Time-Limited and Conditional Credentials

Time-Limited and Conditional Credentials

5.6.1 Why Time and Conditions Are First-Class Governance Constraints

In NSF, trust must be:

• Context-aware

• Revocable by design

• Tied to temporal or policy-specific scopes

• Enforceable in zero-trust, machine-verifiable environments

Time-limited and conditional credentials allow:

• Operators to act during a crisis period—but not before or after

• Jurisdictional agents to access systems only when simulations forecast risk

• Simulations to be used as evidence—but only for defined policy triggers

• Role escalation to occur dynamically under credential-bound logic

These constraints are cryptographically enforced, not merely advisory.

---

5.6.2 Time-Limited Credential Semantics

Every NSF VC supports:

"valid_from": "2025-01-01T00:00Z",
"expires": "2025-06-30T23:59Z"

During clause execution or credential presentation:

• The current UTC time must fall within the defined interval

• Expired credentials are rejected by:

  • Execution environments

  • Simulation verifiers

  • Policy binding clauses

  • Credential oracles

These fields are non-optional for operational, simulation, and legal VCs.

---

5.6.3 Grace Periods and Expiration Policies

DAO governance can define:

• Grace intervals: e.g., allow VC use for 72 hours after expiry for rollback safety

• Soft expiration: trigger alerts without immediate revocation

• Auto-renewal conditions: if clause X or simulation Y executes successfully

• Revocation-linked expiration: if a parent credential is revoked, child VCs expire immediately

These rules are encoded in the Credential Policy Layer and referenced by the Credential Registry.

---

5.6.4 Conditional Credential Logic

NSF credentials can embed policy constraints beyond time:

Constraint Type	Description
Simulation-bound	Only valid if simulation X has run with outcome Y
Sensor-triggered	Valid only when IoT input is above/below threshold
Clause-scoped	VC may only be used for clauses matching a defined pattern
Credential-dependent	VC valid only if another VC is also active
Governance-triggered	VC becomes valid/invalid via DAO vote or emergency override

Example:

"conditions": {
  "simulation_dependency": "FloodForecastSim#0x983f",
  "allowed_clauses": ["[email protected].*"],
  "jurisdiction": "BGD",
  "thresholds": {
    "rainfall": ">= 180mm",
    "disaster_index": ">= 4"
  }
}

---

5.6.5 Binding Conditional VCs to Execution Workflows

Clause logic will enforce:

if hasVC("FloodReliefOperatorVC")  
and VC.condition_satisfied("simulation_dependency")  
and VC.is_valid(now)  
then execute Clause

This turns policy logic into runtime-executed smart authorization filters, without human intervention.

---

5.6.6 Dynamic Role Elevation and Temporary Escalation

NSF supports tiered VC escalation, where:

• A base credential (e.g., FieldAgentVC)

• Can be temporarily upgraded (e.g., EmergencyCoordinatorVC)

• If specific conditions are met, such as:

  • Sensor alerts

  • Simulation outcomes

  • DAO vote

  • Clause logic (e.g., trigger from treaty activation)

These credentials are:

• Time-limited (e.g., 72 hours)

• Audited on issuance and use

• Auto-expiring after escalation window closes

• Logically scoped by binding clause hash

---

5.6.7 Smart Clause Binding with Dynamic Validity Windows

Clauses can reference credentials with logic like:

accept VC where:
  valid_from <= now <= expires  
  and VC.has_simulation("HealthRiskSim#0x55a8")  
  and jurisdiction in ["KEN", "UGA", "TZA"]

These checks are enforced at:

• TEE runtime

• ZK circuit input validation

• Credential oracle pre-verification

• DAO policy oversight

---

5.6.8 Use in Simulation and Forecast Validity

Simulation outputs can only be:

• Used for action

• Trigger credential issuance

• Inform policy

…if the simulation’s own SimulationModelVC and SimulationRunVC are still valid.

Expired simulations must:

• Be rerun

• Use updated models

• Trigger revalidation workflows

This ensures governance decisions reflect current data and models.

---

5.6.9 Credential Oracles and Expiry Propagation

NSF Credential Oracles (see 5.8) monitor:

• Expiry status

• Parent-child VC relationships

• Clause compatibility windows

• Policy-defined retirement schedules

They issue:

• Expiration events to trigger auto-revocation

• Bundled status reports for DAOs and execution layers

• Warnings before credential bundles become invalid

---

5.6.10 Temporal and Conditional Logic as a Pillar of Machine-Led Governance

In NSF:

• Every credential is contextual

• Every policy is time-bound

• Every execution is constrained by cryptographic authorization windows

This removes ambiguity, protects against stale authority, and enables:

• Automated revocation

• Clause-safe execution

• Time-sensitive disaster governance

• Privacy-preserving but verifiable credential lifecycles

Time-limited and conditional credentials make NSF governance safe, flexible, programmable—and fully auditable.

---