The mechanism helps mitigate the malicious intermediary, insufficient authorization, and overlapping trust boundaries security threats. A. Encryption B. Hashing C. Digital Signature D. Public Key Infrastructure (PKI)

A. Encryption        

Explanation:

The encryption mechanism helps mitigate the malicious intermediary, insufficient authorization, and overlapping trust boundaries security threats, it also helps secure remote message exchanges between  consumers by protecting the privacy of message data thus making it inaccessible by hackers.