KR20090042624A - Apparatus and method for symmetric key encryption processing - Google Patents

Abstract

A symmetrical key code processing device and a method are provided to increase the effectiveness of speed and the power consumption by not repeating the production of the round key. A symmetrical key code processing device(200) comprises a control signal unit(201), a round key generating unit(202), a memory unit(203), a symmetric key code encoding/decoding processor(204), and input-output signal processing unit(205). The control signal unit produces the round key generating signal or the symmetric key code encoding/decoding signal. The round key generating unit produces the round key. The round key generated from the round key generating unit is stored in the memory unit. The symmetric key code encoding/decoding processor receives the round key from the memory unit, and performs the encoding/decoding process of external data.

Description

Symmetric key cryptography processing apparatus and method {APPARATUS AND METHOD FOR SYMMETRIC KEY ENCRYPTION PROCESSING}

The present invention relates to an apparatus and method for symmetric key cryptography using two or more keys.

The symmetric cryptographic technique is a cryptographic method in which the key used for encryption and the key used for decryption are the same. The representative symmetric cryptographic method is a block cipher algorithm developed by IBM. The Standard Encryption Standard (DES) and the National Institute of Standards and Technology (NIST), the adopted standards, are the Advanced Encryption Standard (AES), an open order symmetric key cryptography that replaces DES 'next generation of international standard cryptography.

In the prior art, a plurality of keys are repeatedly input r-round to a symmetric key cryptographic processing device that processes data encryption and decryption through such a symmetric cryptographic method, and the symmetric key cryptographic processing device is inputted for each key input. A round key corresponding to the key is generated and used to decrypt data.

For example, the smart card decrypts the content protected by DRM (Digital Rights Management) technology with the content key, re-encrypts it with the secure channel key used for the secure channel, and transmits it to the CE (Customer Electronics) device. The CE device decrypts the content encrypted with the secure channel key and then renders it. In this case, when the same symmetric key cryptographic processing device is used for each of the content protection and security channel, two keys are repeatedly input to the symmetric key cryptographic processing device, and the symmetric key cryptographic processing device is used whenever two keys are input. The round key generated by generating a round key is used to decrypt data.

According to the present invention, when an application service protected by symmetric key cryptography is re-encrypted through its own secure channel, a service generates a round key for two or more keys in one cryptographic processor and stores the same. And a symmetric key cryptographic processing apparatus and method for use without regeneration of the round key.

The present invention provides a symmetric key cryptographic processing apparatus and method which can increase the efficiency of power consumption and speed by not generating the round key by generating, storing and using the round key.

A symmetric key cryptographic processing apparatus according to an embodiment of the present invention includes a control signal unit for generating a round key generation signal or a symmetric key decryption signal, and a round key for each of a plurality of keys input according to the round key generation signal. A round key generation unit for generating a memory, a memory unit for storing the round key, and a symmetric key decryption processing unit for receiving encryption or decryption of external data by receiving a corresponding round key from the memory unit according to the symmetric key decryption signal. Include.

According to an aspect of the present invention, the control signal unit may generate the round key generation signal in the first round, and generate the symmetric key decryption signal in every round.

According to an aspect of the present invention, the memory unit may be stored in a memory area corresponding to the round key in the first round, and maintain the round key until all rounds are finished.

According to an aspect of the present invention, the control signal unit may further generate a memory control signal including an input signal or an output signal, store the round key in the memory unit in accordance with the input signal, and to the output signal Accordingly, the memory unit may further include an input / output signal processor that extracts a corresponding round key. In this case, the memory control signal may include the input signal in the first round and the output signal in all rounds.

The symmetric key cryptographic processing apparatus according to an embodiment of the present invention generates and stores a round key for each key input during the first round, and encrypts and decrypts external data using the stored round key in every round.

In a symmetric key encryption processing method according to an embodiment of the present invention, generating a round key for each of a plurality of keys input according to a round key generation signal, storing the round key in a memory, and a symmetric key decryption signal And extracting a corresponding round key from the memory to process encryption or decryption of external data.

In a symmetric key cryptography processing method according to an embodiment of the present invention, a first step of generating a round key for each of a plurality of keys input in an initial round and storing it in a memory and receiving a corresponding round key from the memory to receive external data A second step of processing the encryption or decryption of.

