Files
ietf-wimse-ect/draft-nennemann-wimse-ect-00.xml
Christian Nennemann 1385ec8af1 Slim down draft to core ECT mechanism for -00 submission
Remove all companion draft (ect-pol) references, regulatory
compliance mappings, pre-defined extension keys, witness concept,
pseudocode blocks, implementation guidance appendix, and redundant
examples. Keep only the core token format, DAG validation,
verification procedure, and one cross-organization use case.
Draft reduced from ~40 pages to 27 pages.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-25 20:30:07 +01:00

2011 lines
88 KiB
XML
Raw Blame History

This file contains invisible Unicode characters
This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="rfc2629.xslt" ?>
<!-- generated by https://github.com/cabo/kramdown-rfc version 1.7.31 (Ruby 3.4.5) -->
<!DOCTYPE rfc [
<!ENTITY nbsp "&#160;">
<!ENTITY zwsp "&#8203;">
<!ENTITY nbhy "&#8209;">
<!ENTITY wj "&#8288;">
]>
<rfc ipr="trust200902" docName="draft-nennemann-wimse-ect-00" category="std" consensus="true" submissionType="IETF" tocInclude="true" sortRefs="true" symRefs="true">
<front>
<title abbrev="WIMSE Execution Context">Execution Context Tokens for Distributed Agentic Workflows</title>
<author fullname="Christian Nennemann">
<organization>Independent Researcher</organization>
<address>
<email>ietf@nennemann.de</email>
</address>
</author>
<date year="2026" month="February" day="25"/>
<area>Security</area>
<workgroup>WIMSE</workgroup>
<keyword>execution context</keyword> <keyword>workload identity</keyword> <keyword>agentic workflows</keyword> <keyword>audit trail</keyword>
<abstract>
<?line 53?>
<t>This document defines Execution Context Tokens (ECTs), an extension
to the Workload Identity in Multi System Environments (WIMSE)
architecture for distributed agentic workflows. ECTs provide
signed, structured records of task execution order across
agent-to-agent communication. By extending WIMSE Workload Identity
Tokens with execution context claims in JSON Web Token (JWT)
format, this specification enables systems to maintain structured
audit trails of agent execution. ECTs use a directed acyclic
graph (DAG) structure to represent task dependencies and integrate
with WIMSE Workload Identity Tokens (WIT) using the same signing
model and cryptographic primitives. A new HTTP header field,
Execution-Context, is defined for transporting ECTs alongside
existing WIMSE headers.</t>
</abstract>
</front>
<middle>
<?line 69?>
<section anchor="introduction"><name>Introduction</name>
<section anchor="motivation"><name>Motivation</name>
<t>The Workload Identity in Multi System Environments (WIMSE)
framework <xref target="I-D.ietf-wimse-arch"/> provides robust workload
authentication through Workload Identity Tokens (WIT) and Workload
Proof Tokens (WPT). The WIMSE service-to-service protocol
<xref target="I-D.ietf-wimse-s2s-protocol"/> defines how workloads authenticate
each other across call chains using the Workload-Identity and
Workload-Proof-Token HTTP headers.</t>
<t>However, workload identity alone does not address execution
accountability. Knowing who performed an action does not record
what was done or in what order.</t>
<t>Regulated environments increasingly deploy autonomous agents that
coordinate across organizational boundaries. Domains such as
healthcare, finance, and logistics require structured, auditable
records of automated decision-making and execution.</t>
<t>This document defines an extension to the WIMSE architecture that
addresses the gap between workload identity and execution
accountability. WIMSE authenticates agents; this extension records
what they did and in what order.</t>
<t>As identified in <xref target="I-D.ni-wimse-ai-agent-identity"/>, call context
in agentic workflows needs to be visible and preserved. ECTs
provide a mechanism to address this requirement with cryptographic
assurances.</t>
</section>
<section anchor="problem-statement"><name>Problem Statement</name>
<t>Three core gaps exist in current approaches to regulated agentic
systems:</t>
<t><list style="numbers" type="1">
<t>WIMSE authenticates agents but does not record what they
actually did. A WIT proves "Agent A is authorized" but not
"Agent A executed Task X, producing Output Z."</t>
<t>No standard mechanism exists to cryptographically order and
link task execution across a multi-agent workflow.</t>
<t>No mechanism exists to reconstruct the complete execution
history of a distributed workflow for audit purposes.</t>
</list></t>
<t>Existing observability tools such as distributed tracing
<xref target="OPENTELEMETRY"/> provide visibility for debugging and monitoring
but do not provide cryptographic assurances. Tracing data is not
cryptographically signed, not tamper-evident, and not designed for
regulatory audit scenarios.</t>
</section>
<section anchor="scope-and-applicability"><name>Scope and Applicability</name>
<t>This document defines:</t>
<t><list style="symbols">
<t>The Execution Context Token (ECT) format (<xref target="ect-format"/>)</t>
<t>DAG structure for task dependency ordering (<xref target="dag-validation"/>)</t>
<t>Integration with the WIMSE identity framework
(<xref target="wimse-integration"/>)</t>
<t>An HTTP header for ECT transport (<xref target="http-header"/>)</t>
<t>Audit ledger interface requirements (<xref target="ledger-interface"/>)</t>
</list></t>
<t>The following are out of scope and are handled by WIMSE:</t>
<t><list style="symbols">
<t>Workload authentication and identity provisioning</t>
<t>Key distribution and management</t>
<t>Trust domain establishment and management</t>
<t>Credential lifecycle management</t>
</list></t>
</section>
</section>
<section anchor="conventions-and-definitions"><name>Conventions and Definitions</name>
<t>The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL
NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
"<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as
described in BCP 14 <xref target="RFC2119"/> <xref target="RFC8174"/> when, and only when, they
appear in all capitals, as shown here.</t>
<?line -18?>
<t>The following terms are used in this document:</t>
<dl>
<dt>Agent:</dt>
<dd>
<t>An autonomous workload, as defined by WIMSE
<xref target="I-D.ietf-wimse-arch"/>, that executes tasks within a workflow.</t>
</dd>
<dt>Task:</dt>
<dd>
<t>A discrete unit of agent work that consumes inputs and produces
outputs.</t>
</dd>
<dt>Directed Acyclic Graph (DAG):</dt>
<dd>
<t>A graph structure representing task dependency ordering where
edges are directed and no cycles exist.</t>
</dd>
<dt>Execution Context Token (ECT):</dt>
<dd>
<t>A JSON Web Token <xref target="RFC7519"/> defined by this specification that
records task execution details.</t>
</dd>
<dt>Audit Ledger:</dt>
<dd>
<t>An append-only, immutable log of all ECTs within a workflow or
set of workflows, used for audit and verification.</t>
</dd>
<dt>Workload Identity Token (WIT):</dt>
<dd>
<t>A WIMSE credential proving a workload's identity within a trust
domain.</t>
</dd>
<dt>Workload Proof Token (WPT):</dt>
<dd>
<t>A WIMSE proof-of-possession token used for request-level
authentication.</t>
</dd>
<dt>Trust Domain:</dt>
<dd>
<t>A WIMSE concept representing an organizational boundary with a
shared identity issuer, corresponding to a SPIFFE <xref target="SPIFFE"/>
trust domain.</t>
</dd>
</dl>
</section>
<section anchor="wimse-integration"><name>WIMSE Architecture Integration</name>
<section anchor="wimse-foundation"><name>WIMSE Foundation</name>
<t>The WIMSE architecture <xref target="I-D.ietf-wimse-arch"/> defines:</t>
<t><list style="symbols">
<t>Workload Identity Tokens (WIT) that prove a workload's identity
within a trust domain ("I am Agent X in trust domain Y")</t>
<t>Workload Proof Tokens (WPT) that prove possession of the private
key associated with a WIT ("I control the key for Agent X")</t>
