Time synchronization is a key service in WSNs for a diversity of purposes; including data fusion, power management, positioning, message integrity, coordination of future actions, and timestamping of sensed events.
To ensure message integrity, the advantages of hash based message authentication code are exploited.
For example, Hanna et al. [21] discovered that two of the most popular users of Web Messaging, Facebook Connect and Google Friend Connect, perform these checks only sporadically; the authors were able to compromise message integrity and confidentiality of both protocols.
Interesting topics for future research include the use of message integrity codes to provide trusted forwarding and the extraction of approximate location information from a node's history of contacts, assuming static nodes are present and georeferenced.
It includes authentication of the parties, authorization to access the given resources, confidentiality of the communication, and the assurance of message integrity.
Afterwards, each sensor node will verify the message integrity using ECDSA with public key of the gateways and compares the received public key with its pre-loaded one.
If Fog nodes are capable of performing user authentication and message integrity checks, it will eliminate message suppression, fabrication, replay and alteration attacks [ 138 ].
The integrity and authenticity of SPS-SE messages are guaranteed using message integrity codes (MICs) and a shared key.
Both symmetric and asymmetric key digital signatures based on CRCs form parts of the cost/performance tradeoff space to improve critical message integrity.
Such message integrity is guaranteed, for example, by the offset code-book (OCB) mode [15] of block cipher encryption.
