CN111162898B - SM4 rapid software implementation method and device based on Android terminal - Google Patents

Abstract

The invention provides a rapid software implementation method based on an SM4 algorithm of an Android terminal, which comprises the following steps: preprocessing a file to be encrypted or decrypted and a secret key; the file and the secret key are persisted to a database of an Android client and stored; and the Android client accesses the database and encrypts or decrypts the file to be encrypted or decrypted. Through the technical means, the invention combines Java native method technology (JNI), vectorization technology and algebra optimization technology, uses the NEON instruction set supporting Single Instruction Multiple Data (SIMD) under the ARM architecture, arranges the storage structure of the data to be processed, realizes the parallel encryption and decryption of 128 groups of data, reduces the complexity of domain operation through the algebra optimization technology, and greatly improves the software realization efficiency.

Description

A kind of SM4 fast software implementation method and device based on Android terminal

technical field

The invention relates to the technical field of computer security, and in particular, to a method and device for implementing SM4 fast software based on an Android terminal.

Background technique

With the development of mobile communication services, the functions of mobile terminal equipment have also undergone tremendous changes. From the initial voice transmission, it developed into short message business and Web browsing, and later expanded into multimedia short message business and various wireless value-added services. With the continuous expansion of mobile terminal users and users' understanding of mobile terminal technology, mobile terminals are facing more and more threats. The boom of big data and the arrival of the 5G era have further exacerbated the security challenges of mobile terminals.

Cryptography is an important technology to protect the security of mobile terminals. The domestic cryptographic algorithm is the security foundation for my country to fundamentally realize the completely independent and controllable modern industry. Block symmetric encryption technology can be used to protect the security of data. The SM4 block cipher algorithm is a block symmetric cipher independently designed by my country. It is an industry standard for commercial cryptographic algorithms officially announced in China. It provides a safe and complete data encryption scheme for many information systems.

The efficient software implementation of the SM4 algorithm is conducive to the further popularization of SM4 as a national standard, and is conducive to the SM4 algorithm's campaign for international standards. The research on the fast software implementation method in the mobile terminal has strong practical application value.

SUMMARY OF THE INVENTION

Aiming at the problems in the related art, the present invention provides a method and device for implementing SM4 fast software based on an Android terminal.

An Android-based SM4 fast software implementation method, comprising:

Preprocessing files and keys to be encrypted or decrypted;

Persist the file and key to the database of the Android client and save it;

The Android client accesses the database, and encrypts or decrypts the to-be-encrypted or decrypted file.

The file to be encrypted or decrypted is any readable text file or binary file.

Wherein, the Android client accesses the database, and encrypts or decrypts the to-be-encrypted or decrypted file, including:

The Android client accesses the encryption or decryption method through the JNI interface.

Wherein, when the Android client accesses the encryption or decryption method through the JNI interface, it needs to verify whether the file to be encrypted or decrypted exists. After the verification is passed, the encryption or decryption method starts to encrypt or decrypt the file. decrypt.

Wherein, the encryption or decryption method starts to encrypt or decrypt the file, including:

Apply the key expansion algorithm to expand the initial key into 32 round keys;

The storage structure of the file and the round key is arranged and processed by applying the data arrangement technology;

32 rounds of iterative operations are performed on the arranged data by applying the composite domain decomposition technology;

The data after the iterative operation is de-arranged by applying the data arrangement technology, and the encryption or decryption calculation is completed.

Wherein, the data arrangement technology caches 128 groups of 128-bit data in advance, and applies the matrix transposition technology to transpose the cached data, so that the same bits of the 128 groups of data are gathered in the same memory block to complete the bit separation operation;

Among them, the composite domain decomposition technology uses the domain isomorphism theory to map the S box isomorphically to the composite domain GF((2 ⁴ ) ² ), transform the inversion operation of the S box to the composite domain, and then inversely map back to the composite domain. S box, thus completing the S box operation.

