KR20120035073A - Method of arranging waveform data for side channel analysis and side channel analysis apparatus using the same - Google Patents

Abstract

PURPOSE: A method for arranging waveform data for analyzing a sub channel and a sub channel analyzing device using the same are provided to reduce time waste for wrongly setting an alignment parameter. CONSTITUTION: Initial parameters are automatically set for a determined test set(S420). Various alignment method is repetitively performed for the test set using the determined parameters. The most proper parameters are determined by obtaining a standard deviation of result sets per each alignment methods(S430). All waveform data are aligned using the determined alignment parameters(S440).

Description

Method of arranging waveform data for side channel analysis and side channel analysis apparatus using the same}

The present invention relates to subchannel analysis, and more particularly, to a method for aligning collected waveform data for subchannel analysis used as a method of obtaining secret information about a secure electronic device, and a subchannel analysis apparatus using the same. will be.

Side channel analysis is an analysis method that obtains secret information such as encryption keys by analyzing leakage information such as power consumption or electromagnetic waves generated from secure electronic devices that perform encryption algorithms.

In other words, the subchannel analysis method finds secret information of the encryption algorithm implemented by using subchannel information such as operation time, power consumption, and electromagnetic wave leaked when the encryption algorithm is implemented in a low power information protection device such as an IC card. Attack method.

After side channel attack was introduced by Kocher et al. (US Patent Publication 2002-0124178, "Differential Power Analysis method and apparatus"), theoretical and experimental studies were conducted by many research groups. come.

For example, the sub-channel analysis method may be used to extract secret information such as key values by statistically using electromagnetic waves leaked from security electronic devices such as smart cards. In this case, using the analog / digital conversion data collection and analysis system using the power consumption or other characteristics of the equipment, statistical analysis may be performed every time an encryption operation is performed on the equipment, thereby obtaining all or some key information.

1 is a conceptual diagram illustrating an exemplary configuration of a conventional subchannel analysis apparatus.

Referring to FIG. 1, a conventional subchannel analysis apparatus collects from a leak information collecting device 120, such as an oscilloscope, which collects a plurality of repeated leak information from an analysis target device 110, and a leak information collecting device 120. It is composed of arithmetic unit 130 for receiving the received data to perform a sub-channel analysis operation.

The operation of such a subchannel analysis device includes a waveform collection step of repeatedly collecting a waveform of leakage information using an oscilloscope and storing the same in a calculation device, and processing a waveform to easily process waveform data collected by the calculation device for subchannel analysis. Step, and the analysis operation step of analyzing to obtain secret information from the processed waveform data in the computing device, each step is carried out sequentially.

In the waveform processing step, data calculation is generally performed independently for each individual waveform data, and data analysis in the analysis calculation step is performed for the entire waveforms.

As such, subchannel analysis can take several to tens of hours of data processing and computation time on a single system, depending on the subject of the analysis. In order to reduce the computation time required for such an analysis, a parallel computing technique using multiple CPU cores in a single system and a method of using a graphics processing unit (GPU) in a video card are known (for example, by 3 people outside Han Dong-guk). "Development of sub-channel analysis S / W speedup program using GPU", KISA Final Research Report, November 2009, KISA-WP-2009-0053).

Meanwhile, sub-channel analysis is a method of processing a plurality of waveform data and calculating secret information by calculating a correlation between the waveform data and the expected secret information. Therefore, in such subchannel analysis, preprocessing to sort, filter and remove noise of collected waveform data is required before inputting the waveform data into the analysis model for subchannel analysis. It is necessary to determine the parameter values needed to sort the data.

The alignment of the waveforms is one of the most essential elements for revealing confidential information. This is because even if multiple waveforms leaked from the same secret device are correlated with the same position (which contains secret information), it is important to align these positions so that the secret information can be estimated with a smaller number of waveforms and more clearly correlated. . For example, when waveforms are collected for a portion of the IC card's security algorithm, a plurality of waveforms are repeatedly collected by triggering the section where the security algorithm operates. However, depending on the IC card, each waveform may not be measured very accurately due to various factors such as the presence of a random frequency and an incomplete trigger, and may delay or come out of the time axis little by little. In other words, as the desired analysis position is widely distributed, the correlation becomes inferior, which is mixed with other noises in the analysis and acts as an obstacle to the analysis. Therefore, the waveforms can be analyzed using various methods such as global alignment using the correlation of the entire waveform, global waveform alignment using the feature interval, elastic alignment using DTW, and the like. Aligning analysis positions by moving them left and right on the time axis plays an important role in increasing the number and correlation of waveforms required for analysis.

For example, conventional methods require the user to adjust the parameters according to the characteristics of the waveform (size, which parts to compare, how much to compare, how much to move the comparing portion, etc.), and the shape of the waveform. The more complicated and longer the waveform is, the more difficult it is to adjust its parameters without specialized skills or experience.

Summary of the Invention An object of the present invention to solve the above problems is to provide a waveform data alignment method that allows the waveform data alignment to proceed without the user's intervention on complex parameters in aligning the collected waveforms for subchannel analysis. have.

