→ CoAP (Constrained Application Protocol): While CoAP is designed for constrained environments and IoT devices, it primarily serves as an application layer protocol for communication, similar to HTTP. It doesn't inherently provide end-to-end encryption and authentication.
→ DTLS (Datagram Transport Layer Security): DTLS operates at the transport layer, securing datagram-based communications. It's suitable for scenarios where transport layer security is needed but doesn't specifically target application-layer security for IoT. It’s essentially TLS adapted for use over UDP.
→ OSCORE (Object Security for Constrained RESTful Environments): OSCORE is explicitly designed to provide end-to-end encryption and authentication at the application layer for constrained IoT devices. It ensures that messages are secured regardless of the underlying transport layer, making it ideal for low-power and resource-constrained environments.
→ TLS (Transport Layer Security): Similar to DTLS, TLS operates at the transport layer and is widely used to secure communications over networks. However, it doesn't specifically cater to the constraints of IoT devices at the application layer.
In a smart home energy management system, various IoT devices like smart thermostats and plugs communicate with a home gateway, which then connects to a cloud server. Using DTLS, each device establishes separate secure channels with the gateway and the gateway with the cloud, allowing the gateway to decrypt and access all data. In contrast, OSCORE encrypts the application data itself at the device level, ensuring end-to-end security so that only the devices and the cloud server can decrypt the information. This means the gateway simply forwards encrypted messages without accessing their contents. OSCORE is more efficient and better suited for constrained IoT environments, providing robust security while reducing computational overhead and preserving data privacy across multiple communication hops.