In cybersecurity, there are so many acronyms, and to be an expert, you really need to dig underneath the methods and understand how they work. One weak area of the industry is in the usage of MACs (Message Authentication Codes). With the public-key signing, we use a public key and a private key, where the private key will digitally sign a hash of the message, and where the public key is verified the signature. With a MAC, we use a shared symmetric key, and where Bob and Alice will share the same secret key (Figure 1).   https://medium.com/@billatnapier/cmac-or-hmac-which-is-better-8e1861f744d0