<t>Multi-hop authentication via the service-to-service protocol
<xref target="I-D.ietf-wimse-s2s-protocol"/></t>
</list></t>
<t>The following execution accountability needs are complementary to
the WIMSE scope and are not addressed by workload identity alone:</t>
<t><list style="symbols">
<t>Recording what agents actually do with their authenticated
identity</t>
<t>Maintaining structured execution records</t>
<t>Linking actions to their predecessors with cryptographic assurance</t>
</list></t>
</section>
<section anchor="extension-model"><name>Extension Model</name>
<t>ECTs extend WIMSE by adding an execution accountability layer
between the identity layer and the application layer:</t>
<figure title="WIMSE Extension Architecture Layers" anchor="fig-layers"><artwork type="ascii-art"><![CDATA[
+--------------------------------------------------+
| WIMSE Layer (Identity) |
| WIT: "I am Agent X (spiffe://td/agent/x)" |
| WPT: "I prove I control the key for Agent X" |
+--------------------------------------------------+
|
v
+--------------------------------------------------+
| ECT Layer (Execution Accountability) [This Spec]|
| ECT: "Task executed, dependencies met, |
| inputs/outputs hashed" |
+--------------------------------------------------+
|
v
+--------------------------------------------------+
| Optional: Audit Ledger (Immutable Record) |
| "ECTs MAY be appended to an audit ledger" |
+--------------------------------------------------+
]]></artwork></figure>
<t>This extension reuses the WIMSE signing model, extends JWT claims
using standard JWT extensibility <xref target="RFC7519"/>, and maintains WIMSE
concepts including trust domains and workload identifiers.</t>
</section>
<section anchor="integration-points"><name>Integration Points</name>
<t>An ECT integrates with the WIMSE identity framework through the
following mechanisms:</t>
<t><list style="symbols">
<t>The ECT JOSE header "kid" parameter <bcp14>MUST</bcp14> reference the public
key identifier from the agent's WIT.</t>
<t>In WIMSE deployments, the ECT "iss" claim <bcp14>SHOULD</bcp14> use the WIMSE
workload identifier format (a SPIFFE ID <xref target="SPIFFE"/>).</t>
<t>The ECT <bcp14>MUST</bcp14> be signed with the same private key associated
with the agent's WIT.</t>
<t>The ECT signing algorithm (JOSE header "alg" parameter) <bcp14>MUST</bcp14>
match the algorithm used in the corresponding WIT.</t>
</list></t>
<t>When an agent makes an HTTP request to another agent, the
Execution-Context header is carried alongside WIMSE identity
headers:</t>
<figure title="HTTP Header Stacking" anchor="fig-http-headers"><artwork type="ascii-art"><![CDATA[
HTTP Request from Agent A to Agent B:
Workload-Identity: <WIT for Agent A>
Execution-Context: <ECT recording what A did>
]]></artwork></figure>
<t>When a Workload Proof Token (WPT) is available per
<xref target="I-D.ietf-wimse-s2s-protocol"/>, agents <bcp14>SHOULD</bcp14> include it
alongside the WIT and ECT. ECT verification does not depend
on the presence of a WPT; the ECT is independently verifiable
via the WIT public key.</t>
<t>The receiving agent (Agent B) verifies in order:</t>
<t><list style="numbers" type="1">
<t>WIT (WIMSE layer): Verifies Agent A's identity within the
trust domain. WPT verification, if present, per
<xref target="I-D.ietf-wimse-s2s-protocol"/>.</t>
<t>ECT (this extension): Records what Agent A did and what
precedent tasks exist.</t>
<t>Ledger (if deployed): Appends the verified ECT to the audit
ledger.</t>
</list></t>
</section>
</section>
<section anchor="ect-format"><name>Execution Context Token Format</name>
<t>An Execution Context Token is a JSON Web Token (JWT) <xref target="RFC7519"/>
signed as a JSON Web Signature (JWS) <xref target="RFC7515"/>. ECTs <bcp14>MUST</bcp14> use
JWS Compact Serialization (the base64url-encoded
<spanx style="verb">header.payload.signature</spanx> format) so that they can be carried in
a single HTTP header value.</t>
<section anchor="jose-header"><name>JOSE Header</name>
<t>The ECT JOSE header <bcp14>MUST</bcp14> contain the following parameters:</t>
<figure title="ECT JOSE Header Example" anchor="fig-header"><sourcecode type="json"><![CDATA[
{
"alg": "ES256",
"typ": "wimse-exec+jwt",
"kid": "agent-a-key-id-123"
}
]]></sourcecode></figure>
<dl>
<dt>alg:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. The digital signature algorithm used to sign the ECT.
<bcp14>MUST</bcp14> match the algorithm in the corresponding WIT.
Implementations <bcp14>MUST</bcp14> support ES256 <xref target="RFC7518"/>. The "alg"
value <bcp14>MUST NOT</bcp14> be "none". Symmetric algorithms (e.g., HS256,
HS384, HS512) <bcp14>MUST NOT</bcp14> be used, as ECTs require asymmetric
signatures for non-repudiation.</t>
</dd>
<dt>typ:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. <bcp14>MUST</bcp14> be set to "wimse-exec+jwt" to distinguish ECTs
from other JWT types, consistent with the WIMSE convention for
type parameter values.</t>
</dd>
<dt>kid:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. The key identifier referencing the public key from
the agent's WIT <xref target="RFC7517"/>. Used by verifiers to look up the
correct public key for signature verification.</t>
</dd>
</dl>
</section>
<section anchor="jwt-claims"><name>JWT Claims</name>
<t>The ECT payload contains both WIMSE-compatible standard JWT claims
and execution context claims defined by this specification.</t>
<section anchor="standard-jwt-claims"><name>Standard JWT Claims</name>
<t>The following standard JWT claims <xref target="RFC7519"/> <bcp14>MUST</bcp14> be present in
every ECT:</t>
<dl>
<dt>iss:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. StringOrURI. A URI identifying the issuer of the
ECT. In WIMSE deployments, this <bcp14>SHOULD</bcp14> be the workload's
SPIFFE ID in the format <spanx style="verb">spiffe://&lt;trust-domain&gt;/&lt;path&gt;</spanx>,
matching the "sub" claim of the agent's WIT. Non-WIMSE
deployments <bcp14>MAY</bcp14> use other URI schemes (e.g., HTTPS URLs or
URN:UUID identifiers).</t>
</dd>
<dt>aud:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. StringOrURI or array of StringOrURI. The intended
recipient(s) of the ECT. Because ECTs serve as both inter-agent
messages and audit records, the "aud" claim <bcp14>SHOULD</bcp14> contain the
identifiers of all entities that will verify the ECT. In
practice this means:
</t>
<t><list style="symbols">
<t><strong>Point-to-point delivery</strong>: when an ECT is sent from one
agent to a single next agent, "aud" contains that agent's
workload identity. The receiving agent verifies the ECT and
forwards it to the ledger on behalf of the issuer.</t>
<t><strong>Direct-to-ledger submission</strong>: when an ECT is submitted
directly to the audit ledger (e.g., after a join or at
workflow completion), "aud" contains the ledger's identity.</t>
<t><strong>Multi-audience</strong>: when an ECT must be verified by both the
next agent and the ledger independently, "aud" <bcp14>MUST</bcp14> be an
array containing both identifiers (e.g.,
["spiffe://example.com/agent/next",
"spiffe://example.com/system/ledger"]). Each verifier checks
that its own identity appears in the array.</t>
</list></t>
<t>In multi-parent (join) scenarios where a task depends on ECTs
from multiple parent agents, the joining agent creates a new ECT
with the parent task IDs in "par". The "aud" of this new ECT
is set according to the rules above based on where the ECT will
be delivered — it is independent of the "aud" values in the
parent ECTs.</t>
</dd>
<dt>iat:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. NumericDate. The time at which the ECT was issued.
The ECT records a completed action, so the "iat" value reflects
when the record was created, not when task execution began.</t>
</dd>
<dt>exp:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. NumericDate. The expiration time of the ECT.
