Abstract
A system without any communication delays, called edge computing, has been introduced for nearer and faster services. The major concern in the edge computing scenario is its privacy risks. A user, as well as a cloud data preservation scheme, is the main aim of this paperwork. Test data is given by the user to access the cloud-based data processing framework. The training of the suitable model is carried out by utilizing the data stored in the cloud. The suggested model divides the entire model into two sections, namely, the untrusted cloud and the trusted edge. On the trusted edge side the data is directly provided to the developed advanced deep learning model called the Atrous Convolution based Cascaded Deep Temporal Convolution Network (ACC-DTCN) for the data analysis process. However, instead of giving the whole data directly to the untrusted cloud side, the test data is protected on the cloud side by utilizing a hybrid encryption technique called the Optimal Hybrid Encryption Model (OHEM). Both Attribute-Based Encryption (ABE) and Homomorphic Encryption (HE) are utilized in the recommended OHEM scheme. The OHEM variables are tuned with the help of an advanced algorithm called the Enhanced Ladybug Beetle Optimization algorithm (ELBOA). The confidence score vector among the testing and training data is predicted by the implemented ACC-DTCN model by utilizing the encrypted data on the cloud side. The suggested privacy preservation scheme provides higher prediction accuracy and prevents interference attacks while contrasting it against conventional methods during extensive experimentations.
Keywords
Introduction
The enhancement and advancement in the field of communication technologies and artificial intelligence led to the development of several sophisticated and intelligent devices that are capable of producing enormous volumes of data that are utilized for training deep learning models, given as input in prediction models, and are used in data mining approaches. This mass production of data paves the way for the development of edge computing technology [21]. The enhanced interaction with the customers and the contravention of the centralized networks make edge computing technology provide enhanced artificial intelligence services with rigid “Quality of Services (QoS)” [23]. This ability makes the edge computing technique applicable in various fields like home automation systems, individualized recommendation models, enhancement models, traffic prediction systems, and so on [12]. But, all the host system in the edge computing platform, which produces enormous volumes of data ranging from scanners, web services, security cameras, laptops, workstations, phones, printers, etc., has a limited amount of computing resources and memory space, which restricts the data processing and data storage needed to provide the required, artificial intelligence-based services [17]. Many research works have been developed for incorporating an efficient artificial intelligence approach to edge computing networks [42].
Security issues, along with delays and inefficient computation, occur while transferring a huge volume of data from the cloud server over the “Wireless Area Networks (WAN)” [19]. Higher privacy and security are offered in the case of decentralized networks. However, these approaches are dependent on the host device’s performance, and it takes more time to come to in agreement with a model [43]. By associating the edge devices with the cloud server, the private data transmission to train the deep learning models, like federated learning, is replaced by the intermediate result transmission. This enhances the security of the data being transmitted in the edge computing network [26]. The process of task offloading to execute the processing of one sensor by various other sensors is one of the notable advantages of the edge computing prototype [36]. This eases the processing and computational burden on each sensor connected to the edge computing system in real-time applications. But, while offloading a task of one sensor to another sensor, both time consumption and privacy issues arise. These two factors need to be considered while offloading the services of one sensor to another in the edge computing network [22]. Privacy affects the overall confidentiality of the data being transmitted in edge computing, while time affects the user experience. Time-stringent industries are the ones mostly affected by the time-consuming edge computing platform on the process of task offloading. Customer dissatisfaction arises as the edge computing server takes more computation and processing time [35]. Security of the transmitted data is at risk because they are more vulnerable to data theft during the task offloading process [46]. The higher processing time requirement and the lower security of the data are the two main constraints that need to be solved in the edge computing paradigm.
The time consumption and privacy-related issues in edge computing platforms can be resolved by integrating the benefits of both decentralized and centralized approaches on the basis of the federated learning concept [8]. Even though the integration of these decentralized and centralized approaches is beneficial, some imperfections still exist. The first disadvantage of including federated learning in the edge computing platform is that the integrity of the data given as input to the learning models generated by the host devices is not verified by the cloud server as it has no access to the host device’s data [9]. When forged or altered data is given as input to these federated models, then inappropriate prediction outcomes would be provided by these approaches. The second drawback is that only training for a few general tasks is provided to these models to perform in an automated manner without user interference [24]. But, individualized services are required by the host devices based on user preferences and requirements which require continuous training of the learning model with historical data generated by a variety of users [7]. It is also worth considering the privacy issues in the training model and the deviations in the training data. A scalable and generalized prediction model is regarded as a crucial digital asset as it can be used for a variety of applications. However, such a system development requires more resources and is usually expensive to develop. It is also important to note the privacy issues in such models as the actual data can be derived in a reverse manner by providing some additional detail to these models [2]. Hence an enhanced privacy and security preservation scheme using an advanced deep learning model is developed in this research work dedicated to the edge computing paradigm.
