WO2019047062A1

WO2019047062A1 - Anti-dpa attack encryption method and computer-readable storage medium

Info

Publication number: WO2019047062A1
Application number: PCT/CN2017/100715
Authority: WO
Inventors: 王磊; 林岑; 柴威荣
Original assignee: 福建联迪商用设备有限公司
Priority date: 2017-09-06
Filing date: 2017-09-06
Publication date: 2019-03-14
Also published as: CN107980212A

Abstract

Disclosed by the present invention are an anti-differential power analysis (DPA) attack encryption method and a computer readable storage medium, the method comprising: generating a plurality of fake keys; obtaining a key set according to a real key and the plurality of fake keys; sequentially acquiring a key in the key set as an encryption key, and encrypting a plaintext to obtain a ciphertext corresponding to the key; sending a ciphertext corresponding to the real key to a receiving terminal after completing the acquisition of the key in the key set. Since the operation time, energy consumption and electromagnetic radiation of the fake key and real key are essentially same, a differential energy analysis method cannot clearly analyze key length and a time sequence of the real key being involved in the operation, and the generated energy analysis curve is not fixed, while the real key cannot be cracked, thereby effectively guaranteeing the security of encrypted data.

Description

Title: Inventive Name: Encryption Method for Anti-DPA Attack and Computer-Readable Storage Medium

[0001] The present invention relates to the field of information security technologies, and in particular, to an encryption method for preventing DPA attacks and a computer readable storage medium.

Background technique

[0002] During the transaction process, the POS machine uses the AES algorithm to encrypt the plaintext. During the AES operation, different energy consumption changes occur due to the operation of calculating data or reading and writing registers. DPA (Differential Energy Attack) technology is under weak signal conditions. The bypass information of the collected signal can be analyzed. According to the occurrence of a specific event, the probability distribution of the energy consumption of the encryption device will be different from the characteristic of the average probability distribution, and the statistical method can be used to analyze the energy consumption information, and the correctness can be identified. Key.

[0003] The current defense against DPA attacks uses a method of adding a mask. However, although the random value mask can defend against DPA attacks, it must calculate the random mask RM and the masked intermediate variables at the same time. In this case, each round of calculation must generate a new mask and re-mask it. Calculate the values of the S-box lookup tables, which not only increase the amount of credit between operations, but also add additional processor load and storage requirements.

technical problem

The technical problem to be solved by the present invention is to provide an encryption method for preventing DPA attacks and a computer readable storage medium, which can improve the security of encrypted data.

Problem solution

Technical solution

[0005] In order to solve the above technical problem, the technical solution adopted by the present invention is: an encryption method for preventing DPA attacks, including:

[0006] generating a plurality of fake keys;

[0007] obtaining a key set according to the true key and the plurality of fake keys;

[0008] sequentially obtaining a key from the set of keys as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one key;

[0009] After the key in the key set is obtained, the ciphertext corresponding to the real key is sent to the receiving end. [0010] The present invention also relates to a computer readable storage medium having stored thereon a computer program, the program being executed by a processor, implementing the following steps:

[0011] generating a plurality of fake keys;

[0012] obtaining a key set according to the true key and the plurality of fake keys;

[0013] sequentially acquiring a key from the set of keys as an encryption key, encrypting the plaintext, and obtaining a ciphertext corresponding to the one key;

[0014] After the key in the key set is obtained, the ciphertext corresponding to the real key is sent to the receiving end.

Advantageous effects of the invention

Beneficial effect

[0015] The beneficial effects of the present invention are: by generating a plurality of fake keys, and engaging these fake keys with the real key in the encryption operation, due to the inter-day, energy consumption and electromagnetic of the fake key and the real key operation The radiation is basically the same, so that the differential energy analysis method can not analyze the length of the key and the inter-order sequence of the real key participating in the operation. The generated energy analysis curve is not fixed, and the real key cannot be cracked. The encryption method proposed by the present invention cannot distinguish the true and false keys by extracting features through the DPA attack, thereby effectively ensuring the security of the encrypted data.

Brief description of the drawing

DRAWINGS

1 is a flowchart of an encryption method for preventing DPA attacks according to the present invention;

2 is a flowchart of a method according to Embodiment 1 of the present invention.

