This paper introduces an original and strong authentication method using a two-factor scheme enhanced by network channels and devices diversity. The proposed solution combines an OTP-based approach using an IoT object as secondary device in addition to the mobile phone. Authentication factors are transmitted over different channels (LTE, LPWAN, ... ) via different devices thus greatly reducing the attack surface. To avoid depending on the protocol security specificities used to instantiate a channel, we use a security layer ensuring end-to-end encryption of the transferred sensitive contents. In addition, diversity can be leveraged by exploiting its inherent modularity to infer other approaches. We give an example of another authentication method equivalent for the robustness to the first one but which is more ergonomic and user friendly.