Patent ID: 8504826

Claim:
A computer-based data security protection method being performed by execution of computer readable program code by a processor of a host that transmits data to a client, the method comprising: (a1) determining a host key K n using a one-way hash function based on a host initial key K 0 stored in the host, wherein n is an integer having an initial value 1; (a2) generating encrypted data X n using a symmetrical encryption algorithm based on original data R n and the host key K n ; (a3) sending the encrypted data X n to the client, wherein the client stores a client initial key K′ 0 and determines a client key K′ n using the one-way hash function based on the client initial key K′ 0 ; (a4) receiving validation data X′ n sent from the client, and decrypting the validation data X′ n using a symmetrical decryption algorithm and the host key K n to obtain decrypted data R′ n ; (a5) checking if the decrypted data R′ n is the same as the original data Rn, and determining that the client fails in the validation, refusing to transmit any more data, and ending the procedure if the decrypted data R′ n is different from the original data R n , or going to block (a6) if the decrypted data R′ n is the same as the original data R n ; and (a6) setting that the client key K′ n−1 equals the host key K n−1 , and returning to block (a2) if there is original data R n+1 to be transmitted, or ending the procedure if there is no more data to be transmitted.