TWI762120B - File encryption and decryption method, device , and electronic device - Google Patents

Abstract

The present application provides a file encryption and decryption method, a file encryption and decryption device, and an electronic device. The file encryption and decryption method includes: generating non-symmetrical keys through a non-symmetric encryption algorithm; generating at least one pair of symmetrical keys through symmetric encryption algorithms, each pair of non-symmetrical keys including public keys and private keys; generating a first encrypted file by encrypting original file by encrypting the symmetric keys; at least one pair of public keys in the symmetrical key encrypting the symmetric key to generate a first ciphertext; calculating a MD5 value of the original file, and calculating the MD5 value, the public keys of at least one pair of the non-symmetrical keys, and a first total length of the first ciphertext; adding the first total length as a header file of the first encrypted file, and adding the header file, at least one pair of public keys in the non-symmetrical key, and the first file to the first encrypted file to generate a second encrypted file.

Description

File encryption and decryption method, device and electronic device

The invention relates to the field of file encryption, in particular to a file encryption and decryption method, device and electronic equipment.

The common encryption method of existing documents is usually to encrypt and decrypt with a symmetric key or two asymmetric keys. The above method restricts the use of a specific and unique key to decrypt, so that when multiple people use the document, they all use the same key to decrypt the document, which reduces the security of the document. In addition, if you want to prevent a third party from having the same key, for example, when you share an encrypted document with a third party, you do not want the third party to have the same key, then you must use another key pair that has been encrypted The document is encrypted again, which will cause inconvenience to use.

In view of the above, it is necessary to propose a file encryption and decryption method, device and electronic device, so as to avoid the problem of reducing the security of the file when using the same key to decrypt the file, and to avoid the inconvenience caused by re-encrypting the file. question.

A first aspect of the present application provides a file encryption and decryption method, the method includes: generating a symmetric key by a symmetric encryption algorithm; generating at least one pair of asymmetric keys by an asymmetric encryption algorithm, each For asymmetric keys, including public key and private key; encrypting the original document with a symmetric key to generate a first encrypted document; encrypting the symmetric key with the public key in the at least a pair of asymmetric keys to generate a first ciphertext; calculating the original document and calculate the MD5 value, the public key of the at least one pair of asymmetric keys, and the first total length of the first ciphertext; take the first total length as the first encryption A header file of the document, and the header file, the public key in the at least one pair of asymmetric keys, and the first ciphertext are added to the first encrypted document to generate a second encrypted document.

Preferably, the method further comprises: decrypting the second encrypted document by using the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys to obtain the symmetric key and all and decrypting the first encrypted document by using the symmetric key to obtain the original document.

Preferably, obtaining the symmetric key by decrypting the second encrypted document with the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys comprises: The private key in each pair of asymmetric keys of at least one pair of asymmetric keys decrypts the ciphertext corresponding to each pair of asymmetric keys in the header file to obtain the symmetric key key.

Preferably, the generating at least one pair of asymmetric keys by the asymmetric encryption method includes: determining the number of the asymmetric keys according to the number of shares of the original document.

Preferably, the method further comprises: receiving an instruction to add one or more pairs of asymmetric keys; adding one or more pairs of newly added asymmetric keys according to the instructions; The public key in the key encrypts the symmetric key to generate a second ciphertext

calculating the MD5 value, the public key of the at least one pair of asymmetric keys, the newly added asymmetric key, the first ciphertext, the second total length of the second ciphertext; and The second total length is used as the header file of the second encrypted document, and the header file of the second encrypted document, the public key in the at least one pair of asymmetric keys, the new The public key in the added asymmetric key, the first ciphertext, and the second ciphertext are added to the first encrypted document to generate a third encrypted document.

Preferably, the method further comprises: using a private key in each pair of asymmetric keys of the at least one pair of asymmetric keys or a pair of private keys in the newly added asymmetric key decrypting the third encrypted document to obtain the symmetric key and the first encrypted document; and decrypting the first encrypted document using the symmetric key to obtain the original document.

