When data is encrypted using Vault, the resulting ciphertext is prepended by the version of the key used to encrypt it. In this case, the version is v2, which means that the encryption key was rotated at least one time. Any data that was encrypted with the original key would have been prepended with vault:v1 To rotate a key, use the command vault write -f transit/keys/<key name>/rotate Reference link:- https://learn.hashicorp.com/vault/encryption-as-a-service/eaas-transit