Low-orbit satellite-assisted safe unloading method

Abstract

The present invention discloses a low-orbit satellite-assisted safe unloading method, comprising: S1, a user requests a service from an edge server, after the user and the edge server establish a connection, the requested task enters a queue sequence in the edge server; S2, if the time the task waits for processing in the edge server is greater than the time consumed by the task forwarding on the edge server, directly forwarding to a low-orbit satellite node for auxiliary unloading; if the time the task waits for processing in the edge server is less than the time consumed by the task forwarding on the edge server, and the resource occupancy rate of the edge server is higher than a certain threshold, a logistic regression algorithm is used to perform a binary classification decision, if the time the task waits for processing in the edge server is less than the time consumed by the task forwarding on the edge server, and the resource occupancy rate of the edge server is lower than a certain threshold, waiting. The present invention can realize low-orbit satellite-assisted safe unloading.

Description

Technical Field

[0001] The present invention relates to the field of computing offloading, and in particular to a low-orbit satellite-assisted safe offloading method. Background Art

[0002] With the recent widespread discussion of the Internet of Things and the centralized deployment of cloud servers, there is still room for improvement in the latency experience of cloud computing. Based on this, edge computing was born. Edge servers are deployed step by step at the edge of space. They bear part of the computing tasks of edge devices, thereby improving the experience of edge devices and reducing the computing burden of cloud servers. On the other hand, Musk's Starlink project is in full swing. The international competition for occupying low-orbit resources has begun, and there are corresponding constellation plans in China. Combining edge servers and low-orbit satellites has great prospects.

[0003] When the ground edge server resources are tight, low-orbit satellite nodes are used as auxiliary unloading nodes for edge servers. It is an effective method. The low latency and strong signal characteristics of low-orbit satellites can provide better services for ground equipment. Ground equipment and satellite communications require satellite signal receiving and sending equipment. It is more reasonable to deploy them on edge servers than on the user side. First, it can save a lot of satellite signal receiving and sending equipment. The cost of laying out equipment, and secondly, low-orbit satellite nodes as auxiliary unloading nodes for edge servers have lower latency than the cloud.

[0004] When low-orbit satellite nodes are used as auxiliary offloading nodes of edge servers, there are offloading decision-making and security issues that need to be resolved. When a task requested by a user is in the queue sequence of the edge server, the task should wait for the edge server to execute or be forwarded to the low-orbit satellite node for offloading. Summary of the invention

[0005] The purpose of the present invention is to provide a low-orbit satellite-assisted safe unloading method, aiming to solve the problem of a low-orbit satellite-assisted safe unloading method.

[0006] A low-orbit satellite-assisted safe unloading method comprising:

[0007] S1: The user requests a service from the edge server. After the user and the edge server establish a connection, the requested task enters the queue sequence in the edge server.

[0008] S2. If the time the task waits for processing on the edge server is greater than the time consumed by forwarding the task on the edge server, the task is directly forwarded to the low-orbit satellite node for auxiliary unloading. The time consumed by forwarding on the edge server is the sum of the time of transmission to the satellite, the time of transmission back to the edge server, and the time of identity authentication;

[0009] If the time a task spends waiting for processing on the edge server is less than the time it takes to forward the task on the edge server, and the resource occupancy rate of the edge server is higher than a certain threshold, a logistic regression algorithm is used to make a binary classification decision to determine whether to continue waiting for execution on the edge server or forward it to a low-orbit satellite node for auxiliary offloading;

[0010] If the time the task waits for processing on the edge server is less than the time consumed by forwarding the task on the edge server, and the resource occupancy rate of the edge server is lower than a certain threshold, wait.

[0011] By adopting the embodiments of the present invention, low-orbit satellite-assisted safe unloading can be achieved.

