Non-transitory computer-readable storage medium and communication device

A communication device that manages user information of a user, the communication device comprising:

• a memory;
• and
• a processor coupled to memory and configured to:
• convert user information acquired from the user into a management format and obtain converted user information,
• calculate a first hash value obtained by hashing the converted user information with a first hash function,
• transmit a confirmation request that includes the first hash value, the first hash function, and conversion content of the conversion to the user, and
• request the user to confirm validity of the user information managed.

A non-transitory computer-readable storage medium storing a program that causes a processor included in a user terminal to execute a process, the process comprising:

• registration processing that converts user information of the user into a management format and transmits converted user information to a business operator's terminal that manages the user information;
• reception processing that receives a confirmation request including a first hash value obtained by hashing the converted user information calculated by the business operator's terminal with a first hash function, the first hash function, and conversion content of the conversion from the business operator's terminal;
• and
• confirmation processing that responds to receipt of the confirmation request, converts the transmitted user information according to the conversion content, calculates a second hash value obtained by hashing the converted user information with the first hash function, compares the first hash value with the second hash value, and confirms validity of the user information managed by the business operator's terminal.