KR101052600B1 - Apparatus for storing encoded data and method thereof - Google Patents

Abstract

PURPOSE: An encoding data storage device and method are provided to easily check the change or conversion of encoded data in case the encoded data is changed or converted. CONSTITUTION: An input interface(12) receives data from an external device(20). A control unit(14) divides the received data into a predetermined length unit, calculates a CECC(Check Error Correcting Code) from data belonging to each length unit, and encodes the calculated CECC with the data of the length unit. A memory(16) receives and stores the encoded data from the control unit.

Description

Encryption data storage device and its storage method {APPARATUS FOR STORING ENCODED DATA AND METHOD THEREOF}

The present invention relates to an encrypted data storage device and a storage method thereof, and more particularly, to a data storage device and a method configured to check whether the encrypted data is arbitrarily changed or modified.

In the modern society, environmental pollution due to automobile exhaust is serious. In order to overcome this, each country is trying to reduce it. To this end, the government is currently trying to reduce the amount of exhaust gas by operating the day of the week system, and in the future, to reduce the amount of exhaust gas by granting preferential benefits to taxes and insurance premiums depending on the distance driven. To this end, a driving recorder is mounted to check the driving distance and time.

A representative tachograph related to environmental regulation is the OBD (On-Board Diagnosis) system currently implemented in the US, Europe, Japan, and Korea. This OBD system is a self-diagnostic computer built into the car to monitor the emission control parts while driving and diagnose the failure, and when the failure is diagnosed, the OBD system notifies the driver in real time to induce maintenance. It is a regulation.

According to this OBD system, from basic OPEN / SHORT electronic circuit checks using a built-in controller such as an ECU (Engine control unit) or PCM (Powertrain Control Module), as well as basic information such as the vehicle's distance and time, (CATALYST), O ₂ sensor, Evaporative Emission Control System (Evaporative Emission Control System), such as failure of the exhaust gas control system and the combustion of the mixture in the combustion chamber (Misfire) phenomenon, etc. Save as data.

As such, the data stored in the OBD system of automobiles is used as important information in granting regulations or tax benefits, so the integrity of information is important. However, the data encryption method developed so far provides only a means of encrypting the data stored in the OBD system so that a third party cannot decrypt it, and there is no way to check even if the encrypted data is arbitrarily changed or modified. .

Therefore, in the future, when the driver or a third party arbitrarily manipulates and presents the driving information of the vehicle, it is anticipated that the verification is not properly performed and the risk of not being able to apply the correct law is expected, so that someone is stored in the driving recorder. There is a need for a way to prevent files from being tampered with or modified.

The present invention was developed to meet the needs of the industry, and after inserting the error correction code (CECC: Check Error Correcting Codes) that can check whether the data stored in the driving recorder of the vehicle for each fixed length unit By encrypting this, a main object of the present invention is to provide an encrypted data storage device and a method of storing the same, which enable the user to easily check whether data has been changed after being encrypted.

The encrypted data storage method of the present invention for achieving the above object, the step of receiving data from an external device; Dividing the received data into predetermined length units and calculating an error correction code for checking from data belonging to each length unit; Encrypting the calculated error correction code for check together with data of a corresponding length unit; And transmitting the encrypted data to the memory and storing the encrypted data.

In addition, the encrypted data storage device according to the present invention, the input interface for receiving data from an external device; A control unit for classifying the data transmitted through the input interface into a predetermined length unit, calculating a check error correction code from data belonging to each length unit, and encrypting the calculated check error correction code together with data of the corresponding length unit ; A memory for receiving and storing encrypted data from the controller; And a communication interface for transmitting encrypted data stored in the memory to a host device.

The external device may be applied to any one that requires periodic data backup or storage. Examples of the external device include a communication data storage server, a factory facility management server, and an OBD system that is a driving recorder of a vehicle. Hereinafter, an OBD system, which is a driving recorder of an automobile, will be described as an example. However, the technical concept of the present invention is not limited thereto.

According to the present invention configured as described above, since the actual information data and the error correction code is encrypted together, it is possible to check exactly when changing or modifying the encrypted data can ensure the integrity of the information data.

In addition, by managing the actual information data and error correction code in the length unit necessary for encryption, it can be encrypted together.

In addition, since the data encrypted with the actual information data and the error correction code are transmitted and stored in the logical basic access unit of the flash memory, the data transfer speed can be improved.

In addition, after storing the encrypted data in the flash memory and calculating the flash error correction code for correcting the transmission error on a page-by-page basis, the transmission error may occur when the encrypted data is read from the flash memory. It can prevent.

