF | +-----------+--------------+-----------------+ | 48 | 0x3 | 0xB0 | +-----------+--------------+-----------------+ | 49 - 63 | - | 0xB1 - 0xBF | +-----------+--------------+-----------------+ | 64 | 0x4 | 0xC0 | +-----------+--------------+-----------------+ | 65 - 79 | - | 0xC1 - 0xCF | +-----------+--------------+-----------------+ | 80 | 0x5 | 0xD0 | +-----------+--------------+-----------------+ | 81 - 95 | - | 0xD1 - 0xDF | +-----------+--------------+-----------------+ | 96 | 0x6 | 0xE0 | +-----------+--------------+-----------------+ | 97 - 111 | - | 0xE1 - 0xEF | +-----------+--------------+-----------------+ | 112 | 0x7 | 0xF0 | +-----------+--------------+-----------------+ | 113 - 127 | - | 0xF1 - 0xFF | +-----------+--------------+-----------------+ Table 9: Flex OGA ID Registry Template Appendix B. Host Identities B.1. RSA Figure 10 is a representation of a RSA Host Identity. See Section 2 of [RFC3110] for details. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 25] Internet-Draft orchid-v3 October 2026 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Exponent Length | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Exponent | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Modulus | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 10: RSA Host Identity B.2. DSA Figure 11 is a representation of a DSA Host Identity. See Section 2 of [RFC2536] for details. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | T | Q | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | P | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | G | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Y | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 11: DSA Host Identity B.3. ECDSA & ECDSA_LOW Figure 12 is a representation of a ECDSA or ECDSA_LOW Host Identity originally defined in Section 5.2.9 of [RFC7401]. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Curve Label | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Public Key | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 12: ECDSA & ECDSA_LOW Host Identity _Curve Label_: Enumeration of specific curve in use. See respective curve label registry based on HI Algorithm. Wiethuechter & Moskowitz Expires 15 April 2027 [Page 26] Internet-Draft orchid-v3 October 2026 _Public Key_ Encoded per HI Algorithm "Public Key Encoding". Authors' Addresses Adam Wiethuechter Independent Email: atw.ietf@gmail.com Robert Moskowitz HTT Consulting Email: rgm@htt-consulting.com Wiethuechter & Moskowitz Expires 15 April 2027 [Page 27]