The key contributions of this research work on providing an enhanced privacy preservation scheme in edge computing networks are listed below.
To generate an efficient privacy preservation prototype for supporting both the cloud and user side data in the edge computing paradigm using an enhanced deep learning approach.
To deploy a novel deep learning technique named ACC-DTCN for performing the task provided to them in both the trusted and untrusted side of the edge-cloud computing environment effectively with the utilization of the optimization technique.
To execute a hybrid cryptography approach called the OHEM, which is developed by fusing the HE and ABE schemes for enhancing the security of the data while being processed in the untrusted cloud side of the edge computing network to avoid accessing of the data by unauthorized persons.
To implement an improved optimization approach called the ELBOA by modifying the conventional LBO algorithm for the purpose of generating the optimal keys required for performing the OHEM scheme to enhance the privacy of the data on the cloud side.
To examine the privacy offered by the suggested privacy preservation model in edge computing by comparing it with conventional mechanisms in order to show the effectiveness of the developed scheme.
A brief outline of this paperwork is provided below. A detailed introduction to edge computing and the requirement of a privacy preservation scheme for edge computing platforms is given in Section 1. A detailed survey of some of the existing privacy preservation schemes dedicated especially to edge computing platforms is given in Section 2. Section 3 provides the formulation of the intelligent privacy preservation framework in edge computing. This section provides with the implementation of the enhanced privacy preservation model in edge computing using advanced deep learning with the meta-heuristic algorithm is elaborated in Section 4. The development of the atrous convolution-based cascaded deep learning network-based privacy preservation in the cloud sector is elucidated in Section 5. The results and discussion on the experimentation conducted on the suggested deep-learning-based data preservation scheme in edge computing systems are provided in Section 6. The summary of this work is given in Section 7.
Literature survey
Related works
In 2021, Qiang et al. [29] executed a “Visual Geometric Graph (VGG-19)”-based privacy preservation model for both cloud-side and user-side data. The test data was provided from the user side, while the data for training was provided from the cloud. The entire VGG-19 model was divided and provided to both the edge and cloud sides. The plaintext was directly given to the edge side VGG-19 model, whereas the encrypted data was given to the VGG-19 network on the cloud side. A binary framework with binarized weight values was utilized on the cloud side. The HE scheme was adopted to encrypt the input data given to the VGG-19 model on the cloud side. This narrowed the gap between the confidence scores on the testing and training data to make the prediction easier. The detection of inference attacks was successfully predicted by the suggested VGG-19 model but with slightly lower accuracy. Experimental outcomes demonstrated that the utilization of HE schemes even provided enhanced security against exploratory and inference attacks was much slower in execution than the encryption-less machine learning prediction models.
In 2022, Zheng et al. [47] introduced an “Unsupervised Recurrent Federated Learning (URFL)” model for providing privacy against attacks on the “Industrial Internet of Things (IIoT)” scenario. A Markov chain-based popularity detection technique was adopted to determine the dynamic popularity of every user. The Markova chain helped in attaining the relationship between the global as well as local popularity of the user. The determined user was then given to the URFL model to identify the user’s distributed popularity along with providing security to the system. The aggregation of the parameters was done with the aid of the “Federated Loss-Weighted Averaging (FedLWA)” function. The non-authenticated user’s behavior was analyzed using this FedLWA approach. Experimental verifications showed that the “Root Mean Squared Error (RMSE)” of the suggested privacy-preservation approach was reduced by 61% to 69% than other distributed and centralized schemes. The implemented privacy-preservation scheme also provided privacy to the user data along with manual labeling of the user’s data to enhance security.
In 2022, He et al. [14] introduced a federated learning-based privacy-preservation scheme aided by a HEscheme to offer security to the end devices with low delays without actual data transmission between the edge nodes. The implemented scheme was known as PL-FedIPEC. A new encryption scheme called the Paillier method was incorporated into the developed privacy-preservation scheme. The generated model minimized the time required for data encryption. The encrypted ciphertext cannot be evaluated by unauthorized individuals in this encryption scheme. Experimental results showed that the security offered by the suggested privacy-preservation scheme was higher as this model was capable of generating accurate detection outcomes similar to that of baseline approaches with reduced computation and training time requirements.
In 2020, Qu et al. [30] introduced a federated learning model with an incentive mechanism for achieving an intelligent cloud-edge model. Then the HE scheme was introduced for providing security to the data being stored in the edge server. The feasibility, as well as the effectiveness of the promoted models, was proved by conducting extensive simulations by utilizing both real-time as well as synthetic data.