More specifically, the NEON instruction set is used to implement data arrangement in parallel, and seven sets of masks are used to complete the bit matrix transposition. The hexadecimal representation is:

MASK0=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

MASK1=CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

MASK2=F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0

MASK3=FF00FF00FF00FF00FF00FF00FF00FF00

MASK4=FFFF0000FFFF0000FFFF0000FFFF0000

MASK5=FFFFFFFF00000000FFFFFFFF00000000

MASK6=FFFFFFFFFFFFFFFF0000000000000000

By choosing appropriate base field Q(y) and quadratic extension field P(x), the inversion operation of S-box can be isomorphically mapped to composite field GF((2 ⁴ ) ² ).

Among them, the base domain is:

Q(y)=y ⁴ +y ³ +1;

The secondary expansion domain is:

P(x)=x ² +x+2;

The isomorphic mapping matrix is:

Furthermore, the inversion on the composite field GF((2 ⁴ ) ² ) is:

Let element a=(a ₁ *x+a ₀ )∈GF((2 ⁴ ) ² ), where a ₁ ,a ₀ ∈GF(2 ⁴ ), then the inverse element a ^-1 of element a can be expressed as:

a ^-1 =(δ ^-1 *a ₁ )*x+(δ ^-1 *(a ₁ +a ₀ ))

in,

According to another aspect of the present invention, an Android-based SM4 fast software implementation device is also provided, the device comprising:

A storage module, used to persist the file to be encrypted or decrypted and the key to the database of the Android client and save it;

The arrangement module is used to arrange the storage structure of the file to be encrypted or decrypted and the key to realize bit separation;

An iterative module for encrypting or decrypting the arranged files to be encrypted or decrypted

Wherein, the orchestration module includes:

The matrix transposition unit uses the NEON instruction set to act on the to-be-encrypted or decrypted file and the key, changes the storage structure of the to-be-encrypted or decrypted file and the key, and realizes bit separation.

The iteration module includes:

The composite domain operation unit uses the NEON instruction set to complete the isomorphic mapping from the S box to the composite domain, and completes the inverse operation of the to-be-encrypted or decrypted file in the composite domain, and then inversely maps back to the S box, thereby completing the nonlinear transformation and Linear transformation.

Description of drawings

1 is a flowchart of an Android-based SM4 fast software implementation method according to an embodiment of the present invention;

2 is a schematic diagram of a system structure of an Android-based SM4 fast software implementation method according to an embodiment of the present invention;

3 is a schematic flow chart of a specific embodiment of the present invention;

FIG. 4 is a block diagram of an Android terminal-based SM4 fast software implementation device according to an embodiment of the present invention.

Detailed ways

According to an embodiment of the present invention, an Android terminal-based SM4 fast software implementation method is provided.

As shown in Figure 1, the Android-based SM4 fast software implementation method according to an embodiment of the present invention includes:

Step S101, preprocessing the file and key to be encrypted or decrypted;

Step S102, the file and the key are persisted to the database of the Android client and saved;

Step S103, the Android client accesses the database, and encrypts or decrypts the to-be-encrypted or decrypted file.

The file to be encrypted or decrypted is any readable text file or binary file.

Wherein, the Android client accesses the database, and encrypts or decrypts the to-be-encrypted or decrypted file, including:

The Android client accesses the encryption or decryption method through the JNI interface.

Wherein, when the Android client accesses the encryption or decryption method through the JNI interface, it needs to verify whether the file to be encrypted or decrypted exists. After the verification is passed, the encryption or decryption method starts to encrypt or decrypt the file. decrypt.

Wherein, the encryption or decryption method starts to encrypt or decrypt the file, including:

Apply the key expansion algorithm to expand the initial key into 32 round keys;

The storage structure of the file and the key is arranged and processed by applying the data arrangement technology;

32 rounds of iterative operations are performed on the arranged data by applying the composite domain decomposition technology;

The data after the iterative operation is de-arranged by applying the data arrangement technology, and the encryption or decryption calculation is completed.

