Abstract: Encryption file system such as eCryptfs and dm-crypt can avoid information leakage by storage lost.But they do not distinguish processes accessing the file,so they can not prevent information leakage by the trojan program.This paper introduced a method which puts the cryptograph in the kernel page cache,and only the specific application can access the plain text.This method eliminates the way by which the trojan program accesses the plain text,improves the security of information system.

Key words: Kernel,Encryption file system,Transparent encrypt,Trojan horse,Security