A Break-Down of Research in

You Have the Right to Remain Filtered

How constitutional classifiers offer a scalable defense against AI jailbreaks and keep large language models aligned with safety standards.

In a world where AI is increasingly woven into customer experiences, productivity tools, and decision-making platforms, a subtle but high-stakes risk has emerged. That risk? Large language models or LLMs (the kind powering generative AI applications like chatbots and copilots) can be tricked into doing things they were specifically programmed not to do. From offering instructions on illegal activity to generating hate speech or misinformation, these models can be manipulated using a method known as a “jailbreak.”

Jailbreaking an AI doesn’t involve hacking its code. Instead, it’s about finding clever ways to rephrase inputs (or chain together prompts, in a way that causes the AI to break its own safety rules). Think of it as finding the exact right way to ask a question that slips through the model’s ethical filters. In the past, these jailbreaks were often very specific and brittle. But researchers are now seeing the rise of “universal jailbreaks”, generic attack strategies that work across many different types of prompts, regardless of topic. That makes them not only more dangerous but also far more scalable, which is especially alarming when these AI systems are deployed widely across consumer and enterprise environments.

This is the problem the researchers behind constitutional classifiers set out to solve. They observed that even the most advanced models, despite being trained with safety in mind, could be exploited with surprisingly little effort by determined users. And while safety filters and “guardrails” were already in place in many systems, they weren’t holding up against these more general, persistent jailbreak methods.

To tackle this, the team didn’t try to fix the model itself. Instead, they added a second layer of defense using a novel framework called constitutional classifiers. Think of this like a security checkpoint for every message going in and out of the AI model. Rather than relying only on hard-coded rules or human moderation, this system uses its own machine learning classifiers that have been trained to recognize unsafe content (even when it’s disguised or embedded in otherwise innocuous language).

The “constitutional” part of the name refers to a kind of AI Bill of Rights, a guiding set of principles that the classifier is trained to follow. These might include statements like “the model should not promote violence” or “the model should not help users engage in illegal activity.” Instead of hand-labeling thousands of examples of bad behavior (which would be slow, expensive, and often incomplete), the researchers used AI to simulate both good and bad responses based on these constitutional principles. This generated a large, synthetic dataset to train the classifiers—making the system adaptable and scalable.

The result? A kind of AI bouncer that evaluates every prompt and every response before it gets through the door—rejecting anything that might violate the constitutional principles. And because it doesn’t rely on hard-coded, scenario-specific rules, this approach can generalize to new types of jailbreaks more easily than previous methods.

This framework doesn’t just provide an extra line of defense; it also fundamentally shifts how we think about content moderation in LLMs. Rather than trying to anticipate every possible bad question someone might ask, it sets values at the center and uses those values to evaluate whether something should be allowed. It’s a flexible, AI-native approach to safety that may become a standard as generative models continue to scale across industries.

To understand how constitutional classifiers perform in the real world, the researchers didn’t just rely on theoretical benefits. They stress-tested the framework under intense, prolonged scrutiny—putting it through one of the most extensive red teaming efforts ever conducted on an LLM. The goal was simple: try to break it. And not just once, but over and over, using a wide variety of prompts and attack strategies to mimic how real users might attempt to jailbreak these systems at scale.

Red teaming, in this context, refers to systematically attempting to bypass the model’s defenses by crafting prompts that elicit unsafe or harmful responses. But this wasn’t a one-off audit. The team ran thousands of hours of adversarial testing—creating an environment that closely resembled real-world conditions (users with varying motivations and levels of technical sophistication, trying all sorts of strategies to trick the model).

The researchers designed these attacks to simulate both targeted jailbreaks and the more dangerous universal jailbreaks, which tend to work across multiple topics and instructions. In this way, they weren’t just looking for isolated failures but evaluating whether the constitutional classifier could hold up under general, persistent pressure. Their focus was on uncovering not just if the system would break, but how, when, and under what conditions it might fail.

The testing setup included two main checkpoints. First, a classifier would evaluate the user’s prompt before it ever reached the LLM. If that prompt seemed likely to violate constitutional principles, it would be filtered out. Second, if a prompt did get through and the model generated a response, another classifier would review the output to ensure it didn’t violate those same principles. This two-stage defense model is what made the approach particularly resilient.

Now, rather than measuring success purely by how many prompts were accepted or rejected, the researchers focused on a more nuanced question: how well does this system prevent harmful responses, without getting in the way of useful ones?