1 is a block diagram of an encrypted data storage device in accordance with the present invention.
2 is a diagram illustrating an example of encrypted data according to the present invention;
3 is a flow chart illustrating a storage step of encrypted data according to the present invention.
4 is a flowchart illustrating a step of transmitting encrypted data according to the present invention.
5 is a flowchart illustrating a step of checking encrypted data according to the present invention.
6 to 10 are diagrams showing an example of checking whether the encrypted data is changed according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the configuration of an encrypted data storage device according to the present invention. The encrypted data storage device 10 includes an OBD interface 12 which receives data related to driving from a vehicle 20 largely; A controller 14 having an algorithm for generating a check error correction code for processing the data transmitted through the OBD interface 12 and an encryption algorithm for encrypting the received data and the check error correction code together; A flash memory 16 for receiving and storing encrypted data from the control unit 14; And a communication interface 18 for transmitting encrypted data stored in the flash memory 16 to the host device 30.

The OBD interface 12 transmits general information (hereinafter referred to as “operation information data”) generated during the operation of the vehicle, such as a record of the mileage, the operation time, and the fault generated during the operation, from the OBD system of the automobile 20. Input interface for receiving. This input interface is designed to meet the communication protocol specifications of the OBD.

The controller 14 is a general-purpose microprocessor having a control function such as data input / output, memory storage, communication, etc., although not shown in FIG. 1, RAM (RAM), etc., is used to temporarily store data to be controlled. This may be further provided. The control unit 14 further includes two algorithms described below to ensure the integrity of data, which is a technical feature of the present invention, in addition to the algorithm for performing the above-described normal control function.

First, the check error correction code generation algorithm divides the driving information data received through the OBD interface 12 into a predetermined length unit, and checks error correction code (CECC) from the driving information data belonging to each length unit. Calculate Correcting Codes and arrange them together with driving information data. The CECC is an algorithm for accurate data transmission and storage by determining whether an error has occurred during data transmission or storage in a storage medium or correcting an error. Reed-Solomon codes, turbo codes, BCH codes, Reed-Muller codes, Binary Golay codes, low-density parity-check codes (LDPC), etc. may be used.

2 illustrates an example in which driving information data and a check error correction code are arranged together. The driving information data received through the OBD interface is divided into fixed length units (＃ 1 to ＃N), and each error correction code for checking is calculated from the driving information data for each length unit. The calculated error correction code for check is inserted at the end of the corresponding driving information data.

Meanwhile, the encryption algorithm encrypts the driving information data and the error correction code for checking corresponding thereto. Encryption algorithms are largely classified into symmetric (secret) algorithms and asymmetric (public key) algorithms. Asymmetric keys are superior to symmetric keys in security, but their algorithms are complicated to apply to embedded terminals. Therefore, symmetric key algorithms are widely used, and representative symmetric key algorithms include DES, 3DES, SEED, ARIA, HIGHT, and the like. Among these, currently established international standards are DES, 3DES, and SEED.

As described above, the controller 14 generates the error correction code for checking by dividing the driving information data into a predetermined length unit, and the length unit is preferably determined according to an encryption algorithm. For example, since a symmetric key algorithm such as SEED encrypts data in units of 16 bytes, as shown in FIG. 2, the operation information data is divided into units of 14 bytes in length, and an error correction code for checking the operation information data of 14 bytes is determined. By generating 2 bytes, the length of the sum of the driving information data and the corresponding error correction code for check is configured to be 16 bytes.

Since encryption algorithms typically produce data that is encrypted so that it cannot be decrypted by a third party according to a certain formula, the data is not compressed. Therefore, when the 16-byte driving information data and the check error correction code are encrypted, 16-byte encrypted data having the same length is generated.

The flash memory 16 is a nonvolatile memory that requires no power to maintain information in a memory chip. The flash memory 16 is classified into a NOR flash memory and a NAND flash memory according to an operating principle. Flash memory has the advantage that it has a very fast reading speed and excellent impact resistance compared to magnetic disks, hard disks, optical disks, etc. Recently, storage media such as USB memory, solid state disk (SSD), MP3 player, digital camera, mobile phone It is used a lot as.

Typically, since the flash memory 16 has a logical basic access unit defined as one page composed of several sectors, the controller 14 controls the encrypted data to be logically accessed by the flash memory 16. It is preferable to transmit in units. For example, as shown in FIG. 2, the data transfer speed can be improved by grouping 16 [bytes] [operation information data + CECC] in page units and transmitting them to the flash memory 16.

