Authority Must Shrink, Not Grow

Part I

Problem Definition

A child agent can receive a credential whose effective resource, action, audience, tenant, time, or budget scope is broader than the authority its parent was allowed to delegate [R1] [R2].

This note treats authority must shrink, not grow as a bounded control question. It does not infer universal product behavior from a paper, standard, interface screenshot, or single test. A demonstrated result applies only to the cited configuration; an authoritative source defines a requirement or design direction but does not certify an implementation. ACE therefore asks whether the tested system can produce the required behavior and evidence under declared versions, policies, topology, identities, and failure conditions.

The operational distinction is between a claim and a control that can be re-performed. The positive control is: Agent B reads invoice 17 under a summary-only grant delegated by Agent A. The adversarial condition is: Agent B requests write access, a second tenant, a longer expiry, and a larger budget than Agent A possessed. A useful result must show both that authorized work remains possible and that the prohibited path is stopped before an irreversible side effect. Missing fields are classified as insufficient evidence, not silently converted into a pass.

Real-world impact

• A narrow pilot can acquire the blast radius of a broad service credential.
• Cross-domain scope translation can create authority that neither principal intended.
• A control claim without versioned evidence can mislead procurement, audit, incident response, and system owners.
• Failing closed without a positive control can conceal a denial-of-service design rather than demonstrate trustworthy behavior.

Part II

Mitigation Direction

Research-backed direction

1. 01
   research proposed

   Append non-removable resource, action, tenant, time, and context restrictions to derived credentials [R1].

2. 02
   research proposed

   Mint one audience-bound token per hop and reject any requested scope outside the incoming grant [R2] [R3].

3. 03
   research proposed

   Evaluate every resource independently under current dynamic policy rather than inheriting a prior allow decision [R4].

LogionOS engineering mapping

Implementation hypotheses only. No production validation is claimed.

1. 01
   implementation hypothesis

   Add a versioned policy object for authority must shrink, not grow and keep its decision inputs outside model-writable context.

2. 02
   implementation hypothesis

   Generate a signed technical receipt linking actor, request, policy version, decision, enforcement point, and observed outcome.

3. 03
   implementation hypothesis

   Export missing evidence explicitly as insufficient evidence and limit every claim to the tested configuration.

Part III

Consequences and Research Agenda

Consequences

• A narrow pilot can acquire the blast radius of a broad service credential.
• Cross-domain scope translation can create authority that neither principal intended.
• A failed acceptance test requires the related capability claim to remain not demonstrated or insufficient evidence.
• A passing test supports only the declared configuration and does not establish universal safety.

Second-order effects

• Stronger enforcement can increase latency, state, operational dependencies, and legitimate denials.
• More evidence can increase privacy and retention exposure unless raw content is minimized and access-controlled.
• A detector or policy service can become a new failure point and must have explicit fail behavior.
• Attackers may adapt to published checks, so the public test direction should be paired with private regression variants.

Limitations

• Several cited AI-agent and reasoning-security sources are preprints or bounded experiments; they are identified as such in the references.
• The proposed ACE acceptance test has not yet been run across all incumbent and AI-native implementations.
• Cryptographic integrity proves that an artifact was not altered after commitment; it does not prove that the artifact was true, complete, or correctly interpreted.
• Legal and contractual applicability remains deployment- and jurisdiction-specific.

Open research questions

1. How can semantic subset relations be proved across different policy languages?
2. How should fan-out and fan-in delegation compose budgets and data scope?
3. Which evidence fields are mandatory for a demonstrated result, and which may be not applicable?
4. How should continuous regression detect policy, model, tool, and provider drift after the initial test?

Sources

References

1. [R1]
   Macaroons: Cookies with Contextual Caveats for Decentralized Authorization in the Cloud

   published · original-paper

2. [R2]
   RFC 8693: OAuth 2.0 Token Exchange

   published · authoritative-standard

3. [R3]
   SPIFFE JWT-SVID Specification

   published · authoritative-standard

4. [R4]
   NIST SP 800-207: Zero Trust Architecture

   published · authoritative-standard

Record

Publication Record

Recommended citation

Ma, Chris. “Authority Must Shrink, Not Grow.” ACE Research Note ACE-RN-2026-001, v1.0, 2026.

Corrections

No corrections recorded.

Organizational disclosure

ACE Research and LogionOS share organizational affiliation. LogionOS mappings in this note are implementation hypotheses, not independently validated product claims.

Evidence boundary

This note synthesizes cited public research and defines an ACE acceptance direction. It does not report a completed cross-vendor experiment unless explicitly stated, and it contains no private ACE prompts, holdout identifiers, customer data, or raw model responses.