# Tag Info

If by "encrypted" you mean generating a keystream, then what you propose is to use in the CTR mode $$C_i = P_i \oplus F_K(IV||i)$$ the following function $F$: $$F_{K_1||K_2||K_3} = E_{K_1}\oplus E_{K_2} \oplus E_{K_3}.$$ This is secure as long as you ensure that for each key all the used IVs are different (i.e. are nonces). As mentioned in another ...