Yes, that's true. Encrypting the data before hashing with a secret key solves this issue if applicable. > You can't know that because you can't see into the f

Yes, that's true. Encrypting the data before hashing with a secret key solves this issue if applicable. > You can't know that because you can't see into the future. The "best cipher" is the single one you would have used if you had not decided to use a cipher cascade. The idea is to make sure that your cascade is never worse than that single cipher.