Detailed ways

[0018] The most critical idea of the present invention is to add a fake key to participate in the encryption operation, so that the differential energy analysis method cannot crack the real key.

[0019] Noun explanation:

[0020] AES: The Advanced Encryption Standard, Advanced Encryption Stardand, is the Rijndael algorithm defined by the National Institute of Standards and Technology and serves as an advanced data encryption standard to replace the original Data Encryption Standard (DES); [0021] Differential Energy Attack (DPA) is a statistical method for analyzing a large number of energy consumption curves generated by encrypting different plaintexts by the same key, and revealing the density by averaging the curves of different sets. Key value and encryption device.

[0022] Please refer to FIG. 1, an encryption method for preventing DPA attacks, including:

[0023] generating a plurality of fake keys;

[0024] obtaining a key set according to the true key and the plurality of fake keys;

[0025] sequentially acquiring a key from the set of keys as an encryption key, encrypting the plaintext, and obtaining a ciphertext corresponding to the one key;

[0026] After the key in the key set is obtained, the ciphertext corresponding to the real key is sent to the receiving end.

[0027] It can be seen from the above description that the DPA attack cannot distinguish the true and false keys by extracting features, and effectively ensures the security of the encrypted data.

[0028] Further, the real key is stored in a first register, and the plurality of fake keys are stored in other registers;

[0029] the "acquiring a key from the set of keys as an encryption key, encrypting the plaintext to obtain a ciphertext corresponding to the one key; and obtaining the key in the key set After the completion, the ciphertext corresponding to the real key is sent to the receiving end.

[0030] if the key is taken from the first register, storing the ciphertext corresponding to the one key into the second register;

[0031] After the key in the key set is acquired, the ciphertext in the second register is sent to the receiving end.

[0032] As can be seen from the above description, by storing the real key and the fake key in different registers, the system can quickly and easily distinguish the true and false of the key.

[0033] Further, the real key includes multiple true subkeys, and each fake key includes multiple fake subkeys respectively.

[0034] the obtaining a key from the set of keys as an encryption key, encrypting the plaintext to obtain a ciphertext corresponding to the one key; and obtaining the key in the key set After the completion, the ciphertext corresponding to the real key is sent to the receiving end.

[0035] sequentially obtaining a real subkey or a fake subkey from the key set as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one subkey; [0036] After the subkey in the key set is acquired, the ciphertext corresponding to the real subkey is sent to the receiving end. [0037] From the above description, the method of the present invention is applicable to a packet cipher operation.

[0038] Further, the encryption algorithm is AES, 3DES, RSA, National Secret SMI, National Secret SM2 or National Secret SM4.

[0039] As can be seen from the above description, the method of the present invention is applicable to a variety of encryption algorithms.

[0040] The present invention also provides a computer readable storage medium having stored thereon a computer program, the program being executed by a processor, implementing the following steps:

[0041] generating a plurality of fake keys;

[0042] obtaining a key set according to the true key and the plurality of fake keys;

[0043] sequentially obtaining a key from the set of keys as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one key;

[0044] After the key in the key set is obtained, the ciphertext corresponding to the real key is sent to the receiving end.

[0045] Further, the real key is stored in a first register, and the plurality of fake keys are stored in other registers;

[0046] the obtaining a key from the set of keys as an encryption key, encrypting the plaintext to obtain a ciphertext corresponding to the one key; and acquiring the key in the key set After the completion, the ciphertext corresponding to the real key is sent to the receiving end.

[0047] if the key is taken from the first register, storing the ciphertext corresponding to the one key into the second register;

[0048] After the key in the key set is acquired, the ciphertext in the second register is sent to the receiving end.

[0049] Further, the real key includes a plurality of true subkeys, and each of the fake keys includes a plurality of fake subkeys

[0050] the obtaining a key from the set of keys as an encryption key, encrypting the plaintext to obtain a ciphertext corresponding to the one key; and obtaining the key in the key set After the completion, the ciphertext corresponding to the real key is sent to the receiving end.

[0051] sequentially obtaining a real subkey or a fake subkey from the key set as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one subkey; [0052] after the subkey in the key set is obtained, sending the ciphertext corresponding to the real subkey to the receiving end

[0053] Further, the encryption algorithm is AES, 3DES, RSA, National Secret SMI, National Secret SM2 or National Secret SM4.

