JP2013098972A - Safe transmission and storage method of electronic data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To resolve problems that, in transmission of electronic data, there is possibility that the electronic data is read out by a third party by wiretapping of a network or by extraction from a transmission destination computer, and that, even if the electronic data is encrypted, there is possibility that the encrypted electronic data is decrypted.SOLUTION: Electronic data is divided into two segments 13 and 14, and encrypted to obtain segments 15 and 16. A network of a transmission path is divided into networks 18 and 19. Thereby, since all segments of the electronic data are not obtained by wiretapping of only one network, original electronic data can be prevented from being read out even if the encryption is decrypted. Since a transmission destination computer 20 stores only the encrypted segment (large) 16 of the electronic data, all segments of the electronic data are not obtained even if a storage device is read out, and thus, the original electronic data can be prevented from being read out.

Description

The present invention relates to electronic data transmitted through a network such as the Internet.

FIG. 1 shows a conventional method.
When transmitting electronic data from one computer to another, a network such as the Internet is used. The network includes application technologies that are generally used to improve communication safety and convenience, such as VPN (Virtual Private Network).
There is electronic data 1 that protects it from being read by a third party.
The transmission source computer 2 encrypts the electronic data by a generally known method, and creates the encrypted electronic data 3 and the key 4 used for decryption.
The encrypted electronic data 3 and the key 4 used for decryption are transmitted to the destination computer 6 through the network 5.
The destination computer 6 decrypts the encrypted electronic data 3 using the key 4 used for decryption. As a result, the same electronic data 7 as the electronic data 1 is restored and stored in a storage device such as a hard disk.

The conventional method has the following problems from the viewpoint of protecting electronic data.
1. By eavesdropping on data flowing through a network such as the Internet, a third party can obtain electronic data. There is a risk that the contents of the electronic data can be read by being decrypted by performing a brute force attack on the obtained electronic data.
2. In order to decrypt the electronic data encrypted for protection, electronic data serving as a key is required. Since this also needs to be transmitted over a network such as the Internet, there is a risk of eavesdropping by a third party. When a third party obtains both the electronic data and the key, the encryption method is generally known, so that it is easily decrypted.
3. There is a risk that a third party reads electronic data stored in a storage device by a computer that has received the electronic data. As a method, there are a method in which an illegal operation is performed directly or from a network, or a computer is disassembled to take out a storage device.
4). If the receiving computer does not store electronic data in order to solve the above problem 3, it is necessary to transmit the electronic data whenever necessary. When the amount of electronic data increases, the time required for transmission increases, so convenience is impaired.

In order to solve the above problems, the present invention employs the following means.
<Means 1>
The encrypted electronic data is divided into a plurality of states.
<Means 2>
When transmitting the encrypted electronic data and the decryption key, a plurality of transmission paths are distributed.
<Means 3>
In the receiving computer, only a large fragment of the electronic data divided into a plurality is stored in the storage device.

