INFORMATION SHARING SYSTEM, INFORMATION SHARING METHOD, AND PROGRAM

PROBLEM TO BE SOLVED: To provide an information sharing system, an information sharing method, and a program that enable rational access to a past article, and thereafter enable improvement of information security.SOLUTION: Article input means inputs an article posted to a first group. Disclosure range determination means determines a second group to which a user belonging to the first group as a post destination of the input article belongs as a disclosure range of the article. Access request input means inputs an access request to the article. Access propriety determination means determines access propriety of a user as a request source of the access request to the article as a target of the input access request based on group information stored in group information storage means, user information stored in user information storage means, and the disclosure range of the article.