An apparatus is provided for channel encoding in a communication system using an LDPC code. The apparatus includes at least one processor configured to encode input bits using a Bose-Chaudhuri-Hocquenghem (BCH) code, shorten one or more bits of the encoded input bits according to a number of bit groups to be shortened and an order among a plurality of orders according to which the bit groups are shortened, wherein the number of bit groups to be shortened is based on a number of bits to be shortened which is based on a number of the encoded input bits, encode information bits including the encoded input bits and the shortened one or more bits, using an LDPC code to generate parity bits, and puncture one or more bits in the parity bits based on a puncturing parameter among puncturing parameters; and a transmitter configured to transmit a signal that is generated from the encoded information bits based on the punctured one or more bits. The plurality of orders are based on the puncturing parameters and include a first order and a second order that is different from the first order.