From what little I know, raw user inputs are not directly submitted to LLMs. Typically, user input is carefully wrapped in a special format before being sent to the LLM. The format usually has tags, including special tags to tell the AI, for example, which topic is prohibited.

As with SQL injection, an attacker can craft malicious user input by introducing special tags. Input sanitization can be seen as a solution, but it seems that it isn't enough. Anyway, it doesn't seem very intuitive, I think a document intended to be read by an LLM should also be very human-readable. I also wonder what happens when an attacker uses obscure Unicode characters to forge a string that looks like a special tag.

Instead of using an XML-like language, my idea is to use a format that seamlessly interweave human-readable structured data with prose within a single document. Also, the format must natively support indentation to remove the need for input sanitization, thereby eliminating an entire class of injection attacks.

I am the author of Braq, a data format that seems to be a good candidate.

The idea to better structure a prompt is described in this Markdown section: https://github.com/pyrustic/braq?tab=readme-ov-file#ai-prompts

And here, ChatML from OpenAI: https://news.ycombinator.com/item?id=34988748

As mentioned above, I can't test this idea. Therefore, I'm asking to you: Can we solve AI prompt injection attacks with an indented data format ?