A computer-readable medium storing a program causing a computer to execute a process includes, acquiring a plurality of data units that belong to a first block in a certain hierarchy among hierarchical blocks defined by a plurality of hierarchies; generating error correction information corresponding to the first block that equals to an exclusive-OR of the plurality of data units; generating, in each individual hierarchy of one or more individual hierarchies that are continuous from and are lower than the certain hierarchy, error correction information corresponding to each individual block that equals to the exclusive-OR of all data units that belong to the individual block among the plurality of data units, where the individual block is one or more individual blocks other than one specific block in two or more blocks in the individual hierarchy that are included in the same block in a hierarchy.