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

1 is a view for explaining the general operation of the symmetric key cryptography processing apparatus according to an embodiment of the present invention.

A plurality of keys are repeatedly input to the symmetric key cryptographic processing apparatus 100. Conventionally, when each of the plurality of keys is repeatedly input, a round key for each of the plurality of keys is generated and external data is encrypted or decrypted by using the generated round key. According to the present invention, a round key for a single key can be generated, stored and used repeatedly. That is, as shown in FIG. 1, in step S101, the symmetric key cryptographic processing apparatus 100 generates a round key for the input key and stores it in the memory. In operation S102, the symmetric key cryptography processing apparatus 100 processes the encryption or decryption of external data using the round key stored in the memory. That is, when the round keys for each of the plurality of keys are generated once, the round keys are stored in the memory, and the corresponding round keys according to the input key without regeneration of the round keys until the application of the same service is terminated. May be extracted from the memory, and external data may be encrypted or decrypted using the extracted round key.

In this case, step S101 may be executed only in the first round, and step S102 may be repeatedly performed for all rounds. Here, the round may mean a process in which the plurality of keys are input once each, and a process of encrypting or decrypting external data is processed using each of the plurality of keys, and all the rounds are applications of a service for one content. This may mean r-round that is repeatedly performed r-times on the content until the end of the content.

That is, step S101 of generating round keys for the plurality of keys is executed only in the first round, and encryption or decryption of the external data is generated in the first round and stored in the memory as in step S102 every round. By extracting and using a corresponding round key among the stored round keys, power consumption and speed can be improved by not generating the round key repeatedly every round. Alternatively, the round key may be generated according to a specific signal generation using various control signals, or the encryption or decryption of external data may be processed using the stored round key.

Hereinafter, a symmetric key cryptography processing apparatus and method for generating a round key only once for the same key input when a plurality of keys input through FIGS. 2 to 5 are repeatedly input will be described in more detail.

2 is a block diagram illustrating an internal configuration of a symmetric key cryptographic processing apparatus according to an embodiment of the present invention. Here, as shown in FIG. 2, the symmetric key cryptographic processing apparatus 200 includes a control signal unit 201, a round key generation unit 202, a memory unit 203, a symmetric key encryption / decryption processing unit 204, and an input / output signal. And a processing unit 205.

The control signal unit 201 generates a round key generation signal or a symmetric key decryption signal. In this case, the control signal unit 201 may generate the round key generation signal when the input key is a new input, and generate the symmetric key decryption signal every time the key is input. In other words, the round key generation signal may be generated only when the input key is first input, and the symmetric key decryption signal may be generated each time a key is input. Alternatively, the control signal unit 201 may generate the round key generation signal in the first round, and generate the symmetric key decryption signal in every round.

The round key generation unit 202 generates a round key for each of the plurality of keys input according to the round key generation signal. That is, in the first round or when the input key is a new input, the control signal unit 201 generates the round key generation signal and transmits it to the round key generation unit 202. At this time, when the round key generation unit 202 receives the round key generation signal, the round key generation unit 202 may generate a round key for the input key. That is, when receiving the round key generation signal, the round key generation unit 202 may generate a round key for each of the plurality of keys according to a value of the plurality of input keys.

The memory 203 stores the round key generated by the round key generator 202. In this case, the round key corresponding to each of the plurality of keys is stored in the memory area of the memory unit 203 in the order of generation, or the round key is stored according to the memory control signal generated by the control signal unit 201. By specifying a memory area to be stored, it can be stored in the designated memory area. The memory unit 203 may store the round key in the corresponding memory area and maintain the round key until the application of the corresponding service is terminated.

The symmetric key decryption processing unit 204 receives a corresponding round key from the memory unit according to the symmetric key decryption signal to process encryption or decryption of external data. That is, when the control signal unit 202 generates the symmetric key decryption signal, and the symmetric key decryption processor 204 receives the symmetric key decryption signal, the symmetric key decryption processor 204 is input. The corresponding round key may be received from the memory unit 203 to perform encryption or decryption of external data.