[0012] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it is implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 is a schematic diagram of a system model of a low-orbit satellite-assisted safe unloading method according to an embodiment of the present invention;

[0015] Figure 2 1 is a schematic diagram of a system model workflow of a low-orbit satellite-assisted safe unloading method according to an embodiment of the present invention;

[0016] Figure 3 1 is a schematic diagram of a logic algorithm regression model of a low-orbit satellite-assisted safety unloading method according to an embodiment of the present invention;

[0017] Figure 4 1 is a schematic diagram of the overall workflow of the low-orbit satellite-assisted safe unloading method according to an embodiment of the present invention;

[0018] Figure 5 1 is a schematic diagram of a registration phase of a low-orbit satellite-assisted safety unloading method according to an embodiment of the present invention;

[0019] Figure 6 It is a schematic diagram of the preliminary identity authentication phase and the rapid identity authentication phase of the low-orbit satellite-assisted security offloading method according to an embodiment of the present invention;

[0020] Figure 7 It is a schematic diagram of the alliance blockchain of the low-orbit satellite-assisted secure unloading method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Method Embodiment

[0023] According to an embodiment of the present invention, a low-orbit satellite-assisted safe unloading method is provided. Figure 1 is a schematic diagram of a system model of a low-orbit satellite-assisted safe unloading method according to an embodiment of the present invention. Figure 1 As shown, specifically including:

[0024] User: Their own computing and storage resources are insufficient, so they can improve their experience through the services provided by edge servers.

[0025] Edge server: can handle computing tasks and provide computing power to users; can provide data access and provide users with a better user experience.

[0026] Low-orbit satellite nodes: have certain computing resources and access resources.

[0027] The time a task waits on the edge server: depends on the task scheduling algorithm of the edge server and the actual queuing time.

[0028] The time it takes to forward a task on the edge server is the sum of the time it takes to transmit to the satellite, the time it takes to transmit back to the edge server, and the authentication time.

[0029] Edge server resources: computing resources (i.e. computing power), storage resources (providing access capabilities)

[0030] Queue sequence 2: Tasks initially waiting are queued in this sequence;

[0031] Queue sequence 1: If the decision algorithm outputs that the task is waiting, the task will enter queue sequence 1 from queue sequence 2, and the task will not enter queue sequence 2 again, and wait to be executed at the edge server;

[0032] Workflow of the system model and consortium blockchain:

[0033] Figure 2 1 is a schematic diagram of a system model workflow of a low-orbit satellite-assisted safe unloading method according to an embodiment of the present invention;

[0034] Workflow 1: The user requests a service from the edge server. After the connection is established, the requested task a enters the queue sequence;

[0035] When task a in workflow 2 makes a decision at the edge server, the following three situations occur:

[0036] 1) If the waiting time of task a is greater than the forwarding time consumption, it will be forwarded directly regardless of the resource occupancy of the edge server;

[0037] 2) When the waiting time of task a is less than the forwarding time and the resource occupancy rate of the edge server is higher than a certain threshold (e.g. 80%), a logistic regression algorithm is used to make a binary classification decision to determine whether to continue waiting for execution on the edge server or forward it to the low-orbit satellite node for auxiliary offloading. The specific description is as follows:

[0038] Since the logistic regression algorithm has fast convergence speed and good performance, and is widely used in the industry, the logistic regression algorithm is used for binary classification of offloading decisions. x1 is the ratio of task waiting time to forwarding time. The larger the x1, the greater the tolerance, and the smaller the x1, the smaller the tolerance. x2 is the occupancy rate of edge server resources. The larger the value, the greater the server occupancy rate, and the smaller the value, the smaller the server occupancy rate. x1 and x2 are the inputs of the logistic regression model, and the output is one of the two: continue to wait for execution on the edge server or forward to the low-orbit satellite node for auxiliary offloading.

[0039] Figure 3 1 is a schematic diagram of a logic algorithm regression model of a low-orbit satellite-assisted safety unloading method according to an embodiment of the present invention;

[0040] Figure 3 The decision boundary is h ω When (x) is equal to 0, h ω (x) is the output Y of the algorithm model, and the output of the sample points where Y is greater than 0 is set to Y = 1 (belonging to Figure 3 The green type indicates that the task is waiting on the edge server, and the output of the sample points where Y is less than 0 is set to Y = -1 (belonging to Figure 3 The blue type) indicates that the task is forwarded to the satellite node for auxiliary offloading. Formula 1 is the functional expression of the decision boundary we are looking for. Formula 2 indicates that the input of the user's tolerance x1 and the edge server resource occupancy rate x2, this sample point is the probability of task waiting.

