A system of accessing a copy-prevented encrypted data file transmitted over a network, the system characterized by comprising: a server apparatus being adapted to store data files, wherein a data file in the server apparatus is stored as a twice encrypted file, a key for decrypting the data file is embedded in a read apparatus, another key for decrypting the data file is stored in the sever apparatus; and a client apparatus comprising the read apparatus and a temporary storage, wherein the client apparatus being adapted to send a download request to the network server for caching the data file into the temporary storage of the client apparatus, to receive the requested data file from the the server apparatus, and to cache the data file into the temporary storage, and wherein the data file cached in the temporary storage is obtainable from the read apparatus for human recognition of the content of the data file; the server apparatus or client apparatus being adapted to decrypt the data file using the key stored in the server apparatus, wherein the client apparatus is allowed to cache the data file from the server apparatus only in the temporary storage, and the client apparatus being adapted to cache the decrypted data file in the temporary storage, and the read apparatus being adapted to decrypt the data file decrypted and cached in the temporary storage using the key embedded in the read apparatus, and is not equipped with functions of save as and/or print. a server apparatus being adapted to store data files, wherein a data file in the server apparatus is stored as a twice encrypted file, a key for decrypting the data file is embedded in a read apparatus, another key for decrypting the data file is stored in the sever apparatus; and a client apparatus comprising the read apparatus and a temporary storage, wherein the client apparatus being adapted to send a download request to the network server for caching the data file into the temporary storage of the client apparatus, to receive the requested data file from the the server apparatus, and to cache the data file into the temporary storage, and wherein the data file cached in the temporary storage is obtainable from the read apparatus for human recognition of the content of the data file; the server apparatus or client apparatus being adapted to decrypt the data file using the key stored in the server apparatus, wherein the client apparatus is allowed to cache the data file from the server apparatus only in the temporary storage, and the client apparatus being adapted to cache the decrypted data file in the temporary storage, and the read apparatus being adapted to decrypt the data file decrypted and cached in the temporary storage using the key embedded in the read apparatus, and is not equipped with functions of save as and/or print. wherein the data file cached in the temporary storage is obtainable from the read apparatus for human recognition of the content of the data file; the server apparatus or client apparatus being adapted to decrypt the data file using the key stored in the server apparatus, wherein the client apparatus is allowed to cache the data file from the server apparatus only in the temporary storage, and the client apparatus being adapted to cache the decrypted data file in the temporary storage, and the read apparatus being adapted to decrypt the data file decrypted and cached in the temporary storage using the key embedded in the read apparatus, and is not equipped with functions of save as and/or print.