CN118573672A - File transmission method, device, medium and equipment - Google Patents

Abstract

The present application discloses a file transmission method, device, medium and equipment, and relates to the field of network security technology. The file is split into multiple independent encrypted fragments, each of which carries an encryption key fragment, and is transmitted through different secure paths, making it difficult for attackers to obtain the complete file content and key information, significantly enhancing the security and flexibility of data transmission. This strategy ensures that even if an attacker can intercept some fragments, the original content of the file cannot be restored by these fragments alone, because the information between the fragments is independent of each other and lacks the necessary decryption information and integrity verification; in addition, through the path encryption information, each relay point can only decrypt the address of the next relay point, preventing the path information from being leaked to unauthorized relay points, and the parallel processing of multiple transmission paths also improves the efficiency of data transmission, making the transmission of large files faster and more reliable.

Description

File transmission method, device, medium and equipment

Technical Field

The present application relates to the field of network security, and in particular to a file transmission method, device, medium and equipment.

Background Art

With the continuous evolution of cyber attack methods, traditional file transfer methods have exposed many security risks. On the one hand, data transmission on the Internet can be easily tracked by third parties, exposing the source and flow of information and threatening user privacy; on the other hand, data may pass through multiple network nodes during transmission. The intrusion of any node or the deployment of monitoring equipment may lead to illegal interception of information, especially when the key management is poor or the encryption algorithm is cracked, the security of files is even more difficult to guarantee.

Existing secure transmission solutions, such as SSL/TLS protocol, HTTPS, etc., have improved the security of data transmission to a certain extent, but they mainly focus on encrypted data transmission, and still have limitations in preventing the tracking of data sources and destinations and ensuring the absolute security of data fragmentation in complex network environments. Especially in the face of APT (Advanced Persistent Threat) and zero-day attacks, a single encryption and direct transmission strategy seems to be inadequate.

Summary of the invention

In order to solve at least one of the technical problems mentioned in the background technology, the purpose of this application is to provide a file transfer method, device, medium and equipment, which can reduce the risk of key leakage, achieve anti-tracking and anti-theft during file transfer, and improve the security of file transfer.

To achieve the above objectives, this application provides the following technical solutions:

In a first aspect, an embodiment of the present application provides a file transmission method, including:

At the sending end, the original file is encrypted by using the key to obtain an encrypted file, and the encrypted file is divided into multiple encrypted slices; the key is encrypted by using the public key to obtain an encryption key, and the encryption key is divided into multiple encryption key slices, and the encryption key slices correspond to the encryption slices one by one; each encryption slice carries an encryption key slice, additional information and path encryption information, and the additional information includes an encryption slice number, the number of encryption slices, and the encryption key slice number; the additional information is encrypted by the public key;

According to the preset transmission path, the encrypted fragments are transmitted through multiple relay points until they are received by the receiving end; each relay point decrypts the path encryption information to obtain the address of the next relay point;

After receiving the encrypted slices at the receiving end, the additional information is decrypted using the private key. After determining that all the encrypted slices have been received according to the number of the encrypted slices, the encrypted slices are assembled into an encrypted file according to the encrypted slice numbers, the encrypted key slices are assembled into an encrypted key according to the encryption key slice numbers, and the encrypted key is decrypted using the private key to obtain the key, and then the encrypted file is decrypted using the key to obtain the original file; wherein the private key corresponds to the public key.

Furthermore, the additional information also includes an encrypted fragment hash value; the encrypted fragment hash value is generated by performing a hash process on the encrypted fragment after the encrypted fragment is obtained;

After the receiving end uses the private key to decrypt the additional information, the encrypted fragment is hashed to determine whether it matches the hash value of the encrypted fragment. If it does not match, a first retransmission request is sent to the sending end, and the sending end resends the corresponding encrypted fragment according to the first retransmission request; if it matches, it is determined that the real encrypted fragment is obtained.

Furthermore, the additional information also includes an original file hash value; the original file hash value is generated by performing hash processing on the encrypted slice before the original file is encrypted;

After the receiving end obtains the original file, a hash check is performed on the original file to determine whether it matches the hash value of the original file. If not, a second retransmission request is sent to the sending end, and the sending end resends the original file according to the second retransmission request; if they match, it is determined that the authentic original file is obtained.

