Network Working Group                                      S. Jovancevic
Internet-Draft                                         SKGO, IKT Support
Intended status: Informational                              25 May 2026
Expires: 26 November 2026

         Verifiable Identity Claims and Delegation Model (VICDM)
                    draft-jovancevic-vicdm-08

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Abstract

   This document defines a conceptual framework for handling identity
   assertions in application-layer protocols. It introduces a model
   in which identity on the Internet is optional, but any asserted
   identity MUST be verifiable.

   It further defines a delegation mechanism that allows entities to
   authorize third-party infrastructure to act on their behalf in a
   verifiable and transparent manner.

   The goal is to reduce identity misrepresentation while fully
   preserving the ability for anonymous and pseudonymous interaction.
   This document does not define a protocol; it defines the principles
   that protocol specifications SHOULD follow when addressing agent
   identity.

   A concrete protocol implementation of these principles is defined
   in [SAIP].

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  The Core Principle  . . . . . . . . . . . . . . . . . . . .  4
   4.  Identity Classes  . . . . . . . . . . . . . . . . . . . . .  5
   5.  Identity Verification . . . . . . . . . . . . . . . . . . .  5
   6.  Delegation Model  . . . . . . . . . . . . . . . . . . . . .  6
     6.1.  Delegation Requirements . . . . . . . . . . . . . . . .  6
     6.2.  DNS-Based Attestation Discovery . . . . . . . . . . . .  7
     6.3.  Cryptographic Delegation Tokens . . . . . . . . . . . .  8
     6.4.  DNS-Native Agent Self-Registration (Alternative) . . .   9
     6.5.  Agent Letter of Intent (ALOI) . . . . . . . . . . . . . 14
       6.5.1.  Definition and Purpose  . . . . . . . . . . . . . . 14
         6.5.1.1.  ALOI Content (Modular)  . . . . . . . . . . . . 15
         6.5.1.2.  The Dual Nature of an ALOI  . . . . . . . . . . 15
         6.5.1.3.  ALOI and Server Response: Three Outcomes  . . . 16
     6.6.  Verifiable Data Access Contract (VDAC)  . . . . . . . . 19
       6.6.1.  Relationship to ALOI  . . . . . . . . . . . . . . . 20
   7.  Trust Classification  . . . . . . . . . . . . . . . . . . . 21
   8.  Policy Enforcement  . . . . . . . . . . . . . . . . . . . . 22
   9.  Relationship to Anonymous Authentication  . . . . . . . . .  9
   10. Non-Goals . . . . . . . . . . . . . . . . . . . . . . . . . 10
   11. Security Considerations . . . . . . . . . . . . . . . . . . 10
   12. Privacy Considerations  . . . . . . . . . . . . . . . . . . 11
   13. IANA Considerations . . . . . . . . . . . . . . . . . . . . 11
   14. References  . . . . . . . . . . . . . . . . . . . . . . . . 11
     14.1. Normative References  . . . . . . . . . . . . . . . . . 11
     14.2. Informative References  . . . . . . . . . . . . . . . . 12
   Appendix A.  Document History . . . . . . . . . . . . . . . . . 12
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . 13

1.  Introduction

   The Internet is built on a principle of openness: entities may
   communicate without being required to identify themselves. This
   property is fundamental and MUST be preserved.

   However, modern internet systems increasingly rely on identity
   assertions for access control, prioritization, rate limiting,
   and trust evaluation. Automated agents -- AI crawlers, IoT devices,
   backup systems, enterprise automation -- routinely assert identities
   to influence how servers treat their requests.

   A critical problem arises when these identity assertions cannot be
   verified. An agent that claims to be "GoogleBot" or "legitimate-
   backup-service" without cryptographic proof provides no more
   assurance than an agent that claims nothing at all. Worse, false
   identity assertions actively harm the ecosystem by:

   o  Allowing malicious actors to impersonate trusted services
   o  Corrupting reputation systems that depend on identity signals
   o  Undermining filtering mechanisms that would otherwise work
   o  Creating false trust that delays detection of abuse

   The fundamental issue is not the presence or absence of identity
   claims -- it is the verifiability of those claims.

   This document defines the VICDM principle:

      Anonymous interaction is permitted.
      Identity assertion is permitted.
      False identity assertion is not.

   This seemingly simple principle has significant architectural
   implications for how protocols handling agent identity should
   be designed.

   A concrete protocol implementing these principles is defined in
   the Signed Agent Identity Protocol [SAIP].

1.1.  Relationship to webbotauth Work

   The IETF webbotauth working group is developing mechanisms for
   bot authentication. Current proposals focus on anonymous
   attestation models in which a bot proves it is vouched for by
   a trusted attester without revealing its specific identity.

   Anonymous attestation and VICDM are complementary, not competing:

   o  Anonymous attestation addresses the privacy use case: a bot
      proves legitimacy without disclosure of its identity.

   o  VICDM addresses the accountability use case: when a bot DOES
      assert an identity, that assertion must be verifiable.

   Both models are needed. They serve different threat models and
   different operational requirements.

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.

   Anonymous Client:      A client that does not assert any identity.
                          This is always a valid and permitted mode
                          of interaction.

   Claiming Client:       A client that asserts an identity, such as
                          a domain name, organization, or service
                          name.

   Verified Client:       A client whose asserted identity has been
                          validated through one or more verifiable
                          mechanisms as defined in Section 5.

   Identity Claim:        Any statement or metadata by which a client
                          represents itself as belonging to a specific
                          domain, organization, or service.

   Delegated             Third-party systems that have been
   Infrastructure:        explicitly authorized to act on behalf of
                          an entity through verifiable mechanisms.

   Attester:              An entity that vouches for the legitimacy
                          of a client without necessarily disclosing
                          the client's identity. Used in anonymous
                          attestation models.

3.  The Core Principle

   The VICDM model is founded on a single, minimal principle:

      Systems MUST allow anonymous interaction.

      A client asserting an identity MUST provide verifiable linkage
      to that identity.

      Failure to provide verifiable linkage to an asserted identity
      MUST result in that identity claim being treated as invalid.

   This principle is deliberately minimal. It does not require
   universal identity. It does not prohibit anonymity. It requires
   only that identity claims, when made, be honest and verifiable.

   The distinction between an Anonymous Client and a Claiming Client
   whose claim is unverifiable is operationally significant:

   o  An Anonymous Client makes no representation about its origin
      or affiliation. Servers may apply default anonymous policies.

   o  An unverified Claiming Client actively misrepresents itself.
      This is categorically different from anonymity and SHOULD be
      treated with lower trust than genuine anonymity.

   Implementations SHOULD distinguish between these two cases and
   SHOULD NOT treat unverified identity claims as equivalent to
   anonymous interaction.

4.  Identity Classes

   Under the VICDM model, clients fall into one of four classes:

   Class 0 -- Anonymous:
      The client asserts no identity. No identity claim is present.
      This is a valid and fully supported mode of interaction.
      Servers apply default anonymous policies.

