Toward the end of 2020, Amazon launched a Live Translation feature for its Alexa virtual assistant — according to a recent report from How-To Geek, the feature is fairly effective in producing translations in languages such as English, French, Hindi, Brazilian Portuguese, Italian, German, and Spanish. Users can speak for up to 25 seconds uninterrupted and Alexa will use a neural machine translation (NMT) engine to produce a translation in the target language.
The feature initially began rolling out in December 2020, however it’s of especial interest now that a group of researchers at the University of Melbourne have found that the translation engines of big companies like Amazon and Google are particularly susceptible to malicious attacks from bad actors.
The researchers found that many of these NMT engines are vulnerable to something known as “back-translation attacks” which occur when attackers manipulate the back-translation process of training an NMT system in order to render undesirable results. “An attacker can design seemingly innocuous monolingual sentences with the purpose of poisoning the final model,” the researchers wrote.
The results of the researchers’ experiment found that NMT models are highly susceptible to such back-translation attacks (which can result in certain innocent phrases being translated from one language into another as a completely different or extremely offensive term) even when such data only represents a very small percentage of the training data used to develop the NMT system (just 1,000 manipulated sentences in a dataset of 5 million could have profound effects on the final product). Because NMT systems are often trained on open-source datasets, this means such systems could be fairly easy to attack.
“This is a big concern to NMT systems in deployment, especially as our attempts at defenses are only partly effective, and incur a substantial cost in translation quality. How to mount a more effective defence is a critical open question,” the researchers conclude.
Amazon launched its own translation engine, Amazon Translate, in 2017, though it has not reached the same level of widespread popularity as other machine translation systems like Google Translate.