QSCS: The Quantum–Classical Orchestration Layer

A deterministic substrate for quantum–classical coordination.

QSCS enables predictable, secure and reproducible coordination between quantum processors and classical compute nodes — without vendor-specific integrations or opaque orchestration layers.


Architecture Overview

QSCS is a three-layer coordination stack. The Integration & API Layer exposes developer-ready interfaces. The QCCP protocol provides hardware-agnostic orchestration.

The State Substrate ensures deterministic, reproducible execution across distributed nodes.

Integration & API Layer HTTP & IPC interfaces · Python / TypeScript client libraries Application & testbed access 🔒 Security & Trust Boundary QSCS Daemon (C++) Quantum–Classical Coordination Protocol (QCCP) Hardware-agnostic orchestration · Job submission & control signals Synchronous & asynchronous execution Deterministic State Substrate Canonical state model · Reproducibility & auditability Distributed synchronisation Jobs ▼ ▲ State Classical Compute Nodes Quantum Processor All interactions occur through authenticated, policy-governed QCCP envelopes mediated by the QSCS daemon

Deterministic State Substrate

The state substrate is the core execution engine. It maintains a canonical state model, enforces deterministic transitions, and records all changes in an append-only register — ensuring reproducibility and auditability across distributed nodes.

Deterministic State Substrate State Machine Core Deterministic transition engine Rule-driven execution Canonical State Representation Structured, serialisable state Stable across nodes Transition Ruleset Defines allowed transitions Ensures reproducibility Audit & Logging Hooks Timestamped state snapshots Evaluation support Incoming QCCP Envelopes State Updates to QCCP / API Distributed Synchronisation Module Instance A Instance B Instance C Ensures consistent state across classical nodes

QCCP Protocol Flow

The Quantum–Classical Coordination Protocol mediates all interactions between classical workflows and quantum hardware. The daemon validates, routes, and orchestrates every request through a deterministic pipeline.

Classical Nodes Application logic Workflow orchestration Pre/post-processing 🔒 Security & Trust Boundary QSCS Daemon (C++) — QCCP Handler Envelope Parser Validates & authenticates Control Signal Router Routes & schedules State Interaction Deterministic transitions Response Constructor Packages state updates Quantum job dispatch Deterministic orchestration via canonical state model Quantum Processor Hardware-agnostic Measurement results QCCP ▸ ◂ Result All interactions mediated through the QSCS daemon

Distributed Quantum–Classical Compute

QSCS enables coordinated workflows across multiple classical nodes and quantum processors through a shared, deterministic state model. Each daemon instance synchronises via an append-only register.

Classical Node A Workflow · Compute · Cache Classical Node B Workflow · Compute · Cache Classical Node C Workflow · Compute · Cache QCCP Envelopes (Job Requests / Control Signals) 🔒 Security & Trust Boundary (Policy-Governed QCCP) QSCS Daemon Cluster (C++) Deterministic state substrate · Canonical state model · QCCP orchestration Substrate Instance A State engine · QCCP · Sync Substrate Instance B State engine · QCCP · Sync Substrate Instance C State engine · QCCP · Sync State Sync (Append-Only) State Sync (Append-Only) Quantum Job Dispatch Quantum Processor 1 Hardware-agnostic · Measurements Quantum Processor 2 / Sim Hardware-agnostic · Measurements Coordinated quantum-classical workflows using a shared deterministic state model

Security & Trust Boundaries

QSCS enforces strict trust boundaries through authenticated QCCP envelopes, deterministic state transitions and controlled access to quantum hardware. Classical nodes never interact directly with hardware.

UNTRUSTED / EXTERNAL COMPUTE ZONE Classical Node A Workflow · Compute · Cache Classical Node B Workflow · Compute · Cache Classical Node C Workflow · Compute · Cache QCCP Envelopes (Authenticated, Policy-Governed) 🔒 Security & Trust Boundary All interactions mediated by QSCS Daemon (C++) Policy-Governed Execution Environment QSCS Daemon (Trusted Zone) Envelope Validator Policy Engine State Substrate Append-Only Register Hardware Interface Authorised Quantum Job Dispatch PROTECTED ZONE — QUANTUM HARDWARE Quantum Processor Hardware-agnostic · Protected interface Quantum Simulator Hardware-agnostic · Protected interface Strict trust boundaries · Authenticated envelopes · Controlled quantum access

Daemon Internal Architecture

The QSCS daemon provides a modular, deterministic pipeline for all quantum–classical interactions. Each module validates, enforces policy, manages state, plans execution, and interfaces with quantum hardware.

Incoming QCCP Envelope (Authenticated, Policy-Governed) 🔒 Trusted Zone — Policy-Governed Execution QSCS Daemon (C++) — Internal Architecture Envelope Validator Structural validation · Sender authentication · Schema enforcement Policy Engine Access control · Operation-level policy · Resource constraints Deterministic State Substrate Canonical state model · Deterministic transitions · Append-only register Execution Planner Sync/async modes · Message preparation · Deterministic ordering Hardware Interface Layer Backend-agnostic transmission · Result ingestion · Protected interface Deterministic Pipeline ▼ Quantum Processor / Simulator Response Constructor Results Modular, deterministic and policy-governed message pipeline

Testbed Deployment

QSCS integrates into the operational testbed as a lightweight coordination layer. Classical workflow nodes communicate through QCCP envelopes, the daemon maintains the canonical state model, and execution requests reach quantum processors through a secure, policy-governed interface.

External Zone Classical Workflow Nodes Node A Workflow · Compute · Cache Node B Workflow · Compute · Cache Node C Workflow · Compute · Cache QCCP Envelopes (Job Requests / State Queries) 🔒 Trusted Zone QSCS Daemon (C++) Envelope Validation Policy Enforcement State Substrate State Register Execution Requests Deterministic pipeline flow → Execution Request (Validated, Policy-Governed) Quantum Backend Quantum Processor Hardware-agnostic execution Quantum Simulator Hardware-agnostic execution Minimal, deterministic and policy-governed message pathway

Design Principles


Summary

QSCS delivers a deterministic, hardware-agnostic orchestration substrate for quantum–classical systems. It provides:

This is a substrate designed for systems that must be predictable, reproducible and secure by construction.

QSCS is designed for environments where correctness, reproducibility and trust are non-negotiable.