Furthermore, the preset transmission path and the number of paths are dynamically adjusted based on the performance of the relay point and the current transmission task volume;

After the preset transmission path and the number of paths are determined, the number of encrypted fragments is also determined, and path encryption information is generated for each of the encrypted fragments according to the preset transmission path.

Furthermore, in the path encryption information, an asymmetric encryption algorithm is used to encrypt the address of the next relay point of each relay point, so that each relay point can only decrypt the address of the next relay point.

In a second aspect, an embodiment of the present application provides a file transmission device, including:

The original file slice encryption unit is used to encrypt the original file with the key at the sending end to obtain the encrypted file, and divide the encrypted file into multiple encrypted slices; encrypt the key with the public key to obtain the encryption key, and divide the encryption key into multiple encryption key slices, and the encryption key slices correspond to the encryption slices one by one; each encryption slice carries the encryption key slice, additional information and path encryption information, and the additional information includes the encryption slice number, the number of encryption slices, and the encryption key slice number; the additional information is encrypted by the public key;

The encrypted fragment transmission unit is used to transmit the encrypted fragments through multiple relay points according to a preset transmission path until they are received by the receiving end; each relay point decrypts the path encryption information to obtain the address of the next relay point;

The encrypted fragment decryption and reassembly unit is used to decrypt the additional information using the private key after receiving the encrypted fragment at the receiving end, assemble the encrypted fragments into an encrypted file according to the encrypted fragment number after determining that all the encrypted fragments have been received according to the number of the encrypted fragments, assemble the encrypted key fragments into an encrypted key according to the encryption key fragment number, decrypt the encrypted key using the private key to obtain the key, and then decrypt the encrypted file using the key to obtain the original file; wherein the private key corresponds to the public key;

Among them, the preset transmission path and the number of paths are dynamically adjusted based on the performance of the relay point and the current transmission task volume. After the number of paths is determined, the number of encrypted fragments is also determined; path encryption information is generated for each encrypted fragment according to the preset transmission path; and the address of the next relay point of each relay point is encrypted using an asymmetric encryption algorithm, so that each relay point can only decrypt the address of the next relay point.

Furthermore, the additional information also includes an encrypted fragment hash value; the encrypted fragment hash value is generated by performing a hash process on the encrypted fragment after the encrypted fragment is obtained; the file transmission device also includes:

The encrypted fragment verification unit is used to perform hash verification on the encrypted fragment after the receiving end uses the private key to decrypt the additional information to determine whether it matches the encrypted fragment hash value. If it does not match, a first retransmission request is sent to the sending end, and the sending end resends the corresponding encrypted fragment according to the first retransmission request; if it matches, it is determined that the real encrypted fragment is obtained.

Furthermore, the additional information also includes an original file hash value; the original file hash value is generated by performing hash processing on the encrypted slice before the original file is encrypted; the file transmission device also includes:

The original file verification unit is used to perform hash verification on the original file after the receiving end obtains the original file to determine whether it matches the hash value of the original file. If it does not match, a second retransmission request is sent to the sending end, and the sending end resends the original file according to the second retransmission request; if it matches, it is determined that the real original file is obtained.

In a third aspect, an embodiment of the present application provides a computer storage medium on which a computer program is stored, and when the program is executed by a processor, the above-mentioned file transfer method is implemented.

In a fourth aspect, an embodiment of the present application provides a terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned file transfer method when executing the computer program.

Compared with the prior art, the beneficial effects of this application are:

The file is split into multiple independent encrypted slices, each of which carries an encryption key slice and is transmitted through different secure paths, making it difficult for attackers to obtain the complete file content and key information, significantly enhancing the security and flexibility of data transmission. This strategy ensures that even if an attacker can intercept some slices, he cannot restore the original content of the file based on these slices alone, because the information between the encrypted slices is independent of each other and lacks the necessary decryption information and integrity verification; in addition, the path encryption information uses an asymmetric encryption algorithm to encrypt the address of the next relay point of each relay point, ensuring the confidentiality of the transmission path, and each relay point can only decrypt the address of the next relay point, preventing the path information from being leaked to unauthorized relay points. The parallel processing of multiple transmission paths also improves the efficiency of data transmission, making the transmission of large files faster and more reliable; it achieves the security, reliability, integrity and efficiency of data transmission, and provides a strong guarantee for the secure transmission of files in complex network environments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a file transmission method provided in Embodiment 1 of the present application;

FIG. 2 is a structural diagram of a file transmission device provided in Embodiment 4 of the present application.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

In order to solve the above problems existing in the prior art, the embodiments of the present application disclose a file transmission method, device, medium and equipment, which are described in detail below.