In 2022, Wang et al. [37] have deployed a model known as the PrivStream to prevent the privacy of the data streaming in the IoT platform. The proposed model prevented the linkage of the untrusted edge server with the IoT data. The filtration of the sensitive information was carried out using a deep learning model. The robustness of the developed privacy preservation scheme was validated by injecting noises into the system’s training stages. Simulation outcomes proved that the storage and computational overhead of this approach was in an acceptable range.
In 2023, Telikani et al. [34] implemented a “High-Performance Evolutionary Data Sanitization scheme for IoT (HEDS4IoT)” on two parallel “Graphical Processing Units (GUP)” in a real-time scenario. Privacy in transmitting streaming data was provided by this technique. The suggested scheme performed two parallel operations as a “Parallel Fitness Function Engine (PF2E)” and “Parallel Indexing Engine (PIE)”. The computation process was fastened by an evolutionary algorithm. The recommended HEDS4IoT was proven to be suited for both dynamic as well as big data environments.
In 2019, Xu et al. [45] utilized a “Strength Pareto Evolutionary Algorithm (SPEA2)”-based privacy-preservation scheme for providing security to the sensors in the edge computing system in order to generate a “Time-efficient Offloading (TEO)” scheme. Both the secret data’s offloading and the time taken to protect these data were evaluated in this approach by the formalized method. Both the joint optimization of the average privacy entropy and the consumed time were achieved by the SPEA2 scheme. The robustness and efficacy of the executed privacy-preservation scheme were verified by carrying out extensive experiments.
In 2020, Xu et al. [44] suggested a “Balanced Service Offloading Method (BSOM)” to offer security and privacy against the data stored in edge nodes. The resources utilized by the network were optimized by this method in an effective way, along with balancing the load in the entire network. Experimental analysis was carried out to prove the enhanced privacy offered by the suggested scheme along with providing a flexible operation with minimized time consumption.
In 2020, Zheng et al. [50] developed a spectrum interference-based two-level data augmentation approach in a deep structured approach for automated modulation categorization. The actual signal was initially converted into the frequency domain with the aid of a short-time Fourier transform. Inverse Fourier transform was introduced according to the interfered spectrum for reconstructing the augmented signals and then, the actual and augmented signals were subjected to the network. The data augmentation at both the testing and training phases can be utilized for enhancing the generalization performance of a deep structured approach. The simulation findings of the developed model have illustrated the model’s effectiveness and advancement.
In 2020, Zheng et al. [52] implemented the Manifold Regularization-aided Deep Convolutional Autoencoder (MR-DCAE) approach for unauthorized broadcasting recognition. In addition, an Autoencoder (AE) was tuned by entropy-stochastic gradient descent, and then the renovation of errors in the testing stage can be adopted to determine whether the received signals are authorized [51]. The simulation outcomes revealed that the designed model has attained elevated performance.
In 2023, Zheng et al. [49] promoted a Priori Regularization Method in Deep Learning (DL-PR) for guiding loss optimization. The main aim of regularizing deep structured approaches was to enhance the accuracy of the Automatic Modulation Classification (AMC) according to the distribution of samples [48]. Furthermore, it can be revealed that the priori regularization can be interpreted as implicit data augmentation. The experimental outcome of the designed model proved the high robustness and the interpretability of the model.
Problem statement
Features and challenges of existing privacy preservation models for edge computing.
Features and challenges of existing privacy preservation models for edge computing.
Edge computing is performed together with AI, which enhances the accurate processing and evaluation of streaming data generated with IoT applications. On the other hand, it also leads to privacy risks owing to the data transmission among the untrusted edge servers and local devices. Therefore, various privacy preservation models are developed in the existing models for edge computing, and they are summarized in Table 1. VGG19 [29] provides successful performance over exploratory attacks. It also provides faster encryption performance. However, it shows a slight deviation in the accuracy performance. URFL [47] assures improved accuracy by minimizing the RMSE rate. It is independent of privacy violations of the user and manual labeling. But, it does not solve the data deficiency problem. PL-FedIPEC [14] requires minimal time for training the model under different environmental settings. On the other hand, it shows a slight deviation in performance when analyzing sensitive information. Federated learning [30] assures model enhancement and end device protection even with the huge amount of edge server computation. Yet, it contains higher computational costs because of the network structure for determining the activation functions. PrivStream [37] gives better inference accuracy for the targeted tasks. It attains enhanced efficiency on practical transmission along with high-speed processing while using streaming data. Still, it does not assure effective performance in terms of energy consumption. HEDS4IoT and PF2E [34] provide faster performance when compared to conventional methods. However, it shows lower performance in terms of convergence and resource utilization. SPEA2 [45] reduces the average time consumption and provides high robustness through this method. But, it is not applicable in real-time applications. Also, it shows a slight deviation in the analysis of energy consumption. BSOM [44] enhances the performance regarding resource utilization and load balancing. However, it is not suitable for practical applications in order to support other specific fields. On considering these conventional challenges in existing approaches, it is necessary to implement privacy preservation techniques for edge computing.