[0054]

[0055] Embodiment 1

[0056] Referring to FIG. 2, Embodiment 1 of the present invention is: An encryption method for preventing DPA attacks, which can be applied to a PO S machine, and includes the following steps:

[0057] S1: generating a plurality of fake keys; wherein, 3-5 fake keys may be generated according to the real key, and the 3-5 fake keys are fixed keys generated by each downtime, and the remaining fakes The key is a random password generated each time the encryption is started.

[0058] S2: obtaining a key set according to the true key and the multiple false keys; that is, the real key and the fake key are mixed together, and the true key is randomly distributed in the fake key, and the position is randomized Distribution, location is not fixed; but in order to enable the system to quickly and accurately distinguish between the real key and the fake key, the real key can be stored in the first register, and the multiple fake keys can be stored in other registers.

[0059] S3: Acquiring a key from the key set as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one key.

[0060] S4: determining whether the key is taken out from the first register, and if yes, performing step S5. Since only the true key is stored in the first register and the fake key is not stored, if a key is retrieved from the first register, it indicates that the key is a true key.

[0061] S5: storing the ciphertext corresponding to the one key into the second register. The fake key needs to encrypt the plaintext, but the obtained ciphertext is not sent to the receiving end, but only participates in the process of encryption calculation, and generates energy consumption information. Therefore, in order to quickly and easily distinguish the ciphertext corresponding to the ciphertext and the fake key corresponding to the real key, the ciphertext corresponding to the ciphertext corresponding to the real key is stored and distributed, that is, the real key is correspondingly The ciphertext is stored separately.

[0062] S6: After the key in the key set is acquired, the ciphertext corresponding to the real key is sent to the receiving end, that is, the ciphertext in the second register is sent to the receiving end.

[0063] Further, the real key includes multiple true subkeys, and each fake key includes multiple fake subkeys respectively. For example, AES's encryption key is 128 bits and can be divided into 16 subkeys, each of which is 8 bits. Therefore, the true subkey can be randomly distributed among the fake subkeys. Similarly, the real subkey is stored in the first register, and the fake subkey is stored in other registers.

[0064] In step S3, a real subkey or a fake subkey is obtained as an encryption key from the key set, and the plaintext is encrypted to obtain a ciphertext corresponding to the subkey. Then storing the ciphertext corresponding to the real subkey in the second register, and finally, after the subkey in the key set is obtained, sending the ciphertext corresponding to the real subkey to the receiving end, that is, the secret in the second register The text is sent to the receiving end.

[0065] Further, the method in this embodiment can be applied to encryption algorithms such as AES, 3DES, RSA, national secret SMI, national secret SM2, and national secret SM4.

[0066] This embodiment generates a plurality of fake keys, and causes these fake keys to participate in the encryption operation together with the true key, since the daytime, energy consumption, and electromagnetic radiation of the fake key and the real key operation are basically the same. Therefore, the differential energy analysis method cannot analyze the length of the key and the inter-order sequence of the real key participating in the operation, and the generated energy analysis curve is not fixed, and the real key cannot be cracked. The security of encrypted data is effectively guaranteed.

[0067] Embodiment 2

[0068] This embodiment is a computer readable storage medium corresponding to the above embodiment, on which a computer program is stored, and the program is executed by the processor to implement the following steps:

[0069] generating a plurality of fake keys;

[0070] obtaining a key set according to the true key and the plurality of fake keys;

[0071] sequentially acquiring a key from the key set as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one key;

[0072] After the key in the key set is obtained, the ciphertext corresponding to the real key is sent to the receiving end.

[0073] Further, the real key is stored in a first register, and the plurality of fake keys are stored in other registers;

[0074] the “acquiring a key from the key set as an encryption key, encrypting the plaintext to obtain a ciphertext corresponding to the one key; and acquiring the key in the key set After the completion, the ciphertext corresponding to the real key is sent to the receiving end.

[0075] if the key is taken from the first register, storing the ciphertext corresponding to the one key To the second register;

[0076] After the key in the key set is acquired, the ciphertext in the second register is sent to the receiving end.

[0077] Further, the true key includes a plurality of true subkeys, and each of the fake keys includes a plurality of fake subkeys

[0078] the obtaining a key from the set of keys as an encryption key, encrypting the plaintext to obtain a ciphertext corresponding to the one key; and acquiring the key in the key set After the completion, the ciphertext corresponding to the real key is sent to the receiving end.