In addition, the controller 14 calculates and stores Flash Error Correcting Codes (FECC) in order to correct transmission errors of the encrypted data. The flash error correction code is for detecting and correcting a transmission error that may occur when data is read from the flash memory. The flash error correction code is usually calculated in units of one page and has a spare area as shown in FIG. 2. It is stored separately (64 bytes per page).

The communication interface 18 is an output interface for transmitting encrypted data stored in the flash memory 16 to the host device 30. This output interface can use both the parallel and serial communication protocols commonly used. For example, parallel communication protocols include ISA, PATA, SCSI, PCI, IEEE-1284, and the like, and RS-232C, USB, SATA, and PCI may be used as the serial communication protocol.

3 to 5 will be described in detail the encrypted data storage method according to the present invention.

As shown in FIG. 3, the method for storing encrypted data according to the present invention includes: receiving driving information data from a vehicle; Dividing the received driving information data by a predetermined length unit, and calculating check error correcting codes (CECC) from the driving information data belonging to each length unit (S30); Encrypting the calculated error correction code for check together with the driving information data of the corresponding length unit (S31); And transmitting and storing the encrypted data to the flash memory (S32).

In step S30, the driving information data is transmitted from the driving recorder of the vehicle such as an OBD system, and the error correction code for checking is calculated from the received driving information data and arranged together with the corresponding driving information data. The length unit of [operation information data + check error correction code] is determined according to the encryption algorithm used in step S32 which will be described later, and the arrangement of a plurality of [operation information data + check error correction codes] is RAM and RAM. It is stored in the same temporary storage memory.

In step S31, the array of [operation information data + check error correction code] is encrypted together through a specific encryption algorithm. A symmetric key algorithm such as SEED encrypts the target data in units of 16 bytes to generate encrypted data having the same size of 16 bytes. Therefore, the length unit of the [operation information data (14 bytes) + check error correction code (2 bytes)] is also 16 bytes. It is configured as described above with reference to FIG. Encrypted data is stored in temporary storage memory, such as RAM.

In step S32, encrypted data is transmitted to and stored in a flash memory. In this case, it is preferable to transmit the encrypted data in units of one page (1 page = 4 to 8 sectors) which is a logical basic access unit of the flash memory. In this configuration, the number of memory accesses for data transmission can be minimized, thereby improving the transmission speed.

Preferably, the step S32 further includes calculating and storing Flash Error Correcting Codes (FECC) in order to correct transmission errors with respect to the encrypted data (S33). The flash error correction code generated in this step S33 is used in the Flash Translation Layer (FTL) built into the control unit to detect and correct transmission errors that occur during the process of reading encrypted data from the flash memory. To help.

4 illustrates a process of transmitting encrypted data to a host device. The encrypted data is sent to the host device periodically or as needed. The host device is an external control device capable of parallel or serial communication with an encrypted data storage device according to the present invention, and may be a smartphone, PDA, netbook, laptop computer, desktop computer, terminal connected to a central server, or the like. The host device has a built-in application program that can decrypt the encrypted data and analyze the decrypted driving information data.

According to the present invention, the control unit reads the encrypted data stored in the flash memory and stores it in a temporary storage memory such as RAM (S40). In the encrypted data, a flash error correction code FECC is stored in the spare area for each page as shown in FIG. Therefore, the controller calculates the flash error correction code for the received encrypted data using the same error correction code generation algorithm. Using the calculated flash error correction code, it is detected whether the encrypted data has changed in the transmission process and corrects it (S41).

When the transmission error detection and correction process is completed, the encrypted data stored in the RAM is transmitted through the communication interface (S42), and the host device separately stores the received encrypted data (S43).

5 shows a process of checking whether encrypted data is changed in a host device. First, the host device decrypts the received encrypted data (S50). To this end, the host device has a built-in decryption algorithm composed of the same principle as the encryption algorithm of the encrypted data storage device according to the present invention. From the decoded data, the driving information data which is actual data and the check error correction code CECC generated from the driving information data are separated and extracted (S51).

A new error correction code is calculated using the respective driving information data (S52). To this end, the host device stores the same error correction code generation algorithm as the encryption data storage device of the present invention. The calculated error correction code is compared with the check error correction code stored together with the corresponding driving information data (S53). As a result of the comparison, if the two error correction codes are different, the data is marked as changed or modified after being encrypted.

