JPH0725437U - Cryptographic device for word processor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a simple and highly confidential encryption device for word processing. An input / output unit for a word processor, an encryption processing unit, a key generation unit, and a secret key input unit are provided, and the encryption processing unit encrypts the data input from the word processor with the key generated by the key generation unit. An encrypted file is created by using the private key input means and the key is encrypted by the private key input by the private key input means to create an encrypted key.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a word processor cryptographic device.

[0002]

[Prior art]

 Document data created by a word processor is stored and stored in an IC memory, a floppy disk or the like built in the word processor.

[0003]

[Problems to be solved by the device]

 Conventionally, there has been a problem that document data recorded in an IC memory or a floppy disk of a word processor can be easily displayed or printed on a display on the word processor by others.

[0004]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention connects the device according to the present invention to a word processor to automatically generate a key used for encryption, encrypts stored document data, and uses the key. An encryption key is created by encrypting with a secret key (keyword) arbitrarily input by a person, and the encryption key is stored in the device according to the present invention or an external device having a storage means, together with a name that identifies the ciphertext, We made it easy to conceal document data and operate it. In addition, the procedure of encryption processing and key generation performed by the device according to the present invention is stored in an external device having a storage means, and this device reads the process to perform processing, thereby facilitating operation and its application. I chose

[0005]

【Example】

 FIG. 1 shows an embodiment of a word processor encryption apparatus according to the present invention as set forth in claim (1). In the present embodiment, (10) shows the device according to the present invention, (11) shows the input / output means for inputting / outputting data by connecting to the input / output connector of the word processor, and (12) shows the control means. , (13) shows an encryption processing means, (14) shows a key generation means, (15) shows a secret key input means, (16) shows a key of the secret key input means, and (17) shows The control line which connects said control means (12) and each means is shown.

In the present embodiment, under the control of the control means (12), the input / output means (11) connected to a connector such as RS232C or Centronics mounted on the word processor is encrypted. At the time of encryption, the data to be encrypted is received from the word processor, transmitted to the encryption processing means (13), and the ciphertext and encryption key encrypted by the encryption processing means (13) are received to receive the connector. From the word processor to the word processor, and at the time of decryption, the ciphertext and the encryption key are received from the word processor, transmitted to the encryption processing means (13), and decrypted by the encryption processing means (13). Send the text (plain text) to the word processor. The encryption processing means (13) encrypts the data (plain text) received from the input / output means (11) by using the key generated by the key generation means (14) as an encryption key and inputs the ciphertext again. It transmits to the output means (11) and also decrypts the ciphertext received from the input / output means (11) and transmits the plaintext again to the input / output means (11). Further, an encryption key is created by encrypting the encryption key with the keyword input from the key (16) of the secret key input means (15) as a secret key, and the encryption key is stored in the same manner as the encrypted text. It transmits to the entry output means (11). When the device according to the present invention is used to store a ciphertext and an encryption key in a word processor or its external storage medium and perform decryption, the user inputs a keyword known only to himself to input the encryption key. By decrypting and further decrypting the ciphertext, it is not necessary to manage the word processing document or the ciphertext.

FIG. 2 shows an example of the encryption algorithm (DES) in the encryption processing means (13). In this example, a plaintext (M = 0100101101) is encrypted with a 12-bit key (K = 001 010000110), and the 12-bit key is divided into 3 bits and the keys at each stage are K1, Let them be K2, K3, and K4. However, for the keys K1 and K3 of the first and third stages, 1 is added to the left of these 3 bits to make 4 bits, and K2 and K 4 are made to be 4 bits by adding 0 to the left. The plaintext M is divided into a left half L1 = 0100 and a right half R1 = 1101, and R1 is converted according to the table of the S box after exclusive-OR operation with the key K1 and exclusive-OR with L1. The result (1101) of the above calculation is the right half R2 of the second stage. The right half R1 of the first stage remains in the left half L2 of the second stage. After that, the same calculation is performed to obtain the ciphertext C = 01111001. Similarly, in decryption, the plaintext can be obtained by reversing the order of this process for the ciphertext.

FIG. 3 shows an example in which a random number generator is used as the key generating means (14). In this example, a 4-bit counter is serially connected, and a pseudo random number generator circuit based on a primitive polynomial F (x) = x ^p + x ^q +1 and a cryptographic algorithm (DES) are combined. The data output from the pseudo random number generation circuit and stored in the shift register is input to the encryption algorithm, and the encryption algorithm given an initial value encrypts the data to obtain a random number.

