Table 21.

Possible attacks on fog node and communication channels (with vs without S × C).

Action	Without S × C	With S × C
Compromising policy	Do not apply, Fog node is not in charge of the security policy -	Compromised policy, but devices’ contracts and codes are unaltered. Attacker can only impede communications through a restricting policy. A more permissive policy cannot cause unexpected information leaks, devices still respect their own contracts ~
DoS attack on Fog node	Do not apply, Fog node is not in charge of the security policy -	Compromised system, but devices’ contracts and codes are unaltered. Devices can potentially negotiate M2M and keep working according to their contracts ~
Man-in-the-Middle (MitM) attack	Attacker can steal and alter data ✗	Attacker can steal and alter data ✗