Abstract: The invention aims to provide an electronic information split restoration processing method/system capable of processing massive electronic information at high speed while preventing leakage of the electronic information with reliability, and without causing deterioration in immediacy, centrally controlling electronic information to be processed by information processing units that are distributed geographically in a wide area, and connected via network. When electronic information is to be retained, a reversible split process and a reversible conversion process are applied to the electronic information (step S8), to thereby generate a plurality of split files (step S10), and store the split files together with dummy files (step S12).