Patent Document

[0001]    This application claims priority to Taiwan Patent Application No. 095140023 filed on Oct. 30, 2006, the disclosures of which are incorporated herein by reference in its entirety. 
       CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    The present invention relates to a system, an apparatus and a method of encryption and decryption. More particularly, the present invention relates to a system, an apparatus, and a method for generating a key by using a biological feature to encrypt and decrypt an input password. 
         [0005]    2. Descriptions of the Related Art 
         [0006]    With a rapid development of information technologies and computer industries, there are more and more digital stored data and meanwhile, sizes of storage mediums become smaller and smaller. Consequently, many users store data in portable storage mediums, such as a flash disk, for the convenience. To secure data, a storage medium is usually divided into a public area and a security area. A user may store the data to be secured in the security area. When the user intends to access the data stored in the security area, an identity authentication is required. After the identity has been authenticated, the information in the security area can be accessed. 
         [0007]    A conventional identity authentication method is to use a password, that is, the user sets a password in a memory in advance, afterward, a processor of a computer compares whether an inputted password from the user is equal to the password. However, when the processor retrieves the password for comparison, the password is easily to be obtained by other people via internet or other collateral access ways. Consequently, how to provide a securer platform to protect the password and the inputted password is very important. 
         [0008]    One of the solutions is to adopt techniques of the cryptography. The password of the user is encrypted and then stored in the memory by an authentication system. By adopting this method, if the password is stolen, only some meaningless random code but not the password will be obtained.  FIG. 1  depicts an authentication system  1 , which comprises an encryption apparatus  11  and a decryption apparatus  12 . The encryption apparatus  11  utilizes an encryption key  131  to encrypt an original data  101 , i.e. the password, by an encryption algorithm to get an encrypted data  102 . The decryption apparatus  12  utilizes a decryption key  132  to decrypt the encrypted data  102  by a decryption algorithm to get a decrypted data  103 . The decrypted data  103  that has been correctly decrypted is the original data  101 . 
         [0009]    According to the contents of the encryption key and the decryption key, the authentication systems can be classified into symmetric (or called as a secret key) authentication systems and asymmetric (or called as a public key) authentication systems. The encryption key and the decryption key of a symmetric authentication system are the same, which has the advantage of high efficiency. However, its difficulty is how to transmit the secret key to a receiver in a secure manner. On the other hand, the encryption key and the decryption key of the asymmetric password system are different so that the problem of transmitting the key can be avoided. However, the algorithm of the asymmetric authentication system is more complicated and results in longer processing time. Thus, most authentication systems do not adopt the asymmetric one. 
         [0010]    Consequently, how to utilize the symmetric password system to protect the stored data in the storage apparatus and to avoid the risk of obtaining the key by others during transmitting is still a topic worth to study. 
       SUMMARY OF THE INVENTION 
       [0011]    An object of this invention is to provide an electronic apparatus for decryption. The electronic apparatus comprises a detection unit, a generation unit, and a decryption unit. The detection unit is configured to randomly detect a biological feature. The generation unit is configured to generate a key and a duplicate key according to the biological feature. The decryption unit is configured to decrypt an encrypted text by a decryption algorithm and the key to derive an input password. The encrypted text is encrypted by an encryption algorithm corresponding to the decryption algorithm and the duplicate key of the key. The input password is used to determine whether the electronic apparatus can be operated. 
         [0012]    Another object of this invention is to provide an electronic apparatus for encrypting an input password. The electronic apparatus comprises a receiving unit, a decryption unit, an encryption unit, and a transmission unit. The receiving unit is configured to receive an encrypted duplicate key. The decryption unit is configured to decrypt the encrypted duplicate key to derive a duplicate key. The encryption unit is configured to encrypt the input password by an encryption algorithm and the duplicate key to derive an encrypted text. The transmission unit is configured to transmit the encrypted text. The duplicate key is essentially equivalent to a key, the key is derived according to a biological feature. The input password is used to determine whether an electronic device can be operated. 
         [0013]    Yet another object of this invention is to provide an electronic system setting a password. The electronic system comprises an electronic apparatus and a password processing apparatus. The electronic apparatus comprises a detection unit, a generation unit, a second original key, and a decryption unit. The detection unit is configured to randomly detect a biological feature. The generation unit is configured to generate a key and a duplicate key according to the biological feature. The second original key is used for encrypting the duplicate key to drive an encrypted duplicate key. The decryption unit is configured to decrypt an encrypted text by a decryption algorithm and the key to derive an input password. The password processing apparatus is configured to encrypt the input password, comprising a first receiving unit, a first decryption unit, a first encryption unit, and a first transmission unit. The first receiving unit is configured to receive the encrypted duplicate key. The first decryption unit is configured to decrypt the encrypted duplicate key. The first encryption unit is configured to encrypt the input password by the duplicate key and an encryption algorithm corresponding to the decryption algorithm to derive the encrypted text. The first transmission unit is configured to transmit the encrypted text to the electronic apparatus. The input password is used to determine whether the electronic apparatus can be operated. 