   Class 1 -- Unverifiable Claim:
      The client asserts an identity but provides no verifiable
      linkage. The claim MUST be treated as invalid. Trust SHOULD
      be lower than for Class 0 (anonymous) clients, as the client
      is actively misrepresenting itself.

   Class 2 -- Partially Verified:
      The client asserts an identity and provides partial verification
      (e.g., DNS consistency but no cryptographic proof). Servers
      MAY grant limited elevated trust based on deployment policy.

   Class 3 -- Fully Verified:
      The client asserts an identity and provides full cryptographic
      verification of that identity. Servers MAY grant elevated
      trust, priority handling, or increased rate limits based on
      deployment policy.

5.  Identity Verification

   Verification of identity claims MAY use one or more of the
   following mechanisms. No single mechanism is mandated; systems
   MAY combine multiple signals to increase confidence.

5.1.  DNS-Based Verification

   The asserted identity SHOULD be consistent with DNS records
   for the claimed domain:

   o  Forward DNS resolution of the claimed domain SHOULD return
      an address associated with the client's network.

   o  Reverse DNS (PTR) resolution of the client's IP address
      SHOULD return a hostname within the claimed domain.

   o  DNS TXT records at a well-known prefix (see Section 6.2)
      MAY carry cryptographic key material for stronger binding.

   DNS-based verification alone provides weak assurance. It SHOULD
   be combined with cryptographic mechanisms where possible.

5.2.  Cryptographic Verification

   The client provides a cryptographic signature over a defined
   canonical string using a private key whose corresponding public
   key is discoverable and bound to the claimed identity.

   This is the strongest form of verification and is RECOMMENDED
   for all deployments where security is a concern. A concrete
   implementation is defined in [SAIP].

5.3.  Transport-Layer Indicators

   Consistency between the identity claim and transport-layer
   signals (e.g., TLS SNI, TLS client certificate) MAY be used
   as a supporting signal. These indicators SHOULD NOT be used
   as the sole verification mechanism.

5.4.  Attester-Based Verification

   A trusted third-party Attester MAY vouch for the legitimacy of
   a client without disclosing the client's specific identity. This
   is the basis of anonymous attestation models such as those being
   developed in the IETF webbotauth working group.

   Attester-based verification satisfies the VICDM requirement
   for Class 2 or Class 3 verification only if the Attester itself
   is verifiable and its delegation is explicit per Section 6.

6.  Delegation Model

   Large-scale internet deployments commonly use third-party
   infrastructure -- CDN providers, cloud services, proxy networks --
   to serve content or operate agents on behalf of a domain owner.

   This creates an identity delegation problem: the actual client
   IP address or User-Agent may belong to the infrastructure
   provider, not the domain owner. Without explicit, verifiable
   delegation, servers cannot determine whether the infrastructure
   is legitimately acting on the domain owner's behalf.

6.1.  Delegation Requirements

   Any infrastructure acting on behalf of an entity and asserting
   that entity's identity MUST be explicitly authorized through
   verifiable mechanisms.

   Specifically:

   o  The domain owner MUST publish an explicit authorization for
      the delegated infrastructure to act on its behalf.

   o  The authorization MUST be verifiable by any server without
      requiring prior coordination with the domain owner.

   o  Absence of verifiable delegation authorization MUST result
      in the identity claim being treated as invalid (Class 1).

   o  The delegation authorization SHOULD be bound to specific
      infrastructure identifiers (IP ranges, ASNs, public keys)
      rather than being open-ended.

   This requirement directly addresses scenarios where large
   infrastructure providers assert client identities on behalf
   of multiple customers without explicit per-customer authorization.
   Such assertions, without verifiable delegation, MUST be treated
   as invalid identity claims under this model.

6.2.  DNS-Based Attestation Discovery

   Entities MAY publish delegation authorization using DNS TXT
   records at the following well-known prefix:

   _saip.<domain>.

   The record format is:

   _saip.<domain>. IN TXT "v=saip1; [parameters]"

   The following parameters are defined:

   v=saip1       Version indicator. MUST be present.

   re=<hostname> Preferred Registration Entity hostname.
                 MAY be present. Multiple re= parameters
                 are permitted.

   pk=<key>      Base64URL-encoded public key for stateless
                 verification. MAY be present.

   asn=<list>    Comma-separated list of authorized ASNs for
                 delegated infrastructure. MAY be present.

   ip=<prefix>   CIDR prefix of authorized delegated
                 infrastructure. MAY be present. Multiple
                 ip= parameters are permitted.

   exp=<ts>      Unix timestamp after which this record
                 SHOULD be considered expired. MAY be present.

   Example DNS records:

   ; Vendor publishing their SAIP public key
   _saip.acme.com. IN TXT "v=saip1; pk=base64urlkey...;
                            re=re1.saip-registry.example"

   ; Vendor authorizing a CDN provider by ASN
   _saip.acme.com. IN TXT "v=saip1; asn=13335,15169;
                            re=re1.saip-registry.example"

   ; Vendor authorizing specific IP ranges
   _saip.acme.com. IN TXT "v=saip1; ip=192.0.2.0/24;
                            ip=2001:db8::/32"

   DNS record TTL SHOULD be set to a value appropriate for
   the key rotation policy of the deployment. A TTL of 3600
   seconds (1 hour) is RECOMMENDED as a default.

   Servers performing DNS-based verification MUST validate
   DNSSEC signatures where available [RFC4033].

6.3.  Cryptographic Delegation Tokens

   As an alternative or supplement to DNS-based Attestation
   Discovery, domain owners MAY issue signed Delegation Tokens
   to authorized infrastructure:

   DelegationToken = Sign(MasterKey,
                          infrastructure_id ||
                          valid_from ||
                          valid_until ||
                          scope)

   Where:

   o  infrastructure_id identifies the authorized infrastructure
      (e.g., ASN, IP range, or public key fingerprint)
   o  valid_from and valid_until define the validity period
   o  scope limits the actions the infrastructure may take

   Infrastructure presenting a valid Delegation Token MAY assert
   the domain owner's identity for requests within the token's scope
   and validity period.

6.4.  DNS-Native Agent Self-Registration (Alternative Trust Model)

   This section defines an alternative trust establishment mechanism
   that replaces the Registration Entity model with the existing DNS
   infrastructure. Vendors adopting this model use their DNS zone as
   the identity registry for their agents, following the same
   principles established by DKIM [RFC6376].

   The DNS-Join trust model rests on three principles: hardware
   secures the Master Key, DNS publishes it and acts as the trust
   circuit breaker, and Rolling Keys provide speed and network
   efficiency.

6.4.1.  Model Overview

   In traditional agent identity systems, a central registry holds
   agent public keys. In the DNS-Native model, the vendor's DNS zone
   serves as the distributed registry. Each agent self-registers by
   publishing its Master Public Key as a DNS TXT record within the
   vendor's delegated subdomain.

