Method of reading data from storage device, error correction device and storage system

Methods of reading data from storage devices may include reading data stored in the storage device using normal read voltages; performing a first low density parity check (LDPC) decoding based on the read data; generating reliability bits of each of read bits according to the decoding result, the read bits being bits of the read data; and performing a second low density parity check (LDPC) decoding based on the read data and the reliability bits to perform a first error correction on the read data.