Mesh messaging app Bridgefy hit the headlines last week after Hong Kong's pro-democracy protestors found in it a crucial ally in their fight against the city state's authorities. The offline chat app, which is based on Bluetooth and allows protesters to communicate with each other without internet connection, has seen downloads go up almost 4000% in the last two months, according to measurement firm Apptopia.
Mesh or off-the-grid messaging apps work on the principle of device-to-device communication, using short-range Bluetooth connections to form their own network, thus bypassing wifi networks, cell networks, or any other type of infrastructure that authorities may control or keep a tab on. Of course, keeping off the government radar wasn't the original aim- these apps were made for use where connectivity is poor or unavailable, as in remote locations or in the aftermath of a natural disaster. The best part -since Bluetooth's phone to phone range is around 100m-is that it uses a mesh network, which links together users' devices allowing the message to hop from one phone to another till it reaches the intended person who could be at the other end of the city. FireChat, another popular messaging app used in previous pro-democracy protests in Hong Kong and also in Taiwan, Iran and Iraq, works on the same principle.
A similar principle is deployed by tracking tags like Tile (read our adjoining story).
The Bridgefy app, which uses end-to-end RSA encryption on private direct and mesh messaging, is designed by a San Francisco-based startup co-founded by Jorge Rios and has been used at music events or stadiums where a huge number of fans would be typically interacting with each other. Twitter founder Biz Stone is one of the investors in the startup. More than 60 developers are using it on their own apps, as it can be easily integrated into Android and iOS apps.
The Hong Kong demonstrators have repeatedly shown their tech savvy skills-using laser pointers to deflect facial scans by CCTVs, defusing cartridges of tear gas with water bottles, using online forums like LIHKG (similar to Reddit) and group chats on Telegram to organise people-all to keep a step ahead of mainland China.