In other words, it wasn’t enough to stop bad outputs. The solution also had to avoid overcorrecting—blocking safe or productive content unnecessarily. This is where many traditional moderation tools falter: they can be too aggressive—silencing legitimate use cases, or too lenient, letting risky content slip through.

To evaluate performance, the team compared outcomes with and without the constitutional classifiers in place, across a range of adversarial and benign interactions. They looked at whether harmful content was still generated, how often safe prompts were mistakenly rejected, and how the UX was affected overall. This helped them strike a critical balance between safety and usability.

The results were encouraging. While the paper doesn’t claim perfection (and no safety system realistically can), it demonstrated that the constitutional classifiers were remarkably effective at preventing jailbreaks, including sophisticated and general ones. The classifiers didn’t just catch attacks from previous datasets; they also held up well against brand-new adversarial techniques discovered during testing.

Equally important, the researchers showed that the framework was not a blunt instrument. It operated with a surprising level of nuance, allowing useful interactions to go through while selectively filtering only those that posed a real risk. This level of precision matters, especially for companies that want to keep their LLMs helpful and responsive, without compromising safety.

One of the strengths of the constitutional classifier framework lies in how success and failure were defined (not just in terms of stopping specific bad behaviors, but in its ability to adapt and stay effective over time). The researchers didn’t just build a filter and declare it a win. They treated safety as a living, evolving challenge, and tested the solution with the same mindset.

Rather than measuring performance solely by whether a system said “no” to problematic prompts, the researchers evaluated how often the classifier made the right judgment call … across a wide spectrum of real-world scenarios. This meant assessing how well it could distinguish between truly harmful prompts and those that were benign but potentially misunderstood. If a system blocks too many legitimate queries, users lose trust. If it fails to catch edge cases, risks scale quickly.

The team leaned heavily on a “generalization-first” evaluation philosophy. In other words, they didn’t want a classifier that could just memorize what bad content looked like last year; they wanted one that could also make principled, contextual decisions based on newly emerging jailbreak strategies. This meant success wasn’t a static checklist of outputs, but a moving target: could the classifier hold up against unfamiliar attacks that weren’t in its training data?

And in many ways, that’s where the broader promise of this work starts to take shape.

As effective as the system proved to be, it’s not without trade-offs. For one, the classifiers do add a small delay to user interactions, since every prompt and response is being reviewed. In high-speed enterprise environments, even fractions of a second can matter. There’s also the ongoing maintenance challenge: the constitutional principles themselves must evolve, especially as AI systems expand into new cultural, legal, or industry-specific domains. A constitution that works well in one country or sector might not map cleanly to another.

Moreover, this approach (like all AI safety systems) is not a silver bullet. It doesn’t make harmful content generation impossible. It just makes it a lot harder, especially at scale. A determined bad actor may still find obscure paths around the system. What’s important is that the cost of those workarounds keeps rising, and that when new vulnerabilities are identified, the classifiers and their constitutional grounding can be updated quickly.

That flexibility may turn out to be the most important legacy of this research. By decoupling safety enforcement from the base model itself, the constitutional classifier framework enables faster iteration, easier customization, and more consistent application of ethical standards. Rather than waiting for the next model release cycle to fix safety issues, developers can revise the constitution and retrain the classifiers in a fraction of the time.

In the broader context, this marks a shift in how AI companies can approach responsibility. Instead of viewing safety as a static compliance checkbox or a fixed feature of the model, the classifier-based approach treats it as a dynamic, modular component of system design, one that can scale and adapt as the landscape changes.

For leaders in sectors like tech, content moderation, education, or cybersecurity (where AI is already embedded in customer experiences and operational workflows), this research presents a viable and forward-looking strategy. It doesn’t just answer the question of how to stop bad outputs; it also reframes the challenge around building AI systems that are aligned, accountable, and equipped to evolve responsibly alongside their users.


Further Reading

  • Mallari, M. (2025, February 2). Prompt and circumstance. AI-First Product Management by Michael Mallari. https://michaelmallari.bitbucket.io/case-study/prompt-and-circumstance/
  • Sharma, M., Tong, M., Mu, J., Wei, J., Kruthoff, J., Goodfriend, S., Ong, E., Peng, A., Agarwal, R., Anil, C., Askell, A., Bailey, N., Benton, J., Bluemke, E., Bowman, S. R., Christiansen, E., Cunningham, H., Dau, A., Gopal, A., … Perez, E. (2025, January 31). Constitutional classifiers: defending against universal jailbreaks across thousands of hours of red teaming. arXiv.org. https://arxiv.org/abs/2501.18837
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