Implementations <bcp14>SHOULD</bcp14> set this to 5 to 15 minutes after "iat"
to limit the replay window while allowing for reasonable clock
skew and processing time.</t>
</dd>
</dl>
<t>The standard JWT "nbf" (Not Before) claim is not used in ECTs
because ECTs record completed actions and are valid immediately
upon issuance.</t>
<dl>
<dt>jti:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. String. A globally unique identifier for both the
ECT and the task it records, in UUID format <xref target="RFC9562"/>. Since
each ECT represents exactly one task, "jti" serves as both the
token identifier (for replay detection) and the task identifier
(for DAG parent references in "par"). Receivers <bcp14>MUST</bcp14> reject
ECTs whose "jti" has already been seen within the expiration
window. When "wid" is present, uniqueness is scoped to the
workflow; when "wid" is absent, uniqueness <bcp14>MUST</bcp14> be enforced
globally across the ECT store.</t>
</dd>
</dl>
</section>
<section anchor="exec-claims"><name>Execution Context</name>
<t>The following claims are defined by this specification:</t>
<dl>
<dt>wid:</dt>
<dd>
<t><bcp14>OPTIONAL</bcp14>. String. A workflow identifier that groups related
ECTs into a single workflow. When present, <bcp14>MUST</bcp14> be a UUID
<xref target="RFC9562"/>.</t>
</dd>
<dt>exec_act:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. String. The action or task type identifier describing
what the agent performed (e.g., "process_payment",
"validate_safety", "calculate_dosage"). Note: this claim is
intentionally named "exec_act" rather than "act" to avoid
collision with the "act" (Actor) claim registered by
<xref target="RFC8693"/>.</t>
</dd>
<dt>par:</dt>
<dd>
<t><bcp14>REQUIRED</bcp14>. Array of strings. Parent task identifiers
representing DAG dependencies. Each element <bcp14>MUST</bcp14> be the "jti"
value of a previously verified ECT. An empty array indicates
a root task with no dependencies. A workflow <bcp14>MAY</bcp14> contain
multiple root tasks. Parent ECTs may have passed their own
"exp" time; ECT expiration applies to the verification window
of the ECT itself, not to its validity as a parent reference
in the ECT store.</t>
</dd>
</dl>
</section>
<section anchor="data-integrity-claims"><name>Data Integrity</name>
<t>The following claims provide integrity verification for task
inputs and outputs without revealing the data itself:</t>
<dl>
<dt>inp_hash:</dt>
<dd>
<t><bcp14>OPTIONAL</bcp14>. String. A cryptographic hash of the input data,
formatted as "hash-algorithm:base64url-encoded-hash" (e.g.,
"sha-256:n4bQgYhMfWWaL-qgxVrQFaO_TxsrC4Is0V1sFbDwCgg"). The
hash algorithm identifier <bcp14>MUST</bcp14> be a lowercase value from the
IANA Named Information Hash Algorithm Registry (e.g., "sha-256",
"sha-384", "sha-512"). Implementations <bcp14>MUST</bcp14> support "sha-256"
and <bcp14>SHOULD</bcp14> use "sha-256" unless a stronger algorithm is
required. Implementations <bcp14>MUST NOT</bcp14> accept hash algorithms
weaker than SHA-256 (e.g., MD5, SHA-1). The hash <bcp14>MUST</bcp14> be
computed over the raw octets of the input data.</t>
</dd>
<dt>out_hash:</dt>
<dd>
<t><bcp14>OPTIONAL</bcp14>. String. A cryptographic hash of the output data,
using the same format and algorithm requirements as "inp_hash".</t>
</dd>
</dl>
</section>
<section anchor="extension-claims"><name>Extensions</name>
<dl>
<dt>ext:</dt>
<dd>
<t><bcp14>OPTIONAL</bcp14>. Object. An extension object for domain-specific
claims not defined by this specification. Implementations
that do not understand extension claims <bcp14>MUST</bcp14> ignore them.</t>
</dd>
</dl>
<t>To avoid key collisions between different domains, extension
key names <bcp14>SHOULD</bcp14> use reverse domain notation (e.g.,
"com.example.custom_field") to avoid collisions between
independently developed extensions. To prevent abuse and
excessive token size, the serialized JSON representation of
the "ext" object <bcp14>SHOULD NOT</bcp14> exceed 4096 bytes, and the JSON
nesting depth within the "ext" object <bcp14>SHOULD NOT</bcp14> exceed 5
levels. Implementations <bcp14>SHOULD</bcp14> reject ECTs whose "ext" claim
exceeds these limits.</t>
<t>Extension keys for domain-specific use cases <bcp14>MAY</bcp14> be defined in
future documents.</t>
</section>
</section>
<section anchor="complete-ect-example"><name>Complete ECT Example</name>
<t>The following is a complete ECT payload example:</t>
<figure title="Complete ECT Payload Example" anchor="fig-full-ect"><sourcecode type="json"><![CDATA[
{
"iss": "spiffe://example.com/agent/clinical",
"aud": "spiffe://example.com/agent/safety",
"iat": 1772064150,
"exp": 1772064750,
"jti": "550e8400-e29b-41d4-a716-446655440001",
"wid": "a0b1c2d3-e4f5-6789-abcd-ef0123456789",
"exec_act": "recommend_treatment",
"par": [],
"inp_hash": "sha-256:n4bQgYhMfWWaL-qgxVrQFaO_TxsrC4Is0V1sFbDwCgg",
"out_hash": "sha-256:LCa0a2j_xo_5m0U8HTBBNBNCLXBkg7-g-YpeiGJm564"
}
]]></sourcecode></figure>
</section>
</section>
<section anchor="http-header"><name>HTTP Header Transport</name>
<section anchor="execution-context-header-field"><name>Execution-Context Header Field</name>
<t>This specification defines the Execution-Context HTTP header field
<xref target="RFC9110"/> for transporting ECTs between agents.</t>
<t>The header field value is the ECT in JWS Compact Serialization
format <xref target="RFC7515"/>. The value consists of three Base64url-encoded
parts separated by period (".") characters.</t>
<t>An agent sending a request to another agent includes the
Execution-Context header alongside the WIMSE Workload-Identity
header:</t>
<figure title="HTTP Request with ECT Header" anchor="fig-http-example"><artwork><![CDATA[
GET /api/safety-check HTTP/1.1
Host: safety-agent.example.com
Workload-Identity: eyJhbGci...WIT...
Execution-Context: eyJhbGci...ECT...
]]></artwork></figure>
<t>When multiple parent tasks contribute context to a single request,
multiple Execution-Context header field lines <bcp14>MAY</bcp14> be included, each
carrying a separate ECT in JWS Compact Serialization format.</t>
<t>When a receiver processes multiple Execution-Context headers, it
<bcp14>MUST</bcp14> individually verify each ECT per the procedure in
<xref target="verification"/>. If any single ECT fails verification, the
receiver <bcp14>MUST</bcp14> reject the entire request. The set of verified
parent task IDs across all received ECTs represents the complete
set of parent dependencies available for the receiving agent's
subsequent ECT.</t>
</section>
</section>
<section anchor="dag-validation"><name>DAG Validation</name>
<section anchor="overview"><name>Overview</name>
<t>ECTs form a Directed Acyclic Graph (DAG) where each task
references its parent tasks via the "par" claim. This structure
provides a cryptographically signed record of execution ordering,
enabling auditors to reconstruct the complete workflow and verify
that required predecessor tasks were recorded before dependent
tasks.</t>
<t>DAG validation is performed against the ECT store — either an
audit ledger or the set of parent ECTs received inline.</t>
</section>
<section anchor="validation-rules"><name>Validation Rules</name>
<t>When receiving and verifying an ECT, implementations <bcp14>MUST</bcp14> perform
the following DAG validation steps:</t>
<t><list style="numbers" type="1">
<t>Task ID Uniqueness: The "jti" claim <bcp14>MUST</bcp14> be unique within the
applicable scope (the workflow identified by "wid", or the
entire ECT store if "wid" is absent). If an ECT with the same
"jti" already exists, the ECT <bcp14>MUST</bcp14> be rejected.</t>
<t>Parent Existence: Every task identifier listed in the "par"
array <bcp14>MUST</bcp14> correspond to a task that is available in the ECT
store (either previously recorded in the ledger or received
inline as a verified parent ECT). If any parent task is not
found, the ECT <bcp14>MUST</bcp14> be rejected.</t>
<t>Temporal Ordering: The "iat" value of every parent task <bcp14>MUST
NOT</bcp14> be greater than the "iat" value of the current task plus a
configurable clock skew tolerance (<bcp14>RECOMMENDED</bcp14>: 30 seconds).
