So What Modes Can You Have For Symmetric Key?

GCM, CBC, CFB8, CFB, OFB, GCM, CTR, and XTS

Symmetric key encryption is the workhorse of cybersecurity. Its main task is to preserve the privacy of data, but sometimes it can also be used to authenticate the message (using a Message Authentication Code — MAC). Generally, it is much faster than asymmetric key (aka public key encryption) and can be run on fairly simple devices. Basically, it uses the same key to encrypt and decrypt:

But, we can add an initialization vector (IV)/salt value to the encryption process, and also either have a stream cipher or a block one. Along with this, we can add some additional data to give AEAD (Authenticated Encryption with Additional Data):

Basically, we have basic classifications for the modes of operation:

• Mode With Initialization Vector (IV): ChaCha20, CBC, CFB8, CFB, and OFB.
• Mode With Initialization Vector (IV) and Tag: GCM.