The present invention provides a highly-safe information processing system that is capable of effectively using nucleotide sequence information differences between individual organisms to offer semantic information useful for each individual organism while properly preventing leakage and illegal use of nucleotide sequence information.Further, the present invention includes steps a and b. Step a is performed to acquire either encrypted nucleotide sequence-related information or cryptographic key that corresponds to positional information indicating a position within a nucleotide sequence. Step b is performed to acquire the encrypted nucleotide sequence-related information or cryptographic key, whichever is not acquired in said step a, decrypt, with the cryptographic key, the encrypted nucleotide sequence-related information corresponding to the positional information compliant at least with a request for an object and/or a service, and acquire the nucleotide sequence-related information corresponding to the positional information compliant at least with the request for an object and/or a service.