This publication presents the Runtime Stability framework, a comprehensive technical framework that defines seven Protection Attributes for structurally maintaining the security of computer systems during execution (runtime). Unlike traditional security approaches focused on perimeter defense, Runtime Stability addresses the protection of systems even after a breach has occurred. The framework consists of three interrelated definition documents: 1. Runtime Stability Definition Document v3.3 — Establishes the overarching framework, including three Design Philosophies (Non-Halting, Homeostasis Maintenance, Integrated Achievement of 7 Attributes), the 7 Protection Attributes (Safety, Reliability, Availability, Controllability, Confidentiality, Data Integrity, Inexploitability), a three-layer defense model, and the RS (Runtime Stability Level) evaluation scale (RS-0 to RS-6). 2. Runtime Security Definition Document v1.3 — Defines the detection-based protection layer (Layer 2: Control Retention). Introduces a 3-axis evaluation framework (Recall, Precision, Response Latency) for the Security Level (SL-0 to SL-3) and systematically positions existing technologies such as RASP, CWPP, and EDR within the framework. 3. Runtime Immunity Definition Document v1.3 — Defines the structure-based protection layer (Layer 3: Outcome Nullification). Introduces the Nullification Level (NL-1 to NL-3) with a 2-axis evaluation (Information-Theoretic Nullification and Economic Nullification) and includes a Post-Quantum Nullification (PQN) extension framework. Key contributions:- Introduces Inexploitability as a novel protection attribute that severs the causal relationship between defense breach and damage occurrence- Provides a quantitative evaluation framework (RS = SL + IL) enabling systematic assessment of runtime protection levels- Bridges cybersecurity and safety engineering through attributes derived from both domains (e.g., Controllability from ISO 26262)- Technology-neutral and algorithm-independent definitions designed for long-term applicability Each document is provided in both English and Japanese (PDF and Markdown formats).
Yoshida et al. (Tue,) studied this question.