https://www.juniper.net/documentation/en_US/junos/topics/concept/ipsec-encryption-solutions.html
AES-GCM is an authenticated encryption algorithm designed to provide both authentication and privacy.
CBC does not have this "authentication" capability
| CBC | Cipher Block Chaining |
|---|---|
| |
IV ( initialization vector ) is to avoid to start at 1 to n, instead random to another random number
| |
| GCM | Galois/Counter Mode |
| to encrypt the data |
|
| GCM but only auth | GMAC |
| just for authenticate the date |
|
...