Electronic-money management device, electronic-money management method, electronic-money management program, and computer-readable recording medium containing said program

An electronic money management device in an electronic money system that stores a balance of electronic money owned by a user in both of a storage device not under control of the user and a storage medium held by the user, comprising:

• a post-update synchronization unit configured to, each time the balance in the storage device is updated based on instruction information for changing the balance in the storage device, reflect a change of the balance in the storage device on the balance in the storage medium through a terminal accessible to the storage medium held by the user having the updated balance;
• and
• a pre-update synchronization unit configured to, before the balance in the storage device is updated based on the instruction information, acquire the balance in the storage medium from the terminal, and reflect a change of the balance in the storage medium on the balance in the storage device using the acquired balance in the storage medium, wherein
• the storage device stores balance information containing a group ID identifying a group sharing one electronic money, a user ID identifying each of users included in the group, and information indicating a consumed amount out of a freely available amount of the electronic money set for each user, and
• when the pre-update synchronization unit determines that the consumed amount is equal to or less than a specified threshold by referring to the balance information corresponding to the user of the terminal, the pre-update synchronization unit skips processing of reflecting a change of the balance in the storage medium on the balance in the storage device.

An electronic money management method performed by an electronic money management device in an electronic money system that stores a balance of electronic money owned by a user in both of a storage device not under control of the user and a storage medium held by the user, comprising:

• a post-update synchronization step of, each time the balance in the storage device is updated based on instruction information for changing the balance in the storage device, reflecting a change of the balance in the storage device on the balance in the storage medium through a terminal accessible to the storage medium held by the user having the updated balance;
• and
• a pre-update synchronization step of, before the balance in the storage device is updated based on the instruction information, acquiring the balance in the storage medium from the terminal, and reflecting a change of the balance in the storage medium on the balance in the storage device using the acquired balance in the storage medium, wherein
• in the pre-update synchronization step, processing of reflecting a change of the balance in the storage medium on the balance in the storage device is skipped when a specified condition is met.