Privacy protection-type data providing system

A control method for an information providing apparatus connected to a plurality of first user terminals and a plurality of second user terminals, wherein the control method for the information providing apparatus includes applying anonymization processing, wherein the anonymization processing is k-anonymization processing, which is processing for converting data including personal information so that an individual is not identified, wherein the data including the personal information is collected from the plurality of first user terminals, and distributed as anonymized data generated as a result of application of the anonymization processing to a respective one of the second user terminals in response to a request from the respective second user terminal, wherein the control method for the information providing apparatus comprises:

• storing the data including the personal information;
• storing first information specifying, for each piece of data of an individual who is an owner of the personal information, a parameter, of a plurality of parameters, of the anonymized data that is allowed to be provided;
• storing second information specifying the personal information to which the anonymization processing is applied;
• storing third information specifying a level of reliability for each user associated with each respective second user terminal that receives the provided anonymized data;
• storing fourth information specifying a respective parameter, of the plurality of parameters, of the anonymized data which the user having the level of reliability can receive in accordance with the level of reliability;
• extracting a portion of data that is allowed to be provided from among the data including the personal information for each of the plurality of parameters based on the first information;
• identifying the personal information to which the anonymization processing is applied from among the personal information of the extracted portion of data based on the second information;
• executing the anonymization processing on the identified personal information with each of the plurality of parameters, thus generating a plurality of anonymized data portions, wherein the anonymized data portions have varying amounts of information;
• identifying the level of reliability of the respective user of the second user terminal based on the third information in response to the request from the second user terminal;
• and
• identifying one of the anonymized data portions to distribute to the respective second user terminal from among the plurality of anonymized data portions based on the fourth information and the level of reliability identified for the respective user.