Method and system for extracting cipher key by using DPA curve polarity

Abstract

The invention relates to the technical field of information security, in particular to a method for extracting a cipher key by using DPA curve polarity. The method comprises the following steps of: testing a chip to be attacked; acquiring the specific implementation condition of AES on the chip to ensure that each bit generates the polarity of a DPA peak value; acquiring the polarity of the DPA peak value of each bit at an attack position; dividing the intermediate state of an enciphering process by using a plain text to obtain the polarity of the peak value; and performing exclusive-OR according to an original DPA polarity digit group and an attack DPA polarity digit group to obtain the cipher key. By improving the original DPA attack method and using the polarity of the peak value in a DPA attack, the method finishes the extraction of polar DPA polarity on the basis of extracting the original DPA polarity, and performs the exclusive-OR operation on the polar DPA polarity and the original DPA polarity to extract the cipher key; and compared with the original DPA attack, the method disclosed by the invention has obvious improvements on time complexity.

Description

technical field

[0001] The invention relates to the technical field of information security, in particular to a method and a system for extracting a key by using the polarity of a DPA curve. Background technique

[0002] The wide application of computers today has brought us huge social and economic benefits, but at the same time it also exposes the vulnerability of computer information security, and passwords are the key to information security. By analyzing the cipher, the content of the communication between the two parties can be obtained, thereby stealing other people's privacy. Therefore, a good cryptographic algorithm needs to have better resistance to attack.

[0003] Compared with cryptanalysis in the traditional sense, side channel attack (Side Channel Attack, SCA) is aimed at the specific implementation of the cryptosystem to obtain useful information. These include various side-channel attacks such as TA, DPA, DFA, and SPA. Compared with other attack methods, ...

Examples

Embodiment Construction

[0052] Below in conjunction with accompanying drawing, the present invention will be further described with specific embodiment:

[0053] In the original DPA attack proposed by Paul Kocher, first use a digital oscilloscope to record the power consumption curve of the encryption chip during each encryption process, and write down N sampling points, replace the plaintext, record a total of M groups of power consumption curves, and then select A D function divides the collected samples, calculates the differential power consumption curve according to the division, obtains ΔD, finds the Ki value that can be the largest ΔD, and then obtains the correct key. In the polar DPA attack used here, the original DPA attack is completed first, the obtained plaintext Plain is XORed with the guessed key K, and then the plaintext Plain is used to divide to obtain ΔD_P, and the DPA curve corresponding to bit j and The polarity of the peak, thus obtaining the key. Accordingly, the specific step...

technical field

[0001] The invention relates to the technical field of information security, in particular to a method and a system for extracting a key by using the polarity of a DPA curve. Background technique

[0002] The wide application of computers today has brought us huge social and economic benefits, but at the same time it also exposes the vulnerability of computer information security, and passwords are the key to information security. By analyzing the cipher, the content of the communication between the two parties can be obtained, thereby stealing other people's privacy. Therefore, a good cryptographic algorithm needs to have better resistance to attack.

[0003] Compared with cryptanalysis in the traditional sense, side channel attack (Side Channel Attack, SCA) is aimed at the specific implementation of the cryptosystem to obtain useful information. These include various side-channel attacks such as TA, DPA, DFA, and SPA. Compared with other attack methods, ...

Examples

Embodiment Construction

[0052] Below in conjunction with accompanying drawing, the present invention will be further described with specific embodiment:

[0053] In the original DPA attack proposed by Paul Kocher, first use a digital oscilloscope to record the power consumption curve of the encryption chip during each encryption process, and write down N sampling points, replace the plaintext, record a total of M groups of power consumption curves, and then select A D function divides the collected samples, calculates the differential power consumption curve according to the division, obtains ΔD, finds the Ki value that can be the largest ΔD, and then obtains the correct key. In the polar DPA attack used here, the original DPA attack is completed first, the obtained plaintext Plain is XORed with the guessed key K, and then the plaintext Plain is used to divide to obtain ΔD_P, and the DPA curve corresponding to bit j and The polarity of the peak, thus obtaining the key. Accordingly, the specific step...

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