Magnetic Media Data Destruction Technology

Data destruction is defined as to erase all the data on the storage media. Currently magnetic storage media is the main carrier of electronic data. Unfortunately, due to the characteristics of the operating system and the limitations of magnetic media itself and the way it records data, the method which is provided by operation system for us can not completely erase the data. Even by low-level disk formatting, the data will be recovered with magnetic force microscopy. Most countries provide their own standards for the method of information removal and destruction. In the United States, the represent guideline is DOD5220.22-M, which is put in the 90s of the last century. But with a variety of hardware and software technologies updated, it is uncertain that whether the U.S. DOD itself use this standard now. There haven't a uniform standard in domestic. Thus, presenting a new software method of data destruction will be significance.This thesis studies main kinds of data destruction techniques. All the methods of data destruction are analyzed, the advantages and disadvantages of them are summaried. After, a new method of soft degaussing override method is proposed. Also, the advantages of the new method are demonstrated, theoretically it is more security than others. In addition, a secure data destruction of magnetic media software architecture based on network is designed in this thesis.There are primarily three advantages in the thesis: First, a new override method of soft data destruction is designed. The new method is safer, erase deeper, more efficient than current popular method. Second, in this thesis, the destruction system has "multi-level, can be defined" characteristics. Different security levels are provided in the system using different destruction technologies, such as SDM method, overwrite all "0" patterns, all "1" patterns technology, DOD5220.22-M standard technology, RCMP TSSIT OPS-II overwrite technology and Gutmann destruction technology. According to sensitivity levels of data destruction, different levels can be chosen. Third, the system is high safety. First of all, usbkey technology is applied to the destruction system to identity authentication and authorization management; Next, the main control computer controls the slave computers in network using unidirectional authentication; Finally, Linux executable files PE technology is introduced to protect code to achieve code security.This thesis describes the architecture of software system, including single mode with one compute and mode with network for destruction. Besides, system reliability design and security design, the system's working process are anlyzed. It focuses on analyzing the log module, the destruction algorithm module, Logical Disk and file destruction module design and implementation. Linux executable code packed technology and the erasure efficiency are described at last.