Securing encrypted data by obtaining a credential including a plaintext string and a seed, deriving from the credential, a scrambling key and a corresponding unscrambling key, where the corresponding unscrambling key is based on a pseudo-random permutation derived from the credential, obtaining encrypted data, where the encrypted data is encrypted with a primary scheme that is independent of the credential, applying the scrambling key to the encrypted data to produce scrambled encrypted data, where recovering the encrypted data from the scrambled encrypted data requires applying the unscrambling key, and replacing the encrypted data with the scrambled encrypted data, thereby securing the encrypted data with the independent credential.