Clean-Label Attacks

One disadvantage of the approach described in this article is that the manipulations are easy to detect. First, the trigger could be found in the training examples. Second, the training examples with triggers have an incorrect label, the one that the attacker wants the model to provide as a response when the trigger is present. Some more advanced approaches might try to hide the manipulations. In clean-label attacks, only the image data is manipulated. The labels remain unchanged so that the label still matches the image. And the image data can even be manipulated in a way that it is imperceptible to the people reviewing the data set.

To inject a backdoor into a model, you do not necessarily need to manipulate an existing data set or create a new, manipulated, labeled data set. Instead, all you need to do is post manipulated images at certain places on the Internet, where they will presumably be accessed by someone at some point, in order to create a model from them. In this case, the images would be labeled by other people (for example, via crowdsourcing) who would not notice the manipulations.

Conclusions

Machine learning and smart systems are currently making giant inroads into every area of daily life. The potential is enormous, and impressive results are repeatedly achieved. But progress always goes hand in hand with new risks. Although the security properties of machine learning models have now been far more thoroughly investigated than a few years ago, still very little is known about them. The AI community will need to develop more effective protections against data poisoning attacks before we can truly trust our smart systems.