One chip encryption processor is disclosed, in which a password process unit for processing a data encryption and an interface for managing a password needed for an encryption are integrated into one chip. The encryption processor includes an encryption interface for connecting an externally connected apparatus and an internal data process apparatus, a password process unit for encrypting the inputted data, a memory unit for temporarily storing the data. The above elements are integrated into one chip, so that a desired data security, non-error operation and stable user verification are obtained.