심층암호 증거물 압수수색의 법적 한계와 개선방안

Steganography enables covert communication by hiding a message that exists itself. This property is being strengthened as more ingenious and complex techniques and methods are developed and utilized. Enemy countries, terrorists, and international criminal organizations use self-made steganography tolls and apply multiple encryptions in combination with other technologies include steganography. Sometimes, they use those methods with physical operations. Considering various file formats, storage and media, complex and covert hiding methods, and self-crafted algorithms, it is difficult to detect deep steganographic evidence through general digital forensics methods. We already know some real cases of security threats using steganographic communications through media and precedents. It is true, however, that legal analysis or discussion of the nature or procedural issues of these steganographic evidence has been neglected in our society. Considering the above problems, the following improvements are needed to search and seizure steganography evidence. First, if the application of steganography is suspected at the site, the original storage or media should be seized and, if necessary, the applied steganography should be fully analyzed through the extension of the period to reveal the truth. Because data hiding techniques can only be found by examining the entire storage media. If the original storage or media is seized, the data required by the subjects must be copied and returned with the same storage or media. Second, evidence examination in court should be carried out through the original storage or media in consideration of the possibilities that the steganography tools are operated only in the original storage or media. Third, internal guidelines are required to clarify such procedures and limit authority. Finally, the expertise of judges and the judiciary is required to recognize the presence of such a reason and to accept flexible situations of the site. This could be realized with the idea of improving the warrant and its attachments of a judge, establishing a digital evidence analysis center in each court, and dispatching experts from the court. Thus, it will be possible to give the investigative agency legitimate authority for efficient and balanced investigations, while protecting the rights of subjects.