Information security attachment device for voice communication and information security method for voice communication using the same

Disclosed herein are an information security attachment device for voice communication and an information security method for voice communication using the same. The information security attachment device includes a user interface unit, a compression unit, an encryption and decryption unit, and a conversion unit. The user interface unit receives an information security request from a user, and displays whether or not information security is being performed. The compression unit compresses a voice signal. The encryption and decryption unit encrypts the compressed voice data in response to an information security request or an information security control command, requests a terminal to send the encrypted voice data, decrypts the encrypted voice data in response to an information security request or an information security control command, and outputs the decrypted voice data. The conversion unit restores the voice data to an analog voice signal, and outputs the restored analog voice signal.