Why Prompt Injection Won't Be "Fixed"

Short summary

Prompt injection is fundamental to LLM architecture, not a fixable bug. LLMs process instructions and data in the same token stream, distinguishing them only through statistical associations learned during training. Without formal grammar-based separation (like SQL's parameterized queries), smarter models or system prompts alone cannot close this gap.

• •Prompt injection is an architectural property, not a model bug—it cannot be patched out
• •LLMs lack formal separation between instructions and data; both are tokenized into the same context window
• •Four defense categories exist (system-prompt rules, input validation, sandboxing, agent design) but none fully solve the problem

Generated with AI, which can make mistakes.