BCS: Behavioral Control System — Model-Agnostic LLM Behavioral Enforcement Framework

BCS (Behavioral Control System) is an external control framework that enforces user-defined behavioral invariants on any Large Language Model without modifying model weights. Architecture: (1) input pre-conditioning via few-shot learning and reward tokens, (2) output validation against pattern rules, (3) progressive regeneration under stricter constraints (up to 3 attempts), (4) guaranteed deterministic fallback. Includes real-time drift detection (Cockpit de Drift v1.3) and 7-layer security filter (CEF Framework, 98.3% attack coverage). Tested on Llama 3.2 (3B): 80% pristine rate, 100% behavioral compliance via fallback, 0.6% fallback rate, 2.8s average latency. This deposit contains the full technical documentation and an executive technical brief. BCS controls observable behavior through external orchestration — it does not claim internal alignment. Files: BCS_BEHAVIORAL_CONTROL_SYSTEM_FINAL.md BCS_TECHNICAL_BRIEF_COPILOT.md Upload type: Publication / Technical note Creator: Ochej, Stéphane Publication date: 2026-01-06 Keywords: behavioral control, LLM safety, AI governance, external orchestration, drift detection, fallback guarantee, model-agnostic, audit trail License: Restricted Access