That is, for each parent: <spanx style="verb">parent.iat &lt; child.iat +
clock_skew_tolerance</spanx>. The tolerance accounts for clock skew
between agents; it does not guarantee strict causal ordering
from timestamps alone. Causal ordering is primarily enforced
by the DAG structure (parent existence in the ECT store), not by
timestamps. If any parent task violates this constraint, the
ECT <bcp14>MUST</bcp14> be rejected.</t>
<t>Acyclicity: Following the chain of parent references <bcp14>MUST NOT</bcp14>
lead back to the current ECT's "jti". If a cycle is detected,
the ECT <bcp14>MUST</bcp14> be rejected.</t>
<t>Trust Domain Consistency: Parent tasks <bcp14>SHOULD</bcp14> belong to the
same trust domain or to a trust domain with which a federation
relationship has been established.</t>
</list></t>
<t>To prevent denial-of-service via extremely deep or wide DAGs,
implementations <bcp14>SHOULD</bcp14> enforce a maximum ancestor traversal limit
(<bcp14>RECOMMENDED</bcp14>: 10000 nodes). If the limit is reached before cycle
detection completes, the ECT <bcp14>SHOULD</bcp14> be rejected.</t>
</section>
</section>
<section anchor="verification"><name>Signature and Token Verification</name>
<section anchor="verification-procedure"><name>Verification Procedure</name>
<t>When an agent receives an ECT, it <bcp14>MUST</bcp14> perform the following
verification steps in order:</t>
<t><list style="numbers" type="1">
<t>Parse the JWS Compact Serialization to extract the JOSE header,
payload, and signature components per <xref target="RFC7515"/>.</t>
<t>Verify that the "typ" header parameter is "wimse-exec+jwt".</t>
<t>Verify that the "alg" header parameter is not "none" and is
not a symmetric algorithm.</t>
<t>Verify the "kid" header parameter references a known, valid
public key from a WIT within the trust domain.</t>
<t>Retrieve the public key identified by "kid" and verify the JWS
signature per <xref target="RFC7515"/> Section 5.2.</t>
<t>Verify that the signing key identified by "kid" has not been
revoked within the trust domain. Implementations <bcp14>MUST</bcp14> check
the key's revocation status using the trust domain's key
lifecycle mechanism (e.g., certificate revocation list, OCSP,
or SPIFFE trust bundle updates).</t>
<t>Verify the "alg" header parameter matches the algorithm in the
corresponding WIT.</t>
<t>Verify the "iss" claim matches the "sub" claim of the WIT
associated with the "kid" public key.</t>
<t>Verify the "aud" claim contains the verifier's own workload
identity. When "aud" is an array, it is sufficient that the
verifier's identity appears as one element; the presence of
other audience values does not cause verification failure.
When the verifier is the audit ledger, the ledger's own
identity <bcp14>MUST</bcp14> appear in "aud".</t>
<t>Verify the "exp" claim indicates the ECT has not expired.</t>
<t>Verify the "iat" claim is not unreasonably far in the past
(implementation-specific threshold, <bcp14>RECOMMENDED</bcp14> maximum of
15 minutes) and is not unreasonably far in the future
(<bcp14>RECOMMENDED</bcp14>: no more than 30 seconds ahead of the
verifier's current time, to account for clock skew).</t>
<t>Verify all required claims ("jti", "exec_act", "par") are
present and well-formed.</t>
<t>Perform DAG validation per <xref target="dag-validation"/>.</t>
<t>If all checks pass and an audit ledger is deployed, the ECT
<bcp14>SHOULD</bcp14> be appended to the ledger.</t>
</list></t>
<t>If any verification step fails, the ECT <bcp14>MUST</bcp14> be rejected and the
failure <bcp14>MUST</bcp14> be logged for audit purposes. Error messages
<bcp14>SHOULD NOT</bcp14> reveal whether specific parent task IDs exist in the
ECT store, to prevent information disclosure.</t>
<t>When ECT verification fails during HTTP request processing, the
receiving agent <bcp14>SHOULD</bcp14> respond with HTTP 403 (Forbidden) if the
WIT is valid but the ECT is invalid, and HTTP 401
(Unauthorized) if the ECT signature verification fails. The
response body <bcp14>SHOULD</bcp14> include a generic error indicator without
revealing which specific verification step failed. The receiving
agent <bcp14>MUST NOT</bcp14> process the requested action when ECT verification
fails.</t>
</section>
</section>
<section anchor="ledger-interface"><name>Audit Ledger Interface</name>
<t>ECTs <bcp14>MAY</bcp14> be recorded in an immutable audit ledger for compliance
verification and post-hoc analysis. A ledger is <bcp14>RECOMMENDED</bcp14> for
regulated environments but is not required for point-to-point
operation. This specification does not mandate a specific storage
technology. Implementations <bcp14>MAY</bcp14> use append-only logs, databases
with cryptographic commitment schemes, distributed ledgers, or
any storage mechanism that provides the required properties.</t>
<t>When an audit ledger is deployed, the implementation <bcp14>MUST</bcp14> provide:</t>
<t><list style="numbers" type="1">
<t>Append-only semantics: Once an ECT is recorded, it <bcp14>MUST NOT</bcp14> be
modified or deleted.</t>
<t>Ordering: The ledger <bcp14>MUST</bcp14> maintain a total ordering of ECT
entries via a monotonically increasing sequence number.</t>
<t>Lookup by ECT ID: The ledger <bcp14>MUST</bcp14> support efficient retrieval
of ECT entries by "jti" value.</t>
<t>Integrity verification: The ledger <bcp14>SHOULD</bcp14> provide a mechanism
to verify that no entries have been tampered with (e.g.,
hash chains or Merkle trees).</t>
</list></t>
<t>The ledger <bcp14>SHOULD</bcp14> be maintained by an entity independent of the
workflow agents to reduce the risk of collusion.</t>
</section>
<section anchor="security-considerations"><name>Security Considerations</name>
<t>This section addresses security considerations following the
guidance in <xref target="RFC3552"/>.</t>
<section anchor="threat-model"><name>Threat Model</name>
<t>The following threat actors are considered:</t>
<t><list style="symbols">
<t>Malicious agent (insider threat): An agent within the trust
domain that intentionally creates false ECT claims.</t>
<t>Compromised agent (external attacker): An agent whose private
key has been obtained by an external attacker.</t>
<t>Ledger tamperer: An entity attempting to modify or delete ledger
entries after they have been recorded.</t>
<t>Time manipulator: An entity attempting to manipulate timestamps
to alter perceived execution ordering.</t>
</list></t>
</section>
<section anchor="self-assertion-limitation"><name>Self-Assertion Limitation</name>
<t>ECTs are self-asserted by the executing agent. The agent claims
what it did, and this claim is signed with its private key. A
compromised or malicious agent could create ECTs with false claims
(e.g., claiming an action was performed when it was not).</t>
<t>ECTs do not independently verify that:</t>
<t><list style="symbols">
<t>The claimed execution actually occurred as described</t>
<t>The input/output hashes correspond to the actual data processed</t>
<t>The agent faithfully performed the stated action</t>
</list></t>
<t>The trustworthiness of ECT claims depends on the trustworthiness
of the signing agent and the integrity of the broader deployment
environment.</t>
</section>
<section anchor="organizational-prerequisites"><name>Organizational Prerequisites</name>
<t>ECTs operate within a broader trust framework. The guarantees
provided by ECTs are only meaningful when the following
organizational controls are in place:</t>
<t><list style="symbols">
<t>Key management governance: Controls over who provisions agent
keys and how keys are protected.</t>
<t>Ledger integrity governance: The ledger is maintained by an
entity independent of the workflow agents.</t>
<t>Agent deployment governance: Agents are deployed and maintained
in a manner that preserves their integrity.</t>
</list></t>
</section>
<section anchor="signature-verification"><name>Signature Verification</name>
<t>ECTs <bcp14>MUST</bcp14> be signed with the agent's private key using JWS
<xref target="RFC7515"/>. The signature algorithm <bcp14>MUST</bcp14> match the algorithm
specified in the agent's WIT. Receivers <bcp14>MUST</bcp14> verify the ECT
signature against the WIT public key before processing any
claims. Receivers <bcp14>MUST</bcp14> verify that the signing key has not been
revoked within the trust domain (see step 6 in
<xref target="verification"/>).</t>
<t>If signature verification fails or if the signing key has been
revoked, the ECT <bcp14>MUST</bcp14> be rejected entirely and the failure <bcp14>MUST</bcp14>
be logged.</t>
<t>Implementations <bcp14>MUST</bcp14> use established JWS libraries and <bcp14>MUST NOT</bcp14>
implement custom signature verification.</t>
</section>
<section anchor="replay-attack-prevention"><name>Replay Attack Prevention</name>
<t>ECTs include short expiration times (<bcp14>RECOMMENDED</bcp14>: 5-15 minutes) to
limit the window for replay attacks. The "aud" claim restricts
replay to unintended recipients: an ECT intended for Agent B
will be rejected by Agent C. The "iat" claim enables receivers to
reject ECTs that are too old, even if not yet expired.</t>
<t>The DAG structure provides additional replay protection: an ECT
referencing parent tasks that already have a recorded child task
with the same action can be flagged as a potential replay.</t>
<t>Implementations <bcp14>MUST</bcp14> maintain a cache of recently-seen "jti"
values to detect replayed ECTs within the expiration window.
