A value holding apparatus for holding value information comprising: an authentication unit operable to authenticate a request apparatus; an encryption unit operable to encrypt communication between the value holding apparatus and the request apparatus; characterized by a receiving unit operable to receive, from the request apparatus, an instruction to add or remove a value relating to a payment, the instruction including an identifier identifying the instruction and time information indicating a time relating to the instruction; an information management unit operable to hold the identifier and time information included in an instruction previously received by the receiving unit, to judge whether or not the identifier included in an instruction currently received from the request apparatus matches the identifier held by the information management unit, to judge whether or not a difference between the time indicated by the time information included in the instruction currently received from the request apparatus and a time indicated by the time information held by the information management unit is within a predetermined range, and to reject the instruction currently received from the request apparatus when the information management unit judges that the identifier included in the instruction currently received from the request apparatus matches the identifier held by the information management unit and the difference between the time indicated by the time information included in the instruction currently received from the request apparatus and the time indicated by the time information held by the information management unit is within the predetermined range, and a balance management unit operable to add or remove a value according to the instruction currently received from the request apparatus when the information management unit judges that the identifier included in the instruction currently received from the request apparatus does not match the identifier held by the information management unit or when the difference between the time indicated by the time information included in the instruction currently received from the request apparatus and the time indicated by the time information held by the information management unit is not within the predetermined range. an authentication unit operable to authenticate a request apparatus; an encryption unit operable to encrypt communication between the value holding apparatus and the request apparatus; characterized by a receiving unit operable to receive, from the request apparatus, an instruction to add or remove a value relating to a payment, the instruction including an identifier identifying the instruction and time information indicating a time relating to the instruction; an information management unit operable to hold the identifier and time information included in an instruction previously received by the receiving unit, to judge whether or not the identifier included in an instruction currently received from the request apparatus matches the identifier held by the information management unit, to judge whether or not a difference between the time indicated by the time information included in the instruction currently received from the request apparatus and a time indicated by the time information held by the information management unit is within a predetermined range, and to reject the instruction currently received from the request apparatus when the information management unit judges that the identifier included in the instruction currently received from the request apparatus matches the identifier held by the information management unit and the difference between the time indicated by the time information included in the instruction currently received from the request apparatus and the time indicated by the time information held by the information management unit is within the predetermined range, and to hold the identifier and time information included in an instruction previously received by the receiving unit, to judge whether or not the identifier included in an instruction currently received from the request apparatus matches the identifier held by the information management unit, to judge whether or not a difference between the time indicated by the time information included in the instruction currently received from the request apparatus and a time indicated by the time information held by the information management unit is within a predetermined range, and to reject the instruction currently received from the request apparatus when the information management unit judges that the identifier included in the instruction currently received from the request apparatus matches the identifier held by the information management unit and the difference between the time indicated by the time information included in the instruction currently received from the request apparatus and the time indicated by the time information held by the information management unit is within the predetermined range, and a balance management unit operable to add or remove a value according to the instruction currently received from the request apparatus when the information management unit judges that the identifier included in the instruction currently received from the request apparatus does not match the identifier held by the information management unit or when the difference between the time indicated by the time information included in the instruction currently received from the request apparatus and the time indicated by the time information held by the information management unit is not within the predetermined range.