The present invention solves the problem as follows.
For Problem 1, by dividing the electronic data into a plurality of pieces by <Means 1>, even if only a part of the electronic data is obtained and decrypted, the original electronic data cannot be read. In order to read the original electronic data, it is necessary to obtain all the divided electronic data, but this is more difficult than obtaining the non-divided electronic data, thereby reducing the risk.
For Problem 2, even if only one network is wiretapped by <Means 2>, information necessary for restoring the original electronic data is not available. In order to gather all necessary information, it is necessary to eavesdrop on all of a plurality of networks, but this is more difficult than eavesdropping on a single network, so the risk is reduced.
For Problem 3, since only a part of the data necessary for restoration exists by <Means 3>, the original electronic data cannot be restored from the electronic data stored in the storage device of the receiving computer. Therefore, danger can be avoided.
For Problem 4, since the large fragment of the electronic data is stored in the storage device of the receiving computer by <Means 3>, only the small fragment needs to be transmitted. This reduces the amount of electronic data to be transmitted.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 2 shows an embodiment of the present invention.
There is electronic data 11 that protects it from being read by a third party.
The transmission source computer 12 divides this into an electronic data fragment (small) 13 and an electronic data fragment (large) 14. Each fragment is encrypted by a generally known method, and an encrypted electronic data fragment (small) 15, an encrypted electronic data fragment (large) 16, and a key 17 used for decryption are created.
The encrypted electronic data fragment (small) 15, the encrypted electronic data fragment (large) 16, and the key 17 used for decryption are transmitted to the destination computer. At that time, a plurality of routes used for transmission are distributed. For example, the encrypted electronic data fragment (small) 15 is transmitted through the network (path A) 18, and the encrypted electronic data fragment (large) 16 and the decryption key 17 are transmitted through the network (path B) 19. To do.
Note that the transmission source computer 12 may not be one. For example, two or more computers may be used, such as one computer connected only to the network (path A) 18 and one computer connected only to the network (path B) 19.
Also,
The destination computer 20 uses the encrypted electronic data fragment (small) 15, the encrypted electronic data fragment (large) 16, and the decryption key 17 to use the electronic data fragment (small) 13 and the electronic data. To restore the fragment (large) 14. Based on these, the electronic data 11 is restored.
The destination computer 20 stores only the encrypted electronic data fragment (large) 21 in the storage device. When the electronic data 11 becomes necessary again, the transmission source computer 12 is caused to transmit the encrypted electronic data fragment (small) 15 and the key 17 used for decryption again.

When creating the encrypted electronic data fragment (small) 15, the encrypted electronic data fragment (large) 16, and the decryption key 17 from the electronic data 11 to be protected, the work for dividing the electronic data and encryption The work to be performed may be reversed as follows.
1. The electronic data 11 to be protected is encrypted by a generally known method, and the encrypted electronic data and a key 17 used for decryption are created.
2. The encrypted electronic data is divided into two fragments, and an encrypted electronic data fragment (small) 15 and an encrypted electronic data fragment (large) 16 are created.
The electronic data 11 to be protected may be divided into three or more regardless of whether encryption or division is performed first.
The key 17 used for decryption may be integrated with any of the encrypted pieces of electronic data. Alternatively, the key 17 itself used for decryption may be considered as one of the encrypted pieces of electronic data, and the electronic data encrypted in the above procedure 2 may be handled without being divided.

It is not necessary for the network connecting the transmission source computer and the transmission destination computer to be physically different lines. For example, one or more logical networks installed using network application technology such as VPN may be included on the same physical line.
The electronic data may be dispersed in time by opening a time interval for transmitting pieces of electronic data.

The transmission and storage of electronic data according to a conventional method are shown. 1 shows a method of transmitting and storing electronic data according to the present invention.

DESCRIPTION OF SYMBOLS 1 Electronic data 2 Source computer 3 Encrypted electronic data 4 Decryption key 5 Network 6 Destination computer 7 Electronic data stored in storage device of destination computer 11 Electronic data 12 Source computer 13 Fragment of electronic data ( small)
14 Large pieces of electronic data
15 Fragment of encrypted electronic data (small)
16 Fragments of encrypted electronic data (large)
17 Key used for decryption 18 Network (path A)
19 Network (Route B)
20 Destination computer 21 Fragment of encrypted electronic data stored in the storage device of the destination computer (large)

Claims (3)

An electronic data protection method that improves safety by dividing the original data so that it cannot be restored alone when protecting electronic data. An electronic data transmission method that reduces the risk of eavesdropping on a network path by distributing a transmission path of each divided data when transmitting electronic data divided into a plurality of parts through a network such as the Internet. A storage method that prevents electronic data theft from a receiving computer while reducing the amount of communication by storing only a part of electronic data divided into a plurality of pieces of data that can be transmitted to the receiving computer.

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