Biometric authentication like fingerprint and iris scans are now widely used but the larger concern is that they may be spied upon. With this fear in mind, a group of researchers now claim to have developed a new potential odorous option for the biometric security toolkit: your breath.
In a report published in Chemical Communications, researchers from Kyushu University’s Institute for Materials Chemistry and Engineering, in collaboration with the University of Tokyo, said that they developed an olfactory sensor capable of identifying individuals by analyzing the compounds in their breath. They said that the ‘artificial nose, built with a 16-channel sensor array, combined with machine learning, was able to authenticate up to 20 individuals with an average accuracy of more than 97 per cent.
First author of the study Chaiyanut Jirayupat said that human scent has recently emerged as a new class of biometric authentication, essentially using one’s unique chemical composition to confirm the identity of the person.
The author further explained that one such target was percutaneous gas—compounds produced from the skin. However, these methods have their limits because the skin does not produce a high enough concentration of volatile compounds for machines to detect. So, the team turned to see if human breath could be used instead. “The concentration of volatile compounds from the skin can be as low as several parts-per-billion or trillion, while compounds exhaled from the breath can go as high as parts-per-million,” said Jirayupat.
“In fact, human breath has already been used to identify if a person has cancer, diabetes, and even COVID-19.”
ANALYSIS AND METHOD
The team began by analyzing the breath of subjects to see which compounds could be used for biometric authentication. A total of 28 compounds were found to be viable options. Based on this, they developed an olfactory sensor array with 16 channels, each which could identify a specific range of compounds. The sensor data was then passed into a machine learning system to analyze the composition of each person’s breath and develop a profile to be used to distinguish an individual. Testing the system with breath samples from six people, the researchers found it could identify individuals with an average accuracy of 97.8%. This high level of accuracy remained consistent even when the sample size was increased to 20 people. “This was a diverse group of individuals of differing age, sex, and nationality. It’s encouraging to see such a high accuracy across the board,” explains Takeshi Yanagida who led the study. Nonetheless, he admits that more work is needed before it arrives on your next smartphone.