Embodiment 1:

As shown in Figure 1, Figure 1 is a flowchart of a file transmission method provided in Example 1 of the present application. The method includes:

At the sending end, the original file is encrypted using the key to obtain an encrypted file, and the encrypted file is divided into multiple encrypted fragments; the key is encrypted using the public key to obtain an encryption key, and the encryption key is divided into multiple encryption key fragments, and the encryption key fragments correspond to the encryption fragments one by one; each encryption fragment carries an encryption key fragment, additional information and path encryption information, and the additional information includes the encryption fragment number, the number of encryption fragments, and the encryption key fragment number; the additional information is encrypted by the public key.

To facilitate the explanation of the file transfer process, an example is given below.

Assume that there is a file sender A, 6 file transfer relays (B1, B2...B6), and a file receiver C. The sender and receiver hold a pair of RSA asymmetric keys, sender A holds the public key P0, and the receiver holds the private key S0. The sender and the 6 relays also create a pair of RSA keys, the sender holds the public keys P1, P2...P6, and the relays B1, B2 to B6 hold the private keys S1, S2, S3, S4, S5, S6 respectively. To transfer file F from sender A to receiver C.

The sender A generates a key K and uses the key K to encrypt the file F using AES (Advanced Encryption Standard) to obtain the encrypted file X. AES encryption and decryption use the same key, i.e. symmetric encryption. The encryption process converts plaintext into ciphertext, while the decryption process converts ciphertext back into plaintext, both using the same key K.

The sender determines the number of fragments of the encrypted file X and the transmission path of the encrypted fragments based on the performance of each relay point, the current transmission task volume (including the number of currently transmitting tasks and the size of the currently transmitting file) and other factors. Suppose the encrypted file X is divided into two parts, and the encrypted fragments X1 and X2 are obtained, which are transmitted by two paths A-B1-B5-C and A-B4-B3-C respectively;

Among them, the file sizes of X1 and X2 can be different, that is, the encrypted file X is randomly divided. In this way, due to the different sizes of encrypted fragments, the processing priority and speed of each encrypted file fragment can be dynamically adjusted according to factors such as network bandwidth and relay point performance. For example, larger encrypted file fragments can be allocated to relay points with higher performance or smaller transmission volume, while smaller encrypted file fragments can be allocated to relay points with lower performance or smaller transmission volume, thereby improving parallel transmission efficiency.

The sender A encrypts the key K using the public key P0, cuts the encrypted key into two parts to obtain K1 and K2, and shuffles the order. It is expected that K1 will be inserted into shard X2 and K2 will be inserted into shard X1.

The encrypted fragment X1 number, the number of fragments of X, and the number of the encrypted key fragment K2 are recorded into a fixed-length string and encrypted with the public key P0 to obtain the encrypted string G1, which is added to the end of the encrypted fragment X1. The encrypted fragment X2 is also encrypted to obtain the encrypted string G2, which is inserted into the end of X2.

You can take the first byte value of the encrypted string G1 and insert the encryption key fragment K2 into the corresponding position of X1; take the first byte value of the encrypted string G2 and insert the encryption key fragment K1 into the corresponding position of X2.

At this point, the preparation of the original file before transmission has been completed.

According to the preset transmission path, the encrypted fragments are transmitted through multiple relay points until they are received by the receiving end; each relay point decrypts the path encryption information to obtain the address of the next relay point.

According to the transmission path generated above, the sender A encrypts C's IP address and port information with public key P5 and attaches it to the header of X1, and then encrypts B5's IP address and port information with public key P1 and attaches it to the header of X1. Similarly, the IP addresses and port information of C and B3 are encrypted with public keys P3 and P4 respectively and attached to the header of X2.

The sender A sends the encrypted fragments X1 and X2 to the relay points B1 and B4 respectively.

After receiving the encrypted fragment X1, relay point B1 takes the header information, decrypts it with private key S1 to obtain the address of the next-hop relay point B5, and sends the encrypted fragment X1 to B5. Similarly, each relay point decrypts the next-hop address in this way and sends it until it reaches the receiving end C.