The existing challenges of the conventional privacy preservation model for edge computing are considered in this research work, and the research problems are summarized as the key points below.
Mostly, edge computing causes privacy leakage for the user data, and it is required to develop an efficient privacy preservation model against inference attacks.
The most important factor, like accuracy loss, affects the performance of the conventional privacy preservation models and, therefore, it is required efficient deep learning techniques for enhancing the accuracy rate.
In addition, the challenge regarding the computational overhead is required to be solved by splitting the data of the edge and cloud side that are given into the deep learning training.
The existing HE scheme faces high computational burdens and computational costs, and therefore, it is required to develop hybrid encryption techniques to solve the conventional challenges.
When considering the transmission time, it relies on the transmission delay and propagation delay, and so a concrete amount of data is necessary for giving into the encryption and transmission phase of the model.
Intelligent privacy preservation framework in edge computing
Developed privacy preservation model in edge computing
A privacy preservation scheme for both the user and the cloud side is recommended in this work to prevent security against the data stored in cloud-based platforms. The user defines the test data to train the suggested deep learning-oriented privacy-preservation model in the cloud environment. Rather than providing the entire test data directly into the classification framework, the suggested privacy preservation system is divided into two main segments. The first segment is the trusted edge computing part with users, and the second segment is the untrusted cloud part with unknown users [4]. Privacy is provided by feeding the untrusted cloud with encrypted data and the trusted edge with plain text data. The segmentation of the recommended model into two units, the overall efficiency and the secrecy provided by the executed deep learning-based privacy preservation approach, is enhanced. At first, the user-defined test data is taken as input on the edge side. These test data are gathered using edge computing devices. Privacy of the gathered data on the edge side is provided by the developed deep learning model [13]. The gathered test data (plaintext) is given directly to the implemented ACC-DTCN model. From the ACC-DTCN framework, the output data is generated on the edge side. To enhance privacy in the untrusted cloud environment, the test data are primarily encrypted using a hybrid encryption scheme known as the OHEM on the cloud side. This OHEM scheme encrypts the test data. The test data is initially given to the HE technique [32]. The keys required by the HE scheme for encrypting the data are optimally selected by the suggested ELBOA. The encrypted data obtained from the HE scheme is then given to the ABE scheme for further encryption of the data. The keys required by the ABE scheme for encrypting the data are also optimally generated by the implemented ELBOA. The optimal generation of the encryption keys helps in minimizing the memory and time requirement of the encryption process. The final encrypted data is generated from the OHEM scheme on the untrusted cloud side [1]. This encrypted data is given to the to the developed ACC-DTCN model on the cloud side. The confidence score vector among the testing and training data is predicted by the implemented ACC-DTCN model by utilizing the encrypted data on the cloud side. While simulating the deployed privacy preservation scheme against existing methods, higher prediction accuracy is provided by the recommended model, and enhanced preservation against interference attacks is given by the executed privacy-preservation scheme. In addition, the strategies employed to develop an efficient privacy preservation model against inference attacks are discussed as follows. Generally, security strategies are needed to mitigate these inference attacks. An advanced encryption of model inputs, secure authentication of all parties, execution integrity, and model confidentiality are significant strategies for promoting an efficient privacy preservation model against inference attacks. While taking privacy leakage for user data, the proposed data privacy-preservation model in the edge-cloud environment model gains higher bandwidth with the help of machine learning and deep learning models that help to transmit more data between end devices and edge servers. It allows more private information while transmitting the data. Edge computing faces challenges with computational overhead like bandwidth and latency limitations. The propagation delay caused by data transmission is denoted as latency and bandwidth challenges can impact the performance of the developed model. Here, the given developed model gains higher bandwidth with the help of deep learning models which helps to resolve the computational overhead effectively. The architecture of the recommended data privacy-preservation model in an edge-cloud environment is illustrated in Figure 1.

Architecture of the recommended data privacy-preservation model in edge-cloud environment.