Wherein, the data arrangement technology caches 128 groups of 128-bit data in advance, and applies the matrix transposition technology to transpose the cached data, so that the same bits of the 128 groups of data are gathered in the same memory block to complete the bit separation operation;

Among them, the composite domain decomposition technology uses the domain isomorphism theory to map the S box isomorphically to the composite domain GF((2 ⁴ ) ² ), transform the inverse operation of the S box to the composite domain, and then inversely map back to the composite domain. S box, thus completing the S box operation.

The encrypted or decrypted data is persisted to the database of the Android client, and the Android application can read, write or display the data.

Please refer to FIG. 2 and FIG. 3 , FIG. 2 is a schematic structural diagram of the system of the present invention, and FIG. 3 is a flowchart of a specific embodiment. For a clearer understanding of the technical solutions of the present invention, a specific embodiment is described below.

Let the file to be encrypted be Plain, the data stored in it is 128 groups of 128-bit hexadecimal data P ₀ , P ₁ ,..., P ₁₂₅ , and the initial key is a group of 128-bit hexadecimal data InitKey .

Among them, P _i =01 23 45 67 89AB CD EF FE DC BA 98 76 54 32 10,0≤i≤127, InitKey=01 23 45 67 89 AB CD EF FE DC BA 98 76 54 32 10.

When the Android client accesses the encryption method through the JNI interface, it first verifies whether the Plain file exists, and after the verification is passed, the encryption method starts to encrypt the file.

Wherein, the encryption method starts to encrypt the file, including:

Apply the key expansion algorithm to expand the initial key into 32 round keys, denoted as rk _i , 0≤i≤31, and the expanded round key is:

rk ₀ = F12186F9

rk ₁ = 41662B61

rk ₂ =5A6AB19A

rk ₃ = 7BA92077

_rk4 = 367360F4

rk ₅ = 776A0C61

rk ₆ = B6BB89B3

_rk7 = 24763151

_rk8 = A520307C

rk ₉ = B7584DBD

rk ₁₀ = C30753ED

rk ₁₁ = 7EE55B57

rk ₁₂ = 6988608C

rk ₁₃ = 30D895B7

rk ₁₄ = 44BA14AF

rk ₁₅ = 104495A1

rk ₁₆ = D120B428

rk ₁₇ = 73B55FA3

rk ₁₈ = CC874966

rk ₁₉ = 92244439

rk ₂₀ = E89E641F

rk ₂₁ = 98CA015A

rk ₂₂ = C7159060

rk ₂₃ = 99E1FD2E

rk ₂₄ = B79BD80C

rk ₂₅ = 1D2115B0

rk ₂₆ = 0E228AEB

rk ₂₇ = F1780C81

rk ₂₈ = 428D3654

rk ₂₉ = 62293496

rk ₃₀ = 01CF72E5

rk ₃₁ = 9124A012

The storage structure of the file and the round key is arranged by applying the data arrangement technology. The data arrangement technology caches 128 groups of 128-bit data in advance, and the matrix transposition technology is applied to transpose the cached data to realize the 128 groups of data. The same bits are gathered in the same memory block to complete the bit separation operation. Denote the arranged data to be encrypted as P _i ′, 0≤i≤127, and the arranged round key as rk _i ′, 0≤i≤31, then:

P _i ′=(P _0,i P _1,i …P _127,i ) ₂ ,0≤i≤127

Among them, P _i,j represents the jth bit of P _i , (.) ₂ represents the binary form of the data, (rk _i,j ) ¹²⁸ represents that the jth bit of the round key rk _i is repeated 128 times and spliced.

32 rounds of iterative operations are performed on the arranged data by applying the composite domain decomposition technique. The composite domain decomposition technique uses the domain isomorphism theory to map the S box isomorphically to the composite domain GF((2 ⁴ ) ² ), and the S The inversion operation of the box is transformed to the composite domain, and then inversely mapped back to the S box to complete the S box operation.