A second aspect of the present application provides a file encryption and decryption device, the device includes: a first key generation module for generating a symmetric key by using a symmetric encryption algorithm; a second key generation module for using generating at least a pair of asymmetric keys by an asymmetric encryption algorithm, each pair of asymmetric keys includes a public key and a private key; the first encryption module is used for encrypting the original document by the symmetric key performing encryption to generate a first encrypted document; a ciphertext generation module, used for encrypting the symmetric key with the public key in the at least one pair of asymmetric keys to generate a first ciphertext; a calculation module, using In calculating the MD5 value of the original document, and calculating the MD5 value, the public key of the at least one pair of asymmetric keys, and the first total length of the first ciphertext; the second encryption module, using taking the first total length as the header file of the first encrypted document, and adding the header file, the public key in the at least one pair of asymmetric keys, and the first ciphertext A second encrypted document is generated from the first encrypted document.

Preferably, the device further includes a decryption module, and the decryption module is used for: Decrypting the second encrypted document by using the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys to obtain the symmetric key and the first encrypted document; and using the The symmetric key decrypts the first encrypted document to obtain the original document.

Preferably, the decryption module uses the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys to pair the header file with each pair of asymmetric keys in the header file. The ciphertext corresponding to the key is decrypted to obtain the symmetric key.

A third aspect of the present application provides an electronic device, the electronic device includes a processor and a memory, and the processor is configured to implement the above file encryption and decryption method when executing a computer program stored in the memory.

In this case, the first total length composed of the MD5 value of the original document, and calculating the MD5 value, the public key of at least one pair of asymmetric keys, and the first ciphertext is used as the header file of the first encrypted document, and The header file, the public key in the at least one pair of asymmetric keys, and the first ciphertext are added to the first encrypted document to generate a second encrypted document, which can avoid using the same key The problem of reducing the security of the file when decrypting the file and avoiding the problem of inconvenience caused by re-encrypting the file.

30: File encryption and decryption device

301: The first key generation module

302: Second key generation module

303: The first encryption module

304: Ciphertext generation module

305: Computing Modules

306: Second encryption module

307: Decryption Module

6: Electronic equipment

61: Memory

62: Processor

63: Computer Programs

S11~S16: Steps

FIG. 1 is a flowchart of a file encryption and decryption method according to an embodiment of the present invention.

FIG. 2 is a structural diagram of a file encryption and decryption apparatus according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of an electronic device in an embodiment of the present invention.

In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments may be combined with each other in the case of no conflict.

In the following description, many specific details are set forth in order to facilitate a full understanding of the present invention, and the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

Preferably, the file encryption and decryption method of the present invention is applied in one or more electronic devices. The electronic device is a device that can automatically perform numerical calculations and/or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application specific integrated circuits (ASICs) , Programmable Gate Array (Field-Programmable Gate Array, FPGA), Digital Signal Processor (Digital Signal Processor, DSP), embedded devices, etc.

The electronic device may be a computing device such as a desktop computer, a notebook computer, a tablet computer, and a cloud server. The device can interact with the user by means of a keyboard, a mouse, a remote control, a touch pad or a voice control device.

Example 1

FIG. 1 is a flowchart of a file encryption and decryption method according to an embodiment of the present invention. According to different requirements, the order of the steps in the flowchart can be changed, and some steps can be omitted.

Referring to FIG. 1 , the file encryption and decryption method specifically includes the following steps.

In step S11, a symmetric key is generated by a symmetric encryption algorithm.

In this embodiment, a symmetric key is generated by a symmetric encryption algorithm, and the original document is encrypted by the symmetric key or the encrypted file is decrypted by the symmetric key to obtain the original document. In this embodiment, the symmetric encryption algorithm includes, but is not limited to, the DES algorithm, the 3DES algorithm, the TDEA algorithm, the Blowfish algorithm, and the RC5 algorithm.