   This is directly analogous to DKIM key publication [RFC6376]:

   DKIM:      mail._domainkey.example.com  TXT "v=DKIM1; p=<pubkey>"
   SAIP-DNS:  agent-id._saip.example.com   TXT "v=saip1; pk=<pubkey>"

   The vendor delegates the _saip.<domain> subdomain, granting
   agents the ability to publish and manage their own TXT records
   within it. The vendor retains control as the DNS zone authority --
   the ultimate trust circuit breaker.

6.4.2.  Key Hierarchy

   The DNS-Native model uses a two-tier key structure:

   Tier 1 -- Master Key (long-term, DNS-published):

   o  The agent generates a Master keypair on its hardware security
      module (TPM, HSM, or Secure Enclave).
   o  The Master Private Key MUST NEVER leave the hardware module.
   o  The Master Public Key is uploaded once to the DNS TXT record:
      agent-id._saip.<vendor-domain>. TXT "v=saip1; pk=<MasterPubKey>"
   o  This record represents the agent's long-term identity.
   o  The vendor, as DNS zone authority, acts as the trust
      circuit breaker: deleting this record instantly revokes
      the agent's identity across the entire ecosystem after
      DNS TTL expiry.

   Tier 2 -- Rolling Keys (per-request, locally generated):

   o  For each request, the agent generates a fresh ephemeral
      keypair (RollingKeypair).
   o  The agent signs the Rolling Public Key with its Master
      Private Key, producing a Rolling Key Certificate (rcert):

      rcert = Sign(MasterPrivateKey,
                   RollingPublicKey ||
                   instanceID       ||
                   ts               ||
                   nonce            ||
                   method           ||
                   path)

   o  The nonce, ts, method, and path fields bind the rcert to
      exactly one request, making it non-replayable by design.
   o  The Rolling Private Key signs the canonical request string.
   o  Both the Rolling Public Key (rpk=) and rcert= are
      transmitted in the SAIP header.

6.4.3.  Verification Flow

   Server verification requires a DNS lookup only once per agent,
   after which the Master Public Key MAY be cached per DNS TTL:

   1. Server receives SAIP header containing rpk= and rcert=.

   2. On first encounter with this agent id=, the server performs
      a DNS TXT lookup:
         agent-id._saip.<vendor-domain>.
      and retrieves the Master Public Key. This result SHOULD be
      cached according to the record TTL.

   3. Server verifies rcert= using the cached Master Public Key.
      This confirms that the Rolling Public Key was authorized
      by the legitimate Master Key holder for this exact request.

   4. Server verifies the request signature using rpk=.
      This confirms the request was made by the holder of the
      Rolling Private Key.

   5. Both verifications MUST succeed for the request to be
      accepted.

   DNS is consulted once per agent (or per TTL expiry), while
   per-request verification is entirely local -- providing both
   strong security and high performance.

6.4.4.  Trust Circuit Breaker

   Because the Master Public Key is published in DNS under the
   vendor's authoritative zone, the vendor retains ultimate control:

   o  To revoke a single agent: delete its _saip TXT record.
      After DNS TTL expiry, servers will reject its rcert= values
      as they can no longer verify them against a Master Public Key.

   o  To revoke all agents: rotate the vendor's zone signing key
      or remove the _saip subdomain delegation entirely.

   o  DNS TTL for _saip records SHOULD be set to 300 seconds
      (5 minutes) to minimize the revocation window while
      maintaining reasonable DNS query load.

   o  Servers MUST NOT cache Master Public Keys beyond the DNS TTL
      of the record from which they were obtained.

6.4.5.  Security Properties

   +====================+===================+======================+
   | Threat             | Mitigation                               |
   +====================+==========================================+
   | Stolen rcert       | Per-request nonce+ts+method+path binding |
   |                    | -- structurally non-replayable            |
   +--------------------+------------------------------------------+
   | Stolen rpk+rcert   | Valid for exactly one request only       |
   +--------------------+------------------------------------------+
   | Master Key theft   | Hardware module (TPM/HSM) -- never        |
   |                    | leaves hardware                          |
   +--------------------+------------------------------------------+
   | DNS poisoning      | DNSSEC + short TTL (300s)                |
   +--------------------+------------------------------------------+
   | Mass compromise    | DNS record deletion -- all instances      |
   |                    | revoked after TTL expiry                 |
   +--------------------+------------------------------------------+

   This model provides stronger replay protection than TLS Session
   Tickets [RFC5077] because rcert= is bound to a single request
   rather than a time window, while retaining equivalent performance
   characteristics through DNS caching.

6.4.6.  Comparison with RE-Based Model

   +====================+===================+======================+
   | Property           | RKDF + RE Model   | DNS-Native Model     |
   +====================+===================+======================+
   | Key registry       | RE infrastructure | DNS TXT records      |
   +--------------------+-------------------+----------------------+
   | Revocation         | RE propagation    | DNS deletion + TTL   |
   |                    | (within 300s)     | (default 300s)       |
   +--------------------+-------------------+----------------------+
   | Per-request key    | HMAC derivation   | Fresh keypair +      |
   |                    | (deterministic)   | MasterKey rcert      |
   +--------------------+-------------------+----------------------+
   | Replay protection  | Nonce + sequence  | Nonce bound in rcert |
   +--------------------+-------------------+----------------------+
   | Infrastructure     | RE ecosystem      | Existing DNS only    |
   +--------------------+-------------------+----------------------+
   | Best suited for    | Enterprise,       | Decentralized, IoT,  |
   |                    | regulated envs    | small vendors, KISS  |
   +--------------------+-------------------+----------------------+

   Both models implement VICDM principles. Implementations MAY
   support both simultaneously. Servers SHOULD apply equivalent
   trust to successfully verified agents regardless of model used.

6.4.7.  MAC-Based Identity Binding (Hardware Identity Layer)

   This section defines an optional extension to the DNS-Native
   model that adds a hardware identity layer through MAC address
   binding. When present, this creates a verifiable triplet:

      MAC address    (hardware identity layer)
    + IP / ASN       (network identity layer)
    + MasterPublicKey (cryptographic identity layer)
    = Complete Agent Identity

   All three components MUST be consistent for an agent to be
   classified as Class 3 (Fully Verified) under this extension.
   Inconsistency in any component MUST result in downgrade to
   Class 1 (Unverifiable Claim).

6.4.7.1.  The Bot as Identity Broker

   Because MAC addresses operate at Layer 2 and are not visible
   beyond the local network segment, direct MAC verification by
   remote servers is not possible. Instead, the agent acts as a
   local identity broker:

   The agent:
   1. Reads the MAC address from its local network interface
      (Real MAC), OR derives a Virtual MAC (V-MAC) from its
      MasterPublicKey (see Section 6.4.7.3).
   2. Signs the MAC address using its MasterPrivateKey,
      producing a MAC Attestation Proof (mac_proof).
   3. Includes mac= and mac_proof= in the SAIP header.