An ECT with a duplicate "jti" value <bcp14>MUST</bcp14> be rejected.</t>
</section>
<section anchor="man-in-the-middle-protection"><name>Man-in-the-Middle Protection</name>
<t>ECTs do not replace transport-layer security. ECTs <bcp14>MUST</bcp14> be
transmitted over TLS or mTLS connections. When used with the WIMSE
service-to-service protocol <xref target="I-D.ietf-wimse-s2s-protocol"/>,
transport security is already established. HTTP Message Signatures
<xref target="RFC9421"/> provide an alternative channel binding mechanism.</t>
<t>The defense-in-depth model provides:</t>
<t><list style="symbols">
<t>TLS/mTLS (transport layer): Prevents network-level tampering.</t>
<t>WIT/WPT (WIMSE identity layer): Proves agent identity and
request authorization.</t>
<t>ECT (execution accountability layer): Records what the agent did.</t>
</list></t>
</section>
<section anchor="key-compromise"><name>Key Compromise</name>
<t>If an agent's private key is compromised, an attacker can forge
ECTs that appear to originate from that agent. To mitigate this
risk:</t>
<t><list style="symbols">
<t>Implementations <bcp14>SHOULD</bcp14> use short-lived keys and rotate them
frequently (hours to days, not months).</t>
<t>Private keys <bcp14>SHOULD</bcp14> be stored in Hardware Security Modules (HSMs)
or equivalent secure key storage.</t>
<t>Trust domains <bcp14>MUST</bcp14> support rapid key revocation.</t>
<t>Upon suspected compromise, the trust domain <bcp14>MUST</bcp14> revoke the
compromised key and issue a new WIT with a fresh key pair.</t>
</list></t>
<t>ECTs signed with a compromised key that were recorded in the
ledger before revocation remain valid historical records but <bcp14>SHOULD</bcp14>
be flagged in the ledger as "signed with subsequently revoked key"
for audit purposes.</t>
</section>
<section anchor="collusion-and-false-claims"><name>Collusion and False Claims</name>
<t>A single malicious agent cannot forge parent task references
because DAG validation requires parent tasks to exist in the
ledger. However, multiple colluding agents could potentially
create a false execution history if they control the ledger.</t>
<t>Mitigations include:</t>
<t><list style="symbols">
<t>Independent ledger maintenance: The ledger <bcp14>SHOULD</bcp14> be maintained
by an entity independent of the workflow agents.</t>
<t>Cross-verification: Multiple independent ledger replicas can be
compared for consistency.</t>
<t>Out-of-band audit: External auditors periodically verify ledger
contents against expected workflow patterns.</t>
</list></t>
</section>
<section anchor="denial-of-service"><name>Denial of Service</name>
<t>ECT signature verification is computationally inexpensive
(approximately 1ms per ECT on modern hardware for ES256). DAG
validation complexity is O(V) where V is the number of ancestor
nodes reachable from the parent references; for typical shallow
DAGs this is efficient.</t>
<t>Implementations <bcp14>SHOULD</bcp14> apply rate limiting at the API layer to
prevent excessive ECT submissions. DAG validation <bcp14>SHOULD</bcp14> be
performed after signature verification to avoid wasting resources
on unsigned or incorrectly signed tokens.</t>
</section>
<section anchor="timestamp-accuracy"><name>Timestamp Accuracy</name>
<t>ECTs rely on timestamps ("iat", "exp") for temporal ordering.
Clock skew between agents can lead to incorrect ordering
judgments. Implementations <bcp14>SHOULD</bcp14> use synchronized time sources
(e.g., NTP) and <bcp14>SHOULD</bcp14> allow a configurable clock skew tolerance
(<bcp14>RECOMMENDED</bcp14>: 30 seconds).</t>
<t>Cross-organizational deployments where agents span multiple trust
domains with independent time sources <bcp14>MAY</bcp14> require a higher clock
skew tolerance. Deployments using trust domain federation <bcp14>SHOULD</bcp14>
document their configured clock skew tolerance value and <bcp14>SHOULD</bcp14>
ensure all participating trust domains agree on a common tolerance.</t>
<t>The temporal ordering check in DAG validation incorporates the
clock skew tolerance to account for minor clock differences
between agents.</t>
</section>
<section anchor="ect-size-constraints"><name>ECT Size Constraints</name>
<t>ECTs with many parent tasks or large extension objects can
increase HTTP header size. Implementations <bcp14>SHOULD</bcp14> limit the "par"
array to a maximum of 256 entries. Workflows requiring more
parent references <bcp14>SHOULD</bcp14> introduce intermediate aggregation
tasks. The "ext" object <bcp14>SHOULD NOT</bcp14> exceed 4096 bytes when
serialized as JSON and <bcp14>SHOULD NOT</bcp14> exceed a nesting depth of
5 levels (see also <xref target="extension-claims"/>).</t>
</section>
</section>
<section anchor="privacy-considerations"><name>Privacy Considerations</name>
<section anchor="data-exposure-in-ects"><name>Data Exposure in ECTs</name>
<t>ECTs necessarily reveal:</t>
<t><list style="symbols">
<t>Agent identities ("iss", "aud") for accountability purposes</t>
<t>Action descriptions ("exec_act") for audit trail completeness</t>
<t>Timestamps ("iat", "exp") for temporal ordering</t>
</list></t>
<t>ECTs are designed to NOT reveal:</t>
<t><list style="symbols">
<t>Actual input or output data values (replaced with cryptographic
hashes via "inp_hash" and "out_hash")</t>
<t>Internal computation details or intermediate steps</t>
<t>Proprietary algorithms or intellectual property</t>
<t>Personally identifiable information (PII)</t>
</list></t>
</section>
<section anchor="data-minimization"><name>Data Minimization</name>
<t>Implementations <bcp14>SHOULD</bcp14> minimize the information included in ECTs.
The "exec_act" claim <bcp14>SHOULD</bcp14> use structured identifiers (e.g.,
"process_payment") rather than natural language descriptions.