In step S12, at least one pair of asymmetric keys is generated by an asymmetric encryption algorithm, and each pair of asymmetric keys includes a public key and a private key.

In this embodiment, at least one pair of asymmetric keys is generated by an asymmetric encryption algorithm, wherein the public key in the at least one pair of asymmetric keys is used to encrypt the original document, and the at least one pair of asymmetric keys is used to encrypt the original document. The private key in the asymmetric key is used to decrypt the original document. In this embodiment, the asymmetric key algorithm includes, but is not limited to, the RSA algorithm, the Elganal algorithm, the knapsack algorithm, the Rabin algorithm, the D-H algorithm, and the elliptic curve encryption algorithm.

In this embodiment, the asymmetric keys include multiple pairs, and the generating at least one pair of asymmetric keys by an asymmetric encryption method includes: determining the asymmetric keys according to the number of shares of the original document quantity. For example, when the original document needs to be distributed to three users, user A, user B, and user C, the method determines that the original sharing quantity is three, and determines the original sharing quantity according to the sharing quantity of the original document. The number of asymmetric keys is three, and three pairs of asymmetric keys are generated by an asymmetric encryption algorithm. Among them, the private keys in each of the three pairs of asymmetric keys are allocated to user A, user B, and user C, respectively, so that user A, user B, and user C The key decrypts the document encrypted by the corresponding public key.

Step S13, encrypting the original document with a symmetric key to generate a first encrypted document.

Step S14, encrypting the symmetric key with the public key in the at least one pair of asymmetric keys to generate a first ciphertext.

Step S15: Calculate the MD5 value of the original document, and calculate the MD5 value, the public key of the at least one pair of asymmetric keys, and the first total length of the first ciphertext.

Step S16, use the first total length as the header file of the first encrypted document, and use the header file, the public key in the at least one pair of asymmetric keys, and the first encryption key. document is added to the first encrypted document to generate a second encrypted document.

In this embodiment, the method further includes: decrypting the second encrypted document by using the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys to obtain the symmetric key and the first encrypted document; and decrypt the first encrypted document using the symmetric key Get the original document. In this embodiment, the obtaining the symmetric key by decrypting the second encrypted document using the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys includes: The private key in each pair of asymmetric keys of the at least one pair of asymmetric keys decrypts the ciphertext corresponding to each pair of asymmetric keys in the header file to obtain the symmetric key key. The ciphertext corresponding to each pair of asymmetric keys is generated by encrypting the symmetric key with the public key in each pair of asymmetric keys.

In this embodiment, the method further includes: receiving an instruction to add one or more pairs of asymmetric keys; adding one or more pairs of newly added asymmetric keys according to the instructions; The public key in the symmetric key encrypts the symmetric key to generate a second ciphertext; calculates the MD5 value, the public key of the at least one pair of asymmetric keys, and the newly added asymmetric key key, the first ciphertext, the second total length of the second ciphertext; and the second total length as the header file of the second encrypted document, and the second encrypted document The header file, the public key in the at least one pair of asymmetric keys, the public key in the newly added asymmetric key, and the first ciphertext and the second ciphertext are added to the A third encrypted document is generated from the first encrypted document.

In this embodiment, the method further includes: using a private key in each pair of asymmetric keys of the at least one pair of asymmetric keys or a private key in the newly added asymmetric key Decrypting the third encrypted document to obtain the symmetric key and the first encrypted document; and decrypting the first encrypted document using the symmetric key to obtain the original document.