   The server:
   1. Retrieves the MasterPublicKey from DNS.
   2. Verifies mac_proof using MasterPublicKey.
      This proves the MAC was attested by the legitimate
      MasterKey holder -- not merely asserted.
   3. Applies identity binding policy.

   The MasterPublicKey in DNS is the root of trust that validates
   everything -- both Real MAC and V-MAC attestations. The DNS
   record is the single source of truth; the bot is the
   cryptographic bridge between local hardware and remote
   verification.

6.4.7.2.  Real MAC -- Physical Hardware Binding

   A Real MAC is the hardware MAC address of the agent's network
   interface, as reported by the operating system:

   Linux:   /sys/class/net/<interface>/address
   Windows: Get-NetAdapter | Select-Object MacAddress
   macOS:   ifconfig en0 | grep ether

   Real MAC binding is RECOMMENDED for:
   o  IoT devices with fixed network interfaces
   o  Physical servers with stable hardware
   o  High-assurance deployments where hardware binding
      is a compliance requirement

   The MAC Attestation Proof for a Real MAC:

   mac_proof = Sign(MasterPrivateKey,
                    "real"    ||
                    mac_bytes ||
                    ts        ||
                    nonce)

   Where mac_bytes is the 6-byte IEEE 802 MAC address in
   canonical form (big-endian, no separators).

6.4.7.3.  Virtual MAC (V-MAC) -- Cryptographic Identity

   A V-MAC is derived mathematically from the MasterPublicKey,
   providing a stable, unique, human-readable identifier for
   virtual agents, cloud instances, and software bots that do
   not have a meaningful physical MAC address.

   V-MAC derivation:

   raw     = SHA256(MasterPublicKey)[0:6]   (first 6 bytes)
   v_mac   = raw with bit 1 of byte 0 set to 1 (LAA bit)
           = (raw[0] | 0x02) || raw[1:6]

   The LAA (Locally Administered Address) bit distinguishes
   V-MAC from globally assigned hardware MACs per IEEE 802.

   Example:
   MasterPublicKey -> SHA256 -> first 6 bytes: AC:CE:7F:3A:B1:09
   Set LAA bit:                               AE:CE:7F:3A:B1:09
   V-MAC:                                     AE:CE:7F:3A:B1:09

   The V-MAC is mathematically bound to the MasterPublicKey.
   Any server can verify:
   (SHA256(claimed_MasterPublicKey)[0] | 0x02) == v_mac[0]
   AND SHA256(claimed_MasterPublicKey)[1:6] == v_mac[1:6]

   The MAC Attestation Proof for a V-MAC:

   mac_proof = Sign(MasterPrivateKey,
                    "virtual" ||
                    mac_bytes ||
                    ts        ||
                    nonce)

   V-MAC is RECOMMENDED for:
   o  Cloud agents and virtual machines
   o  Software bots without meaningful hardware identity
   o  Privacy-sensitive deployments (V-MAC reveals no
      hardware manufacturer information)

6.4.7.4.  DNS Record Format with MAC Binding

   When MAC binding is used, the DNS TXT record SHOULD include
   the mac= parameter:

   ; Real MAC binding (IoT device)
   wm-bg-4471._saip.manufacturer.com. 300 IN TXT
     "v=saip1;
      mac=B8:27:EB:4A:3C:11;
      mac-type=real;
      pk=<MasterPublicKey>;
      asn=1234"

   ; V-MAC binding (cloud agent)
   crawler-nyc-042._saip.acme.com. 300 IN TXT
     "v=saip1;
      mac=AE:CE:7F:3A:B1:09;
      mac-type=virtual;
      pk=<MasterPublicKey>;
      asn=64496"

   Defined MAC-related DNS parameters:

   mac=        The MAC address (real or virtual) in
               XX:XX:XX:XX:XX:XX format.

   mac-type=   Either "real" or "virtual". MUST be present
               when mac= is present.

6.4.7.5.  Network Identity: IP and ASN Binding

   The network identity component of the triplet MAY be
   expressed as either an IP address, CIDR prefix, or ASN:

   For stable deployments (physical servers, IoT):
     ip=203.0.113.42          (exact IP)
     ip=203.0.113.0/24        (CIDR prefix)

   For dynamic deployments (cloud, autoscaling):
     asn=64496                (Autonomous System Number)

   IP/ASN binding is OPTIONAL. When present, servers SHOULD
   verify that the source network matches the registered value.
   Mismatch SHOULD result in trust downgrade but MUST NOT
   cause automatic rejection without additional policy context,
   as legitimate network changes (ISP failover, cloud
   migration) may cause temporary mismatches.

6.4.7.6.  Verification Triplet Summary

   +=================+==============+==============================+
   | Component       | Source       | Verification Method          |
   +=================+==============+==============================+
   | MasterPublicKey | DNS TXT pk=  | Signature verification       |
   +-----------------+--------------+------------------------------+
   | MAC (real)      | DNS TXT mac= | mac_proof verified by        |
   |                 | + hardware   | MasterPublicKey              |
   +-----------------+--------------+------------------------------+
   | MAC (virtual)   | DNS TXT mac= | SHA256(pk) derivation check  |
   |                 | + derivation | + mac_proof by MasterKey     |
   +-----------------+--------------+------------------------------+
   | IP / ASN        | DNS TXT      | Source address comparison    |
   |                 | ip= / asn=   | (advisory, not mandatory)    |
   +-----------------+--------------+------------------------------+

   All cryptographic verifications (MasterPublicKey signature,
   mac_proof) are REQUIRED for Class 3 classification.
   IP/ASN verification is RECOMMENDED but OPTIONAL.

6.5.  Agent Letter of Intent (ALOI)

   This section defines the fourth principle of the VICDM model,
   extending the core framework with behavioral commitment:

      Anonymous interaction is permitted.
      Identity assertion is permitted if cryptographically proven.
      Delegated infrastructure must be explicitly authorized.
      Declared intent MUST be honored.
      Self-reported deviation is good faith.
      Concealed deviation is fraud.

   This principle is analogous to voluntary disclosure in financial
   regulation: entities that self-report violations to regulators
   receive reduced penalties compared to those discovered through
   external audit. SAIP applies this principle cryptographically --
   an agent that self-reports an ALOI deviation is demonstrably
   acting in good faith, and the ecosystem SHOULD reward that
   behavior with reduced sanctions.

6.5.1.  Definition and Purpose

   An Agent Letter of Intent (ALOI) is an optional, cryptographically
   bound declaration that an agent publishes, stating its intended
   operational conduct.

   The name is deliberate. An ALOI is a Letter of Intent: a signed,
   binding declaration by which an agent announces what it intends
   to do. It is an invitation to enter into agreement -- not an
   agreement in itself. An ALOI commits the agent to its declared
   intent; it does not, by itself, bind any server.