In addition, by displaying whether the data has been changed for each length unit for encryption, it is possible to inform more detailed information about the location and extent of the data change, and depending on the error correction code generation algorithm, the changed part may be restored to the original data. have. Through this process, the integrity of the driving information data, which is the main object of the present invention, is guaranteed.

An embodiment of checking whether encrypted data is changed according to the present invention will be described with reference to FIGS. 6 to 10.

As shown in FIG. 6, the operation information data of 14 bytes and the error correction code of 2 bytes calculated using the operation information data constitute one length unit, and the operation information data + error correction of 16 bytes is used. Codes] are arranged in plural. For example, a check error correction code (CECC A) for the first driving information data of 14 bytes is calculated as [89,72] and stored together.

As shown in Fig. 7, the arrangement of a plurality of [run information data + check error correction codes] is changed into encrypted data having the same size of 16 bytes according to the encryption algorithm. In this way, since the actual driving information data cannot be read until it is decrypted, it cannot be changed.

However, it is possible to change the encrypted data itself. This is because the encryption is only to make it impossible to decrypt the driving information data, and thus cannot change the encrypted data itself. When the encrypted data is changed, decrypting it changes the driving information data itself so that the integrity of the driving information data cannot be guaranteed.

8 shows an example in which the encrypted data itself is changed. The 10th and 14th data of the first driving information data array shown in FIG. 7 are changed from 96, 23 to 48, 98, respectively.

9 shows a state in which the changed [operation information data + check error correction code] array is decoded. In comparison with FIG. 7, it can be seen that all data values of the first array of [operation information data + check error correction code] have been changed since decoding is performed in units of 16 bytes. Since the error correction code part for checking is also decoded together, the error correction code part for checking (CECC B) also has a new value [23,43].

As shown in FIG. 10, when the new check error correction code CECC C is calculated using the decoded 14-byte driving information data, it is [56,67]. Comparing the computed check error correcting code (CECC C) with the decrypted check error correcting code (CECC B), it is a completely different value as [56,67] ≠ [23,43]. It can be easily checked.

The encrypted data storage device and method according to the present invention can ensure the integrity of the encrypted data through the above process.

10: encrypted data storage 12: OBD interface
14: control unit 16: flash memory
18: communication interface 20: car
30: host device

Claims (10)

An input interface for receiving data from an external device;
The data transmitted through the input interface is divided into a predetermined length unit, a check error correction code (CECC) is calculated from the data belonging to each length unit, and the calculated error correction code for the check is applied to the corresponding length. A control unit for encrypting the data with the unit;
A memory for receiving and storing encrypted data from the controller; And
And a communication interface for transmitting encrypted data stored in the memory to a host device. An OBD interface 12 for receiving driving information data from a vehicle;
The driving information data received through the OBD interface 12 is divided into a predetermined length unit, a check error correction code (CECC) is calculated from the driving information data belonging to each length unit, and the calculated check A controller 14 for encrypting the error correction code together with the driving information data of the corresponding length unit;
A flash memory 16 for receiving and storing encrypted data from the control unit 14; And
An encrypted data storage device comprising a communication interface (18) for transmitting encrypted data stored in the flash memory (16) to a host device (30). The method according to claim 2,
The control unit (14) is characterized in that for determining the length unit according to an encryption algorithm. The method according to claim 2,
The control unit (14) is characterized in that for transmitting the encrypted data for each logical basic access unit of the flash memory (16). The method according to claim 2,
The control unit (14) is characterized in that to calculate the flash error correction code (FECC: Flash Error Correcting Codes) in order to correct the transmission error for the encrypted data, characterized in that the storage device. Receiving data from an external device;
Dividing the received data into units of a predetermined length and calculating Check Error Correcting Codes (CECC) from data belonging to each unit of length;
Encrypting the calculated error correction code for check together with data of a corresponding length unit; And
And transmitting the encrypted data to a memory and storing the encrypted data. Receiving driving information data from a vehicle;
Dividing the received driving information data into fixed length units and calculating check error correcting codes (CECC) from the driving information data belonging to each length unit;
Encrypting the calculated error correction code for check together with the driving information data of the corresponding length unit; And
And transmitting the encrypted data to a flash memory and storing the encrypted data. The method according to claim 7,
The length unit is encrypted data storage method, characterized in that determined by the encryption algorithm. The method according to claim 7,
The storing of the flash memory is performed according to a logical basic access unit of the flash memory. The method according to claim 7,
The storing of the flash memory may further include calculating and storing Flash Error Correcting Codes (FECC) to correct transmission errors of the encrypted data. .

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