After the iteration is completed, the corresponding output ciphertext is obtained, and then the ciphertext after the iteration is de-arranged by applying the data arrangement technology, so as to obtain the real ciphertext C _i , 0≤i≤127, where:

C _i = 68 1E DF 34D2 06 96 5E 86 B3 E9 4F 53 6E 42 46

The encrypted data is persisted to the database of the Android client, and the Android application can read, write or display the data.

The present invention mainly studies the fast encryption and decryption of various types of files by applying the SM4 algorithm on mobile terminals such as mobile phones with limited resources. The main technologies applied are: Android intelligent platform, NEON instruction set, bit slicing technology, Java native method technology, and domain isomorphism technology. The focus is mainly on the Java application mounted on the Android intelligent platform, using Java to call the C language interface through the local method, and completing the encryption and decryption of the file through the composite domain decomposition technology.

1. Main application technology points.

The invention is based on Java calling JNI technology, Android mobile development technology, Java calling and executing C language technology;

NEON instruction set;

Bit slicing technology;

Domain isomorphism techniques.

2. The principle and function of the present invention are described in detail.

After the Android client application is launched, the user needs to manually input the file path to be encrypted or decrypted. For the encryption function, the user also needs to provide a key for file encryption.

The Android client application needs to verify whether the file to be encrypted or decrypted exists. After the verification is passed, the file to be encrypted or decrypted and the key are imported and saved in the database of the Android client.

The Android client application invokes the corresponding encryption or decryption method according to the input file to be encrypted or decrypted and the key. It mainly accesses the SM4 method encoded in C language through the JNI interface.

After the interface receives it, it reads the file and key data to be encrypted or decrypted from the database, and performs the corresponding encryption or decryption operation. After the encryption or decryption is completed, the data is stored in the database and the operation result is returned.

According to the returned result, the Android client displays whether the encryption or decryption is successful through the Android UI components.

According to an embodiment of the present invention, an Android-based SM4 fast software implementation device is also provided. As shown in FIG. 4 , the device includes:

The storage module 51 is used to store the files and keys to be encrypted or decrypted;

The arrangement module 52 is used to arrange the storage structure of the file to be encrypted or decrypted and the key to realize bit separation;

The iterative module 53 is used to perform compound domain operations on the programmed files to be encrypted or decrypted to complete nonlinear and linear operations.

To sum up, with the help of the above technical solutions of the present invention, the present invention can efficiently implement the SM4 algorithm on resource-constrained mobile terminals such as Android terminals, can effectively reduce computational complexity, reduce resource consumption, and provide safe and efficient data protection scheme.

Finally, it should be noted that the above embodiments are only to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be modified. Any modification or partial replacement without departing from the spirit and scope of the present invention shall be included in the scope of the claims of the present invention.

Claims (4)

1. a kind of SM4 fast software realization method based on Android side, is characterized in that, comprises: Preprocessing files and initial keys to be encrypted or decrypted; Persist the file and key to the database of the Android client and save it; The Android client accesses the database, and encrypts or decrypts the to-be-encrypted or decrypted file; including: The Android client accesses the encryption or decryption method through the JNI interface; Wherein, when the Android client accesses the encryption or decryption method through the JNI interface, it needs to verify whether the file to be encrypted or decrypted exists. After the verification is passed, the encryption or decryption method starts to encrypt or decrypt the file. decrypt; The encryption or decryption method starts to encrypt or decrypt the file, including: Apply the key expansion algorithm to expand the initial key into 32 round keys; The storage structure of the file and the round key is arranged and processed by applying the data arrangement technology; 32 rounds of iterative operations are performed on the arranged data by applying the composite domain decomposition technology; Applying the data arrangement technology to perform de-arrangement processing on the data after the iterative operation, and the encryption or decryption calculation is completed; The data arrangement technology caches 128 groups of 128-bit data in advance, and applies the matrix transposition technology to transpose the cached data, so that the same bits of the 128 groups of data are gathered in the same memory block to complete the bit separation operation; The composite domain decomposition technique uses the domain isomorphism theory to map the S box isomorphically to the composite domain GF((2 ⁴ ) ² ), transform the inverse operation of the S box to the composite domain, and then inversely map it back to the S box, so that Complete the S-box operation; Use the NEON instruction set to implement data arrangement in parallel, and use seven sets of masks to complete the bit matrix transposition. The hexadecimal representation is: MASK0=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA MASK1=CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC MASK2=F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0 MASK3=FF00FF00FF00FF00FF00FF00FF00FF00 MASK4=FFFF0000FFFF0000FFFF0000FFFF0000 MASK5=FFFFFFFF00000000FFFFFFFF00000000 MASK6=FFFFFFFFFFFFFFFF0000000000000000. 2. The method according to claim 1, characterized in that, by selecting an appropriate base field Q(y) and a quadratic expansion field P(x), the inversion operation of the S box can be isomorphically mapped to the composite field GF ((2 ⁴ ) ² ), where, The base domain is: Q(y)=y ⁴ +y ³ +1 The secondary expansion domain is: P(x)=x ² +x+2 The isomorphic mapping matrix is:

