What is your opinion on this scheme:
1)get IV from CSPRNG
2)set 3 encryption keys k1,k2,k3 (3*key_lenght) (KDF/PBKDF)
3)Use 3 ciphers in CTR mode like this: The initial IV is encrypted using cipher1 with key k1 , then the iv is incremented and encrypted by using cipher 2 that uses the second key and so on, the output of the respective ciphers is xored with the plaintext to obtain the ciphertext.
Is this secure?