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Mobile Phone Patent Abstract
A mobile phone has an encryption module, a decryption module, an
antenna, a microphone, a speaker, a main memory, and a memory connector
for connecting to an expansion memory. When the expansion memory
connects to the memory connector to store a document received from
the mobile phone, the encryption module first generates a crypto-key
and then encrypts the document into a ciphered document by utilizing
the crypto-key. The ciphered document is stored in the expansion
memory, and crypto-key is restricted from being stored in the main
memory.
Mobile Phone Patent Claims
What is claimed is:
1. A mobile phone comprising: a control circuit for controlling
operations of the mobile phone; an encryption module for encrypting
data; a decryption module for decrypting data; an antenna electrically
connected to the control circuit for receiving and generating radio
signals; a microphone electrically connected to the control circuit
for converting input voices into voice signals and transmitting
the voice signals to the control circuit so that the control circuit
controls the antenna to generate corresponding radio signals according
to the voice signals; a speaker electrically connected to the control
circuit for receiving voice signals from the control circuit and
converting the received voice signals into output voices; a main
memory electrically connected to the control circuit for storing
data and a password of the mobile phone; and a memory connector
electrically connected to the control circuit for connecting an
expansion memory; wherein when the expansion memory connects to
the memory connector to store a document received from the mobile
phone, the control circuit compares a password entered by a user
of the mobile phone with the password stored in the main memory,
and after the control circuit determines that the entered password
matches the password stored in the main memory, the encryption module
generates a crypto-key according to an identity of the mobile phone
and encrypts the document into a ciphered document by utilizing
the crypto-key, and then the ciphered document is stored in the
expansion memory and the crypto-key is restricted from being stored
in the expansion memory.
2. The mobile phone of claim 1 wherein the identity is a serial
number of the mobile phone.
3. the mobile phone of claim 1 wherein the identity is an international
mobile station equipment identity (IMEI) of a subscriber identity
module (SIM) card of the mobile phone.
4. The mobile phone of claim 1 further comprising a display device
electrically connected to the control circuit for displaying the
document.
5. The mobile phone of claim 1 wherein the decryption module is
capable of utilizing the crypto-key to decrypt the ciphered document
into the document.
6. The mobile phone of claim 5 wherein before the ciphered document
is decrypted into the document, the control circuit determines whether
the crypto-key is capable of being used to decrypt the ciphered
document.
7. The mobile phone of claim 5 wherein before the decryption module
utilizes the crypto-key to decrypt the ciphered document into the
document, the encryption module generates the crypto-key according
to the identity of the mobile phone.
8. The mobile phone of claim 5 wherein the decryption module utilizes
the crypto-key, which Is read from the main memory, to decrypt the
ciphered document into the document.
Mobile Phone Patent Description
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a mobile phone with an encryption
function, and more particularly to a mobile phone capable of connecting
to an expansion memory to store a ciphered document and restricting
a crypto-key used for decrypting the ciphered document from being
stored in the expansion memory.
2. Description of the Prior Art
Widely available mobile communications is one of the distinctive
hallmarks of modern information-based society. In order to improve
the functions of the mobile phones, expansion slots are designed
for connecting the mobile phones to additional devices. For example,
a user can purchase an MP3 (Moving Pictures Experts Group Layer
III Audio) module to plug in his/her mobile phone to enjoy MP3 quality
music.
Moreover, the expansion memory card, such as a secure digital card
(SD card), multi media card, smart media card, or compact flash
card, etc., is one of the widespreadusages of the expansion modules
for data storage purpose. Users can first use the expansion memory
cards to store files, such as electronic books and MP3 files, and
then uses their mobile phones to read or listen the books or the
music. However, because the prior art mobile phones are improperly
designed to protect the data stored in these expansion memory cards,
the data stored in these memory cards may be stolen when the memory
cards are lost. Moreover, if the users store their secrets, such
as bank accounts and passwords, in the memory cards, they may have
huge economic loss when the data stored in the memory card is stolen.
Among the various memory cards, the secure digital card (SD card)
is a memory card with an encryption and decryption function. The
SD card uses a pair of crypto-keys to encrypt and decrypt data.
However, because the pair of crypto-keys is stored in a hidden area
of the SD card and the operations for encryption and decryption
of the SD card are performed by internal circuits of the SD card,
the data stored in the SD card is not safe from hackers when the
SD card is lost.
SUMMARY OF INVENTION
It is therefore a primary objective of the claimed invention to
provide a mobile phone capable of connecting an expansion memory
to store a ciphered document and restricting a crypto-key for decrypting
the ciphered document from being stored in the expansion memory.
