The invention discloses an encrypted reading and writing method at the kernel state
file system layer. The method is located between the
virtual file system and the physical
file system. During the reading operation, the read
ciphertext data is first decrypted and then transmitted to the upper layer
virtual file system; when writing, first determine the type of write operation, if it is a write operation, first encrypt the
plaintext data to be written, and then pass the intercepted
ciphertext data to the underlying physical
file system, if it is a modification operation , the
ciphertext data read into the memory will be partially decrypted, overwritten, globally encrypted, and partially intercepted. This method not only has the inherent high efficiency of kernel state operations, but also uses partial decryption and partial interception to improve the efficiency of
data operations. From the test process and
test data, it can be known that using the encrypted reading and writing method of the present invention can simultaneously overcome the inconvenience of the
application layer encryption program and the low efficiency of the
user state encrypted file system.