Envelope Encryption
While we encrypt the data to secure it, we also need to ensure that our data encryption key is also secure. How to secure the data encryption key then? Just encrypt it and that's what Envelope encryption is. It involves first encrypting plaintext data with a data encryption key, and then encrypting the data encryption key using another encryption key. And we can even encrypt the second encryption key under a third encryption key, and so on... Still, eventually, one encryption key must remain in plaintext so that we can decrypt the other encryption keys and finally retrieve our data. The top-level encryption key, which is in plaintext, is known as the root key . - Reminds of Matryoshka dolls