It appears that interest in the Internet of things (IoT) has recently reached its peak, with a great deal of focus from both the private and public sectors. IoT, a technology that enables the exchange of data through linkage among all objects surrounding the user, can create new services. Data communication among objects is not limited to personal information, but can also deliver different data types, such as sensing information collected from the surrounding environment. When such data is collected and used maliciously by an attacker, it is more vulnerable to threats than in conventional network environments. Security of all data transmitted in the IoT environment is therefore essential for preventing attacks. However, it is difficult to apply the conventional cipher algorithm to lightweight devices. Therefore, we propose a method for sharing and managing data using the conventional cipher algorithm on lightweight devices in various circumstances. This method implements proxy re-encryption in order to manage data with fewer encryptions, and provides a data sharing function to supplement the insufficient capacity of lightweight device networks.