[0041] h ω (x) = ω1x1 + ω2x2 + b = ω T +b (1)

[0042]

[0043] Formula 4 is the loss function that logistic regression ultimately optimizes. This loss function is converted from the maximum likelihood function formula 3, and the optimization direction is also transformed from solving the maximum value of the likelihood function to solving the minimum value of the loss function. However, due to the existence of two unknown parameters, ω and b, it is difficult to directly solve the loss function. This paper uses the stochastic gradient descent algorithm to solve Formula 5.

[0044]

[0045] Loss function:

[0046] Gradient update process:

[0047]

[0048] Where k is the number of iterations, each time the parameters are updated, we can compare || J(ω k+1 )-J(ω k )|| is less than the threshold or reaches the maximum number of iterations to stop the iteration and find the optimal solution, that is, the task is to continue to wait for execution on the edge server or forward it to the low-orbit satellite node for auxiliary offloading.

[0049] 3) When the waiting time of task a is less than the forwarding time and the resource occupancy rate of the edge server is lower than a certain threshold (e.g. 80%), wait;

[0050] Workflow 3: When the task needs to be forwarded to the satellite for processing, considering the openness and mobility between the edge server and the satellite, an identity encryption algorithm based on the alliance blockchain is adopted. The algorithm authenticates the edge server before unloading the task to prevent the data on the satellite from being accessed by any user and the computer resources from being used.

[0051] Figure 4 1 is a schematic diagram of the overall workflow of the low-orbit satellite-assisted safe unloading method according to an embodiment of the present invention;

[0052] The overall workflow of communication between edge servers and low-orbit satellite nodes is as follows: Figure 4 shown.

[0053] Figure 5 1 is a schematic diagram of a registration phase of a low-orbit satellite-assisted safety unloading method according to an embodiment of the present invention;

[0054] There are three stages of identity encryption-based authentication: registration stage Figure 5 ;

[0055] Figure 6 It is a schematic diagram of the preliminary identity authentication phase and the rapid identity authentication phase of the low-orbit satellite-assisted security offloading method according to an embodiment of the present invention;

[0056] Initial authentication phase and fast authentication phase. The authentication between the edge server and the low-orbit satellite is considered successful when there are no errors in the three phases of registration phase, initial authentication phase, and fast authentication phase.

[0057] Registration stage:

[0058] KGC (Key Generation Center) is a trusted third-party key generation center responsible for calculating the public key, private key and user token of the edge server. Registered users can access the satellite system at any time during the validity period of the token. Authorized users submit their identities to KGC to obtain a pair of public and private keys calculated by KGC and a token signed by KGC. KGC sends the identity information (ID a ) and your own public key (P KGC ) obtains the public key (P) of edge server A through a hash function y a ). Then KGC constructs the private key of edge server A (d a ) and use your own private key (d KGC ) to d a Signature to obtain the token Auth after KGC authorization Token_a Then KGC sends the public and private keys of edge server A and token Auth through a secure channel. Token_a And your public key P KGC Return to edge server A, edge server A will send its identity information ID a , KGC's public key P KGC and your own public key P a The low-orbit satellite S obtains its own public key P through the same process as the edge server. s and private key d S , and then returns it to satellite S through a secure channel. Then satellite S sends its identity information ID S and the public key P s Upload to the consortium blockchain.

[0059] Initial identity verification phase:

[0060] (a) When edge server A accesses satellite S, it first looks for the satellite S’s ID on the block. S , and then find the public key of satellite S (P S ), and finally edge server A sends its identity information (ID a ) is sent to satellite S.

[0061] (b) Satellite S receives information from edge server A, verifies its identity, and searches for the edge server’s public key P on the block. a , then satellite S uses its own private key d S The randomly generated number r on the satellite is signed with the session key k formed by the symmetric encryption Rijndael algorithm and the timestamp, and the signature, r, k and timestamp are encrypted with the public key P of the edge server. a Encrypt and then send m1 to A.