After receiving the encrypted fragments at the receiving end, the additional information is decrypted using the private key. After determining that all encrypted fragments have been received based on the number of fragments, the encrypted fragments are assembled into encrypted files according to the encrypted fragment numbers, and the encrypted key fragments are assembled into encrypted keys according to the key fragment numbers. The encrypted keys are decrypted using the private key to obtain the key, and the encrypted files are then decrypted using the key to obtain the original files; the private key corresponds to the public key.

After receiving each encrypted fragment, the receiving end C obtains the encrypted strings G1 and G2, and then obtains the encryption key fragments K2 and K1 from the first byte values of G1 and G2, and uses the private key S0 to decrypt G1 and G2. According to the number of encrypted fragments, it is determined that all encrypted fragments have been received, and the encrypted fragments are reassembled into a complete encrypted file X according to the encryption fragment number, and the encryption key fragments are assembled into an encryption key according to the encryption key fragment number.

The receiving end C uses the private key S0 to decrypt the encryption key to obtain the key K, and then uses the key K to decrypt the encrypted file X to obtain the original file F.

The embodiment of the present application provides a file transmission method, which splits a file into multiple independent encrypted fragments, each of which carries an encryption key fragment, and is transmitted through different secure paths, making it difficult for attackers to obtain the complete file content and key information, significantly enhancing the security and flexibility of data transmission. This strategy ensures that even if an attacker can intercept some fragments, he or she cannot restore the original content of the file based on these fragments alone; in addition, the path encryption information uses an asymmetric encryption algorithm to encrypt the next relay point address of each relay point, ensuring the confidentiality of the transmission path, and each relay point can only decrypt the address of the next relay point, preventing the path information from being leaked to unauthorized relay points. The parallel processing of multiple transmission paths also improves the efficiency of data transmission, making the transmission of large files faster and more reliable; the security, reliability, integrity and efficiency of data transmission are achieved, providing a strong guarantee for the secure transmission of files in a complex network environment.

Embodiment 2:

Based on the first embodiment, the additional information also includes an encrypted fragment hash value; the encrypted fragment hash value is generated by performing a hash process on the encrypted fragment after the encrypted fragment is obtained.

After the receiving end uses the private key to decrypt the additional information, it performs a hash check on the encrypted fragment to determine whether it matches the hash value of the encrypted fragment. If it does not match, a first retransmission request is sent to the sending end, and the sending end resends the corresponding encrypted fragment according to the first retransmission request; if it matches, it is determined that the real encrypted fragment is obtained.

When the hash values of the encrypted segments do not match, this usually means that the segment may have been tampered with or damaged during transmission. In this case, the sender only needs to resend the unmatched encrypted segment to the receiver, and the receiver performs a hash check again to ensure that the retransmitted segment is complete and has not been tampered with.

Embodiment three:

Based on the first or second embodiment, the additional information further includes an original file hash value; the original file hash value is generated by performing hash processing on the encrypted slice before the original file is encrypted.

After the receiving end obtains the original file, a hash check is performed on the original file to determine whether it matches the hash value of the original file. If not, a second retransmission request is sent to the sending end, and the sending end resends the original file according to the second retransmission request; if they match, it is determined that the authentic original file is obtained.

If the hash value of the original file does not match, this usually means that there is a problem somewhere in the encryption, transmission, decryption, or file processing process. This is not just a problem with one encrypted slice, but a problem with the entire file. Therefore, the sender needs to re-execute the entire process, including re-encrypting the original file, transmitting all encrypted slices, and the receiver decrypting and verifying the hash value of the entire file.

When combining multiple encrypted fragments into a complete encrypted file and decrypting it, if an error occurs during the combination process (such as incorrect fragment order, fragment loss or duplication, etc.), even if each fragment itself is complete, the decrypted file may not be able to correctly restore the original file. By performing hash verification on the decrypted file, such combination errors can be discovered in a timely manner.