To this end, the symmetric key encryption / decryption processing unit 204 includes a corresponding round from the memory unit 203 according to the memory control signal further generated by the external data receiver (not shown) and the control signal unit 201 for receiving external data. A round key receiving unit (not shown) for receiving a key key and an encryption / decryption unit (not shown) for encrypting or decrypting the external data using the round key.

For example, when two keys used for each of the content protection and security channel are repeatedly used, the symmetric key cryptography processing apparatus 200 may generate the first round key and the security channel generated according to the content key for content protection. The second round key generated according to the secure channel key for the memory is stored in the memory unit 203, and the symmetric key decryption processing unit 204 decrypts the external data content with the first round key or the second round key. Can be encrypted. Subsequently, when the content key or the secure channel key is re-entered, the round key generator 202 does not regenerate the round key for the content key or the secure channel key, and the symmetric key decryption processor 204 stores the memory unit. The content may be encrypted by using the first round key or the second round key stored in 203.

The memory control signal is a symmetric key encryption / decryption processor that extracts a corresponding round key from an input signal or memory unit 203 for storing a round key generated from the round key generator 202 in the memory unit 203. And an output signal for transmission to 204. In this case, the input signal may be included in the memory control signal when the first round or the input key is a new input, and the output signal may be included in the memory control signal whenever every round or key is input.

The input / output signal processing unit 205 stores the round key in the memory unit 203 according to the input signal, and extracts the corresponding round key from the memory unit 203 according to the output signal. That is, when the memory control signal including the input signal is input, the input / output signal processing unit 205 stores the round key generated by the round key generation unit 203 in the current round in the memory unit 203 and outputs the same. When a memory control signal including a signal is input, the round key corresponding to the output signal may be extracted from the memory unit 203 and transmitted to the symmetric key decryption processor 204.

As such, the symmetric key cryptographic processing apparatus 200 according to an embodiment of the present invention generates the round key according to the round key generation signal, and repeats the round key previously generated and stored according to the symmetric key decryption signal. This eliminates the need to generate a round key every time a key is entered, improving power consumption and speed.

3 is a block diagram illustrating another internal configuration of a symmetric key cryptographic processing apparatus according to an embodiment of the present invention.

The symmetric key cryptographic processing apparatus 300 generates and stores a round key for each key input during the first round, and encrypts and decrypts external data using the stored round key in every round. To this end, the symmetric key cryptography processing apparatus 300 may include a round key generation unit 301, a memory unit 302, and a symmetric key encryption / decryption processing unit 303 as shown in FIG. 3.

The round key generation unit 301 generates a round key for each of the keys input during the first round. That is, in the symmetric key cryptographic processing apparatus 300, a plurality of keys may be repeatedly input for each round, during the r-round which is all the rounds, and the round key generation unit 301 may perform the plurality of keys during the first round. A round key may be generated for each of the four keys.

In the memory unit 302, the round key is stored in a corresponding memory area. In this case, the memory unit 302 may be stored in the memory area corresponding to the round key in the first round, and maintain the round key until all rounds are completed. That is, the round keys may be generated one by one corresponding to each of the plurality of keys, and the generated round keys may be respectively stored in a corresponding area among a plurality of areas included in the memory unit 302. Alternatively, the data may be stored in the plurality of regions in the order of being simply generated.

The symmetric key encryption / decryption processing unit 303 receives a corresponding round key from the memory unit for each round to process encryption or decryption of external data. That is, the symmetric key encryption / decryption processor 303 may encrypt or decrypt the external data by receiving a round key corresponding to an input key among a plurality of round keys generated in the first round.

For example, if two keys for each of the content protection and security channel are repeatedly used, the symmetric key cryptographic processing apparatus 300 may be configured for the first round key and the security channel generated according to the content key for content protection. The second round key generated according to the secure channel key may be stored in the memory unit 302, and the symmetric key encryption / decryption processor 303 may decrypt the external data content with the content key or encrypt the secure channel key. Subsequently, when the content key or the secure channel key is input again, the first round key or the second round key stored in the memory unit 302 is regenerated without regenerating the round key for the content key or the secure channel key. It is possible to decrypt and decode the content.