[0079] sequentially obtaining a real subkey or a fake subkey from the key set as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one subkey;

[0080] after the subkey in the key set is obtained, sending the ciphertext corresponding to the real subkey to the receiving end

[0081] Further, the encryption algorithm is AES, 3DES, RSA, National Secret SMI, National Secret SM2 or National Secret SM4.

In summary, the present invention provides an anti-DPA attack encryption method and a computer readable storage medium, by generating a plurality of fake keys, and participating in the encryption operation together with the real keys. Since the inter-day, energy consumption and electromagnetic radiation of the fake key and the real key operation are basically the same, the differential energy analysis method cannot analyze the length of the key and the inter-order of the real key participating in the operation, and the generated energy analysis The curve is not fixed and the real key cannot be cracked. The encryption method proposed by the invention cannot distinguish the true and false keys by extracting features through the DPA attack, thereby effectively ensuring the security of the encrypted data.

[0083]

Claims

Claim

[Claim 1] An encryption method for preventing DPA attacks, comprising:

Generate multiple fake keys;

Obtaining a key set according to the real key and the plurality of fake keys; sequentially acquiring a key from the key set as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one key ;

After the key in the key set is obtained, the ciphertext corresponding to the real key is sent to the receiving end.

[Claim 2] The method for encrypting an anti-DPA attack according to claim 1, wherein the true key is stored in a first register, and the plurality of fake keys are stored in other registers; "Acquiring a key from the set of keys as an encryption key, encrypting the plaintext, and obtaining the ciphertext corresponding to the one key; when the key in the key set is acquired, it will be true The ciphertext corresponding to the key is sent to the receiving end. Specifically, if the key is taken out from the first register, the ciphertext corresponding to the key is stored in the second register.

After the key in the key set is acquired, the ciphertext in the second register is sent to the receiving end.

[Claim 3] The method for encrypting an anti-DPA attack according to claim 1, wherein the true key includes a plurality of true subkeys, and each of the fake keys includes a plurality of fake subkeys respectively; Deleting a key from the set of keys as an encryption key, encrypting the plaintext, and obtaining the ciphertext corresponding to the one key; when the key in the key set is acquired, The ciphertext corresponding to the real key is sent to the receiving end. Specifically,: a real subkey or a fake subkey is obtained from the key set in sequence as an encryption key, and the plaintext is encrypted to obtain the subtitle. The ciphertext corresponding to the key; after the subkey in the key set is obtained, the ciphertext corresponding to the real subkey is sent to the receiving end.

[Claim 4] The method for encrypting an anti-DPA attack according to claim 1, wherein the encryption algorithm is AES, 3DES, RSA, National Secret SMI, National Secret SM2 or National Secret SM4.

[Claim 5] A computer readable storage medium having stored thereon a computer program, wherein the program is executed by a processor to implement the following steps:

Generate multiple fake keys;

[Claim 6] The computer readable storage medium according to claim 5, wherein the true key is stored in a first register, and the plurality of fake keys are stored in other registers; Obtaining a key from the set of keys as an encryption key, and encrypting the plaintext to obtain a ciphertext corresponding to the one key; when the key in the key set is obtained, the secret is true The ciphertext corresponding to the key is sent to the receiving end. Specifically, if the key is taken out from the first register, the ciphertext corresponding to the key is stored in the second register.

[Claim 7] The computer readable storage medium according to claim 5, wherein the true key comprises a plurality of true subkeys, each of the fake keys respectively comprising a plurality of fake subkeys; "Acquiring a key from the set of keys as an encryption key, encrypting the plaintext, and obtaining the ciphertext corresponding to the one key; when the key in the key set is acquired, it will be true The ciphertext corresponding to the key is sent to the receiving end. Specifically,: a real subkey or a fake subkey is obtained from the key set in sequence as an encryption key, and the plaintext is encrypted to obtain the subkey. Corresponding ciphertext; after the subkey in the key set is obtained, the ciphertext corresponding to the real subkey is sent to the receiving end.

[Claim 8] The computer readable storage medium according to claim 5, wherein the encryption algorithm is AES, 3DES, RSA, National Secret SMI, National Secret SM2 or National Secret SM4.