   The ALOI serves three purposes:

   o  Commitment: The agent formally declares what it will do,
      creating a verifiable, signed statement of intent.

   o  Detection: Servers can automatically detect deviation from
      declared intent without subjective judgment.

   o  Accountability: Deviation is cryptographically attributable
      to a specific agent instance, enabling proportional sanctions.

   ALOI is OPTIONAL. An agent that does not publish an ALOI operates
   under standard identity verification only (Section 5). An agent
   that publishes an ALOI is held to its declared intent.

6.5.1.1.  ALOI Content (Modular)

   An ALOI declaration is modular. It MAY carry two distinct kinds
   of content, independently:

   o  Operational boundaries: the agent's own declared scope,
      access boundaries, rate limits, and exclusions. These
      parameters are defined in Section 6.5.2.

   o  Policy compliance (OPTIONAL): a declaration that the agent
      has observed, and commits to honor, a site's published,
      resolved policy outcome.

   The policy compliance content is policy-source-agnostic. The
   resolved policy outcome MAY originate from any external
   preference or policy system. The AIPREF framework [AIPREF] is
   one such system; robots.txt is another. ALOI does not privilege
   any particular policy source: it references the resolved policy
   outcome, not the system that produced it.

   When an ALOI carries policy compliance content, it MUST name the
   policy source it refers to (for example, "aipref" or "robots"),
   so that a server can apply the correct interpretation. This
   mirrors the identity-mechanism naming used elsewhere in this
   document family: the mechanism is named, never assumed.

   Declaring policy compliance in an ALOI is a unilateral act. The
   agent states, on its own, that it will honor the site's already-
   published policy. This requires no response from the site; the
   agent has bound itself.

6.5.1.2.  The Dual Nature of an ALOI

   An ALOI has a dual nature.

   As an initial proposal: an ALOI is the agent's opening position
   toward forming a bilateral agreement. An agent that wishes to
   enter into a Verifiable Data Access Contract [VDAC] MAY use its
   ALOI as the agent-side initial proposal.

   As a standing declaration: independently of any agreement, an
   ALOI is a valid unilateral declaration of intent. It is in force
   from the moment it is issued. Its effect does not depend on any
   server's response.

   These two roles coexist. The same ALOI is simultaneously an
   opening proposal (should agreement formation follow) and a
   standing declaration (whether or not it does).

6.5.1.3.  ALOI and Server Response: Three Outcomes

   Because an ALOI is a Letter of Intent and not an agreement,
   what follows from it depends on how the server responds. There
   are exactly three outcomes:

   1. The server explicitly accepts. If the server cryptographically
      accepts the ALOI, the declaration transitions into a bilateral
      agreement. The mechanics of that agreement -- dual signatures,
      per-request binding, mutual logging -- are specified in [VDAC].
      At this point the agent is a Contracted Agent (the highest
      trust class; see Section 7).

   2. The server explicitly declines. The server may issue a signed
      refusal. No agreement is formed. The agent knows, unambiguously,
      that it was declined, and acts accordingly -- operating
      anonymously, or not accessing the site.

   3. The server is silent. If the server does not respond, NO
      agreement is formed. Server silence MUST NOT be interpreted
      as acceptance. The absence of a "no" is not a "yes".

   The third outcome is the critical one. Earlier informal
   treatments of ALOI left the silent case implicit, which risked
   the assumption that an unanswered ALOI was somehow agreed to.
   This specification removes that ambiguity: an unanswered ALOI
   forms no agreement.

   However -- and this is the value of the standing-declaration
   nature -- an unanswered ALOI does not vanish. It remains in
   force as a unilateral declaration of intent. The agent operates
   under its own declared ALOI constraints and is held to them
   (Sections 6.5.5 through 6.5.8), but it does so as an
   Intent-Declaring agent, NOT as a Contracted Agent. It carries
   no agreement and the elevated trust and protections of a
   contract do not apply.

   In short:

      ALOI issued                  -> declaration in force
      ALOI + server acceptance     -> bilateral agreement [VDAC]
      ALOI + server refusal        -> no agreement; declined
      ALOI + server silence        -> no agreement; declaration
                                      remains in force

   The ALOI complements robots.txt:

      robots.txt:  The server declares what bots MAY access.
                   (server-defined policy, unilateral)

      ALOI:        The bot declares what it WILL do.
                   (agent-defined commitment, cryptographic)

   These are complementary mechanisms. A well-behaved agent SHOULD
   respect both robots.txt restrictions and its own ALOI declaration.

6.5.2.  ALOI Parameters

   The following parameters are defined for ALOI publication in
   DNS TXT records. All ALOI parameters use the "aloi-" prefix
   for namespace isolation:

   aloi=         Primary intent category. MUST be one of:
                 "crawl"   -- web crawling and indexing
                 "backup"  -- data backup and archival
                 "monitor" -- monitoring and health checks
                 "api"     -- API integration and data sync
                 "smtp"    -- mail relay and delivery
                 "iot"     -- IoT telemetry and control
                 "sync"    -- file and data synchronization
                 Implementations MAY define additional values.

   aloi-scope=   URL path scope the agent declares it will
                 access. Supports glob patterns:
                 /public/*     -- all paths under /public/
                 /blog/*.html  -- HTML files under /blog/
                 *             -- unrestricted (use with caution)

   aloi-rate=    Maximum request rate the agent self-imposes.
                 Format: <number>/<unit>
                 Examples: 10/sec, 1000/day, 60/min

   aloi-exclude= Comma-separated list of paths or categories
                 the agent declares it will NOT access:
                 /admin, /api, /private, /user-data

   aloi-ua=      User-Agent string the agent declares it will
                 use. MUST be consistent with the agent
                 identity asserted by the identity mechanism
                 in use (for example, the SAIP id= field, or
                 the corresponding identifier of whichever
                 other mechanism is in use). Servers SHOULD
                 flag mismatches.

   aloi-expires= Unix timestamp after which this ALOI
                 declaration should be considered expired.
                 Agents SHOULD refresh ALOI before expiry.

6.5.3.  ALOI Cryptographic Binding

   The ALOI declaration MUST be cryptographically bound to the
   agent's identity. This binding is achieved in two ways:

   First, publication in the agent's DNS TXT record ties the ALOI
   to the MasterPublicKey in the same record. Any server can verify
   that the ALOI was published by the legitimate key holder.

   Second, each request MUST include an ALOI commitment hash:

   aloi-hash = SHA256(canonical ALOI string from DNS record)

   The aloi-hash= value is carried in the request-authentication
   data of the identity mechanism in use (for example, within the
   SAIP header, where SAIP is the mechanism in use) and MUST be
   covered by that mechanism's request signature. Where SAIP is
   used, the canonical signed string is:

   id=<id>;ts=<ts>;nonce=<nonce>;method=<METHOD>;path=<path>;
   aloi-hash=<aloi-hash>

   Other identity mechanisms carry and sign the aloi-hash value
   using their own equivalent request-authentication data; the
   requirement is that aloi-hash be present and signed, not that
   any particular mechanism be used.

