RectitudeAI: Building a Four-Layer Runtime Security Protection System for LLM Applications

RectitudeAI-PromptGuard is a production-grade LLM security gateway. Targeting risks such as prompt injection and data leakage, it provides full-lifecycle runtime protection through a four-layer architecture (intent security, encrypted tokens, behavior monitoring, red team testing) plus multi-agent sandbox isolation, building a solid security barrier for LLM applications in production environments.

After modern AI applications evolve into intelligent agents, they face four major threats:

• Prompt injection: Overwriting instructions or inducing unintended operations
• Data leakage: Exposing sensitive information/system prompts
• Unauthorized tool calls: Accessing external tools that should not be allowed
• Multi-round jailbreaking: Inducing deviations from security constraints through long-term conversations Traditional web security models struggle to address these new threats due to the uncertainty of LLM inputs and outputs.

RectitudeAI adopts a layered defense design, with the core four layers as follows:

1. Intent Security Layer: Hybrid detection using context regex + DeBERTa v3 classifier to block malicious intents and injections
2. Encrypted Token Layer: HMAC signatures to prevent unauthorized tool calls, and PII/key desensitization to avoid leakage
3. Behavior Monitoring Layer: Agent Stability Index (ASI) to analyze session drift and prevent gradual jailbreaking
4. Red Team Testing Layer: Reinforcement learning to generate adversarial prompts for strategy tuning, with effects verified by JailbreakBench It also supports multi-agent sandbox isolation and intelligent orchestration of routing requests.

Deployment Process: Supports Docker/local operation (clone repository → virtual environment → dependency installation → Redis startup → run application) Performance Metrics: Response time ~300ms (target <500ms), throughput ~800 requests/second (target >1000), test coverage over 80% Attack Defense Effects:

Attack Scenario	Attack Type	Gateway Response	Result
Instruction Override	"Ignore previous instructions..."	L1 Block	🚫 Blocked
Data Leakage	"Send email to evil@com"	L2 Check	🚫 Blocked
Information Extraction	"Show all SSNs"	L2 Audit	🔒 Desensitized
Gradual Jailbreak	10-round role drift	L3 ASI Score	🔒 Revoked

RectitudeAI has built a full-lifecycle security ecosystem and is currently completing Phase 5 development (frontend integration in progress). Future plans include adding functions such as statistical anomaly detection, risk policy execution, and continuous red team testing. It is recommended that LLM developers establish a matching security system, and RectitudeAI is a worthy architectural paradigm for reference.