Abstract: A code obfuscation device and a method of obfuscating a code of an application program file are disclosed. The code obfuscation device includes an extraction circuit uncompressing an application program file to extract a Dalvik executable file, a code analysis circuit analyzing a bytecode of the Dalvik executable file, a control circuit determining an obfuscation character and a number and a location of the obfuscation character to be inserted in the bytecode, and an identifier conversion circuit inserting the obfuscation character in the bytecode to convert an identifier of the bytecode. Since the identifier of the bytecode is converted using an obfuscation character, which corresponds to a character that is invisible on a screen or has a different Unicode from another character displayed on the screen as a same shape as the character, the application program file has an increased resistance to a reverse engineering attack.

Abstract: A user terminal includes a communication circuit, an encryption-decryption circuit, and an execution circuit. The communication circuit receives a core code file of an application from a peripheral device, which stores the core code file of the application, when certifying a core code of the application. The encryption-decryption circuit encrypts the core code file and transmits the encrypted core code file to the peripheral device, and, when executing the application, receives the encrypted core code file from the peripheral device and decrypts the encrypted core code file. The execution circuit executes the application using the decrypted core code file and a normal code file of the application stored in the user terminal. Since the normal code file is stored in the user terminal and the core code file is stored in the peripheral device, the core code of the application is protected from reverse engineering attacks.

Abstract: A laundry machine capable of washing and/or drying laundry is provided. The laundry machine includes a first washing tub provided in a cabinet, a housing having a space formed therein, the housing being insertable into and withdrawable from the cabinet, a second washing tub provided in the housing to receive laundry separately from the first washing tub, and a fixing member that fixes the second washing tub to restrict movement of the second washing tub.