Extension keys in "ext" (<xref target="extension-claims"/>) deserve particular
attention: human-readable values risk exposing sensitive operational
details. See <xref target="extension-claims"/> for guidance on using
structured identifiers.</t>
</section>
<section anchor="storage-and-access-control"><name>Storage and Access Control</name>
<t>ECTs stored in audit ledgers <bcp14>SHOULD</bcp14> be access-controlled so that
only authorized auditors can read them. Implementations <bcp14>SHOULD</bcp14>
consider encryption at rest for ledger storage. ECTs provide
structural records of execution ordering; they are not intended
for public disclosure.</t>
<t>Full input and output data (corresponding to the hashes in ECTs)
<bcp14>SHOULD</bcp14> be stored separately from the ledger with additional access
controls, since auditors may need to verify hash correctness but
general access to the data values is not needed.</t>
</section>
</section>
<section anchor="iana-considerations"><name>IANA Considerations</name>
<section anchor="media-type-registration"><name>Media Type Registration</name>
<t>This document requests registration of the following media type
in the "Media Types" registry maintained by IANA:</t>
<dl>
<dt>Type name:</dt>
<dd>
<t>application</t>
</dd>
<dt>Subtype name:</dt>
<dd>
<t>wimse-exec+jwt</t>
</dd>
<dt>Required parameters:</dt>
<dd>
<t>none</t>
</dd>
<dt>Optional parameters:</dt>
<dd>
<t>none</t>
</dd>
<dt>Encoding considerations:</dt>
<dd>
<t>8bit; an ECT is a JWT that is a JWS using the Compact
Serialization, which is a sequence of Base64url-encoded values
separated by period characters.</t>
</dd>
<dt>Security considerations:</dt>
<dd>
<t>See the Security Considerations section of this document.</t>
</dd>
<dt>Interoperability considerations:</dt>
<dd>
<t>none</t>
</dd>
<dt>Published specification:</dt>
<dd>
<t>This document</t>
</dd>
<dt>Applications that use this media type:</dt>
<dd>
<t>Applications that implement agentic workflows requiring execution
context tracing and audit trails.</t>
</dd>
<dt>Additional information:</dt>
<dd>
<t>Magic number(s): none
File extension(s): none
Macintosh file type code(s): none</t>
</dd>
<dt>Person and email address to contact for further information:</dt>
<dd>
<t>Christian Nennemann, ietf@nennemann.de</t>
</dd>
<dt>Intended usage:</dt>
<dd>
<t>COMMON</t>
</dd>
<dt>Restrictions on usage:</dt>
<dd>
<t>none</t>
</dd>
<dt>Author:</dt>
<dd>
<t>Christian Nennemann</t>
</dd>
<dt>Change controller:</dt>
<dd>
<t>IETF</t>
</dd>
</dl>
</section>
<section anchor="header-registration"><name>HTTP Header Field Registration</name>
<t>This document requests registration of the following header field
in the "Hypertext Transfer Protocol (HTTP) Field Name Registry"
maintained by IANA:</t>
<dl>
<dt>Field name:</dt>
<dd>
<t>Execution-Context</t>
</dd>
<dt>Status:</dt>
<dd>
<t>permanent</t>
</dd>
<dt>Specification document:</dt>
<dd>
<t>This document, <xref target="http-header"/></t>
</dd>
</dl>
</section>
<section anchor="claims-registration"><name>JWT Claims Registration</name>
<t>This document requests registration of the following claims in
the "JSON Web Token Claims" registry maintained by IANA:</t>
<texttable title="JWT Claims Registrations" anchor="_table-claims">
<ttcol align='center'>Claim Name</ttcol>
<ttcol align='left'>Claim Description</ttcol>
<ttcol align='center'>Change Controller</ttcol>
<ttcol align='center'>Reference</ttcol>
<c>wid</c>
<c>Workflow Identifier</c>
<c>IETF</c>
<c><xref target="exec-claims"/></c>
<c>exec_act</c>
<c>Action/Task Type</c>
<c>IETF</c>
<c><xref target="exec-claims"/></c>
<c>par</c>
<c>Parent Task Identifiers</c>
<c>IETF</c>
<c><xref target="exec-claims"/></c>
<c>inp_hash</c>
<c>Input Data Hash</c>
<c>IETF</c>
<c><xref target="data-integrity-claims"/></c>
<c>out_hash</c>
<c>Output Data Hash</c>
<c>IETF</c>
<c><xref target="data-integrity-claims"/></c>
<c>ext</c>
<c>Extension Object</c>
<c>IETF</c>
<c><xref target="extension-claims"/></c>
</texttable>
</section>
</section>
</middle>
<back>
<references title='References' anchor="sec-combined-references">
<references title='Normative References' anchor="sec-normative-references">
<reference anchor="RFC7515">
<front>
<title>JSON Web Signature (JWS)</title>
<author fullname="M. Jones" initials="M." surname="Jones"/>
<author fullname="J. Bradley" initials="J." surname="Bradley"/>
<author fullname="N. Sakimura" initials="N." surname="Sakimura"/>
<date month="May" year="2015"/>
<abstract>
<t>JSON Web Signature (JWS) represents content secured with digital signatures or Message Authentication Codes (MACs) using JSON-based data structures. Cryptographic algorithms and identifiers for use with this specification are described in the separate JSON Web Algorithms (JWA) specification and an IANA registry defined by that specification. Related encryption capabilities are described in the separate JSON Web Encryption (JWE) specification.</t>
</abstract>
</front>
<seriesInfo name="RFC" value="7515"/>
<seriesInfo name="DOI" value="10.17487/RFC7515"/>
</reference>
<reference anchor="RFC7517">
<front>
<title>JSON Web Key (JWK)</title>
<author fullname="M. Jones" initials="M." surname="Jones"/>
<date month="May" year="2015"/>
<abstract>
<t>A JSON Web Key (JWK) is a JavaScript Object Notation (JSON) data structure that represents a cryptographic key. This specification also defines a JWK Set JSON data structure that represents a set of JWKs. Cryptographic algorithms and identifiers for use with this specification are described in the separate JSON Web Algorithms (JWA) specification and IANA registries established by that specification.</t>
</abstract>
</front>
<seriesInfo name="RFC" value="7517"/>
<seriesInfo name="DOI" value="10.17487/RFC7517"/>
</reference>
<reference anchor="RFC7519">
<front>
<title>JSON Web Token (JWT)</title>
<author fullname="M. Jones" initials="M." surname="Jones"/>
<author fullname="J. Bradley" initials="J." surname="Bradley"/>
<author fullname="N. Sakimura" initials="N." surname="Sakimura"/>
<date month="May" year="2015"/>
<abstract>
<t>JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. The claims in a JWT are encoded as a JSON object that is used as the payload of a JSON Web Signature (JWS) structure or as the plaintext of a JSON Web Encryption (JWE) structure, enabling the claims to be digitally signed or integrity protected with a Message Authentication Code (MAC) and/or encrypted.</t>
</abstract>
</front>
<seriesInfo name="RFC" value="7519"/>
<seriesInfo name="DOI" value="10.17487/RFC7519"/>
</reference>
<reference anchor="RFC7518">
<front>
<title>JSON Web Algorithms (JWA)</title>
<author fullname="M. Jones" initials="M." surname="Jones"/>
<date month="May" year="2015"/>
<abstract>
<t>This specification registers cryptographic algorithms and identifiers to be used with the JSON Web Signature (JWS), JSON Web Encryption (JWE), and JSON Web Key (JWK) specifications. It defines several IANA registries for these identifiers.</t>
</abstract>
</front>
<seriesInfo name="RFC" value="7518"/>
<seriesInfo name="DOI" value="10.17487/RFC7518"/>
</reference>
<reference anchor="RFC9562">
<front>
<title>Universally Unique IDentifiers (UUIDs)</title>
<author fullname="K. Davis" initials="K." surname="Davis"/>
<author fullname="B. Peabody" initials="B." surname="Peabody"/>
<author fullname="P. Leach" initials="P." surname="Leach"/>
<date month="May" year="2024"/>
<abstract>
<t>This specification defines UUIDs (Universally Unique IDentifiers) --
also known as GUIDs (Globally Unique IDentifiers) -- and a Uniform
Resource Name namespace for UUIDs. A UUID is 128 bits long and is
intended to guarantee uniqueness across space and time. UUIDs were
originally used in the Apollo Network Computing System (NCS), later
in the Open Software Foundation's (OSF's) Distributed Computing
Environment (DCE), and then in Microsoft Windows platforms.</t>
<t>This specification is derived from the OSF DCE specification with the
kind permission of the OSF (now known as "The Open Group"). Information from earlier versions of the OSF DCE specification have
been incorporated into this document. This document obsoletes RFC
4122.</t>
</abstract>
</front>
<seriesInfo name="RFC" value="9562"/>
<seriesInfo name="DOI" value="10.17487/RFC9562"/>
</reference>
<reference anchor="RFC9110">
<front>
<title>HTTP Semantics</title>
<author fullname="R. Fielding" initials="R." role="editor" surname="Fielding"/>
<author fullname="M. Nottingham" initials="M." role="editor" surname="Nottingham"/>
<author fullname="J. Reschke" initials="J." role="editor" surname="Reschke"/>
<date month="June" year="2022"/>
<abstract>
<t>The Hypertext Transfer Protocol (HTTP) is a stateless application-level protocol for distributed, collaborative, hypertext information systems. This document describes the overall architecture of HTTP, establishes common terminology, and defines aspects of the protocol that are shared by all versions. In this definition are core protocol elements, extensibility mechanisms, and the "http" and "https" Uniform Resource Identifier (URI) schemes.</t>
<t>This document updates RFC 3864 and obsoletes RFCs 2818, 7231, 7232, 7233, 7235, 7538, 7615, 7694, and portions of 7230.</t>
</abstract>
</front>
<seriesInfo name="STD" value="97"/>
<seriesInfo name="RFC" value="9110"/>
<seriesInfo name="DOI" value="10.17487/RFC9110"/>
</reference>
<reference anchor="I-D.ietf-wimse-arch">
<front>
<title>Workload Identity in a Multi System Environment (WIMSE) Architecture</title>
<author fullname="Joseph A. Salowey" initials="J. A." surname="Salowey">
<organization>CyberArk</organization>
</author>
<author fullname="Yaroslav Rosomakho" initials="Y." surname="Rosomakho">
<organization>Zscaler</organization>
</author>
<author fullname="Hannes Tschofenig" initials="H." surname="Tschofenig">
<organization>University of Applied Sciences Bonn-Rhein-Sieg</organization>
</author>
<date day="30" month="September" year="2025"/>
<abstract>
<t> The increasing prevalence of cloud computing and micro service
architectures has led to the rise of complex software functions being
built and deployed as workloads, where a workload is defined as a
running instance of software executing for a specific purpose. This
document discusses an architecture for designing and standardizing
protocols and payloads for conveying workload identity and security
context information.
