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Vulnerability in Speech Recognition Systems Exposed

Research reveals risks in multi-task speech models like Whisper.

― 5 min read


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Speech Recognition Systems, such as OpenAI's Whisper, are becoming popular tools for both recording and translating spoken language. These models can take voice input and either write it down or translate it into another language. However, new research shows that these systems might be vulnerable to attacks that could interfere with their intended tasks.

The Rise of Multi-Task Speech Models

Modern speech systems have evolved to do more than just transcribe spoken words. Models like Whisper can switch between different tasks, such as writing down what someone says or translating it into another language. The ability to handle multiple tasks means that these models can be used for a variety of applications, making them much more useful.

However, this flexibility also introduces new risks. The research points out that while these systems can do many things, they can also be tricked. By slightly altering the audio that is fed into them, it becomes possible to change their behavior without needing access to their internal settings.

Weaknesses in Speech Models

The main concern with these flexible models is the risk of "model-control adversarial attacks." This means that someone could use a clever audio trick to make the model do something different from what it was originally set up to do. For example, if the model is meant to write down what is said, an attacker could possibly change its behavior to start translating instead.

How Attacks Work

The research shows that by adding a short piece of specially crafted audio to the front of any spoken input, it can convince the model to switch its task. This "universal adversarial acoustic segment" can be made very short-less than three seconds-and can work across different languages. The attacker does not need to know anything about the text prompts used internally by the model; they only need to manipulate the audio input.

Practical Implications

This is a critical discovery because it could have real-world consequences if such systems are used in sensitive areas. For example, if a speech recognition system used in courts or medical settings could be easily manipulated, it could lead to misunderstandings or even legal issues.

The Research Findings

To illustrate the risks, the researchers tested the Whisper model. They found that by adding their short audio segment to other input speech signals, they could make Whisper always perform translation, even when it was supposed to be transcribing speech. This shows how vulnerable these systems are to simple audio changes.

Attack Methodology

The method is not complex. An attacker only needs to prepend a short audio snippet to whatever speech they want to process. The research demonstrated that this attack could succeed in many cases, showing that the built-in protections of these models are not sufficient to prevent such manipulations.

Performance Results

In their tests, the researchers focused on specific language pairs, particularly French to English. They found that their attack method could force Whisper to translate most of the time, resulting in an average probability of producing English outputs. Using metrics like Word Error Rate and BLEU scores indicated varying levels of success in manipulating the model's task.

Understanding Errors

Interestingly, while the attacks were mostly effective, they didn't always produce results as good as when Whisper operated freely in translation mode. In some cases, the Translations generated during the attack were of lower quality due to additional incorrect words being added (insertions) or existing words being forced to be changed (substitutions).

The Binary Nature of Success

One remarkable finding is that the attacks did not create a gradual shift in output. Instead, they demonstrated a binary pattern: the model either fully complied and translated or completely failed, continuing to transcribe instead. This means that there is no middle ground; the model is either fully under the attack's influence or not affected at all.

Language Variety

To investigate the reach of these attacks, the researchers also looked at other languages. They wanted to see if their method worked outside of the French-English pair. The results showed that the attacks could effectively manipulate Whisper for German, Russian, and Korean as well.

Consistent Results

For all languages tested, the attacks caused Whisper to produce a high degree of English output, indicating the effectiveness of the model-control method. However, the quality of the translations varied, with some languages showing more errors in the output compared to others.

Conclusion

The research reveals a significant vulnerability within multi-task speech systems. By using simple audio tricks, attackers can take control of these models and force them to carry out tasks they are not intended for. The ability to manipulate models like Whisper highlights the need for better security measures as speech recognition technology continues to improve and expand into new areas.

Future Considerations

It is essential to take these risks seriously. As these systems become capable of performing more complex tasks, the potential for misuse increases. Ongoing research and development must focus on protecting these models from adversarial attacks, ensuring that they function as intended without falling prey to manipulation.

Developing stronger defenses against such attacks will be crucial for the safe deployment of speech-enabled technologies.

Original Source

Title: Controlling Whisper: Universal Acoustic Adversarial Attacks to Control Speech Foundation Models

Abstract: Speech enabled foundation models, either in the form of flexible speech recognition based systems or audio-prompted large language models (LLMs), are becoming increasingly popular. One of the interesting aspects of these models is their ability to perform tasks other than automatic speech recognition (ASR) using an appropriate prompt. For example, the OpenAI Whisper model can perform both speech transcription and speech translation. With the development of audio-prompted LLMs there is the potential for even greater control options. In this work we demonstrate that with this greater flexibility the systems can be susceptible to model-control adversarial attacks. Without any access to the model prompt it is possible to modify the behaviour of the system by appropriately changing the audio input. To illustrate this risk, we demonstrate that it is possible to prepend a short universal adversarial acoustic segment to any input speech signal to override the prompt setting of an ASR foundation model. Specifically, we successfully use a universal adversarial acoustic segment to control Whisper to always perform speech translation, despite being set to perform speech transcription. Overall, this work demonstrates a new form of adversarial attack on multi-tasking speech enabled foundation models that needs to be considered prior to the deployment of this form of model.

Authors: Vyas Raina, Mark Gales

Last Update: 2024-10-11 00:00:00

Language: English

Source URL: https://arxiv.org/abs/2407.04482

Source PDF: https://arxiv.org/pdf/2407.04482

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

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