[0062]

[0063] (c) After receiving the information, edge server A uses its own private key d a Decrypt this message using the satellite S’s public key (P S ) verifies the signatures of r and k and saves r and k. Edge server A packages its own user information (including its own ID, location, and timestamp of the requested task), the requested service Service, the random number r, and the KGC authorized token and encrypts them with k. Then edge server A sends m2 to satellite S.

[0064] m2=Encry k (r,Auth Token ,Service,UserInfo) (7)

[0065] (d) After receiving the message, satellite S uses k to decrypt the message and verify the correctness of r, and then uses KGC's public key (P KGC ) and the public key P of the edge server a Auth Token_a The correctness of the signature. Last satellite S verification ID a Is it related to Auth Token_a After the above steps are completed perfectly, the edge server A establishes a secure connection with the satellite S. The satellite S sends the UserInfo of the edge server A, the requested service Service, and the KGC authorized token Auth Token_a The records are uploaded to the blockchain.

[0066] Fast authentication phase:

[0067] Once edge server A successfully passes the preliminary identity authentication, its information will be stored in the access satellite S. Through the data traceability in the blockchain, when the edge server A connects to a satellite S3 for service, it only needs to send m3 to satellite S3.

[0068]

[0069] After receiving the information, satellite S3 a Find the Auth block on the satellite node Token_a and P a , according to P a Verify signature a And verify ID s After verification, satellite S3 returns a session key (based on S3's private key (d S3 ) Signature and P a encrypted), and provides the service requested by edge server A.

[0070] Figure 7 This is a schematic diagram of a consortium blockchain for a low-orbit satellite-assisted secure offloading method according to an embodiment of the present invention;

[0071] Consortium blockchain

[0072] This article's alliance blockchain is divided into three layers: network infrastructure layer, consensus layer, and application layer. Figure 7 As shown in the figure, the network infrastructure layer consists of low-orbit satellite nodes and edge servers to form a consortium chain; the main function of the consensus layer is to reach a consensus on a transaction (communication) among the nodes in the consortium chain, and the nodes in the consortium chain upload the login information and related communication information of the edge server to the chain; the application layer mainly uses smart contracts to enable the edge server to regularly update the public and private key pairs to KGC to ensure the security of the secret key.

[0073] When the low-orbit satellite node serves as an auxiliary offloading node, the user task encrypted based on the edge server identity will be offloaded to the low-orbit satellite, which can conceal the user's information and protect the user's privacy.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements of the technical solutions of the embodiments of the present invention do not cause the essence of the corresponding technical solutions to deviate from the scope of this solution.

Claims

1. A low-orbit satellite-assisted safe unloading method, characterized in that: include, S1, the user requests a service from the edge server. After the user and the edge server establish a connection, the requested task enters the queue sequence in the edge server; S2. If the time the task waits for processing on the edge server is greater than the time consumed by forwarding the task on the edge server, the task is directly forwarded to the low-orbit satellite node for auxiliary unloading. The time consumed by forwarding on the edge server is the sum of the time of transmission to the satellite, the time of transmission back to the edge server, and the time of identity authentication. If the time a task spends waiting for processing on the edge server is less than the time it takes to forward the task on the edge server, and the resource occupancy rate of the edge server is higher than a certain threshold, a logistic regression algorithm is used to make a binary classification decision to determine whether to continue waiting for execution on the edge server or forward it to a low-orbit satellite node for auxiliary offloading; If the time the task waits for processing on the edge server is less than the time consumed by the task being forwarded on the edge server, and the resource occupancy rate of the edge server is lower than a certain threshold, wait; The use of a logistic regression algorithm to make a binary classification decision to determine whether to continue waiting for execution at the edge server or forwarding to a low-orbit satellite node for auxiliary offloading specifically includes: That is, the ratio of the time the task waits for processing on the edge server to the time it is forwarded on the edge server. The larger the value, the more tolerant it is; the smaller the value, the less tolerant it is. It is the utilization rate of edge server resources. The larger the value, the greater the server utilization rate. The smaller the value, the smaller the server utilization rate. and As the input of the logistic regression model, the output is one of the two: continue to wait for execution at the edge server or forward to the low-orbit satellite node for auxiliary offloading; The task forwarding to the low-orbit satellite node for auxiliary unloading specifically includes: using an identity encryption algorithm based on the alliance blockchain to authenticate the edge server, and forwarding the task to the low-orbit satellite node for auxiliary unloading.

