Helium has a proprietary consensus process known as proof-of-coverage (PoC), which compensates users for helping to mine (validate transactions) and maintain stability.
PoC is based on the HoneyBadger BFT protocol, which was created expressly for node communication in unstable settings.
According to Helium, the most likely attack vector is incoming ports of Hotspots, which affect node operators. To provide users with private key security, the platform's own wallet employs asymmetric keys. So, Helium seems real and safe enough to invest in.