In this implementation manner, when it is determined that the number of the asymmetric keys is three according to the number of shares of the original documents, the three asymmetric keys are respectively a first pair of asymmetric keys and a second pair of asymmetric keys. Symmetric key and a third pair of asymmetric keys. The method encrypts the symmetric key with the public key in the first pair of asymmetric keys to generate a first sub-ciphertext, and encrypts the public key in the second pair of asymmetric keys with all the keys. encrypting the symmetric key to generate a second sub-ciphertext, encrypting the symmetric key with the public key in the third pair of asymmetric keys to generate a third sub-ciphertext, calculating the MD5 value, the The public key in the first pair of asymmetric keys, the public key in the second pair of asymmetric keys, the public key in the third pair of asymmetric keys, the first subkey text, the second sub-ciphertext, the The first total length of the third sub-ciphertext, the first total length is used as the header file of the first encrypted document, and the header file, the first pair of asymmetric keys are public key, the public key in the second pair of asymmetric keys, the public key in the third pair of asymmetric keys, the first sub-ciphertext, the second sub-ciphertext, The third sub-ciphertext is added to the first encrypted document to generate a second encrypted document.

The present invention uses the MD5 value of the original document, and calculates the MD5 value, the public key of at least a pair of asymmetric keys, and the first total length of the first ciphertext as the header file of the first encrypted document, The header file, the public key in the at least one pair of asymmetric keys, and the first ciphertext are added to the first encrypted document to generate a second encrypted document, which can avoid using the same key When the key is used to decrypt the file, the security of the file is reduced, and the problem of inconvenience caused by re-encrypting the file is avoided.

Example 2

FIG. 2 is a structural diagram of a file encryption and decryption apparatus 30 according to an embodiment of the present invention.

In some embodiments, the file encryption and decryption device 30 may include a plurality of functional modules composed of code segments. The code of each program segment in the file encryption and decryption device 30 can be stored in memory and executed by at least one processor.

In this embodiment, the file encryption and decryption device 30 can be divided into a plurality of functional modules according to the functions performed by the file encryption and decryption device 30 . 2, the file encryption and decryption device 30 may include a first key generation module 301, a second key generation module 302, a first encryption module 303, a ciphertext generation module 304, a calculation module Group 305 , second encryption module 306 and decryption module 307 . The module referred to in the present invention refers to a series of computer program segments that can be executed by at least one processor and can perform fixed functions, and are stored in a memory. In some embodiments, the functions of each module will be described in detail in subsequent embodiments.

The first key generation module 301 generates a symmetric key through a symmetric encryption algorithm.

In this embodiment, a symmetric key is generated by a symmetric encryption algorithm, and the original document is encrypted by the symmetric key or the encrypted file is decrypted by the symmetric key to obtain the original document. In this embodiment, the symmetric encryption algorithm includes, but is not limited to, the DES algorithm, the 3DES algorithm, the TDEA algorithm, the Blowfish algorithm, and the RC5 algorithm.

The second key generation module 302 generates at least a pair of asymmetric keys through an asymmetric encryption algorithm, and each pair of asymmetric keys includes a public key and a private key.

In this embodiment, at least one pair of asymmetric keys is generated by an asymmetric encryption algorithm, wherein the public key in the at least one pair of asymmetric keys is used to encrypt the original document, and the at least one pair of asymmetric keys is used to encrypt the original document. The private key in the asymmetric key is used to decrypt the original document. In this embodiment, the asymmetric key algorithm includes, but is not limited to, the RSA algorithm, the Elganal algorithm, the knapsack algorithm, the Rabin algorithm, the D-H algorithm, and the elliptic curve encryption algorithm.

In this embodiment, the asymmetric keys include multiple pairs, and the second key generation module 302 determines the number of the asymmetric keys according to the number of shares of the original document. For example, when the original document needs to be distributed to three users, user A, user B, and user C, the second key generation module 302 determines that the original sharing quantity is three, and according to the original document The number of sharing determines that the number of the asymmetric keys is three, and three pairs of asymmetric keys are generated by an asymmetric encryption algorithm. Among them, the private keys in each of the three pairs of asymmetric keys are allocated to user A, user B, and user C, respectively, so that user A, user B, and user C The key decrypts the document encrypted by the corresponding public key.

The first encryption module 303 is used for encrypting the original document with a symmetric key to generate a first encrypted document.

The ciphertext generating module 304 is configured to generate a first ciphertext by encrypting the symmetric key with the public key in the at least one pair of asymmetric keys.