The three major components in the suggested scheme are the cloud server, edge devices, and the edge server. The cameras, sensors, and other devices in the IoT system with lower computational ability serve as the edge devices. The processing of the devices collected from the edge devices is done by the cloud server, which is installed near the edge devices. Both securities, as well as efficient computation, are offered by the edge server. The pre-processing of the user data is done by the edge server. On the basis of its own dataset, the suggested model is trained using the cloud platform. The ACC-DTCN is used by the cloud to train the qualified model for preventing data privacy. The plaintext is processed locally, and then encryption takes place in order to prevent the privacy of the user data. On the basis of the encryption results, the remaining processing is completed by the cloud. The decryption of the data is not possible without the appropriate private key. Thus, enhanced privacy is provided by this model. The generated model is generic and suitable for performing any task.
Enhanced privacy preservation model in edge computing using advanced deep learning with a meta-heuristic algorithm
Deep learning on encrypted data
As the computation of the encrypted data is possible in the case of the HE and ABE schemes, it is an ideal choice for the “privacy-preserving deep learning” technique. The random processing of the ciphertext is carried out using “Fully Homomorphic Encryption (FHE)”. But, in practical application, this FHE scheme results in a larger cost. Hence, “Leveled Homomorphic Encryption (LHE)” like the SEAL is adopted. The SEAL is capable of performing both summation and product operation on a “depth-bounded arithmetic device”. However, it is also noted that only the processing of the polynomial operations is supported by the SEAL. The processing of the non-linear operations is carried out using linear operations. The implementation of deep learning techniques is usually carried out in the Python paradigm. So, the processing of these ciphertexts is complicated without any codes for processing. This issue is tackled by Intel’s graph compile, nGraph-HE scheme, which allows the processing of ciphertexts executed in any platform. Thus, the deep learning model can be trained into a suitable “privacy-preserving system”.
Use of edge computing
The resource and computing to the cloud from the source of data is described by edge computing. Edge computing is utilized because it prevents issues such as delay and data leakage while transmitting the data by the cloud server itself. The edges are implemented closer to the data sources. The computation of the data generated by the edge devices and sending the computed data to the cloud server is performed by the edge server. Thus the delays in data transmission are reduced, and at the same time, the privacy of the data is improved. The processing of the raw data securely and transmitting it without any data leakage to the cloud server is achieved by the edge server. The LHE is utilized in this work as the edge server.
Ladybug beetle optimization algorithm
The LBO [31] algorithm is designed by considering the migration patterns of the swarm of ladybugs. As a social insect, there is always an interaction with every ladybug in a swarm. It is also noted that the ladybug coordinates with one another in the swarm to spot a warmer place in winter. The swarm intelligence of the ladybug is utilized for determining the safe and warmer place in winter. While following the path towards the warmer place, some ladybugs may lose track and die out of cold weather. The number of ladybugs involved in the search process is decreasing. The population of the ladybugs in the swarm is determined. On the basis of the fitness value, the population of ladybugs is sorted. On every cycle, the number of ladybugs in the swarm is determined, and their fitness values are re-evaluated. This process is simulated to determine the number of ladybugs that sustain the cold weather and move toward the warmer place. Once the required cycles are executed, the optimal ladybug is then determined. The sole inspiration behind LBO is its movement toward a warmer location to escape from the cold weather. The initial ladybug swarm population has
On the basis of the uniform distribution function, the initial ladybug population is distributed arbitrarily throughout the lookup area. The pre-defined fitness value is evaluated to determine the initial ladybug population, and it is saved in the memory. With the utilization of a coordinated swarm movement, the entire swarm moves toward the warmer location. Even in search of a warmer location, the entire ladybug population moves as a swarm because of its social nature. By following the signals emitted from the group member, every member in the swarm follows one another. So, every ladybug tends to follow the lady prior to it. The ladybug in the frontline of the swarm is more capable of determining the best location with warmer temperatures than the other ladybugs in the swarm. The balancing of the exploration and exploitation phases is achieved by incorporating a mutation process arbitrarily to some ladybugs in every cycle of the LBO algorithm. Therefore, the location of the ladybug in every cycle in the lookup area is determined either by the mutation process or by the location of the other ladybugs in the swarm. Every ladybug in the swarm updates its location in every cycle of the LBO algorithm. By combining the old as well as the new location of the ladybug, the optimal swarm is selected on the basis of its fitness value. In the upcoming cycle, the location of the new ladybug population is determined. A ladybug in one swarm is amended with respect to another ladybug in the same swarm. This process is explained as follows. Let us assume the ladybug that needs to be amended as c. For the purpose of amending this
The term
The roulette wheel selection process is adopted in the conventional LBO algorithm to update the location of the ladybird. However, this step increases the computational complexity in the LBOA. Hence, it is removed in the suggested ELBOA.
