Disclosure Control of Natural Language Information to Enable Secure and Enjoyable Communication over the Internet

Disclosure control of natural language information (DCNL), which we are trying to realize, is described. DCNL will be used for securing human communications over the internet, such as through blogs and social network services. Before sentences in the communications are disclosed, they are checked by DCNL and any phrases that could reveal sensitive information are transformed or omitted so that they are no longer revealing. DCNL checks not only phrases that directly represent sensitive information but also those that indirectly suggest it. Combinations of phrases are also checked. DCNL automatically learns the knowledge of sensitive phrases and the suggestive relations between phrases by using co-occurrence analysis and Web retrieval. The users' burden is therefore minimized, i.e., they do not need to define many disclosure control rules. DCNL complements the traditional access control in the fields where reliability needs to be balanced with enjoyment and objects classes for the access control cannot be predefined.