Message authentication codes are hidden bits of code within online communications. In SSL/TLS connections, MAC “tags” offer assurance a message you received came from an authentic person and helps prove the message wasn’t altered in transit
In computer systems, data is binary, meaning that computers use bits (1s and 0s) to communicate it. Data frequently gets processed in either blocks or streams of individual bits (blocks = groups of 1s and 0s, streams = 1s or 0s). But how can you know whether the messages you receive via data streams online were sent by authentic users and haven’t been altered in transit?
You need a way to verify that a message came from an authentic sender (not an imposter) and that the data hasn’t been modified (i.e., it arrived as intended). This is where message authentication codes can come in handy. But what is a message authentication code and what role does it play in internet security?
Let’s hash it out.