         [0014]    A further object of this invention is to provide a method for decryption, which is adapted to an electronic apparatus that has been set a password. The method comprises the steps of: detecting a biological feature randomly; generating a key and a duplicate key according to the biological feature; and decrypting an encrypted text by a decryption algorithm and the key to derive an input password. The encrypted text is encrypted by an encryption algorithm corresponding to the decryption algorithm and the duplicate key of the key and the input password is used to determine whether the electronic apparatus can be operated. 
         [0015]    Yet a further object of this invention is to provide a method for encrypting an input password. The method comprises the following steps of: receiving an encrypted duplicate key; decrypting the encrypted duplicate key to derive a duplicate key; encrypting the input password by an encryption algorithm and the duplicate key to derive an encrypted text; and transmitting the encrypted text. The duplicate key is essentially equivalent to a key, the key is derived according to a biological feature. The input password is used to determine whether an electronic device can be operated. 
         [0016]    This invention utilizes a biological feature to generate a key to provide the key dynamically. In other words, when the inputted biological feature is different, different keys are generated. Meanwhile, this invention utilizes the key to encrypt an input password. Consequently, security threats caused by transmitting the key and the input password can be avoided by this invention. 
         [0017]    The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in the art to well appreciate the features of the claimed invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  illustrates a schematic authentication system; 
           [0019]      FIG. 2  illustrates a first embodiment of this invention; 
           [0020]      FIG. 3  illustrates a second embodiment of this invention; and 
           [0021]      FIG. 4  illustrates a third embodiment of this invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]      FIG. 2  illustrates a first embodiment of this invention, which is an electronic system  2  having been set with a password. The electronic system  2  comprises an electronic apparatus and a password processing apparatus. The electronic apparatus of this embodiment is a USB disk  21 , the password processing apparatus is a personal computer  22  which encrypts and decrypts by a Twofish encryption and decryption algorithm at the same time. The USB disk  21  comprises a detection unit  211 , a generation unit  212 , a decryption unit  213 , a second encryption unit  214 , a comparison unit  215 , a second transmission unit  216 , a second receiving unit  217 , and a memory  218 . The personal computer  22  comprises a first receiving unit  221 , a first encryption unit  222 , a first transmission unit  223 , and a first decryption unit  224 . 
         [0023]    When the USB disk  21  is just manufactured, it has not been set with a password, but it has an original key and a second original key. Meanwhile, the personal computer  22  comprises a second duplicate key, which is substantially equivalent to the second original key. When a user intends to set a password to the USB disk  21 , the USB disk  21  will be connected to the personal computer  22  first and then the password is keyed in through the personal computer  22 . The first transmission unit  223  of the personal computer  22  transmits the password to the USB disk  21  and the second receiving unit  217  of the USB disk  21  receives the password. And then, the second encryption unit  214  encrypts the password by the original key and the Twofish encryption algorithm to generate an original encrypted text. The original encrypted text is stored in the memory  218 . Therefore, the user accomplishes the password setting of the USB disk  21 . 
         [0024]    Afterward, once the user intends to use the USB disk  21 , an authentication of the password is required. At first, the user connects the USB disk  21  to the personal computer  22 . Next, the detection unit  211  detects a biological feature, which is a fingerprint in this embodiment. Next, the generation unit  212  generates a key and a duplicate key according to the fingerprint. The key is stored in the memory  218 , and the duplicate key after encrypted by the second original key is transmitted to the personal computer  22  via the second transmission unit  216 . The personal computer  22  receives the encrypted duplicate key via the first receiving unit  221 . Next, the first decryption unit  224  derives the duplicate key by using the second duplicate key to decrypt the encrypted duplicate key. And then, the user enters an input password in the personal computer  22 . The first encryption unit  222  encrypts the input password by using the duplicate key via a Twofish encryption algorithm to derive the encrypted text. The first transmission unit  223  transmits the encrypted text to the USB disk  21  and the second receiving unit  217  receives the encrypted text. 
         [0025]    Next, the decryption unit  213  decrypts the encrypted text by the key stored in the memory  218  via the Twofish decryption algorithm to derive the input password. The decryption unit  213  also decrypts the original encrypted text by the original key stored in the memory  218  via the Twofish decryption algorithm to derive the password. Next, the comparison unit  215  compares the input password and the password, if the input password is equal to the password, the USB disk  21  can be operated. 