The calculation module 305 is configured to calculate the MD5 value of the original document, and calculate the MD5 value, the public key of the at least one pair of asymmetric keys, and the first total length of the first ciphertext.

The second encryption module 306 is configured to use the first total length as the header file of the first encrypted document, and use the header file and the public key in the at least one pair of asymmetric keys. The key and the first ciphertext are added to the first encrypted document to generate a second encrypted document.

The decryption module 307 decrypts the second encrypted document by using the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys to obtain the symmetric key and the first encrypting the document, and decrypting the first encrypted document using the symmetric key to obtain the original document. In this embodiment, the decryption module 307 uses the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys to pair the header file with each pair of asymmetric keys The ciphertext corresponding to the key is decrypted to obtain the symmetric key. The ciphertext corresponding to each pair of asymmetric keys is generated by encrypting the symmetric key with the public key in each pair of asymmetric keys.

In this embodiment, the second key generation module 302 is further configured to receive an instruction for adding one or more pairs of asymmetric keys, and add one or more pairs of newly added asymmetric keys according to the instruction . The ciphertext generating module 304 is configured to encrypt the symmetric key with the public key in the newly added asymmetric key to generate a second ciphertext. The calculation module 305 is further configured to calculate the MD5 value, the public key of the at least one pair of asymmetric keys, the newly added asymmetric key, the first ciphertext, the second The second total length of the ciphertext. The second encryption module 306 is further configured to use the second total length as the header file of the second encrypted document, and use the header file of the second encrypted document, the at least one pair of asymmetric The public key in the key, the public key in the newly added asymmetric key, and the first ciphertext and the second ciphertext are added to the first encrypted document to generate a third encryption documentation.

In this embodiment, the decryption module 307 is further configured to use the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys or the key in the newly added asymmetric key The private key decrypts the third encrypted document to obtain the symmetric key and the first encrypted document, and uses the symmetric key to decrypt the first encrypted document to obtain the original document.

In this embodiment, when the second key generation module 302 determines that the number of the asymmetric keys is three according to the number of shares of the original documents, the generated three asymmetric keys are the first pair respectively. Asymmetric keys, a second pair of asymmetric keys, and a third pair of asymmetric keys. The ciphertext generating module Group 304 encrypts the symmetric key with the public key in the first pair of asymmetric keys to generate a first sub-ciphertext, and encrypts the public key in the second pair of asymmetric keys with the symmetric key. The symmetric key is encrypted to generate a second sub-ciphertext, and the public key in the third pair of asymmetric keys is encrypted to the symmetric key to generate a third sub-ciphertext. The calculation module 305 calculates the MD5 value, the public key in the first pair of asymmetric keys, the public key in the second pair of asymmetric keys, and the third pair of asymmetric keys. The public key in the key, the first sub-ciphertext, the second sub-ciphertext, and the first total length of the third sub-ciphertext. The second encryption module 306 uses the first total length as the header file of the first encrypted document, and uses the header file, the public key in the first pair of asymmetric keys, The public key in the second pair of asymmetric keys, the public key in the third pair of asymmetric keys, the first sub-ciphertext, the second sub-ciphertext, the third sub-ciphertext The sub-ciphertext is added to the first encrypted document to generate a second encrypted document.

The present invention uses the MD5 value of the original document, and calculates the MD5 value, the public key of at least a pair of asymmetric keys, and the first total length of the first ciphertext as the header file of the first encrypted document, The header file, the public key in the at least one pair of asymmetric keys, and the first ciphertext are added to the first encrypted document to generate a second encrypted document, which can avoid using the same key When the key is used to decrypt the file, the security of the file is reduced, and the problem of inconvenience caused by re-encrypting the file is avoided.

Example 3

FIG. 3 is a schematic diagram of an electronic device 6 in an embodiment of the present invention.