   This cryptographically proves that the agent is operating under
   the stated ALOI for this specific request. A server that detects
   deviation has cryptographic proof of the commitment and the
   violation simultaneously.

6.5.4.  DNS Record Format with ALOI

   Example DNS TXT records with ALOI declaration:

   ; Web crawler with strict scope declaration
   crawler-nyc-042._saip.acme.com. 300 IN TXT
     "v=saip1;
      pk=<MasterPublicKey>;
      aloi=crawl;
      aloi-scope=/public/*,/blog/*,/sitemap.xml;
      aloi-rate=10/sec;
      aloi-exclude=/api,/admin,/private,/user-data;
      aloi-ua=AcmeBot/2.0 (+https://acme.com/bot)"

   ; Backup agent with narrow scope
   backup-agent-01._saip.corp.com. 300 IN TXT
     "v=saip1;
      pk=<MasterPublicKey>;
      aloi=backup;
      aloi-scope=/exports/*,/snapshots/*;
      aloi-rate=100/min;
      aloi-exclude=/live,/user-sessions"

   ; IoT monitoring device
   sensor-bg-4471._saip.vendor.com. 300 IN TXT
     "v=saip1;
      pk=<MasterPublicKey>;
      aloi=iot;
      aloi-scope=/telemetry/submit,/config/read;
      aloi-rate=1/sec;
      aloi-exclude=/config/write,/admin,/firmware"

6.5.5.  Server-Side ALOI Enforcement

   Servers implementing ALOI enforcement MUST perform the following
   checks on each request from an ALOI-declaring agent:

   1. Retrieve ALOI from DNS cache (same lookup as MasterPublicKey).

   2. Verify aloi-hash=, as carried by the identity mechanism in
      use, matches SHA256 of the DNS ALOI record. Mismatch
      indicates ALOI substitution attempt and MUST be treated
      as a Class 1 violation.

   3. Check request path against aloi-scope=:
      If path does not match declared scope -> scope violation.

   4. Check request path against aloi-exclude=:
      If path matches any excluded pattern -> exclusion violation.

   5. Check request rate against aloi-rate=:
      If rate exceeds declared maximum -> rate violation.

   6. Check User-Agent against aloi-ua= (if present):
      If User-Agent does not match -> identity inconsistency.

   Violation detection MUST trigger the sanctions defined in
   Section 6.5.7.

6.5.6.  ALOI Violation Response Header

   When a server detects an ALOI violation, it SHOULD include a
   structured violation signal in the response. The header is named
   for the layer to which it belongs -- the ALOI layer -- and not
   for any identity mechanism. Its name is fixed and does not vary
   with the identity mechanism in use:

   ALOI-Violation: <violation-type>;
                   mechanism=<identity-mechanism>;
                   declared=<declared-value>;
                   attempted=<attempted-value>;
                   penalty=<applied-penalty>

   The mechanism= field names the identity mechanism under which
   the agent was operating (for example, "saip" or "vicdm-dns").
   The header name itself remains ALOI-Violation regardless of
   that value: a server always knows which header to read, while
   the identity mechanism is recorded in the content.

   Example:

   ALOI-Violation: scope-exceeded;
                   mechanism=saip;
                   declared=/public/*;
                   attempted=/api/private-data;
                   penalty=throttle

   Defined violation types:

   scope-exceeded    Request path outside declared aloi-scope=
   exclusion-breach  Request path matches aloi-exclude=
   rate-exceeded     Request rate exceeds aloi-rate=
   ua-mismatch       User-Agent inconsistent with aloi-ua=
   aloi-expired      aloi-expires= timestamp has passed
   aloi-hash-mismatch aloi-hash= does not match DNS record

6.5.7.  Violation Sanctions and Scoring

   ALOI violations MUST be handled proportionally. The following
   scoring model is RECOMMENDED:

   +=================+============+================================+
   | Violation Count | Penalty    | Action                         |
   +=================+============+================================+
   | 1               | Warning    | ALOI-Violation header only.    |
   |                 |            | Log for audit. No rate change. |
   +-----------------+------------+--------------------------------+
   | 2-3             | Throttle   | Reduce to minimal rate limit.  |
   |                 |            | Report to vendor via header.   |
   +-----------------+------------+--------------------------------+
   | 4-5             | Downgrade  | Trust downgrade to Class 1.    |
   |                 |            | Report to RE (optional).       |
   +-----------------+------------+--------------------------------+
   | 6-10            | Block      | Reject all requests.           |
   |                 |            | Report to RE for revocation.   |
   +-----------------+------------+--------------------------------+
   | >10             | Revocation | RE revokes InstanceID.         |
   |                 |            | Vendor notified.               |
   +-----------------+------------+--------------------------------+

   Violation scores SHOULD decay over time. A RECOMMENDED decay
   rate is -1 point per 24 hours of compliant behavior.

   Servers MAY report violations to the RE using a standardized
   violation report:

   POST <re-endpoint>/violation
   Content-Type: application/json

   {
     "instance-id": "<agent-id>",
     "violation":   "<violation-type>",
     "declared":    "<declared-value>",
     "attempted":   "<attempted-value>",
     "ts":          <unix-timestamp>,
     "server-sig":  "<MasterKeySig_over_report>"
   }

6.5.8.  Agent Self-Reporting (Good Faith Mechanism)

   An agent that detects it has unintentionally violated its own
   ALOI declaration MAY self-report the violation before the server
   detects it. This is the Good Faith Mechanism.

   This principle is directly analogous to voluntary disclosure
   in financial and regulatory contexts: entities that proactively
   report their own violations to authorities receive reduced
   penalties compared to those discovered through external audit.

   Self-reporting is performed by including a self-report signal
   in the immediately following request. As with the violation
   header (Section 6.5.6), the header name belongs to the ALOI
   layer and is fixed; it does not vary with the identity
   mechanism in use:

   ALOI-Self-Report: violation=<violation-type>;
                     mechanism=<identity-mechanism>;
                     declared=<declared-value>;
                     attempted=<attempted-value>;
                     ts=<unix-timestamp-of-violation>;
                     self-sig=<Sign(identity-private-key,
                                   violation-type||declared||
                                   attempted||ts||nonce)>

   The mechanism= field names the identity mechanism in use (for
   example, "saip" or "vicdm-dns"). The self-sig= MUST be signed
   by the agent's identity private key under whichever mechanism
   is in use (under SAIP, the MasterPrivateKey). This proves the
   self-report is genuine and cannot be fabricated by a third
   party.

