fractionate
verb
Definitions
To separate (a mixture) into its individual constituents by exploiting differences in some chemical or physical property, such as boiling point, particle size, solubility etc.
Example: Crude oil is fractionated in a refinery to produce a number of different petroleum products.
To divide each plaintext symbol into several ciphertext symbols as a preliminary stage of encryption.
To use the technique of fractionation in hypnosis.