The electronic device 6 includes a memory 61 , a processor 62 and a computer program 63 stored in the memory 61 and executable on the processor 62 . When the processor 62 executes the computer program 63 , the steps in the above-described file encryption and decryption method embodiments are implemented, such as steps S11 to S16 shown in FIG. 1 . Alternatively, when the processor 62 executes the computer program 63, the functions of each module/unit in the above-mentioned embodiment of the file encryption and decryption apparatus, such as modules 301-307 in FIG. 2, are realized.

Exemplarily, the computer program 63 can be divided into one or more modules/units, and the one or more modules/units are stored in the memory 61 and executed by the processor 62. to complete the present invention. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 63 in the electronic device 6 . For example, the computer program 63 can be divided into the first key generation module 301, the second key generation module 302, the first encryption module 303, the ciphertext generation module 304, and the calculation module in FIG. 2 . 305, the second encryption module 306 and the decryption module 307, the specific functions of each module refer to Embodiment 2.

Those skilled in the art can understand that the schematic diagram is only an example of the electronic device 6, and does not constitute a limitation to the electronic device 6, and may include more or less components than the one shown, or combine some components, or different Components such as the electronic device 6 may also include input and output devices, network access devices, bus bars, and the like.

The processor 62 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs) ), Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor 62 can also be any conventional processor, etc. The processor 62 is the control center of the electronic device 6, and uses various interfaces and lines to connect the entire electronic device 6. various parts.

The memory 61 can be used to store the computer programs 63 and/or modules/units, and the processor 62 runs or executes the computer programs and/or modules/units stored in the memory 61, And call the data stored in the memory 61 to realize various functions of the electronic device 6 . The memory 61 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; storage data The area may store data (such as audio data, phone book, etc.) created according to the use of the electronic device 6, and the like. In addition, the memory 61 may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, Smart Media Card (SMC), Secure Digital (Secure Digital, SD) card, flash memory card (Flash Card), at least one disk memory device, flash memory device, or other volatile solid state memory device.

If the modules/units integrated in the electronic device 6 are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the present invention realizes all or part of the processes in the methods of the above embodiments, and can also be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, When the computer program is executed by the processor, the steps of the above method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of original code, object code, executable file, or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a flash drive, a removable hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM, Read-Only Memory); Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to the legislation and patent practice, the computer-readable medium Electric carrier signals and telecommunication signals are not included.

In the several embodiments provided by the present invention, it should be understood that the disclosed electronic devices and methods may be implemented in other manners. For example, the above-described electronic device embodiments are only illustrative. For example, the division of the modules is only a logical function division, and other division methods may be used in actual implementation.

In addition, each functional module in each embodiment of the present invention may be integrated in the same processing module, or each module may exist physically alone, or two or more modules may be integrated in the same module. The above-mentioned integrated modules can be implemented in the form of hardware, or can be implemented in the form of hardware plus software function modules.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as exemplary and not restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description, and is therefore intended to fall within the scope of the patent application. All changes within the meaning and scope of equivalents to the scope are encompassed within the invention. Any reference signs in the patentable scope should not be construed as limiting the claimed scope. Furthermore, it is clear that the word "comprising" does not exclude other modules or steps, and the singular does not exclude the plural. Multiple modules or electronic devices stated in the scope of the electronic device patent application can also be implemented by the same module or electronic device through software or hardware. The terms first, second, etc. are used to denote names and do not denote any particular order.

To sum up, the present invention complies with the requirements of an invention patent, and a patent application can be filed in accordance with the law. However, the above descriptions are only the preferred embodiments of the present invention, and for those who are familiar with the techniques of this case, equivalent modifications or changes made in accordance with the creative spirit of this case shall be included in the scope of the following patent application.