</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-wimse-arch-06"/>
</reference>
<reference anchor="I-D.ietf-wimse-s2s-protocol">
<front>
<title>WIMSE Workload-to-Workload Authentication</title>
<author fullname="Brian Campbell" initials="B." surname="Campbell">
<organization>Ping Identity</organization>
</author>
<author fullname="Joseph A. Salowey" initials="J. A." surname="Salowey">
<organization>CyberArk</organization>
</author>
<author fullname="Arndt Schwenkschuster" initials="A." surname="Schwenkschuster">
<organization>SPIRL</organization>
</author>
<author fullname="Yaron Sheffer" initials="Y." surname="Sheffer">
<organization>Intuit</organization>
</author>
<date day="16" month="October" year="2025"/>
<abstract>
<t> The WIMSE architecture defines authentication and authorization for
software workloads in a variety of runtime environments, from the
most basic ones up to complex multi-service, multi-cloud, multi-
tenant deployments. This document defines the simplest, atomic unit
of this architecture: the protocol between two workloads that need to
verify each other&#x27;s identity in order to communicate securely. The
scope of this protocol is a single HTTP request-and-response pair.
To address the needs of different setups, we propose two protocols,
one at the application level and one that makes use of trusted TLS
transport. These two protocols are compatible, in the sense that a
single call chain can have some calls use one protocol and some use
the other. Workload A can call Workload B with mutual TLS
authentication, while the next call from Workload B to Workload C
would be authenticated at the application level.
</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-wimse-s2s-protocol-07"/>
</reference>
<reference anchor="RFC2119">
<front>
<title>Key words for use in RFCs to Indicate Requirement Levels</title>
<author fullname="S. Bradner" initials="S." surname="Bradner"/>
<date month="March" year="1997"/>
<abstract>
<t>In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t>
</abstract>
</front>
<seriesInfo name="BCP" value="14"/>
<seriesInfo name="RFC" value="2119"/>
<seriesInfo name="DOI" value="10.17487/RFC2119"/>
</reference>
<reference anchor="RFC8174">
<front>
<title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
<author fullname="B. Leiba" initials="B." surname="Leiba"/>
<date month="May" year="2017"/>
<abstract>
<t>RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.</t>
</abstract>
</front>
<seriesInfo name="BCP" value="14"/>
<seriesInfo name="RFC" value="8174"/>
<seriesInfo name="DOI" value="10.17487/RFC8174"/>
</reference>
</references>
<references title='Informative References' anchor="sec-informative-references">
<reference anchor="RFC3552">
<front>
<title>Guidelines for Writing RFC Text on Security Considerations</title>
<author fullname="E. Rescorla" initials="E." surname="Rescorla"/>
<author fullname="B. Korver" initials="B." surname="Korver"/>
<date month="July" year="2003"/>
<abstract>
<t>All RFCs are required to have a Security Considerations section. Historically, such sections have been relatively weak. This document provides guidelines to RFC authors on how to write a good Security Considerations section. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t>
</abstract>
</front>
<seriesInfo name="BCP" value="72"/>
<seriesInfo name="RFC" value="3552"/>
<seriesInfo name="DOI" value="10.17487/RFC3552"/>
</reference>
<reference anchor="RFC8693">
<front>
<title>OAuth 2.0 Token Exchange</title>
<author fullname="M. Jones" initials="M." surname="Jones"/>
<author fullname="A. Nadalin" initials="A." surname="Nadalin"/>
<author fullname="B. Campbell" initials="B." role="editor" surname="Campbell"/>
<author fullname="J. Bradley" initials="J." surname="Bradley"/>
<author fullname="C. Mortimore" initials="C." surname="Mortimore"/>
<date month="January" year="2020"/>
<abstract>
<t>This specification defines a protocol for an HTTP- and JSON-based Security Token Service (STS) by defining how to request and obtain security tokens from OAuth 2.0 authorization servers, including security tokens employing impersonation and delegation.</t>
</abstract>
</front>
<seriesInfo name="RFC" value="8693"/>
<seriesInfo name="DOI" value="10.17487/RFC8693"/>
</reference>
<reference anchor="RFC9421">
<front>
<title>HTTP Message Signatures</title>
<author fullname="A. Backman" initials="A." role="editor" surname="Backman"/>
<author fullname="J. Richer" initials="J." role="editor" surname="Richer"/>
<author fullname="M. Sporny" initials="M." surname="Sporny"/>
<date month="February" year="2024"/>
<abstract>
<t>This document describes a mechanism for creating, encoding, and verifying digital signatures or message authentication codes over components of an HTTP message. This mechanism supports use cases where the full HTTP message may not be known to the signer and where the message may be transformed (e.g., by intermediaries) before reaching the verifier. This document also describes a means for requesting that a signature be applied to a subsequent HTTP message in an ongoing HTTP exchange.</t>
</abstract>
</front>
<seriesInfo name="RFC" value="9421"/>
<seriesInfo name="DOI" value="10.17487/RFC9421"/>
</reference>
<reference anchor="I-D.ni-wimse-ai-agent-identity">
<front>
<title>WIMSE Applicability for AI Agents</title>
<author fullname="Ni Yuan" initials="N." surname="Yuan">
<organization>Huawei</organization>
</author>
<author fullname="Peter Chunchi Liu" initials="P. C." surname="Liu">
<organization>Huawei</organization>
</author>
<date day="20" month="October" year="2025"/>
<abstract>
<t> This document discusses WIMSE applicability to Agentic AI, so as to
establish independent identities and credential management mechanisms
for AI agents.
</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft" value="draft-ni-wimse-ai-agent-identity-01"/>
</reference>
<reference anchor="SPIFFE" target="https://spiffe.io/docs/latest/spiffe-about/overview/">
<front>
<title>Secure Production Identity Framework for Everyone (SPIFFE)</title>
<author >
<organization></organization>
</author>
<date />
</front>
</reference>
<reference anchor="OPENTELEMETRY" target="https://opentelemetry.io/docs/specs/otel/">
<front>
<title>OpenTelemetry Specification</title>
<author >
<organization>Cloud Native Computing Foundation</organization>
</author>
<date />
</front>
</reference>
<reference anchor="I-D.ietf-scitt-architecture">
<front>
<title>An Architecture for Trustworthy and Transparent Digital Supply Chains</title>
<author fullname="Henk Birkholz" initials="H." surname="Birkholz">
<organization>Fraunhofer SIT</organization>
</author>
<author fullname="Antoine Delignat-Lavaud" initials="A." surname="Delignat-Lavaud">
<organization>Microsoft Research</organization>
</author>
<author fullname="Cedric Fournet" initials="C." surname="Fournet">
<organization>Microsoft Research</organization>
</author>
<author fullname="Yogesh Deshpande" initials="Y." surname="Deshpande">
<organization>ARM</organization>
</author>
<author fullname="Steve Lasker" initials="S." surname="Lasker">
</author>
<date day="10" month="October" year="2025"/>
<abstract>
<t> Traceability in supply chains is a growing security concern. While
verifiable data structures have addressed specific issues, such as
equivocation over digital certificates, they lack a universal
architecture for all supply chains. This document defines such an
architecture for single-issuer signed statement transparency. It
ensures extensibility, interoperability between different
transparency services, and compliance with various auditing
procedures and regulatory requirements.
</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-scitt-architecture-22"/>
</reference>
<reference anchor="I-D.ietf-oauth-transaction-tokens">
<front>
<title>Transaction Tokens</title>
<author fullname="Atul Tulshibagwale" initials="A." surname="Tulshibagwale">
<organization>SGNL</organization>
</author>
<author fullname="George Fletcher" initials="G." surname="Fletcher">
<organization>Practical Identity LLC</organization>
</author>
<author fullname="Pieter Kasselman" initials="P." surname="Kasselman">
<organization>Defakto Security</organization>
</author>
<date day="24" month="January" year="2026"/>
<abstract>
<t> Transaction Tokens (Txn-Tokens) are designed to maintain and
propagate user identity and authorization context across workloads
within a trusted domain during the processing of external requests,
such as API calls. They ensure that this context is preserved
throughout the call chain, even when new transactions are initiated
internally, thereby enhancing security and consistency in complex,
multi-service architectures.
