An apparatus and a method capable of effectively providing services in a mobile communication system, and a data processing method of a data reception apparatus are provided. The apparatus and method includes obtaining, by a first lower packet data convergence protocol (PDCP) layer and a second lower PDCP layer, a plurality of PDCP packet data units (PDUs) based on data received from a first base station (BS) and a second BS, parallel deciphering, by the first and second lower PDCP layers, the plurality of PDCP PDUs, transmitting, from the first and second lower PDCP layers to an upper PDCP layer, the plurality of deciphered PDCP PDUs, and reordering, by the upper PDCP layer, the plurality of deciphered PDCP PDUs.