Embodiment 4:

As shown in FIG2 , the fourth embodiment of the present application also provides a structural diagram of a file transmission device. The device includes:

The original file shard encryption unit is used to encrypt the original file with a key at the sending end to obtain an encrypted file, and divide the encrypted file into multiple encrypted shards; encrypt the key with a public key to obtain an encryption key, and divide the encryption key into multiple encryption key shards, and the encryption key shards correspond to the encryption shards one by one; each encryption shard carries an encryption key shard, additional information and path encryption information, and the additional information includes an encryption shard number, the number of encryption shards, and the encryption key shard number; the additional information is encrypted by the public key.

The encrypted fragment transmission unit is used to transmit the encrypted fragments through multiple relay points according to a preset transmission path until they are received by the receiving end; each relay point decrypts the path encryption information to obtain the address of the next relay point.

The encrypted fragment decryption and reassembly unit is used to decrypt the additional information using the private key after receiving the encrypted fragment at the receiving end, assemble the encrypted fragments into an encrypted file according to the encrypted fragment number after determining that all the encrypted fragments have been received according to the number of the encrypted fragments, assemble the encrypted key fragments into an encrypted key according to the encryption key fragment number, decrypt the encrypted key using the private key to obtain the key, and then decrypt the encrypted file using the key to obtain the original file; wherein the private key corresponds to the public key.

Among them, the preset transmission path and the number of paths are dynamically adjusted based on the performance of the relay point and the current transmission task volume. After the number of paths is determined, the number of encrypted fragments is also determined; path encryption information is generated for each encrypted fragment according to the preset transmission path; an asymmetric encryption algorithm is used to encrypt the address of the next relay point of each relay point, so that each relay point can only decrypt the address of the next relay point.

The file transfer device provided in the fourth embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment 1. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment 1.

Embodiment five:

On the basis of the fourth embodiment, the additional information further includes an encrypted fragment hash value; the encrypted fragment hash value is generated by performing a hash process on the encrypted fragment after the encrypted fragment is obtained; and the file transmission device further includes:

The encrypted fragment verification unit is used to perform hash verification on the encrypted fragment after the receiving end uses the private key to decrypt the additional information to determine whether it matches the encrypted fragment hash value. If it does not match, a first retransmission request is sent to the sending end, and the sending end resends the corresponding encrypted fragment according to the first retransmission request; if it matches, it is determined that the real encrypted fragment is obtained.

The file transfer device provided in the fifth embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment 2. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment 2.

Embodiment six:

Based on the fourth or fifth embodiment, the additional information further includes an original file hash value; the original file hash value is generated by performing hash processing on the encrypted slice before the original file is encrypted; and the file transmission device further includes:

The original file verification unit is used to perform hash verification on the original file after the receiving end obtains the original file to determine whether it matches the hash value of the original file. If it does not match, a second retransmission request is sent to the sending end, and the sending end resends the original file according to the second retransmission request; if it matches, it is determined that the real original file is obtained.

The file transfer device provided in the sixth embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment three. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment three.

Embodiment seven:

The embodiment of the present application also provides a computer storage medium on which a computer program is stored, and when the program is executed by a processor, the above-mentioned file transfer method is implemented.

Embodiment eight:

An embodiment of the present application also provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned file transfer method when executing the computer program.

It is obvious to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present application.

Claims (10)

