Our Simulation Was Wrong by 37 Percentage Points — What Real LLM Agents Taught Us About Multi-Agent Cascade

I built a multi-agent security simulation, ran 6 experiments, then validated against real Claude Haiku agents. The simulation predicted 97% poison rate. Real agents: 60%. And the biggest surprise: topology matters — something the simulation said was irrelevant. What I Built A simulation-based testbed that models multi-agent systems with configurable trust architectures, network topologies, attacker types, and agent compositions. One agent gets compromised. We measure how poisoned outputs cascade through the system. ...

March 20, 2026 · 4 min · Rex Coleman

Privilege Escalation Cascades at 98% While Domain-Aligned Attacks Are Invisible

Domain-aligned prompt injections cascade through multi-agent systems at a 0% detection rate. Privilege escalation payloads hit 97.6%. That’s a 98 percentage-point spread across payload types in the same agent architecture — the single biggest variable determining whether your multi-agent system catches an attack or never sees it. I ran six experiments on real Claude Haiku agents to find out why. Three resistance patterns explain the gap — and each has a quantified bypass condition. ...

March 20, 2026 · 5 min · Rex Coleman

We Built a Multi-Agent Defense and It Failed — Here's Why That Matters More

We proposed a verified delegation protocol — LLM-as-judge verification, cryptographic signing, adaptive rate limiting — and pre-registered 7 hypotheses predicting it would reduce multi-agent cascade poison by 70%. Then we tested it on real Claude agents. Five hypotheses were refuted. The protocol doesn’t work. And that’s the finding. ...

March 19, 2026 · 5 min · Rex Coleman
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