4 is a flowchart illustrating a symmetric key cryptography processing method according to an embodiment of the present invention.

In step S401, the symmetric key cryptography processing apparatus generates a round key for each of the plurality of keys input according to the round key generation signal. In this case, the round key generation signal may be generated when a key input among the plurality of keys is newly input. In other words, the round key for the input key may be generated only when the input key is first input.

In step S402, the symmetric key cryptographic processing apparatus stores the round key in a memory. In this case, the round key stored in the memory may be stored or extracted in the memory according to a predetermined memory control signal, and the memory control signal is an input signal for storing the round key in a corresponding region of the memory. Or it may include an output signal for extracting a corresponding round key from the memory.

In step S403, the symmetric key cryptography processing apparatus extracts a corresponding round key from the memory according to a symmetric key decryption signal to process encryption or decryption of external data. To this end, the symmetric key cryptographic processing apparatus receives external data, extracts a corresponding round key from the memory based on the memory control signal, and encrypts or decrypts the external data based on the extracted round key. Can be. In this case, the symmetric key decryption signal may be generated every round.

That is, the symmetric key cryptographic processing apparatus generates and stores the round key using the round key generation signal, and then repeatedly uses the stored round key according to the input key through the symmetric key decryption signal. Decryption of data can be handled. Accordingly, when providing a service using a plurality of keys for one content, the symmetric key cryptographic processing apparatus generates a round key for the input key whenever a key is input. There is no need to do it. In other words, it is necessary to repeat generation of the round key by generating and storing the round key only by the round key generation signal, and selecting and using the stored round key according to the input key by the symmetric key decryption signal. This disappears. Accordingly, power consumption and speed according to symmetric key cryptographic processing can be improved.

5 is a flowchart illustrating another symmetric key cryptography processing method according to an embodiment of the present invention.

In step S501, the symmetric key cryptography processing apparatus generates a round key for each of the plurality of keys input in the first round and stores it in the memory. Here, the memory may be stored in a memory area corresponding to the round key in the first round, and the round key may be maintained until all rounds are completed.

In step S502, the symmetric key cryptography processing apparatus receives a corresponding round key from the memory to process encryption or decryption of external data. To this end, the symmetric key cryptographic processing apparatus receives external data, receives the round key from the memory based on a predetermined memory control signal, and then encrypts or decrypts the external data based on the round key. Can be. In this case, the memory control signal may include a signal for determining a round key to be used in the current round among the round keys included in the memory. That is, the symmetric key cryptography processing apparatus may extract a key to be used for the current round among a plurality of round keys included in the memory by using the memory control signal, and use the same to encrypt or decrypt the input external data.

In step S503, the symmetric key cryptographic processing apparatus repeats step S502 for all rounds. That is, the symmetric key cryptographic processing apparatus generates a round key for each of a plurality of keys input only in the first round, and stores the round key in a memory, and the corresponding one of the round keys stored in the memory during the first round and the remaining rounds is stored. A round key can be selected and used.

Therefore, according to an embodiment of the present invention, when providing a service using a plurality of keys for one content, the symmetric key cryptographic processing apparatus does not need to generate a round key for each of the plurality of keys every round. By selecting and using the first generated round key according to the input key, there is no need to repeat the generation of the round key. Accordingly, power consumption and speed according to symmetric key cryptographic processing can be improved.

Embodiments according to the present invention can be implemented in the form of program instructions that can be executed by various computer means can be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described by specific embodiments such as specific components and the like, but the embodiments and drawings are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations are possible from these descriptions.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all the things that are equivalent to or equivalent to the claims as well as the following claims will belong to the scope of the present invention. .

1 is a view for explaining the general operation of the symmetric key cryptography processing apparatus according to an embodiment of the present invention.

2 is a block diagram illustrating an internal configuration of a symmetric key cryptographic processing apparatus according to an embodiment of the present invention.

3 is a block diagram illustrating another internal configuration of a symmetric key cryptographic processing apparatus according to an embodiment of the present invention.

4 is a flowchart illustrating a symmetric key cryptography processing method according to an embodiment of the present invention.