The population of the ladybug gets updated by considering the mutation process, which is regarded as the crucial process in the LBO algorithm to avoid local minima and to explore more areas in the lookup region. Also, the convergence rate of the LBO algorithm is enhanced with the inclusion of this mutation process. Therefore, the amending of a ladybug with respect to the mutation procedure and with respect to other ladybugs is evaluated arbitrarily. Let us assume the ladybug that has to be mutated is at the
In Eq. (3), the term h denotes the decision variable’s length, the term
In Eq. (4), the term
In Eq. (5), the term
The flowchart of the generated ELBOA is given in Figure 2.

Flowchart of generated ELBOA.
Proposed atrous convolution-based cascaded deep temporal convolution network
The raw data collected from various online sources
In Eq. (6), the term E indicates DCC’s depth. Because of the disappearing gradient issues, deep neural networks become hard to train. This issue is resolved by including residual blocks in the deep structures. The stability of the network while training is enhanced by incorporating skip connections. The addition of the skip connection on the residual units prevents the gradient’s norm. The residual block’s input is the output from the final DCC layer. The output from one residual unit is provided as input to the next residual unit. To maintain the size of the output similar to that of the input
The term
In Eq. (8), the term v indicates the degree of expansion of the convolutional layers. In between the successive filters,

Diagrammatic illustration of the recommended ACC-DTCN-based classification model for data analysis.
The encryption of the test data
HE: The encryption scheme in which the data that needs to be protected is converted into a ciphertext, which can be evaluated and processed without revealing its original format, is known as HE [10]. Without compromising the encryption, HE allows complicated mathematical functions to be carried out on the ciphertext. It should be noted that there must exist a correlation between the ciphertext and the plaintext in order to implement mathematical functions in the case of a HE scheme. The major challenges for homomorphic encryption are computationally intensive and slow. The operations like encrypting, performing operations on ciphertexts, and decrypting need more resources and it takes more time. The data in its original format is denoted as plaintext, whereas the data being encrypted by the encryption algorithm is termed ciphertext. Multiple summation and multiplication operations are carried out in a HE scheme. On the basis of the mathematical operation implemented in the homomorphic scheme, it is categorized as “multiplicatively homomorphic, as well as additively homomorphic”. It is further classified into “somewhat homomorphic, fully homomorphic, and partially homomorphic” encryption schemes. A brief description of these types of HE schemes is provided as follows.
Additively Homomorphic: If the results obtained on summing two ciphertexts are equal to the results on encrypting the integration of two the plaintext, then the homomorphic scheme is said to be an additively HE scheme.
Multiplicatively Homomorphic: If the results obtained on multiplying two ciphertexts are equal to the secret key raised to the power of product between two plaintexts, then the homomorphic scheme is said to be a multiplicative HE scheme.
Somewhat Homomorphic: In this scheme, only a finite number of either of the one mathematical operations (multiplication or addition) is carried out. This scheme is complicated to design, unlike the other schemes with infinite operations.
Fully Homomorphic: In this scheme, infinite multiplication and addition take place on the ciphertext for encryption.
Partially Homomorphic: This scheme is the easiest of the entire types of homomorphic schemes as it performs an infinite number of defined operations (either multiplication or addition) on the ciphertext.
An encryption technique is regarded as homomorphic when the provided security key H satisfies the function given in below Eq. (9).
In Eq. (9), the term Θ indicates the mathematical function. The symbol Θ is replaced by ⊕ in the case of additively HE as
ABE: The ABE [16] is a generalized version of the public key encryption protocol. With the execution of an authentication process, fine-grained access control over the data that is being encrypted is obtained in the case of ABE. Both the encrypted ciphertexts and the user’s secret keys are interrelated with the user attributes. Only when the ciphertext’s attributes when matched with the secret key attributes enables the decryption of the ciphertexts. The important security concern in the ABE is collision resistance property. Two ABE schemes exist. One is the Ciphertext-Policy (CP)-ABE, and the other is the Key Policy (KP)-AE. The main difference between the CP-ABE and the KP-ABE is that in CP-ABE, the data is encrypted using the access tree, while the secret keys for the user are obtained by utilizing a certain set of attributes; whereas in KP-ABE, the data is decrypted by utilizing a certain set of attributes and the secret keys for the user is obtained using access trees. Four major “polynomial-time” functions, such as the Setup, Key Generation, Encryption, and Decryption, are performed in both the CP-ABE and KP-ABE. These four mechanisms are provided as follows for both types of ABEs.
Setup Phase: A group of decryption policies ρ supported by the ABE scheme, a security variable ϕ, and attributes
Key Generation Phase: Along with O and P obtained from the setup phase, a decryption policy
Encryption: The message S, a group of attributes
Decryption: The secret key
The overall processes in the KP-ABE scheme are given below:
Setup Phase: A group of decryption policies ρ supported by the ABE scheme, a security variable ϕ, and attributes
Key Generation Phase: Along with O and P obtained from the setup phase, a group of attributes
Encryption: The message S, the decryption policy
Decryption: The secret key
The overall processes in the CP-ABE scheme are given below:
Initially, the test data generated
In Eq. (10), the term
In Eq. (11), the term
In Eq. (12), the term

Encryption of the protected data using suggested OHEM.
