1. Technical Field
The present disclosure relates to devices for transmitting electronic files and, particularly, to a device for encrypting electronic files before transmitting the electronic files.
2. Description of Related Art
During transmission of electronic files on the Internet, the electronic files are generally encrypted using an encryption key. However, the encryption key is usually constant, and consequently, relatively easily cracked.
Therefore, it is desirable to provide a device for encrypting data by using a dynamic secret key to overcome the above-mentioned limitations.
Many aspects of the present disclosure should be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Embodiments of the present disclosure will now be described in detail below, with reference to the accompanying drawings.
Referring to
Referring to
The storage unit 101 stores the electronic files and a function f(x). The function f(x) can be any suitable mathematical function, such as f(x)=2x.
The receiver 20 includes a storage unit 201, a communication module 202, a timer 203, and a decryption module 204. The storage unit 201 stores the same function f(x) of the storage unit 101. The receiver 20 communicates with the transmitter 10 via the communication module 202 and the communication module 102.
When the receiver 20 wants to obtain an electronic file from the transmitter 10, the receiver 20 transmits a request signal to the transmitter 10 via the communication module 202. The request signal includes an Internet protocol address (IP address) of the receiver 20 and information about a desired electronic file, the information can be a file name of the desired electronic file and other suitable information. The transmitter 10 receives the request signal via the communication module 102. The timer 203 of the receiver 20 starts to time when the communication module 202 of the receiver 20 transmits the request signal, and the timer 103 of the transmitter 10 starts to time when the communication module 102 of the transmitter 10 receives the request signal.
The obtaining module 104 of the transmitter 10 obtains the function f(x) and the desired electronic file from the storage unit 101 according to the request signal, when the communication module 102 receives the request signal.
The encryption module 105 obtains a timing length t1 from the timer 103 after the obtaining module 104 obtains the electronic file completely. The timing length t1 is a time duration during the obtaining module 104 starts to obtain the electronic file until the obtaining module 104 obtains the electronic file completely from the storage unit 101. The encryption module 105 substitutes the timing length t1 into the function f(x) to obtain a constant, and the constant is the encryption key. The encryption key is then used to encrypt the electronic file by the encryption module 105.
In the embodiment, after the obtaining module 104 obtains the electronic file completely, the communication module 102 of the transmitter 10 transmits a ready signal to the receiver 20. The decryption module 204 obtains a timing length t2 from the timer 203 when the communication module 201 of the receiver 20 receives the ready signal. The timing length t2 is a time duration during which the communication module 202 starts to transmit the request signal until the communication module 202 receives the ready signal. Because the speed of transmitting the request signal and the ready signal is very quick and the time spent transmitting the request signal and the ready signal is very short, the timing length t1 can be regarded as equal to the timing length t2.
The decryption module 204 obtains the function f(x) from the storage unit 201 and substitutes the timing length t2 into the function f(x), then obtains a decryption key. Because the timing length t2 is equal to the timing length t1, and the function f(x) stored in the storage unit 201 is the same as that stored in the storage unit 101, then the encryption key is the same as the decryption key. The decryption module 204 decrypts the electronic file received by the communication unit 202 using the decryption key and obtains the original electronic file.
In the embodiment, the timing lengths t1 and t2 are determined by the file size of the electronic file to be transmitted to the receiver 20, namely, if the file size of the electronic file is different, the time duration from the obtaining module 104 starts to obtain the electronic file until the electronic file has been obtained completely is also different. Therefore, in the embodiment, for different electronic file, the encryption key and decryption key are different, which increases the safety of transmitting electronic files via the network.
In step S402, the obtaining module 104 obtains a function f(x) from the storage unit and the desired electronic file according to the request signal, and the timer 103 starts to time when the communication module 102 receives the request signal.
In step S403, the encryption module 103 obtains the timing length t1 from the timer 103 when the obtaining module 104 has obtained the electronic file completely.
In step S404, the encryption module 103 substitutes the timing length t1 into the function f(x) to obtain the encryption key.
In step S405, the encryption module 103 encrypts the electronic file using the encryption key.
In step S406, the communication module 102 transmits the encrypted electronic file to the receiver 20 according to the IP address of the receiver 20.
In step S502, the decryption module 204 obtains the timing length t2 from the timer 203 when the communication module 202 receives a ready signal from the transmitter 10.
In step S503, the decryption module 204 obtains the function f(x) and substitutes the timing length t2 into the function f(x) to obtain the decryption key.
In step S504, the decryption module 204 decrypts the electronic file using the decryption key when the communication module 202 receives the electronic file.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being exemplary embodiments of the present disclosure.
Number | Date | Country | Kind |
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201010237989.X | Jul 2010 | CN | national |