The present innovation extends the innovations inherent in our prior work on security and privacy enhanced geolocation to address specific problems of determining the proximity of two Internet connected devices. This could be used for applications such as determining proximity of a user's smartphone to an ATM machine they are using. Or to determine the physical proximity of a shopper and a cashier at a check out line. A straightforward application of the prior work will not suffice, as devices may have very different types of connectivity to the Internet. We solve this problem by placing reciprocal slave servers on each of the devices and giving high weight to the time taken for messages to travel from each device to the slave on the other device. The system can be extended to more than two entities by performing the calculation in a pairwise fashion and using further optimizations.