Patent ID: 8533493

Claim:
A method for securing transmission data from an upload device to a download device through a server, said method to be implemented by the upload device, and comprising the following steps of: A) configuring the upload device to generate a first matrix serving as an encryption key and a second matrix serving as a decryption key, and to generate a re-encryption vector based upon the relationship between the first and second matrices; B) configuring the upload device to encrypt a plaintext data file using the first matrix so as to obtain an ciphertext data file, and to transmit the ciphertext data file and the re-encryption vector to the server, so as to allow the server to re-encrypt the ciphertext data file using the re-encryption vector to obtain a re-encrypted data file, which can be decrypted using the second matrix to obtain a decrypted data file corresponding to the plaintext data file; and C) configuring the upload device to transmit the second matrix to the download device, so as to allow the download device to decrypt the re-encrypted data file using the second matrix upon downloading the re-encrypted data file from the server; wherein each of the first and second matrices is a Latin square matrix including a plurality of rows and a plurality of columns, being composed of a particular set of elements; wherein each of the elements in the particular set occurs once in each of the rows and occurs once in each of the columns, and wherein the following condition is satisfied: that all possible combinations of two elements in the particular set can be found as adjacent two elements in the rows.