The mobile phone comprises a control circuit for controlling operations
of the mobile phone, an encryption module for encrypting data, a
decryption module for decrypting data, an antenna electrically connected
to the control circuit for receiving and generating radio signals,
a microphone electrically connected to the control circuit for converting
input voices into voice signals and transmitting the voice signals
to the control circuit so that the control circuit controls the
antenna to generate corresponding radio signals according to the
voice signals, a speaker electrically connected to the control circuit
for receiving voice signals from the control circuit and converting
the received voice signals into output voices, a main memory electrically
connected to the control circuit for storing data, and a memory
connector electrically connected to the control circuit for connecting
an expansion memory. When the expansion memory connects to the memory
connector to store a document received from the mobile phone, the
encryption module generates a crypto-key according to an identity
of the mobile phone and encrypts the document into a ciphered document
by utilizing the crypto-key, and then the ciphered document is stored
in the expansion memory and the crypto-key is restricted from being
stored in the expansion memory.
Because the mobile phone restricts the crypto-key from being stored
in the expansion memory, even if the expansion memory is stolen,
the data stored in the expansion memory cannot be successfully decrypted
without the crypto-key. The data stored in the expansion memory,
thus, is under a proper protection.
These and other objectives and advantages of the present invention
will no doubt become obvious to those of ordinary skill in the art
after reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a functional block diagram of a base station, some user
clients, and a mobile phone according to the present invention.
FIG. 2 is a perspective view of the mobile phone and an expansion
memory shown in FIG. 1.
FIG. 3 is a flowchart of the mobile phone in FIG. 2 when storing
data into the expansion memory in FIG. 2.
FIG. 4 is a flowchart of the mobile phone in FIG. 2 while reading
data from the expansion memory in FIG. 2.
DETAILED DESCRIPTION
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a functional block
diagram of a base station 70, some user clients 60, and a mobile
phone 10 according to the present invention. FIG. 2 is a perspective
view of the mobile phone 10 and an expansion memory 50 shown in
FIG. 1. The mobile phone 10, the user clients 60, and the base station
70 are located in a wireless communication system. The mobile phone
10 can wirelessly communicate with the user clients 60 via the base
station 70. In this embodiment, the mobile phone 10 is a GSM (Global
System for Mobile Communications) mobile phone, and comprises a
control circuit 12, an encryption module 14, a decryption module
16, a display device 18, an antenna 20, a microphone 22, a speaker
24, a main memory 26, a SIM card (Subscriber Identity Module Card)
34, a memory connector 38, a housing 40, a switch 42, and a plurality
of buttons 44. Most of the elements of the mobile phone 10 are installed
inside the housing 40. The switch 42 is used to turn on/off the
mobile phone 10, and the buttons 44 are used to generate signals
and commands for the mobile phone 10. The control circuit 12 is
used to control operations of the mobile phone 10, such as data
processes, graphic display, and analog/digital conversion etc. The
display device 18, the antenna 20, the microphone 22, the speaker
24, the main memory 26, and the memory connector 38 are electrically
connected to the control circuit 12. The encryption module 14 is
used to encrypt data, and the decryption module 16 is used to decrypt
data. Both the encryption module 14 and the decryption module 16
can be embodied in circuit forms or software forms. The display
device 18 is a liquid crystal display for displaying information,
and the antenna 20 is controlled by the control circuit 12 for receiving
and generating radio signals. The microphone 22 is used to convert
input voices into voice signals and transmit the voice signals to
the control circuit 12 so that the control circuit 12 controls the
antenna 20 to generate corresponding radio signals according to
the voice signals and transmit the radio signals to the base station
70. The speaker 24 is used to receive voice signals from the control
circuit 12 and convert the received voice signals into output voices.
The main memory 26 is composed of all the elements of the mobile
phone 10 that are capable of storing data. The main memory 26 may
comprise only non-volatile memories or volatile memories, but the
main memory 26 may comprise both the non-volatile memories and the
volatile memories. In the embodiment, the main memory 26 records
a plurality of phone numbers, a serial number 28, and a document
30. The serial number 28 is burned in the main memory 26 according
to a specific coding rule by the manufacturer during the manufacturing
of the mobile phone 10, and the document 30 is received from a server.
The SIM card 34 is used to record an identity of the mobile phone
10, such as the international mobile station equipment identity
(IMEI) 36, so that the base station 70 is capable of distinguishing
different users according to the IMEI 36 stored in the SIM card
34. The memory connector 38 is used to connect an expansion memory
50. The expansion memory 50 may be the multi media card, the smart
media card, or the compact flash card. The expansion memory 50 comprises
a plurality of connecting pins 54 for transmitting and receiving
signals. When the expansion memory 50 is plugged into the memory
connector 38, the control circuit 12 can use the expansion memory
50 to store data so that the total memory capacity of the mobile
phone 10 is increased.