Another object of the present invention for solving the above problems is to use a waveform data alignment method that allows waveform data alignment to proceed without user intervention on complex parameters in aligning the collected waveforms for subchannel analysis. It is to provide a sub-channel analysis device.

In order to achieve the above object, the present invention provides a method for defining a set of collected waveform data as a test set for determining parameters for automatic alignment, and automatically setting initial parameters with respect to the test set determined in the test set definition step. Using the parameters determined in the pre-parameter test proceeding step and the pre-parameter test proceeding step, various sorting methods are repeatedly performed on the test set to obtain the standard deviation of the result sets derived for each sorting method to determine the most appropriate parameters. According to the present invention, there is provided a waveform data sorting method for subchannel analysis including a full waveform data sorting step of performing a sorting on the entire waveform data collected by using the sorting parameter determined in the pre-aligning test step and the pre-aligning test step.

The present invention for achieving the above another object is configured to include a waveform collector, waveform data alignment parameter determination unit, waveform processing unit, intermediate value calculation unit and analysis unit, the waveform data alignment parameter determination unit waveforms transmitted from the waveform collector Provided is a sub-channel analysis apparatus configured to input alignment parameters determined using a part of data to the waveform processing unit to perform alignment on the collected entire parameters.

Here, the waveform data alignment parameter determiner defines a part of the collected waveform data as a test set for determining a parameter for automatic alignment, and automatically sets the parameters for the test set determined by the test set definer. By using the parameters determined by the preparameter test progress unit and the preparameter test progress unit to perform a variety of alignment methods for the test set iteratively and the standard deviation of the result set derived for each alignment method It can be configured to include a pre-alignment test section for obtaining the most suitable parameters.

According to the configuration of the present invention as described above, by eliminating the process of setting the parameter for the alignment operation on the waveform data collected for the sub-channel analysis, the user can perform the alignment necessary for the sub-channel analysis more easily It is possible to reduce the waste of time due to incorrect setting.

1 is a conceptual diagram illustrating an exemplary configuration of a conventional subchannel analysis apparatus.
2 is a block diagram illustrating a configuration of a subchannel analysis apparatus to which a waveform data alignment method for subchannel analysis according to the present invention is applied.
3 is a block diagram illustrating a detailed configuration of a waveform data alignment parameter determination unit of a subchannel analysis apparatus according to the present invention.
4 is a flowchart illustrating a waveform data alignment method for subchannel analysis according to an embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that another component may exist in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

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

2 is a block diagram illustrating a configuration of a subchannel analysis apparatus to which a waveform data alignment method for subchannel analysis according to the present invention is applied.

Referring to FIG. 2, the subchannel analysis apparatus 200 according to the present invention may include a waveform collector 210, a waveform processor 230, an intermediate value calculator 240, and an analyzer 250. have.

In addition, the sub-channel analysis apparatus 200 according to the present invention includes a waveform data alignment parameter determiner 220 for performing the waveform data alignment method according to the present invention. In this case, the alignment parameters determined by using a part of the waveform data transferred from the waveform collector 210 in the waveform data alignment parameter determiner 220 are input to the waveform processor 230 and are aligned with respect to all collected parameters. It can be configured to perform.

For reference, the roles of the waveform collector 210, the waveform processor 230, the intermediate value calculator 240, and the analyzer 250 will be described in detail.

First, the waveform collector 210 is a component that receives waveform data. The waveform collector 210 may be configured of an external measuring device for collecting leakage information (power consumption, electromagnetic wave, etc.) leaked from the target security electronic device, and an oscilloscope connected to the measuring device. That is, it may be configured to measure the leakage information by using an external measuring device, and to collect waveform data through the oscilloscope. Next, the waveform processing unit 220 is a component that receives at least a portion of the waveform data collected by the waveform collecting unit 210 and processes the waveform to facilitate analysis. Next, the intermediate value calculator 230 is a component that receives at least a portion of the waveform data processed by the waveform processor 220 and calculates an intermediate value necessary for subchannel analysis. Lastly, the analyzer 240 receives all of the median values calculated from the intermediate value calculator 230 and generates a subchannel analysis result for the entire waveform.

Meanwhile, in FIG. 2, the waveform data alignment parameter determiner 220 is illustrated as a separate component from the waveform collector 210 and the waveform processor 230, but the waveform data alignment parameter determiner 220 is a waveform. It may be present as a subcomponent present in the collection, or may be present as a subcomponent present in the corrugation processing. That is, it should be noted that the waveform data alignment parameter determiner 220 is merely a name of a functionally divided component, not a physically separated component.

3 is a block diagram illustrating a detailed configuration of a waveform data alignment parameter determination unit of a subchannel analysis apparatus according to the present invention.

Referring to FIG. 3, the waveform data alignment parameter determiner 220 that operates in conjunction with the waveform processor 230 may again include a test set definition unit 221, a preparameter test progress unit 222, and a pre-alignment test unit 223. It may be configured to include).

