Fecha de publicación: 07/12/2016 Fuente: Wipo "IOT" The present invention provides a block encrypting method using a symmetric key, which waits for additional data even when a final block is not filled with data, adds data to the final block, and encrypts the data. The block encrypting method using a symmetric key in an Internet of things (IoT) network comprises the following steps. An IoT device acquires at least one piece of data having a reference size. The IoT device divides the at least one piece of data into block units. When a spare region is greater than the reference size, the IoT device waits for a reference time, wherein the spare region is a region to which data is not allocated in a final block into which the at least one piece of data divided. When the IoT device acquires at least one piece of additional data having the reference size while waiting for the reference time, the additional data is allocated to the final block and the final block is encrypted by using the symmetric key. COPYRIGHT KIPO 2016