5 is a flowchart illustrating another symmetric key cryptography processing method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

200: symmetric key cryptographic processing device

201: control signal unit

202: round key generation unit

203: memory

204: symmetric key encryption and decryption processing unit

205: input and output signal processing unit

Claims (21)

A control signal unit for generating a round key generation signal or a symmetric key decryption signal; A round key generation unit generating a round key for each of a plurality of keys input according to the round key generation signal; A memory unit in which the round key is stored; And A symmetric key encryption / decryption processor that receives a corresponding round key from the memory unit according to the symmetric key encryption / decryption signal and processes encryption or decryption of external data. Symmetric key cryptographic processing device comprising a. The method of claim 1, The control signal unit, And generating a round key generation signal and generating the symmetric key encryption / decryption signal each time the key is input when the input key of the plurality of keys is a new input. The method of claim 1, The control signal unit, And generating the round key generation signal in the first round, and generating the symmetric key decryption signal in every round. The method of claim 1, The memory unit, And the round key is stored in a corresponding memory area, and the round key is held until the application of the corresponding service is terminated. The method of claim 1, The control signal unit, Further generates a memory control signal comprising an input signal or an output signal, An input / output signal processor configured to store the round key in the memory unit according to the input signal, and extract a corresponding round key from the memory unit according to the output signal Symmetric key cryptographic processing device further comprising. The method of claim 5, And the memory control signal includes the input signal in the first round and the output signal in every round. The method of claim 1, The symmetric key encryption / decoding process An external data receiver for receiving external data; A round key receiving unit for receiving a corresponding round key from the memory unit according to a memory control signal further generated by the control signal unit; And An encryption / decryption unit encrypting or decrypting the external data using the round key. Symmetric key cryptographic processing apparatus comprising a. A symmetric key cryptographic processing apparatus for generating and storing a round key for each key input during the first round, and encrypting and decrypting external data using the stored round key in every round. The method of claim 8, A round key generation unit generating a round key for each of the keys input during the first round; A memory unit in which the round key is stored in a corresponding memory area; And Symmetric key decryption processing unit for processing the encryption or decryption of external data by receiving the corresponding round key from the memory unit for each round Symmetric key cryptographic processing device comprising a. The method of claim 9, The memory unit, And the round key is stored in a memory area corresponding to the first round, and the round key is held until all rounds are terminated. The method of claim 9, Control signal unit for generating a memory control signal More, The symmetric key decryption processing unit, And a corresponding round key among the round keys included in the memory unit based on the memory control signal to encrypt or decrypt the external data. Generating a round key for each of the plurality of keys input according to the round key generation signal; Storing the round key in a memory; And Extracting a corresponding round key from the memory according to a symmetric key decryption signal to process encryption or decryption of external data; Symmetric key encryption processing method comprising a. The method of claim 12, The round key generation signal is generated when a key input among the plurality of keys is newly input, And the symmetric key decryption signal is generated each time the key is input. The method of claim 12, The round key is stored or extracted in the memory according to a predetermined memory control signal, And the memory control signal comprises an input signal for storing the round key in a corresponding area of the memory or an output signal for extracting a corresponding round key from the memory. The method of claim 12, The step of extracting a corresponding round key from the memory in accordance with a symmetric key decryption signal to process encryption or decryption of external data, Receiving external data; Extracting a corresponding round key from the memory based on a predetermined memory control signal; And Encrypting or decrypting the external data based on the round key Symmetric key cryptography processing method comprising a. Generating a round key for each of the plurality of keys input in the first round and storing the round key in a memory; And Receiving a corresponding round key from the memory to process encryption or decryption of external data; Symmetric key encryption processing method comprising a. The method of claim 16, A third step of repeating the second step for all rounds Symmetric key cryptography processing method further comprising. The method of claim 16, And wherein the memory is stored in a memory area corresponding to the round key in the first round, and the round key is maintained until all rounds are terminated. The method of claim 16, The second step, Receiving external data; Receiving the round key in the memory based on a predetermined memory control signal; And Encrypting or decrypting the external data based on the round key Symmetric key cryptography processing method comprising a. The method of claim 19, The memory control signal includes a signal for determining a round key to be used in the current round of the round key included in the memory. A computer-readable recording medium in which a program for executing the method of any one of claims 11 to 20 is recorded.

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