With the coming of the digital era, encryption has become common in everyday life. Almost anyone can easily acquire encryption software and use it to prevent unwanted third parties from accessing one’s private information. However, the spread of encryption has also seriously hindered law enforcement during the investigation of cybercrimes, which hides incriminating digital evidence in encrypted hard drives and files. Therefore, many countries have attempted to compel criminals to decrypt encrypted evidence and it has been inevitable to examine privilege against self-incrimination as basic right on the side of constitution. This study analyzed the past court decisions on the issue of compelled decryption in the US and whether the Government can compel a defendant to disclose his password in Korean legal system on the constitutional side. Finally, this study suggests an approach to create a legal procedure to make it a crime for a suspect or defendant to refuse to disclose his password to law enforcement for criminal cases in Korea.