2. The method according to claim 1, characterized in that: The identity encryption algorithm based on the alliance blockchain is adopted, and the identity authentication of the edge server specifically includes: S31. The edge server registers with the third-party key generation center to obtain the registration information of the edge server. The third-party key generation center packages the registration information of the edge server into blocks and uploads it to the alliance blockchain. The low-orbit satellite node registers with the third-party key generation center to obtain the registration information of the low-orbit satellite node. The third-party key generation center packages the registration information of the low-orbit satellite node into blocks and uploads it to the alliance blockchain. S32. The edge server establishes a secure connection with the low-orbit satellite node, and the low-orbit satellite node uploads the relevant information of the edge server to the alliance blockchain; S33, the edge server performs fast identity authentication.

3. The method according to claim 2, characterized in that The S31 specifically includes: the third-party key generation center generates the identity information of the edge server and your own public key The public key of the edge server is obtained through a hash function y , the third-party key generation center builds the private key of the edge server , using your own private key Give Signature obtained from the token authorized by the third-party key generation center The third-party key generation center sends the public and private keys and tokens of the edge server through a secure channel. and your public key Return to the edge server, the edge server will send its identity information , the public key of the third-party key generation center and your own public key The blocks are packaged and uploaded to the alliance blockchain. The low-orbit satellite nodes obtain their own public keys through the same process as the edge servers. and private key , and then returns it to the low-orbit satellite node through a secure channel, and then the low-orbit satellite node will send its identity information and the public key Upload to the consortium blockchain.

4. The method according to claim 3, characterized in that: The S32 specifically includes: S321: When the edge server accesses the low-orbit satellite node, the edge server searches for the identity information of the low-orbit satellite node on the block. , and then look for the public key of the low-orbit satellite node , and finally the edge server will send its identity information Sent to low-orbit satellite nodes; S322, the low-orbit satellite node receives the identity information of the edge server Verify the identity of the edge server and find the public key of the edge server on the block Then the low-orbit satellite node uses its own private key to sign the random number r generated by the low-orbit satellite node, the session key k obtained by the symmetric encryption Rijndael algorithm, and the timestamp of the requested task, and encrypts the signature and r, k and the timestamp of the requested task with the public key of the edge server to obtain m1, and finally sends m1 to the edge server; S323, after receiving the information m1, the edge server uses the private key Decrypt this message using the public key of the LEO satellite node Verify the signatures of r and k and save r and k. The edge server will store its own user information The requested service Service, the random number r, and the token authorized by the third-party key generation center are packaged and encrypted with k to obtain m2. Then the edge server sends the encrypted information m2 to the low-orbit satellite node. The user information Includes the edge server ID, edge server location, and timestamp of the requested task; m2 = ； S324, after receiving m2, the low-orbit satellite node uses k to decrypt m2 and verify the correctness of r's signature, and then uses the third-party secret key to generate the center's public key and the public key of the edge server verify Correctness of signature; final verification by low-orbit satellite node Whether The session key k is the symmetric encryption Rijndel algorithm; The edge server establishes a secure connection with the low-orbit satellite node, and the low-orbit satellite node sends the UserInfo of the edge server and the requested service Service. The records are uploaded to the blockchain.

5. The method according to claim 4, characterized in that The S33 specifically includes: when the edge server connects to the low-orbit satellite node for service, it sends m3 to the low-orbit satellite node. After the low-orbit satellite node receives m3, Block found on satellite node and ,according to and Verify the signature And verify Is it on the block? After verification, satellite S3 returns a private key based on S3 Signature and The session key is encrypted and the requested service is provided by the edge server.

6. The method according to claim 5, characterized in that The m1 formula is as follows: 。 7. The method according to claim 6, characterized in that The m3 formula is as follows: 。

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