   Self-reported violations MUST result in reduced penalties:

   +=================+====================+======================+
   | Condition       | Server-Detected    | Self-Reported        |
   +=================+====================+======================+
   | 1st violation   | Warning            | No penalty           |
   +-----------------+--------------------+----------------------+
   | 2nd-3rd         | Throttle           | Warning only         |
   +-----------------+--------------------+----------------------+
   | 4th-5th         | Downgrade          | Throttle             |
   +-----------------+--------------------+----------------------+
   | 6th-10th        | Block              | Downgrade            |
   +-----------------+--------------------+----------------------+
   | >10             | RE Revocation      | Block (no revocation)|
   +-----------------+--------------------+----------------------+

   Agents that consistently self-report SHOULD receive elevated
   trust scores over time, as self-reporting demonstrates that
   the agent's vendor has implemented responsible operational
   practices.

   The Good Faith Mechanism creates a positive incentive structure:
   vendors who build self-reporting into their agents benefit from
   higher trust levels and reduced sanctions, while vendors whose
   agents conceal violations face progressively harsher penalties.

6.6.  Verifiable Data Access Contract (VDAC)

   This section introduces the fifth principle of the VICDM model.
   The full protocol specification is defined in a companion
   document, the Verifiable Data Access Contract [VDAC].

   The VICDM Core Principle is extended as follows:

      Anonymous interaction is permitted.
      Identity assertion is permitted if cryptographically proven.
      Delegated infrastructure must be explicitly authorized.
      Declared intent MUST be honored (ALOI).
      Agreed intent MUST be honored bilaterally (VDAC).
      Self-reported deviation is good faith.
      Concealed deviation is fraud.

   VDAC is the natural bilateral extension of ALOI. Where ALOI
   (Section 6.5) is a unilateral declaration by the agent ("here
   is what I intend to do"), VDAC is a cryptographic agreement
   between a site and an agent ("here is what we have agreed I
   will do").

   Under VDAC, a site publishes an access Offer, an agent accepts
   that Offer, both parties sign the resulting Contract, and each
   subsequent request references the Contract cryptographically.
   Both parties retain non-repudiable logs, making any divergence
   between agreed terms and actual behavior provable rather than
   merely asserted.

   An agent operating under a valid VDAC contract is classified
   as Class 4 (Contracted Agent) under the VICDM trust model
   (Section 7), receiving the highest trust level in that
   classification.

   VDAC verifies the existence of an agreement, not the wisdom
   of its terms. Pricing, payment, commercial settlement, and the
   substantive content of agreements are explicitly outside the
   scope of both VICDM and VDAC. These remain entirely between
   the contracting parties.

   The complete VDAC wire protocol -- including the Offer, the
   Acceptance, and the Contract document formats; discovery
   mechanisms; per-request contract reference; mutual tracking
   obligations; reconciliation; violation handling; and contract
   termination -- is specified in [VDAC]. Implementers requiring
   the bilateral agreement mechanism should refer to that
   document.

6.6.1.  Relationship to ALOI

   ALOI and VDAC are complementary, not alternative:

   o  ALOI is unilateral. The agent declares; the site receives.
   o  VDAC is bilateral. Both parties agree; both are bound.

   An agent MAY operate under both simultaneously. ALOI defines
   the agent's general operational scope across all interactions;
   VDAC defines the specific terms for one particular site. When
   in conflict, the more specific commitment governs: VDAC terms
   supersede ALOI declarations for requests under the contract,
   while ALOI continues to apply for interactions outside any
   VDAC contract.

   This creates a natural progression: agents start with ALOI for
   general accountability, then enter VDAC agreements with
   specific sites where bilateral terms are warranted.

7.  Trust Classification

   The VICDM trust model classifies every interacting entity into
   one of five trust classes. Servers use this classification to
   apply proportionate access policy.

   +=========+=====================+=========+====================+
   | Class   | Identity Status     | Trust   | Recommended        |
   |         |                     | Level   | Policy             |
   +=========+=====================+=========+====================+
   | Class 4 | Contracted Agent    | Highest | Contract terms     |
   |         | (VDAC)              |         | govern access      |
   +---------+---------------------+---------+--------------------+
   | Class 3 | Fully Verified      | High    | Full access, may   |
   |         |                     |         | receive elevated   |
   |         |                     |         | rate limits        |
   +---------+---------------------+---------+--------------------+
   | Class 2 | Partially Verified  | Medium  | Standard access    |
   |         |                     |         | with monitoring    |
   +---------+---------------------+---------+--------------------+
   | Class 0 | Anonymous           | Low     | Default anonymous  |
   |         |                     |         | policy             |
   +---------+---------------------+---------+--------------------+
   | Class 1 | Unverifiable Claim  | Minimal | Lower than Class 0 |
   |         |                     |         | log for audit      |
   +---------+---------------------+---------+--------------------+

   Note that Class 1 (unverifiable claim) receives LOWER trust than
   Class 0 (anonymous). This is intentional: an entity that actively
   misrepresents its identity is more concerning than one that simply
   does not identify itself.

8.  Policy Enforcement

   Systems SHOULD NOT rely on binary allow/deny decisions. Instead,
   they SHOULD apply adaptive trust-based policies proportional to
   the verified identity class.

   Policy actions MAY include:

   o  Full acceptance and priority handling for Class 3 clients
   o  Standard acceptance with monitoring for Class 2 clients
   o  Default anonymous handling for Class 0 clients
   o  Throttling and logging for Class 1 clients
   o  Rejection in high-risk or sensitive contexts for Class 1

   The specific thresholds and actions are deployment-specific and
   outside the scope of this document.

9.  Relationship to Anonymous Authentication

   Anonymous authentication systems (such as Privacy Pass and
   related mechanisms being developed in the IETF webbotauth
   working group) allow a client to prove it is vouched for by a
   trusted Attester without revealing its specific identity.

   Anonymous authentication is fully compatible with VICDM:

   o  A client using anonymous attestation falls under Class 0
      (Anonymous) or Class 2 (Partially Verified, via Attester)
      depending on the Attester's trust level.

   o  A client using identified authentication (such as SAIP [SAIP])
      falls under Class 3 (Fully Verified) when verification
      succeeds.

   The two models serve different operational requirements:

   Anonymous attestation is appropriate when:
   o  The site's primary concern is rate limiting and abuse
      prevention at the Attester level
   o  Bot privacy is a design requirement
   o  Per-instance accountability is not needed

   Identified authentication is appropriate when:
   o  Per-instance revocation is required
   o  Audit trails are a compliance requirement
   o  Reputation systems depend on persistent agent identity
   o  IoT or enterprise fleet management is involved

   Systems MAY support both models simultaneously and apply
   different policies to each class of client.

10.  Non-Goals

   This document does NOT:

   o  Eliminate or restrict anonymous interaction. Anonymous access
      MUST remain a first-class mode of operation.

   o  Require universal identity adoption. Identity remains opt-in.

   o  Define a mandatory implementation protocol. Protocol
      specifications implementing these principles are separate
      documents (see [SAIP]).

   o  Replace existing standards for authentication, authorization,
      or access control.

   o  Define specific rate limits, trust scores, or policy
      thresholds. These are deployment-specific.

