An encoding method for error correction of digital information data is provided. The encoding method comprises the steps of arranging the digital information data in a plurality of blocks each including a plurality of symbols, and generating first redundacy data from first respective groups of digital information data constituting symbols which exist in at least two blocks in a first direction. Second redundancy data is generated from second respective groups of digital information data constituting symbols which are included in the plurality of blocks in a second direction. First code sequences are formed for first error detection from the first digital information data groups and the first redundancy data, and second code sequences are formed for second error detection from the second digital information data group and the second redundancy code. Blocks including at least one of the digital information data and the first redundancy data are transmitted, and blocks including the second redundancy data are also transmitted.