</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-oauth-transaction-tokens-07"/>
</reference>
<reference anchor="I-D.oauth-transaction-tokens-for-agents">
<front>
<title>Transaction Tokens For Agents</title>
<author fullname="Ashay Raut" initials="A." surname="Raut">
<organization>Amazon</organization>
</author>
<date day="10" month="February" year="2026"/>
<abstract>
<t> This document specifies an extension to the OAuth Transaction Tokens
framework (https://drafts.oauth.net/oauth-transaction-tokens/draft-
ietf-oauth-transaction-tokens.html) to support agent context
propagation within Transaction Tokens for agent-based workloads. The
extension defines two new context fields: &#x27;actor&#x27; and &#x27;principal&#x27;.
The &#x27;actor&#x27; field identifies the agent performing the action, while
the &#x27;principal&#x27; field identifies the human or system entity that
initiated the agent&#x27;s action. For autonomous agents operating
independently, the &#x27;principal&#x27; field MAY be omitted. These
additional context fields enable services within the call graph to
make more granular access control decisions, thereby enhancing
security.
</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft" value="draft-oauth-transaction-tokens-for-agents-04"/>
</reference>
</references>
</references>
<?line 986?>
<section numbered="false" anchor="use-cases"><name>Use Cases</name>
<t>This section describes a representative use case demonstrating how
ECTs provide structured execution records.</t>
<t>Note: task identifiers in this section are abbreviated for
readability. In production, all "jti" values are required to be
UUIDs per <xref target="exec-claims"/>.</t>
<section numbered="false" anchor="cross-organization-financial-trading"><name>Cross-Organization Financial Trading</name>
<t>In a cross-organization trading workflow, an investment bank's
agents coordinate with an external credit rating agency. The
agents operate in separate trust domains with a federation
relationship. The DAG records that independent assessments from
both organizations were completed before trade execution.</t>
<figure title="Cross-Organization Trading Workflow" anchor="fig-finance"><artwork><![CDATA[
Trust Domain: bank.example
Agent A1 (Portfolio Risk):
jti: task-001 par: []
iss: spiffe://bank.example/agent/risk
exec_act: analyze_portfolio_risk
Trust Domain: ratings.example (external)
Agent B1 (Credit Rating):
jti: task-002 par: []
iss: spiffe://ratings.example/agent/credit
exec_act: assess_credit_rating
Trust Domain: bank.example
Agent A2 (Compliance):
jti: task-003 par: [task-001, task-002]
iss: spiffe://bank.example/agent/compliance
exec_act: verify_trade_compliance
Agent A3 (Execution):
jti: task-004 par: [task-003]
iss: spiffe://bank.example/agent/execution
exec_act: execute_trade
]]></artwork></figure>
<t>The resulting DAG:</t>
<figure title="Cross-Organization DAG" anchor="fig-finance-dag"><artwork><![CDATA[
task-001 (analyze_portfolio_risk) task-002 (assess_credit_rating)
[bank.example] [ratings.example]
\ /
v v
task-003 (verify_trade_compliance)
[bank.example]
|
v
task-004 (execute_trade)
[bank.example]
]]></artwork></figure>
<t>Task 003 has two parents from different trust domains,
demonstrating cross-organizational fan-in. The compliance agent
verifies both parent ECTs — one signed by a local key and one by
a federated key from the rating agency's trust domain.</t>
</section>
</section>
<section numbered="false" anchor="related-work"><name>Related Work</name>
<section numbered="false" anchor="wimse-workload-identity"><name>WIMSE Workload Identity</name>
<t>The WIMSE architecture <xref target="I-D.ietf-wimse-arch"/> and service-to-
service protocol <xref target="I-D.ietf-wimse-s2s-protocol"/> provide the
identity foundation upon which ECTs are built. WIT/WPT answer
"who is this agent?" and "does it control the claimed key?" while
ECTs record "what did this agent do?" Together they form an
identity-plus-accountability framework for regulated agentic
systems.</t>
</section>
<section numbered="false" anchor="oauth-20-token-exchange-and-the-act-claim"><name>OAuth 2.0 Token Exchange and the "act" Claim</name>
<t><xref target="RFC8693"/> defines the OAuth 2.0 Token Exchange protocol and
registers the "act" (Actor) claim in the JWT Claims registry.
The "act" claim creates nested JSON objects representing a
delegation chain: "who is acting on behalf of whom." While
the nesting superficially resembles a chain, it is strictly
linear (each "act" object contains at most one nested "act"),
represents authorization delegation rather than task execution,
and carries no task identifiers or input/output integrity
data. The "act" chain cannot represent
branching (fan-out) or convergence (fan-in) and therefore
cannot form a DAG.</t>
<t>ECTs intentionally use the distinct claim name "exec_act" for the
action/task type to avoid collision with the "act" claim. The
two concepts are orthogonal: "act" records "who authorized whom,"
ECTs record "what was done, in what order."</t>
</section>
<section numbered="false" anchor="transaction-tokens"><name>Transaction Tokens</name>
<t>OAuth Transaction Tokens <xref target="I-D.ietf-oauth-transaction-tokens"/>
propagate authorization context across workload call chains.
The Txn-Token "req_wl" claim accumulates a comma-separated list
of workloads that requested replacement tokens, which is the
closest existing mechanism to call-chain recording.</t>
<t>However, "req_wl" cannot form a DAG because:</t>
<t><list style="symbols">
<t>It is linear: a comma-separated string with no branching or
merging representation. When a workload fans out to multiple
downstream services, each receives the same "req_wl" value and
the branching is invisible.</t>
<t>It is incomplete: only workloads that request a replacement
token from the Transaction Token Service appear in "req_wl";
workloads that forward the token unchanged are not recorded.</t>
<t>It carries no task-level granularity, no parent references,
and no execution content.</t>
</list></t>
<t>Extensions for agentic use cases
(<xref target="I-D.oauth-transaction-tokens-for-agents"/>) add agent
identity and constraints ("agentic_ctx") but no execution
ordering or DAG structure.</t>
<t>ECTs and Transaction Tokens are complementary: a Txn-Token
propagates authorization context ("this request is authorized
for scope X on behalf of user Y"), while an ECT records
execution accountability ("task T was performed, depending on
tasks P1 and P2"). An
agent request could carry both a Txn-Token for authorization
and an ECT for execution recording. The WPT "tth" claim
defined in <xref target="I-D.ietf-wimse-s2s-protocol"/> can hash-bind a
WPT to a co-present Txn-Token; a similar binding mechanism
for ECTs is a potential future extension.</t>
</section>
<section numbered="false" anchor="distributed-tracing-opentelemetry"><name>Distributed Tracing (OpenTelemetry)</name>
<t>OpenTelemetry <xref target="OPENTELEMETRY"/> and similar distributed tracing
systems provide observability for debugging and monitoring. ECTs
differ in several important ways: ECTs are cryptographically
signed per-task with the agent's private key; ECTs are
tamper-evident through JWS signatures; ECTs enforce DAG validation
rules; and ECTs are designed for regulatory audit rather than
operational monitoring. OpenTelemetry data is typically controlled
by the platform operator and can be modified or deleted without
detection. ECTs and distributed traces are complementary: traces
provide observability while ECTs provide signed execution records.
ECTs may reference OpenTelemetry trace identifiers in the "ext"
claim for correlation.</t>
</section>
<section numbered="false" anchor="scitt-supply-chain-integrity-transparency-and-trust"><name>SCITT (Supply Chain Integrity, Transparency, and Trust)</name>
<t>The SCITT architecture <xref target="I-D.ietf-scitt-architecture"/> defines a
framework for transparent and auditable supply chain records.
ECTs and SCITT are complementary: the ECT "wid" claim can serve
as a correlation identifier in SCITT Signed Statements, linking
an ECT audit trail to a supply chain transparency record.</t>
</section>
</section>
<section numbered="false" anchor="acknowledgments"><name>Acknowledgments</name>
<t>The author thanks the WIMSE working group for their foundational
work on workload identity in multi-system environments. The
concepts of Workload Identity Tokens and Workload Proof Tokens
provide the identity foundation upon which execution context
tracing is built.</t>
</section>
</back>
<!-- ##markdown-source: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-->
</rfc>