The encrypted data
Split of encrypted deep learning network
The computational burden reduction as well as the efficiency-boosting of the HE transform function, is obtained by offloading the tasks in the edge server. This also enhances the security of the data stored in the cloud server. However, the offloading of the tasks in the cloud to the edge server also leads to the leakage of the information to the edge devices. The proper splitting of the ACC-DTCN network’s data for offloading purposes without compromising privacy as well as efficiency by properly allocating the number of tasks to each edge device is a complicated task to achieve. The number of encrypted data also needs to be considered. The balancing of the transmitting and computation time also needs to be carried out. Hence, on the basis of the network’s structure, the amount of data that needs to be transmitted to the cloud from the edge devices is determined.
Result and discussion
Experimental setup
The implemented data privacy preservation scheme in edge-cloud computing system was developed and executed in Python platform with a maximum iteration count of 50, population count of 10, and chromosome length of
Processing datasets
The experimental dataset used in this proposed system is gathered from standard databases. A detailed description of the gathered dataset is provided in Table 2. The gathered data is indicated as
Dataset description.
Dataset description.
The evaluation indices used for the validation of the recommended privacy-preservation scheme in a cloud-edge environment are listed below.
(a) The “Negative Predictive Value (NPV)”
The term
(b) The calculation of recall
The term
(c) The determination of accuracy is followed by Eq. (15).
The term
(d) The evaluation of the “False Positive rate (FPR)”
(e) The calculation of specificity
(f) The determination of “False Negative Rate (FNR)”
(g) The computation of “Matthews Correlation Coefficient (MCC)”
(h) The F1-score
(i) The “False Discovery Rate (FDR)”
(j) The value of precision
The ROC examination of the implemented data analysis model is illustrated in Figure 5. The “True Positive Rate (TPR)” of the implemented ACC-DTCN model is 13.4%, 32.99%, 46.39%, and 56.7% are improved than the GRU, VGG-16, LSTM, and RNN frameworks, respectively for dataset 1 at FRP of 0.1. Thus the performance provided by the implemented ACC-DTCN model is higher than many state-of-the-art methods.

ROC assessment of the implemented data analysis model regarding “(a) dataset 1, (b) dataset 2, and (c) dataset 3”.
The validation of the developed data analysis model in both cloud and edge sides is depicted in Figure 6. The accuracy of the developed ACC-DTCN model is 9.3%, 14.63%, 13.25%, and 17.5% is improved than the GRU, LSTM, VGG-16, and RNN frameworks, respectively for dataset 3 in the edge side. The accuracy of the developed ACC-DTCN model is 2.67%, 5.49%, 4.35%, and 5.49% is improved than the GRU, LSTM, VGG-16, and RNN frameworks, respectively for dataset 3 on the cloud side. Hence, it is proved that the developed ACC-DTCN model provides enhanced performance on the task assigned to them on the cloud side than edge side.

Validation of the performance of the developed data analysis model in terms of “(a) FNR, (b) recall, (c) accuracy, (d) Fi-Score, and (e) FPR”.
The confusion matrix examination of the generated analysis model is provided in Figure 7. The number of correct predictions made by the ACC-DTCN framework is

Confusion matrix examination of the generated data analysis framework regarding “(a) dataset 1, (b) dataset 2, and (c) dataset 3”.
The performance assessment of the recommended data privacy preservation scheme is illustrated in Figure 8. The memory size of the recommended ELBOA-OHEM scheme is 2.7%, 2.7%, 5.26%, and 26.15% is improved than the TSA-OHEM, GEO-OHEM, LBOA-OHEM, and HHO-OHEM schemes, respectively for dataset 2 at block size 4. Improved privacy for data in the edge-cloud environment is offered by the recommended ELBOA-OHEM scheme.

Performance assessment of the recommended data privacy-preservation scheme in terms of “(a) computation time, (b) encryption time, (c) memory size, and (d) decryption time”.
The cryptography scheme-based performance analysis of the generated data privacy-preservation model is given in Figure 9. The computation time required by the generated ELBOA-OHEM scheme is 28.13%, 34.29%, 11.54%, and 14.82% is enhanced than the TSA-OHEM, HHO-OHEM, LBOA-OHEM, and GEO-OHEM schemes, respectively for dataset 1 at block size 5. Thus, it is assured that the generated ELBOA-OHEM scheme offers more preservation for data in an edge-cloud environment.

