The apparatus and method for scrambling high-rate data is disclosed. The apparatus includes a first storing unit for storing a transport stream (TS) inputted from an external device; a common key (CK) generating unit for generating a CK by receiving a control word (CW) from an external conditional access system (CAS); a key scheduling unit for generating predetermined number of keys (KK)s by receiving the CK from the CK generating unit; a plurality of enciphering units for enciphering the TS transmitted from the first storing unit based on the predetermined number of KKs and the CK; a second storing unit for storing the TS enciphered by the enciphering units and outputting the enciphered TS; and a controlling unit for controlling the multiple enciphering units.