         [0026]    It has to be emphasized that the Twofish encryption algorithm and the Twofish decryption algorithm of the first embodiment correspond to each other. That is, the encrypted text encrypted by the Twofish encryption algorithm can also be decrypted by the Twofish decryption algorithm. The Twofish encryption and decryption algorithm can be substituted by other symmetric encryption and decryption algorithms which are adapted to an advanced encryption standard, such as encryption and decryption algorithms of MARS, RC6, RIJNDALE, and SERPENT, etc. 
         [0027]    Furthermore, the fingerprint of the first embodiment can also be substituted by one of an iris, a voice frequency, other biological features, and a combination thereof. Since the detection unit  211  detects the biological feature randomly, the probability that detecting results of different times being the same is very low. By the randomness, the problem that duplicate key being stolen can be avoided. Meanwhile, encrypting the input password by the key can reduce security hazard caused by transmitting the input password. 
         [0028]    The USB disk  21  of the first embodiment can be substituted by other electronic apparatuses, while the personal computer  22  can also be substituted by other processing apparatuses capable of calculations. The electronic apparatus and the password processing apparatus can exist independently. The only requirement is that the encryption algorithm and the decryption algorithm comprised in the electronic apparatus and the password processing apparatus correspond to each other. 
         [0029]    With the aforementioned configurations, the first embodiment is able to provide the key to the user dynamically to avoid the security threat caused by re-using the same key. 
         [0030]      FIG. 3  illustrates a second embodiment of this invention, which is a flow chart comprising a decryption method. The method is suitable for an electronic apparatus. The method is mainly divided into two parts, which is a setting password part and a decryption part, respectively. 
         [0031]    Step  301  is executed first to receive a password which is the password of the electronic apparatus. Next, step  302  is executed to encrypt the password by an original key to derive an original encrypted text, wherein the original encrypted text is stored in the electronic apparatus. Step  301  and step  302  accomplish the setting password part of the method. 
         [0032]    After setting the password, if the user intends to use the electronic apparatus, step  303  is executed to detect a biological feature randomly. Next, step  304  is executed to generate a key and a duplicate key based on the biological feature, wherein the key is stored in the electronic apparatus and the duplicate key is encrypted by a second original key. Step  305  is executed next to transmit the encrypted duplicate key. After a period of time, step  306  is executed to receive an encrypted text, wherein the encrypted text is derived by an encryption algorithm using the duplicate key to encrypt an input password. Next, step  307  is executed to decrypt the encrypted text by a decryption algorithm and the key to derive the input password, and step  308  is executed to decrypt the original encrypted text by the decryption algorithm using the original key to derive the password. Next, step  309  is executed to determine whether the input password is equal to the password. If yes, step  310  is executed to make the electronic apparatus be able to be operated; if not, step  311  is executed to display a password error message. To be explained here is that if the encryption algorithm and the decryption algorithm of the encrypted text received by step  306  are not symmetric, the correct result cannot be obtained. That is, after step  307  is executed, the encrypted text cannot be decrypted, and the comparison result of step  309  shows non-equivalent between the input password and the password. 
         [0033]    After setting the password, once the user intends to use the electronic apparatus, repeat only step  303  to step  311  is enough. In addition to the aforementioned steps, the second embodiment is able to execute all the aforementioned operations and functions of the USB disk  21  of the first embodiment. 
         [0034]      FIG. 4  depicts a third embodiment of this invention, which is a flow chart of a method of protecting an input password. First, step  41  is executed to receive an encrypted duplicate key, wherein the encrypted duplicate key is the encrypted duplicate key transmitted in step  305  of the second embodiment. Next, step  42  is executed to decrypt the encrypted duplicate key by a second duplicate key. Next, step  43  is executed to encrypt the input password by the duplicate key via an encryption algorithm to generate en encrypted text. Finally, step  44  is executed to transmit the encrypted text which is identical to the encrypted text received in step  306  of the second embodiment. Except the aforementioned steps, the third embodiment can further execute all the described operations or functions of the personal computer  22  of the first embodiment. 
         [0035]    With the aforementioned embodiments, it is able to understand that the present invention provides a key dynamically. That is, the key is generated by a randomly detected biological feature. With the randomly generated key to execute the encryption function of the input password, the security leakage caused by the key and the input password been stolen is avoided. 
         [0036]    The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in the art may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. For instance, it is also applicable that the user can key in an input password to the personal computer first, after the first encryption unit receives the duplicate key, the encryption algorithm is used to encrypt the input password to derive the encrypted text. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.

Technology Category: h