Stage286: QSP Internal Connection as a Product Specification

Overview

Stage286 upgrades the QSP-to-VEP connection from an implementation detail into a product specification.

This stage defines a stable internal contract for how QSP:

• receives normalized input
• produces a decision
• enforces fail-closed behavior
• exports a public-facing exposure contract for VEP

This transforms:

• connected components

into:

• a reproducible product interface

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Why This Stage Matters

Earlier stages proved that:

• evidence can be generated
• trust signals can be measured
• QSP and VEP can be connected

Stage286 makes that connection stable, portable, and productizable.

The main goal is not a new cryptographic primitive.

The goal is to define a durable internal contract so that future engines (QKD-backed, PQC-backed, hybrid, remote-attested, SaaS, etc.) can be swapped in without breaking the external verification experience.

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Core Product Model

Stage286 defines four product layers:

1. Input Layer

   • normalized session input
   • subject
   • policy
   • evidence

2. Decision Layer

   • accept / pending / reject
   • reason
   • trust scores
   • verified claims

3. Enforcement Layer

   • explicit fail-closed requirement
   • execution state
   • allowed outputs

4. Exposure Layer

   • stable export to VEP
   • public status
   • public artifacts
   • contract digest

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What This Stage Proves

• QSP internal connection can be formalized as a product contract
• fail-closed behavior can be represented as a first-class specification rule
• VEP can consume a normalized contract instead of ad hoc files
• future engine replacement is possible without changing the public contract

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Repository Structure

spec/
  qsp_product_spec.json

schemas/
  qsp_product_contract.schema.json

tools/
  build_stage286_product_contract.py
  verify_stage286_product_contract.py

out/product/
  qsp_product_contract.json
  qsp_product_contract.json.sha256
Build
python3 tools/build_stage286_product_contract.py
Verify
python3 tools/verify_stage286_product_contract.py
Expected Output

The build step generates:

out/product/qsp_product_contract.json
out/product/qsp_product_contract.json.sha256

The verification step checks:

correct stage binding
explicit fail-closed requirement
valid decision enum
public status consistency
SHA-256 integrity
Product Significance

This stage is important because it moves QSP from:

a research pipeline
a verification stack
a connected demo

toward:

a product contract
a replaceable architecture
a future-proof public trust interface

In short:

Stage285 connected QSP and VEP.
Stage286 defines the product contract that governs that connection.

Future Directions

Possible future upgrades built on this stage include:

QKD session binding
PQC signature binding
threshold approval policies
remote attested execution
multi-tenant deployment
policy version negotiation
compatibility guarantees across product versions
License

MIT License
Copyright (c) 2025