S11~S16: Steps

Claims (9)

A file encryption and decryption method, applied in electronic equipment, the improvement is that the method comprises: generating a symmetric key by a symmetric encryption algorithm; generating at least a pair of asymmetric keys by an asymmetric encryption algorithm , each pair of asymmetric keys includes a public key and a private key, wherein the generating at least one pair of asymmetric keys by an asymmetric encryption algorithm includes: determining the number of shares according to the original document. the number of the asymmetric keys; encrypt the original document with the symmetric key to generate a first encrypted document; encrypt the symmetric key with the public key in the at least one pair of asymmetric keys to generate the first encrypted document Ciphertext; calculate the MD5 value of the original document, and calculate the MD5 value, the public key of the at least one pair of asymmetric keys, and the first total length of the first ciphertext; The total length is used as the header file of the first encrypted document, and the header file, the public key in the at least one pair of asymmetric keys, and the first ciphertext are added to the first encrypted file A second encrypted document is generated from the document. The file encryption and decryption method according to claim 1, wherein the method further comprises: pairing the second asymmetric key with a private key in each pair of asymmetric keys of the at least one pair of asymmetric keys Decrypt the encrypted document to obtain the symmetric key and the first encrypted document; and decrypt the first encrypted document by using the symmetric key to obtain the original document. The file encryption and decryption method according to claim 2, wherein the second encrypted file is decrypted by using the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys Obtaining the symmetric key includes: pairing the header file with the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys The ciphertext corresponding to the key is decrypted to obtain the symmetric key. The file encryption and decryption method according to claim 1, wherein the method further comprises: receiving an instruction to add one or more pairs of asymmetric keys; adding one or more pairs of newly added asymmetric keys according to the instruction key; encrypt the symmetric key with the public key in the newly added asymmetric key to generate a second ciphertext, calculate the MD5 value, the public key of the at least one pair of asymmetric keys , the newly added asymmetric key, the first ciphertext, the second total length of the second ciphertext; and the second total length as the header file of the second encrypted document, and the header file of the second encrypted document, the public key in the at least one pair of asymmetric keys, the public key in the newly added asymmetric key, and the first ciphertext . The second ciphertext is added to the first encrypted document to generate a third encrypted document. The file encryption and decryption method according to claim 4, wherein the method further comprises: using the private key in each pair of asymmetric keys of the at least one pair of asymmetric keys or the new addition Decrypt the third encrypted document with the private key in the asymmetric key to obtain the symmetric key and the first encrypted document; and use the symmetric key to decrypt the first encrypted document to obtain the original document. A file encryption and decryption device, which is improved in that the device comprises: a first key generation module for generating a symmetric key by a symmetric encryption algorithm; a second key generation module for using The asymmetric encryption algorithm generates at least a pair of asymmetric keys, each pair of asymmetric keys includes a public key and a private key, wherein the at least a pair of asymmetric keys is generated by the asymmetric encryption algorithm The key includes: determining the number of the asymmetric keys according to the number of shares of the original document; a first encryption module for encrypting the original document by the symmetric key to generate a first encrypted document; A ciphertext generation module, configured to encrypt the symmetric key with the public key in the at least a pair of asymmetric keys to generate a first ciphertext; a calculation module, used to calculate the MD5 of the original document value, and calculate the MD5 value, the public key of the at least one pair of asymmetric keys, and the first total length of the first ciphertext; the second encryption module is used to convert the first total length As a header file of the first encrypted document, and adding the header file, the public key in the at least one pair of asymmetric keys, and the first ciphertext to the first encrypted document A second encrypted document is generated. The file encryption and decryption device according to claim 6, wherein the device further comprises a decryption module, and the decryption module is used for: using each pair of asymmetric keys of the at least one pair of asymmetric keys Decrypt the second encrypted document with the private key in the key to obtain the symmetric key and the first encrypted document; and use the symmetric key to decrypt the first encrypted document to obtain the original document . The file encryption and decryption device of claim 7, wherein the decryption module pairs the target with a private key in each pair of asymmetric keys of the at least one pair of asymmetric keys. The ciphertext corresponding to each pair of asymmetric keys in the header file is decrypted to obtain the symmetric key. An electronic device, wherein the electronic device includes a processor and a memory, and the processor is configured to implement file encryption and decryption as described in any one of claim 1 to 5 when executing a computer program stored in the memory method.

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