The test set defining unit 221 is a component that defines a part of the collected waveform data as a test set for determining a parameter for automatic alignment. The collected waveform data refers to waveform data obtained from an external measurement device for collecting leakage information (power consumption, electromagnetic waves, etc.) leaked from a target security electronic device by the waveform collector 210 described above and an oscilloscope connected to the measurement device. it means.

The pre-parameter test progress unit 222 is a component that performs a pre-parameter test for automatically setting the parameters for the test set determined by the test set definition unit 221.

At this time, in the preparameter test, parameters necessary for the alignment according to the waveform length-for example, window size (window size, comparison section), threshold (maximum amount of movement of the comparison section), step size (step size) Parameters such as the degree of movement at a time) are appropriately set to a predetermined value.

The pre-alignment test unit 223 uses various parameters determined by the pre-parameter test proceeding unit 222 (eg, alignment through correlation, alignment through interval average value and correlation, elastic alignment, energy-based alignment). And the like) for the test set. Next, the alignment result (the shift value of each waveform) is received for each waveform and the parameters are reset through the largest waveform shift value. However, if the pre-parameter test result is similar to the threshold value (maximum degree of movement of the waveform comparison section), the threshold value is reset to be larger.

Using the reset parameters, the pre-sort test is repeated for the test set, and the accuracy of the sort is calculated by the standard deviation of the result sets derived by each sorting method and the mean of the correlation. In other words, this is to determine the degree of alignment of the result sets according to each sorting method.

Finally, after the parameter is repeatedly reset in the pre-alignment test unit 223, the finally determined alignment parameter is output to the waveform processing unit 230, and the waveform processing unit 230 is collected using the determined alignment parameter. The entire waveform data is sorted.

4 is a flowchart illustrating a waveform data alignment method for subchannel analysis according to an embodiment of the present invention.

Referring to FIG. 4, the waveform data sorting method according to the present invention includes a test set definition step S410, a preparameter test progress step S420, a prearrangement test step S430, and an entire waveform data sorting step S440. Can be configured.

Here, the test set definition step (S410), the pre-parameter test progress step (S420) and the pre-alignment test step (S430) are performed by the waveform data alignment parameter determiner 220 described with reference to FIGS. 2 and 3. The entire waveform data alignment step S440 is performed by the waveform processing unit 230 using the alignment parameters determined by the waveform data alignment parameter determiner 220 through the steps S410, S420, and S430. .

The test set definition step S410 is a component that defines a part of the collected waveform data as a test set for determining a parameter for automatic alignment. The waveform data collected as described above is an external measurement device for collecting leakage information (power consumption, electromagnetic waves, etc.) leaked from the target security electronic device by the waveform collector 210 and a waveform obtained from an oscilloscope connected to the measurement device. Means data.

The preparameter test progress step S420 is a step of performing a preparameter test for automatically setting the parameters for the test set determined in the test set definition step S410.

At this time, in the preparameter test, parameters necessary for the alignment according to the waveform length-for example, window size (window size, comparison section), threshold (maximum amount of movement of the comparison section), step size (step size) Parameters such as the degree of movement at a time) are appropriately set to a predetermined value. At this time, the initial parameters set in the pre-parameter test progress step S420 are reset to optimal values through the pre-arrangement test step S430 to be described later.

The pre-sort test step S430 is performed by using the parameters determined in the pre-parameter test process step S420 (eg, sorting by correlation, sorting by interval average value and correlation, elastic sorting, energy-based sorting). And the like) for the test set. Next, the alignment result (the shift value of each waveform) is received for each waveform and the parameters are reset through the largest waveform shift value. However, if the pre-parameter test result is similar to the threshold value (maximum degree of movement of the waveform comparison section), the threshold value is reset to be larger.

Using the reset parameters, the pre-sort test for the test set is repeated again, and the accuracy of the sort is calculated by using the standard deviation of the result sets derived for each sorting method. In other words, this is to determine the degree of alignment of the result sets according to each sorting method.

Finally, after repeatedly performing parameter reset in the pre-alignment test step S430, the finally determined alignment parameter is used to perform alignment on the entire waveform data collected in the entire waveform data alignment step S440.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

200: subchannel analysis system
210: waveform collector
220: waveform data alignment parameter determiner
221: test set definition unit 222: pre-parameter test progress unit
223: pre-alignment test unit
230: waveform processing unit 240: intermediate value calculation unit
250: analysis unit

Claims (1)

A test set defining step of defining a part of the collected waveform data as a test set for determining a parameter for automatic alignment;
A pre-parameter test progress step of automatically setting initial parameters with respect to the test set determined in the test set definition step;
A pre-alignment test step of determining the most appropriate parameters by obtaining a standard deviation of the result sets derived for each alignment method by repeatedly performing various alignment methods on the test set using the parameters determined in the pre-parameter test proceeding step; And
And aligning the entire waveform data collected using the alignment parameters determined in the pre-alignment test step.

Images