基于磁盘冗余空间的数据隐藏

Data hiding based on disk slack space

为保护计算机磁盘上的敏感数据,提出基于磁盘冗余空间的数据隐藏方法。该方法在分析磁盘分区策略和簇式文件系统的文件管理机制的基础上,将分散的文件簇冗余空间有机组合以存储敏感数据,并利用存储于分区策略冗余空间的数据结构来维护恢复原始数据所需数据。实验结果表明,基于磁盘冗余空间的数据隐藏方法不占用文件系统有效空间,具有隐蔽性高、系统开销小、隐藏容量与文件系统内部文件总量正相关,以及抗干扰性易受到宿主文件稳定性影响等特点。此外,当文件总量较大时,隐藏容量将十分可观,而通过选取稳定性强的文件作为宿主文件,可提高该方法的抗干扰性。

For protecting sensitive data stored on computer disks, this paper presented a data hiding method based on disk slack space. Based on analyzing disk partitioning scheme and file management mechanism of cluster-based file system, it made dispersed file-cluster slack spaces organic combination to store sensitive data, and maintained data which was used to restore the original data by using data structure which was stored in partitioning-scheme slack spaces. Experimental results show that data hiding method based on disk slack space does not take up the file system effective space, has characteristics of high con- cealment, low system overhead, positive correlation between hiding capacity and overall number of files within file system, and anti-interference performance is susceptible to the stability of host files. Moreover, hiding capacity will be very considerable when overall number of files is large, and anti-interference performance can be improved by selecting host files with good sta- bility.