Social interaction plays a pivotal role in human cognition and well-being. Hyperscanning studies of social interaction using functional near-infrared spectroscopy (fNIRS) have associated increases in interbrain synchrony with positive outcome measures of cooperation, learning, and mutual understanding. Neurofeedback, a well-established method for modulating and training brain activity, has shown promise in improving cognitive functions. Consequently, it would be advantageous to determine the feasibility of creating a neurofeedback system for enhancing interbrain synchrony to potentially benefit human interaction. However, the feasibility of hyperfeedback, i.e. training interbrain synchrony of two interacting individuals, remains uncertain. This study presents a crucial step towards hyperfeedback by demonstrating the methodological feasibility of short-time assessment of interbrain synchrony using fNIRS. To meet this end, we re-analyzed two interbrain synchrony experiments and performed simulations. Our results indicate that using the current wavelet transform coherence method to determine interbrain synchrony, integration windows of about one minute are feasible. This is compatible with an intermittent neurofeedback setup where people receive feedback on their brain synchrony after each task unit. The feasibility of short-time interbrain synchrony assessments is a crucial first step in the development of a hyperfeedback system designed to train and enhance interbrain synchrony. The potential implications of such hyperfeedback interventions are vast, offering a neuroscientific approach to sharing cognition and improving human interaction in both health and disease.