In order to protect the data stored in the expansion memory 50
from being stolen, the mobile phone 10 has an encryption and decryption
function to utilize the encryption module 14 and the decryption
module 16 to encrypt or decrypt data. Please refer to FIG. 3, which
is a flowchart of the mobile phone 10 when storing data into the
expansion memory 50. For example, when the mobile phone 10 stores
the document 30 into the expansion memory 50 (step 80), the control
circuit 12 determines whether to encrypt the document 30 according
to a prior setting of the mobile phone 10 set by the user (step
82). If the document 30 does not need to be encrypted, then the
control circuit 12 directly writes the data of the document 30 into
the expansion memory 50 (step 94). Otherwise, the encryption module
14 first generates a crypto-key 32 according to an identity of the
mobile phone 30, such as the serial number 34 or the IMEI 36 (step
84), and then utilizes the crypto-key 32 to encrypt the document
30 into a ciphered document 52 (step 86). Moreover, after the crypto-key
32 is generated, the control circuit 12 determines whether to store
the crypto-key 32 according to the prior setting of the mobile phone
10 (step 88). If the crypto-key 32 needs to be stored, then the
crypto-key 32 is stored in the main memory 26 (step 90). Otherwise,
the mobile phone 10 continues the next step. The ciphered document
52 then is written into the expansion memory 50 (step 92), and then
the procedure for storing data into the expansion memory 50 is terminated
(step 96).
Without decryption, the information of the ciphered document 52
is not readable. When the user wets to bow the information included
in the ciphered document 52, the ciphered document 52 must be decrypted
into the document 30 by using the crypto-key 32. However, the crypto-key
32 is not stored In the expansion memory 50, so the ciphered document
52 stored in the expansion memory 50 cannot be easily decrypted
or hacked while the expansion memory 50 is lost or stolen. Moreover,
the crypto-key 32 is generated according to an identify of the mobile
phone, such as the serial number 28 or the IMEI 36, so the crypto-key
32 cannot be hacked easily and the safety of the ciphered document
52 can be ensured.
Please refer to FIG. 4, which is a flowchart of the mobile phone
10 while reading data from the expansion memory 50. When the mobile
phone 10 reads the ciphered document 52 or other data from the expansion
memory 50 (step 100 and 102), the control circuit 12 determines
whether to decrypt the received data according to the prior setting
of the mobile phone 10 (step 104). If the received data does not
need to be decrypted, the control circuit 12 can directly use the
received data without decryption, and then the procedure for reading
data from the expansion memory 50 is terminated (step 118). However,
if the received data needs to be decrypted, the control circuit
12 then determines whether a user needs to input a password 46 according
to the prior setting of the mobile phone 10 (step 106). The password
46, thus, needs to be stored in the main memory 26 for comparison
in advance if the user needs to input the password 46 in step 106.
Therefore, any non-authorized user who wants to use the mobile phone
10 to read the ciphered document 52 and does not know the password
46 is restricted from accessing the ciphered document 52. So if
the user needs to input the password 46 and the inputted password
46 is incorrect (step 106 and step 108), the procedure for reading
data from the expansion memory 50 is terminated immediately (step
118). Otherwise, if the user does not need to input the password
46 or if the inputted password 46 is correct, then the control circuit
12 determines whether to read the crypto-key 32 from the main memory
26 according to the setting of the mobile phone 10 (step 110). If
the reading of the crypto-key 32 from the main memory 26 is not
required, the control circuit 12 uses the encryption module 14 to
generate the crypto-key 32 according to the identity of the mobile
phone 10, such as the serial number 28 or the IMEI 36 (step 114).
Otherwise, the control circuit 12 reads the crypto-key 32 from the
main memory 26. Then the control circuit 12 determines whether the
crypto-key is correct and can be used to decrypt the ciphered document
52 according to the identity of the mobile phone 10 (step 112).
If the crypto-key 32 is correct, the control circuit 12 controls
the decryption module 16 to utilize the crypto-key 32 to decrypt
the ciphered document 52 into the document 30. However, if the crypto-key
32 is incorrect, then the procedure for reading data from the expansion
memory 50 is terminated (step 118) and any data received from the
expansion memory 50 is eliminated from the main memory 26. Summarized,
if the inputted password 46 or the identity of the mobile phone
10 is incorrect, the ciphered document 52 cannot be decrypted successfully
into the document 52, and the ciphered document 52, thus, is under
a proper protection from non-authorized users.
In contrast to the prior art, the present invention mobile phone
restricts a crypto-key from being stored in an expansion memory
to protect a ciphered document, so the ciphered document cannot
be easily hacked when the expansion memory is stolen. Moreover,
the crypto-key is generated according to an identity of the mobile
phone, such as an IMEI, so the crypto-key cannot be generated without
the correct identify of the mobile phone and the ciphered document,
thus, cannot be decrypted successfully by any non-authorized user.
Those skilled in the art will readily observe that numerous modifications
and alterations of the device may be made while retaining the teachings
of the invention. Accordingly, the above disclosure should be construed
as limited only by the metes and bounds of the appended claims. |