  As wearable devices become increasingly miniaturized and powerful, a new
opportunity arises for instant and dynamic device-to-device collaboration and
human-to-device interaction. However, this progress presents a unique
challenge: these minimalist wearables lack inherent mechanisms for real-time
authentication, posing significant risks to data privacy and overall security.
To address this, we introduce Proteus that realizes an innovative concept of
time-bound contextual bio-IDs, which are generated from on-device sensor data
and embedded into a common latent space. These bio-IDs act as a time-bound
unique user identifier that can be used to identify the wearer in a certain
context. Proteus enables dynamic and contextual device collaboration as well as
robust human-to-device interaction. Our evaluations demonstrate the
effectiveness of our method, particularly in the context of minimalist
wearables.
