The disclosure of domestic abuse or help needed is challenging for victims due to factors such as intimidation and fear of being caught. Domestic abuse is especially pernicious as the abuser can be a powerful adversary who may have complete control over all technological means of communication within the premises. We have developed a novel sensor-based method to unobtrusively create a shared secret between the victim and the supportive friend without exchanging data over the network. The generated secret shows entropy similar to some methods used in OpenSSL.