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What is Prompt Injection

Prompt injection has become a subject of growing concern in the field of AI cybersecurity. Its increasing prevalence has triggered an urgent need to understand this threat and develop robust countermeasures. This article aims to demystify prompt injection, highlighting its impact on AI systems, and suggesting ways to build more secure, agentic systems.

Understanding Prompt Injection

Prompts in AI systems or large language models serve as the initial instructions to the bot. They set the scene for the bot, guiding its responses and behavior. The significance of this system message or developer message means that any data included within it can significantly influence the system's performance.

Prompt injection occurs when an attacker manipulates this prompt to include their controlled data. This injection could be as simple as adding extra rules under the guise of their name. The result is a fundamentally altered prompt that can now be exploited to manipulate the AI system.

The Danger of Prompt Injection

Prompt injection isn't a new phenomenon. It belongs to a class of attacks that has been around for 25-30 years, including SQL Injection, Cross-Site Scripting, and XML Entity Injection. String concatenation, the process of combining strings to create a single new one, is the common culprit behind these attacks.

In the wild, prompt injection attacks have become more prevalent, primarily because the tools used to build AI systems, while powerful, are also immature. These tools often lack understanding about such attacks, leaving systems vulnerable.

Defending Against Prompt Injection Attacks

There's no single solution for defending against prompt injection attacks. However, a crucial first step is to avoid string concatenation whenever possible. With large language models dealing mostly with natural text, it's challenging to write sanitization rules. Therefore, the best defense against these attacks is often to avoid string concatenation altogether.

An alternative approach, adopted by ChatBotKit, is to flip the traditional input-output paradigm. Instead of concatenating the results at the end, the agent is placed at the center. It can then use various tools to fetch data and carry out other tasks. This design ensures that while external data can enter the agent, it doesn't form part of the system prompt, therefore avoiding injection attacks.

Building a Secure AI System

When building an AI system, the primary goal should be to avoid injection attacks. This can be achieved by adopting a design that places the agent at the center and avoids string concatenation whenever possible.

If string concatenation is unavoidable, take steps to ensure the input data is trusted. This could involve sanitizing the data, shortening it, or carrying out other pre-processing methods.

In conclusion, understanding prompt injection and its potential threats is crucial for AI development. By prioritizing secure designs and adopting best practices, developers can build more robust and secure AI systems.