Abstract: An IoT water purification system includes a water purification device and a cloud management device. The water purification device includes a filter element, a water tank, a water quantity sensing circuit, a filter element sensing circuit, and a water purification side wireless transmission circuit. The water quantity sensing circuit measures a current storage quantity of the drinking water to generate respective water quantity information. The filter element sensing circuit measures a water quality of the tap water to generate water quality information. The cloud management device includes a cloud wireless transmission circuit and a cloud processing circuit.

Abstract: An IoT water purification system includes a water purification device and a cloud management device. The water purification device includes a filter element, a water tank, a water quantity sensing circuit, a filter element sensing circuit, and a water purification side wireless transmission circuit. The water quantity sensing circuit measures a current storage quantity of the drinking water to generate respective water quantity information. The filter element sensing circuit measures a water quality of the tap water to generate water quality information. The cloud management device includes a cloud wireless transmission circuit and a cloud processing circuit.

Abstract: A digital content application system comprises a first user means, a second user means and a digital content application platform. The first user means comprises a storage unit and an information management unit. The storage unit stores personal secure information and an electronic file. The electronic file comprises an encrypted digital content and an encrypted symmetric key. The information management unit decrypts the encrypted symmetric key by using the personal secure information so as to generate a symmetric key, and decrypts the encrypted digital content by using the symmetric key for generating a digital content. In conjunction with the decryption of the digital content, the information management unit determines the integrity of the digital content based on two hash values. The digital content application platform receives the digital content from the second user means and transmitting the electronic file to the first user means.