Initialize a new
MessageEncryptor. secret must be at least as long as the cipher
key size. For the default ‘aes-256-gcm’ cipher, this is 256 bits. If
you are using a user-entered secret, you can generate a suitable key by
using ActiveSupport::KeyGenerator
or a similar key derivation function.
First additional parameter is used as the signature key for MessageVerifier. This
allows you to specify keys to encrypt and sign
data.