1. A file transmission method, comprising: At the sending end, the original file is encrypted by using the key to obtain an encrypted file, and the encrypted file is divided into multiple encrypted slices; the key is encrypted by using the public key to obtain an encryption key, and the encryption key is divided into multiple encryption key slices, and the encryption key slices correspond to the encryption slices one by one; each encryption slice carries an encryption key slice, additional information and path encryption information, and the additional information includes an encryption slice number, the number of encryption slices, and the encryption key slice number; the additional information is encrypted by the public key; According to the preset transmission path, the encrypted fragments are transmitted through multiple relay points until they are received by the receiving end; each relay point decrypts the path encryption information to obtain the address of the next relay point; After receiving the encrypted slices at the receiving end, the additional information is decrypted using the private key. After determining that all the encrypted slices have been received according to the number of the encrypted slices, the encrypted slices are assembled into an encrypted file according to the encrypted slice numbers, the encrypted key slices are assembled into an encrypted key according to the encryption key slice numbers, and the encrypted key is decrypted using the private key to obtain the key, and then the encrypted file is decrypted using the key to obtain the original file; wherein the private key corresponds to the public key. 2. The file transmission method according to claim 1, characterized in that the additional information further includes an encrypted fragment hash value; the encrypted fragment hash value is generated by performing a hash process on the encrypted fragment after the encrypted fragment is obtained; After the receiving end uses the private key to decrypt the additional information, the encrypted fragment is hashed to determine whether it matches the hash value of the encrypted fragment. If it does not match, a first retransmission request is sent to the sending end, and the sending end resends the corresponding encrypted fragment according to the first retransmission request; if it matches, it is determined that the real encrypted fragment is obtained. 3. The file transmission method according to claim 1 or 2, characterized in that the additional information also includes an original file hash value; the original file hash value is generated by performing hash processing on the encrypted fragment before the original file is encrypted; After the receiving end obtains the original file, a hash check is performed on the original file to determine whether it matches the hash value of the original file. If not, a second retransmission request is sent to the sending end, and the sending end resends the original file according to the second retransmission request; if they match, it is determined that the authentic original file is obtained. 4. The file transmission method according to claim 1, characterized in that the preset transmission path and the number of paths are dynamically adjusted based on the performance of the relay point and the current transmission task volume; After the preset transmission path and the number of paths are determined, the number of encrypted fragments is also determined, and path encryption information is generated for each of the encrypted fragments according to the preset transmission path. 5. According to the file transfer method described in claim 1 or 4, in the path encryption information, an asymmetric encryption algorithm is used to encrypt the address of the next relay point of each relay point, so that each relay point can only decrypt the address of the next relay point. 6. A file transmission device, comprising: The original file slice encryption unit is used to encrypt the original file with the key at the sending end to obtain the encrypted file, and divide the encrypted file into multiple encrypted slices; encrypt the key with the public key to obtain the encryption key, and divide the encryption key into multiple encryption key slices, and the encryption key slices correspond to the encryption slices one by one; each encryption slice carries the encryption key slice, additional information and path encryption information, and the additional information includes the encryption slice number, the number of encryption slices, and the encryption key slice number; the additional information is encrypted by the public key; The encrypted fragment transmission unit is used to transmit the encrypted fragments through multiple relay points according to a preset transmission path until they are received by the receiving end; each relay point decrypts the path encryption information to obtain the address of the next relay point; The encrypted fragment decryption and reassembly unit is used to decrypt the additional information using the private key after receiving the encrypted fragment at the receiving end, assemble the encrypted fragments into an encrypted file according to the encrypted fragment number after determining that all the encrypted fragments have been received according to the number of the encrypted fragments, assemble the encrypted key fragments into an encrypted key according to the encryption key fragment number, decrypt the encrypted key using the private key to obtain the key, and then decrypt the encrypted file using the key to obtain the original file; wherein the private key corresponds to the public key; Among them, the preset transmission path and the number of paths are dynamically adjusted based on the performance of the relay point and the current transmission task volume. After the number of paths is determined, the number of encrypted fragments is also determined; path encryption information is generated for each encrypted fragment according to the preset transmission path; and the address of the next relay point of each relay point is encrypted using an asymmetric encryption algorithm, so that each relay point can only decrypt the address of the next relay point. 7. The file transmission device according to claim 6, characterized in that the additional information also includes an encrypted fragment hash value; the encrypted fragment hash value is generated by performing a hash process on the encrypted fragment after the encrypted fragment is obtained; the file transmission device also includes: The encrypted fragment verification unit is used to perform hash verification on the encrypted fragment after the receiving end uses the private key to decrypt the additional information to determine whether it matches the encrypted fragment hash value. If it does not match, a first retransmission request is sent to the sending end, and the sending end resends the corresponding encrypted fragment according to the first retransmission request; if it matches, it is determined that the real encrypted fragment is obtained. 8. The file transmission device according to claim 7, characterized in that the additional information also includes a hash value of the original file; the hash value of the original file is generated by performing a hash process on the encrypted fragment before the original file is encrypted; the file transmission device also includes: The original file verification unit is used to perform hash verification on the original file after the receiving end obtains the original file to determine whether it matches the hash value of the original file. If it does not match, a second retransmission request is sent to the sending end, and the sending end resends the original file according to the second retransmission request; if it matches, it is determined that the real original file is obtained. 9. A computer storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the method according to any one of claims 1 to 5 is implemented. 10. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 5 when executing the computer program.