JPH09116532A - Information distribution method hiding cryptographic key contents - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information distribution method where a sending terminal sends a cryptographic key that is hidden against other terminals ad a receiving terminal and the receiving terminal performs the decoding processing by means of the hidden cryptographic key. SOLUTION: A sending terminal hides a decoding cryptographic key against other terminals and a receiving terminal and sends this cryptographic key to the receiving terminal. The receiving terminal use the hidden cryptographic key to produce and carry out a decoding processing application 4. A layer 6 is prepared between a secret communication protocol layer 5 and the application 4 to treat the cryptographic key for the software which is used by the receiving terminal. Thus it is possible to hide the contents of the cryptographic key that contain a function which stores plural cryptographic keys by means of a secret communication protocol, a function which decodes the cipher information by means of the cryptographic keys, a function which erases the cryptographic keys out of their treating layer, and a function which shows a cryptographic key identifier to the application 4 for designation of one of these cryptographic keys.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for concealing an encryption key, and more particularly to information distribution in which a cipher key content is concealed in a system including a transmission terminal and a reception terminal having encryption information, and a public network or computer network connecting them. Regarding the method.

[0002]

2. Description of the Related Art A technique for keeping secret information in a communication message repeatedly communicated between a sender and a receiver from a third party can be solved by encryption of the communication message or a secret communication protocol such as SSL or HTTP. And the technology to prove that the confidential information has not been tampered with by a third party on the way,
It can be solved by an electronic signature or the like.

However, even by using these techniques, the receiver can find the encryption key sent by monitoring the output of the secret communication protocol. Therefore, the encryption key cannot be kept secret to the recipient.

Also, if the encryption key is completely hidden by hardware implementation, programming technology, etc., the recipient cannot create and execute an application using the encryption key.

[0005]

In the above-mentioned conventional method, the encryption key can be kept secret from a third party but cannot be hidden from the recipient. Therefore, either the encryption key cannot be kept secret to the recipient, or an application using the encryption key cannot be created and executed.

The present invention has been made in view of the above, and an object thereof is to provide a transmitting terminal, a receiving terminal having cryptographic information, and a public network or a computer network connecting them, in which the transmitting terminal is
Provide an information distribution method in which an encryption key to be concealed from another terminal and a reception terminal is transmitted to the reception terminal, and the reception terminal creates and executes an application including a decryption process using the encryption key and conceals the encryption key content. Especially.

[0007]

The information distribution method of the present invention in which the encryption key content is hidden is an information distribution method in which the encryption key content is hidden, and the encryption code for the transmitting terminal to decrypt the encrypted commercial information. The decryption key information of the key is encrypted from an application program of another terminal including the receiving terminal to a state in which the content of the decryption key information cannot be identified, and transmitted to the receiving terminal, and the application program of the receiving terminal, Using the received encrypted decryption key information as it is, decrypt the encrypted commercial information,
There is the step of utilizing the decrypted commercial information.

The application program of the receiving terminal decrypts the decryption key information of the encryption key from the transmitting terminal between the layer of the application program and the secret communication protocol layer, and the application program of the application program Is a step of providing a layer for handling an encryption key in which the decryption status of the encryption key and the decryption result cannot be detected, and in the layer for handling the encryption key, the decryption key information itself which is the output of the secret communication protocol layer is the application program. Decrypting the encrypted commercial information without passing the encrypted commercial information to the application program and passing the decrypted commercial information to the application program while deleting the decryption key information after the commercial information is decrypted. Have.

Further, in the hierarchy handling the encryption key, one of the labels is selected by a step of labeling the decryption key information itself and holding a plurality of types of the decryption key information, and a process of the application program. There is a step of designating one of the decryption key information held in plural types.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the information distribution method of the present invention in which the contents of an encryption key are concealed, since the decryption key information of the encryption key is not directly passed from the layer handling the encryption key to the application, the receiver Even if an application that monitors the exit of the hierarchy that handles the encryption key is created, the decryption key information of the encryption key cannot be obtained.

Further, if an identifier for operating the encryption key is used, an application including a decryption process can be created by using the decryption key information of the encryption key. Moreover, since the decryption key information of a plurality of encryption keys can be stored, it is possible to create an application that handles a large number of encryption information.

Further, since the decryption key information of the encryption key can be erased, it is possible to create an application that erases the decryption key information of the unnecessary encryption key as needed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall view of a system comprising a transmitting terminal 1, a receiving terminal 2 and a public network / computer network 3 connecting them.

