March 22, 2016 by Naim Hilal
Let's start with Jamming/Infrastructure Independency. The device uses a mesh network topology where every message sent from each device is packetized and routed by any available route. This protects against a centralized take down or disabled cell infrastructure, and is somewhat resilient to jamming, as it can route around trouble areas, but it is not totally invulnerable.
To make the device almost invulnerable to jamming, we turn to the backup RFID sneaker-net system. In heavy jamming situations, users would touch devices together with all their closest neighbors, thereby passing on messages like nodes in a network. For instance, in a large crowed, we estimate that roughly 10 hops will get the message across the crowd, so as long as people tap devices ~10 times a minute, communication latency would be fairly low. To prevent messages propagating for ever, TTL hop limiting would be used. The power requirement of jamming near range, shielded (by the interlocking bodies of the device) RFID communications would be so large, they are well outside the range of conventional or military hardware.
Passing messages via RFID is a little clumsy and slow, but in the event of Jamming, it is the only way to ensure message delivery. Also, in more social uses, passing messages only via direct contact has an element of interactivity.