3. The method according to claim 2, wherein the inversion on the composite field GF((2 ⁴ ) ² ) is: Let element a=(a ₁ *x+a ₀ )∈GF((2 ⁴ ) ² ), where a ₁ ,a ₀ ∈GF(2 ⁴ ), then the inverse element a ^-1 of element a can be expressed as: a ^-1 =(δ ^-1 *a ₁ )*x+(δ ^-1 *(a ₁ +a ₀ )) in,

4. a kind of SM4 fast software implementation device based on Android side, is characterized in that, comprises: The storage module is used to persist and save the files and keys to be encrypted or decrypted to the database of the Android client; The Android client accesses the database, and encrypts or decrypts the to-be-encrypted or decrypted file; including: The Android client accesses the encryption or decryption method through the JNI interface; Wherein, when the Android client accesses the encryption or decryption method through the JNI interface, it needs to verify whether the file to be encrypted or decrypted exists. After the verification is passed, the encryption or decryption method starts to encrypt or decrypt the file. Decryption; an encryption or decryption method begins to encrypt or decrypt the file, including: The initial key is expanded into 32 round keys by applying the key expansion algorithm; the arrangement module is used to arrange the storage structure of the file to be encrypted or decrypted and the key to achieve bit separation; the iterative module is used to arrange the files to be encrypted or decrypted. Encrypt or decrypt files to encrypt or decrypt; The orchestration module includes: The matrix transposition unit uses the NEON instruction set to act on the file to be encrypted or decrypted and the key, and changes the storage structure of the file to be encrypted or decrypted and the key to achieve bit separation; Iteration modules include: The composite domain operation unit uses the NEON instruction set to complete the isomorphic mapping from the S box to the composite domain, and completes the inverse operation of the to-be-encrypted or decrypted file in the composite domain, and then inversely maps back to the S box, thereby completing the nonlinear transformation and linear transformation; Among them, the data arrangement technology caches 128 groups of 128-bit data in advance, and applies the matrix transposition technology to transpose the cached data, so that the same bits of the 128 groups of data are gathered in the same memory block to complete the bit separation operation; The composite domain decomposition technique uses the domain isomorphism theory to map the S box isomorphically to the composite domain GF((2 ⁴ ) ² ), transform the inverse operation of the S box to the composite domain, and then inversely map it back to the S box, so that Complete the S-box operation; Use the NEON instruction set to implement data arrangement in parallel, and use seven sets of masks to complete the bit matrix transposition. The hexadecimal representation is: MASK0=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA MASK1=CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC MASK2=F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0 MASK3=FF00FF00FF00FF00FF00FF00FF00FF00 MASK4=FFFF0000FFFF0000FFFF0000FFFF0000 MASK5=FFFFFFFF00000000FFFFFFFF00000000 MASK6=FFFFFFFFFFFFFFFF0000000000000000.

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