FIG. 2 shows a hierarchical view of the software of the receiving terminal. As shown in FIG. 2, the software of the receiving terminal has a layer 6 (called a key storage layer 6) between the application 4 and the secret communication protocol layer 5 that handles an encryption key. For example, SSL is used as the secret communication protocol.

FIG. 3 shows the structure of the key storage layer 6. The key storage layer 6 includes an encryption key storage unit 7, an identifier correspondence unit 8 and an encryption information decryption unit 9.

The encryption key storage unit 7 can store the decryption key information of a plurality of encryption keys by the secret communication protocol, where the decryption key information of the encryption keys received from the transmitting terminal 1 is stored.

The identifier correspondence unit 8 is where the identifier passed to the application 4 is associated with the storage position of the encryption key storage unit 7.

The encryption information decryption unit 9 is for decrypting the encryption information using the decryption key information of the encryption key.

The interfaces that can be used from the application 4 to the key storage layer 6 are as follows.

(1) Obtaining the encryption key identifier The receiving terminal 2 sends an encryption key request message to the transmitting terminal 1. Sending terminal 1 that received a request message for an encryption key
Sends the decryption key information of the requested encryption key. Receiving the decryption key information, the receiving terminal 2 stores the decryption key information of the encryption key in the encryption key storage unit 7, records the storage position in the identifier corresponding unit 8, calculates the corresponding identifier, and returns it to the application 4. .

(2) Designate the identifier of the encryption key and the encryption information, and decrypt the encryption information. The identifier correspondence unit 8 calculates the position of the encryption key corresponding to the specified identifier, and the encryption key storage unit 7 , Decryption key information of the corresponding encryption key is extracted. The encryption information is decrypted using the decryption key information that has been taken out.

(3) Designate the identifier of the encryption key and delete the decryption key information of the encryption key. The identifier correspondence unit 8 calculates the position of the encryption key corresponding to the designated identifier, and the encryption key storage unit The decryption key information of the corresponding encryption key is searched from 7 and deleted.

[0024]

According to the present invention, even when the transmitting terminal transmits to the receiving terminal the cryptographic key which is to be concealed from the other terminals and the receiving terminal, not only the other terminal but also the receiving terminal provides the interface to the application. It is not possible to see the encryption key on the screen.

Further, since the operation using the encryption key can be performed through the identifier of the encryption key, it is possible to provide a method of creating and executing an application using the encryption key.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an entire system for implementing an information distribution method in which an encryption key is hidden according to an embodiment of the present invention.

FIG. 2 is a diagram showing a hierarchical structure of software of a receiving terminal in the above embodiment.

FIG. 3 is a diagram showing a configuration of a key storage layer in software of a receiving terminal in the above embodiment.

[Explanation of symbols]

 1 Sending Terminal 2 Receiving Terminal 3 Public Network / Computer Network 4 Application 5 Secret Communication Protocol Layer 6 Key Storage Layer 7 Cryptographic Key Storage Section 8 Identifier Corresponding Section 9 Cryptographic Information Decoding Section

Claims (3)

[Claims] 1. An information distribution method in which the contents of an encryption key are hidden, wherein a transmitting terminal receives decryption key information of an encryption key for decrypting encrypted commercial information from an application program of another terminal including a receiving terminal. , A step of encrypting the content of the decryption key information in an unidentifiable state and transmitting it to the receiving terminal, and the application program of the receiving terminal uses the received encrypted decryption key information as it is, An information distribution method in which the contents of an encryption key are concealed, including the step of decrypting the encrypted commercial information and using the decrypted commercial information. 2. The application program of the receiving terminal decrypts the decryption key information of the encryption key from the transmitting terminal between the layer of the application program and the secret communication protocol layer, and from the application program Is a step of providing a layer for handling an encryption key in which the decryption status of the encryption key and the decryption result cannot be detected, and in the layer for handling the encryption key, the decryption key information itself which is an output of the secret communication protocol layer is the application program. Decrypting the encrypted commercial information without passing the encrypted commercial information to the application program, and deleting the decryption key information after the commercial information is decrypted, and passing the decrypted commercial information to the application program. An information stream concealing the encryption key content according to claim 1 Common way. 3. A step of labeling the decryption key information itself and holding a plurality of types of the decryption key information, wherein a layer handling the encryption key selects one of the labels by a process of the application program. The information distribution method according to claim 2, further comprising the step of designating one of the decryption key information held in plural types.