Performance assessment of the recommended data privacy-preservation model in terms of “(a) computation time, (b) encryption time, (c) memory size, and (d) decryption time”.
The statistical validation of the developed data privacy-preservation model is listed in Table 3. The mean value of the ELBOA-OHEM scheme is 8.25%, 9.05%, 8.45%, and 7.78% is higher than the TSA-OHEM, GEO-OHEM, HHO-OHEM, and LBOA-OHEM schemes, respectively for dataset 1. Thus, it is proven that more privacy is given by the developed ELBOA-OHEM scheme in preventing the data in an edge-cloud environment.
Statistical validation of the developed data privacy-preservation model.
Statistical validation of the developed data privacy-preservation model.
The convergence examination of the proposed algorithm is shown in Figure 10. The cost function of the proposed ELBOA is 8.33%, 8.33%, 4.84%, and 4.84% more than the HHO, GEO, LBOA, and TSA, respectively, for dataset 2 at 40th iteration. The convergence curve of the loss function is mean-squared-error. The objective function of the convergence graph is how the target result is modified with each iteration of the solution. Here, improved performance is shown by the proposed ELBOA.

Convergence evaluation of the proposed algorithm regarding “(a) dataset 1, (b) dataset 2, and (c) dataset 3”.
The ablation experiments of the developed data privacy-preservation scheme in an edge-cloud environment are shown in shown in Table 4. Generally, an ablation examination is a set of experiments in which modules of expert systems are replaced with the purpose of computing the efficacy of the system. Here, the ablation experiments of the designed approach revealed that it achieves enriched performance based on accuracy metrics.
Ablation experiments of the developed model.
Ablation experiments of the developed model.
The estimation of the computational time for the developed data privacy-preservation scheme in an edge-cloud environment approach is shown in Table 5. The computational complexity of the developed model is shown in Table 6. From Table 6, the term
Evaluation of computational time of the developed model.
Evaluation of computational time of the developed model.
Computational complexity of the developed model.
The estimation of the convergence curve of the loss function for the implemented model is shown in Figure 11. The accuracy score is the total count of correct predictions attained in implementation. Accuracy loss values demonstrate the difference from the preferred target states. While analyzing Figure 11, the model accuracy and loss are validated regarding the number of epochs.

Evaluation of convergence curve of loss function for the proposed model regarding (a) model accuracy and (b) model loss.
The comprehensive experimental evaluation of the designed model is given in Figure 12. While taking Figure 12, the validation of the designed model shows a better accuracy rate regrading number of epoches. The elevated accuracy rate is attained while the count of epoches is in 250.

Comprehensive experimental evaluation of the designed model regarding (a) dataset 1, (b) dataset 2, and (b) dataset 3.
The comparison among the suggested data privacy-preservation schemes in an edge-cloud environment model using recent approaches is shown in Table 7. The DKN model attains a lower accuracy rate. Due to this, it cannot be suitable for the larger dataset. The CL model attains a second better performance. Finally, the better accuracy rate of the developed model attained as 95.78% for dataset 3. Therefore, it is revealed that the given developed model attains elevated performance.
Comparison among the suggested models using recent approaches.
Comparison among the suggested models using recent approaches.
An enhanced data privacy-preservation scheme in an edge-cloud environment was deployed successfully utilizing cryptography and deep learning techniques. The user data were gathered from the data source. The gathered data were provided to the ACC-DTCN model for performing the task assigned to them on the trusted edge side. On the cloud-side, in order to protect the test data, an encryption scheme was implemented. The test data was encrypted by the developed OHEM scheme. The encrypted data was then again provided as input to the ACC-DTCN model on the untrusted cloud side. Thus enhanced security of the transmitted data was provided in both edge and cloud-side environments. The experimental validation was carried out to prove the efficacy and privacy provided by the suggested data privacy-preservation scheme. The suggested ACC-DTCN model was 2.67%, 5.49%, 4.35%, and 5.49% more accurate than the GRU, LSTM, VGG-16, and RNN frameworks, respectively on the cloud side. Hence, enhanced privacy was proved to be provided by the suggested scheme on both users as well as the cloud side in the edge-cloud environment. However, need to include the concept of cooperative privacy preservation which will be perfectly suitable for smart health. In addition, the given proposed model needs more investigation of the security properties like mutual authentication, data confidentiality, and integrity, privacy preservation, and forward security. In the future, we will include the concept of cooperative privacy preservation for smart healthcare. Especially, the investigation of security properties will help to enhance the trustworthiness of the offered approach.
Footnotes
Conflict of interest
The authors have no conflict of interest to report.