11.  Security Considerations

11.1.  False Identity Claims

   The primary security concern addressed by this document is false
   identity assertion -- clients that claim to be trusted entities
   without cryptographic proof.

   By defining Class 1 (unverifiable claim) as receiving lower trust
   than Class 0 (anonymous), this model removes the incentive to
   make unverifiable identity claims. An agent that cannot prove its
   identity is better served by not claiming one.

11.2.  DNS Security

   DNS-based verification (Section 5.1 and 6.2) is subject to
   DNS spoofing and cache poisoning attacks. Implementations MUST
   use DNSSEC [RFC4033] where available to validate DNS responses
   used for identity verification.

11.3.  Delegation Scope Creep

   Delegation tokens and DNS delegation records SHOULD be scoped
   as narrowly as possible. Overly broad delegation (e.g., an open-
   ended authorization for all infrastructure operated by a large
   provider) defeats the purpose of the delegation model by creating
   de facto anonymous identity claims under a trusted name.

11.4.  Attester Compromise

   In anonymous attestation models, compromise of an Attester
   allows issuance of credentials to malicious clients. This model
   does not address Attester security directly; that is the
   responsibility of the attestation protocol specification.

12.  Privacy Considerations

   This document preserves anonymity as a first-class mode of
   operation. No client is required to assert an identity.

   When a client does assert an identity, the verification
   mechanisms in Section 5 may disclose information about the
   client's network location and infrastructure to the verifying
   server. Clients that wish to preserve privacy SHOULD use
   anonymous interaction (Class 0) rather than identity assertion.

   DNS-based Attestation Discovery records (Section 6.2) are publicly
   accessible. Entities publishing such records should be aware
   that the records disclose information about their infrastructure
   and delegation relationships.

13.  IANA Considerations

   This document requests IANA to create the following new registry:

   Registry name:        VICDM DNS Delegation Record Parameters
   Registration policy:  Specification Required
   Initial contents:     v, re, pk, asn, ip, exp
                         as defined in Section 6.2 of this document.

   This document has no other IANA actions.

14.  References

14.1.  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>.

   [RFC1034]  Mockapetris, P., "Domain names - concepts and
              facilities", STD 13, RFC 1034,
              DOI 10.17487/RFC1034, November 1987,
              <https://www.rfc-editor.org/info/rfc1034>.

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035,
              DOI 10.17487/RFC1035, November 1987,
              <https://www.rfc-editor.org/info/rfc1035>.

   [RFC4033]  Arends, R., Austein, R., Larson, M., Massey, D.,
              and S. Rose, "DNS Security Introduction and
              Requirements", RFC 4033, DOI 10.17487/RFC4033,
              March 2005,
              <https://www.rfc-editor.org/info/rfc4033>.

14.2.  Informative References

   [RFC7208]  Kitterman, S., "Sender Policy Framework (SPF) for
              Authorizing Use of Domains in Email, Version 1",
              RFC 7208, DOI 10.17487/RFC7208, April 2014,
              <https://www.rfc-editor.org/info/rfc7208>.

   [RFC6376]  Crocker, D., Ed., Hansen, T., Ed., and M.
              Kucherawy, Ed., "DomainKeys Identified Mail (DKIM)
              Signatures", STD 76, RFC 6376,
              DOI 10.17487/RFC6376, September 2011,
              <https://www.rfc-editor.org/info/rfc6376>.

   [RFC9110]  Fielding, R., Ed., Nottingham, M., Ed., and J.
              Reschke, Ed., "HTTP Semantics", STD 97, RFC 9110,
              DOI 10.17487/RFC9110, June 2022,
              <https://www.rfc-editor.org/info/rfc9110>.

   [SAIP]     Jovancevic, S., "SAIP: Signed Agent Identity
              Protocol", draft-jovancevic-saip-08, April 2026,
              <https://datatracker.ietf.org/doc/
              draft-jovancevic-saip/>.

   [AIPREF]   IETF AI Preferences (AIPREF) Working Group,
              "Vocabulary for Expressing AI Usage Preferences",
              Work in Progress, Internet-Draft, 2026,
              <https://datatracker.ietf.org/wg/aipref/>.

   [VDAC]     Jovancevic, S., "Verifiable Data Access Contract
              (VDAC)", draft-jovancevic-vdac-01, May 2026,
              <https://datatracker.ietf.org/doc/
              draft-jovancevic-vdac/>.

Appendix A.  Document History

   This appendix is informative and will be removed before
   publication as an RFC.

   Changes in draft-jovancevic-vicdm-08:

   o  Made the ALOI layer explicitly identity-mechanism-agnostic.
      Earlier text tied ALOI to SAIP in several places, which
      misrepresented ALOI as a SAIP extension. ALOI is an
      independent layer; SAIP is only one of several identity
      mechanisms that may carry it. This is a conceptual
      correction, not an editorial one.

   o  Section 6.5.2 (aloi-ua): the User-Agent consistency
      requirement now refers to the agent identity asserted by
      the identity mechanism in use, with SAIP id= given only as
      one example.

   o  Section 6.5.3 (ALOI Cryptographic Binding): the aloi-hash
      commitment is now described as carried by whichever identity
      mechanism is in use, not by SAIP specifically.

   o  Section 6.5.5: the server-side aloi-hash verification step
      is likewise mechanism-independent.

   o  Sections 6.5.6 and 6.5.8: the violation and self-report
      response headers were renamed from SAIP-Violation and
      SAIP-Self-Report to ALOI-Violation and ALOI-Self-Report,
      because these headers belong to the ALOI layer, not to any
      identity mechanism. The header name is fixed and does not
      vary with the identity mechanism in use. A mechanism= field
      was added to both headers to record, in the content, which
      identity mechanism was in use.

   Changes in draft-jovancevic-vicdm-07:

   o  Expanded Section 6.5.1 (ALOI Definition and Purpose) into a
      precise definition plus three subsections. ALOI is defined
      as a Letter of Intent: an invitation to enter into agreement,
      not an agreement in itself.

   o  Added Section 6.5.1.1 (ALOI Content, Modular): ALOI may carry
      operational boundaries and optional policy-compliance
      content. The policy-compliance content is policy-source-
      agnostic; AIPREF is given as one example, robots.txt as
      another. The policy source must be named.

   o  Added Section 6.5.1.2 (Dual Nature): an ALOI is both an
      initial proposal toward agreement and a standing unilateral
      declaration.

   o  Added Section 6.5.1.3 (Three Outcomes): server acceptance,
      refusal, or silence. Server silence forms no agreement;
      the absence of a refusal is not acceptance.

   o  Added the [AIPREF] reference; updated the [VDAC] reference.

Author's Address

   Srecko Jovancevic
   SKGO, IKT Support
   Makedonska 22
   11000 Belgrade
   Serbia

   Email: srecko.jovancevic@skgo.org
   Email: srecko.jovancevic@gmail.com
   URI:   https://github.com/sreckojovancevic