An embodiment of the device according to the present invention as set forth in claim (2) is shown in FIG. (40) shows the apparatus in this embodiment, (11) to (17) are the same as in FIG. 1, and (18) shows a storage means. In the present embodiment, the device (10) in the embodiment of FIG. 1 is further provided with the storage means (18), and at the time of encryption, the encryption key is used together with a name for specifying the ciphertext or independently. The encryption key corresponding to the ciphertext to be decrypted is stored in the storage means (18) from the storage means (18) to the encryption processing means (13) at the time of decryption, and the secret is stored. It is possible to obtain a plaintext by performing decryption using the secret key input from the key input means (15) and decrypting the ciphertext with the decrypted key. By using the device according to the present invention to store a ciphertext and a name (file name) for identifying the ciphertext in a word processor or a storage medium managed by the word processor, and storing the encryption key and the name in the device according to the present invention, Furthermore, management and its operation can be facilitated.

An embodiment of the device according to the present invention as set forth in claim (3) is shown in FIG. (50) shows the device in this embodiment, (11) to (17) are the same as those in FIG. 1, and (19) shows the input / output means of the external storage device. In this embodiment, the device (10) in the embodiment of FIG. 1 is further provided with an input / output means (19) for the external storage device, and the encryption key is input to the external storage device at the time of encryption. The encryption key corresponding to the ciphertext is stored in an external storage device connected to the output means (19) and is decrypted at the time of decryption, from the external storage device via the input / output means (19) of the external storage device. It is possible to obtain a plaintext by inputting it to the encryption processing means (13), decrypting it using the secret key input from the secret key inputting means (15), and decrypting the ciphertext with the decrypted key. By using the device according to the present invention to store the ciphertext in a word processor or a storage medium managed by the word processor, and storing the encryption key in an external storage device, a plurality of users of the device according to the present invention can individually encrypt the encrypted data. It is possible to manage the activation key. Here, the external storage device refers to a device having storage means such as a memory card and a floppy disk, and the input / output means refers to a connector including those interface circuits, a floppy disk driver, and the like.

An embodiment of the device according to the present invention as defined in claim (4) is shown in FIG. (60) shows the device in this embodiment, (11), (13) to (17) are the same as in FIG. 1, and (20) and (21) show the input / output means and the memory of the external device, respectively. (22) shows the control means. In this embodiment, the procedure of the encryption processing means and / or the key generation means and / or the secret key input means is stored in an external device, and the procedure is stored in the memory (the memory device) by the external device connected to the input / output means (20). 21) and the control means (22) controls the device according to the present invention according to the procedure stored in the memory (21). By using the device according to the present invention and the external device, ciphertexts can be stored and managed by various different procedures. Here, the external device refers to a device having storage means such as a memory card or a floppy disk, and the input / output means refers to a connector including those interface circuits, a floppy disk driver, or the like.

[0012]

[Effect of device]

 By connecting the device according to the present invention to the data input / output connector of the word processor, the document data and graphic data created by the word processor can be encrypted without paying attention to the encryption key and stored as an encrypted file. Can be set. Further, by storing the encryption key in the storage means or the external storage means built in the device according to the present invention, it is possible to realize a highly confidential encryption system that is easy to manage and operate.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an apparatus according to the present invention.

FIG. 2 is a diagram showing an encryption algorithm (DES) and an S box.

FIG. 3 is a diagram showing an embodiment of a random number generation circuit.

FIG. 4 is a diagram showing an embodiment of an apparatus according to the present invention having a built-in storage means.

FIG. 5 is a diagram showing an embodiment of an apparatus according to the present invention having an input / output means of an external storage device.

FIG. 6 is a diagram showing an embodiment of the device according to the present invention, which is connected to an external device having a control procedure.

[Explanation of symbols]

 10 device according to the present invention 11 input / output means 12 control means 13 cryptographic processing means 14 key generation means 15 secret key input means 16 keys 17 control line 18 storage means 19 external storage device input / output means 20 external device input / output means 21 memory 22 Control means 40 Device according to the present invention 50 Device according to the present invention 60 Device according to the present invention SS Box

Claims (4)

[Scope of utility model registration request] 1. An input / output unit for inputting and outputting data by connecting to a data input / output connector of a word processor, an encryption processing unit, a key generation unit, and a secret key input unit, wherein the encryption processing unit is provided. Using the key generated by the key generation means, the word processor data input from the input / output means is encrypted to create encrypted data, or the encrypted data is decrypted and the key is stored as the secret. An encryption device for word processing, characterized in that an encryption key is created by encrypting with a secret key input by a key input means. 2. The storage means is further provided, and the name for specifying the encrypted data according to claim 1 and the secret key according to claim 1 are stored in the storage means. The encryption device for word processing according to claim 1. 3. The word processor according to claim 1, further comprising storing a name for specifying the encrypted data and a secret key in an external storage device according to claim 2. Cryptographic device. 4. The external device is further provided with the procedure of the encryption processing means and / or the procedure of the key generation means and / or the procedure of the secret key input means according to claim 1. The cryptographic device for word processing according to 1) to 3).