Leveraging Centrality Matrix and Enhanced Walrus Evoked Learning Framework for Digital Forensics Anomaly Data Detection

Leveraging Centrality Matrix and Enhanced Walrus Evoked Learning Framework for Digital Forensics Anomaly Data Detection

Srikanth Addagatla G. Madhukar Rao*

Department of Computer Science and Engineering, Koneru Lakshmaiah Education Foundation, Hyderabad 500075, Telangana, India

Corresponding Author Email: 
madhusw511@klh.edu.in
Page: 
297-307
|
DOI: 
https://doi.org/10.18280/ijsse.150210
Received: 
31 December 2024
|
Revised: 
23 January 2025
|
Accepted: 
13 February 2025
|
Available online: 
28 February 2025
| Citation

© 2025 The authors. This article is published by IIETA and is licensed under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/).

OPEN ACCESS

Abstract: 

Digital forensics (DF) has emerged as a crucial strategy for tracing offenders and ensuring social justice for the common man. With the increasing exploitation of digital gadgets by criminals, cybercrimes have risen significantly, affecting people’s daily lives. Consequently, the primary goal of DF is to ensure that digital evidence remains unaltered by identifying, collecting, analyzing, and assessing data to reconstruct historical events. However, detecting data anomalies that indicate illegal behavior remains one of the most daunting challenges in DF. Current systems hinder DF investigations due to inaccuracies in identifying aberrant patterns in forensic data. With the advent of artificial intelligence (AI), unusual activities in DF data can now be detected more effectively. However, achieving higher accuracy remains a major challenge in this field. This research article proposes a novel hybrid learning framework that integrates centrality measures with an Enhanced Walrus Evoked Extreme Feedforward Neural Network (EW-EFNN) to identify intrusions in crime-related digital forensic data. The proposed framework is trained using different traffic data generated on computers to determine whether they have been tampered with by specific intruder programs. Real-time datasets are created using Wireshark to analyze various DF anomaly patterns, followed by centrality measures for feature extraction and an enhanced walrus-evoked learning network for optimal detection performance. Comprehensive experiments are conducted using real-time traffic data, evaluating performance metrics such as accuracy, precision, recall, specificity, and F1-score. The results demonstrate that the proposed model achieves 96% accuracy, 95.7% precision, 95.8% recall, and a 96% F1-score. Compared to existing systems, the proposed learning framework outperforms others in detecting anomaly patterns in DF data.

Keywords: 

digital forensics (DF), artificial intelligence (AI), centrality measures, enhanced walrus evoked multi-layer neural network

1. Introduction

Smart environments today provide a wide array of advanced technologies and services, including smart transportation systems, autonomous vehicles, intelligent homes, urban lighting solutions, ticketing for travel, energy-efficient grids, and sophisticated sensors [1]. The functionality of these systems is largely reliant on small-scale electronic chips and IoT devices like sensors, wireless communication technologies, Radio-Frequency Identification (RFID) devices, location-tracking systems, and Near-Field Communication (NFC) tools.

The rise of smart environments has attracted criminal activity, with offenders exploiting these digital platforms. In response, DF has become an essential method for identifying these criminals and supporting law enforcement in holding them accountable [2-4]. The process of reviewing, scrutinizing, and drawing conclusions from electronic data is regarded as DF and plays a significant role in criminal investigations [5-7].

Suspicious activities and unsafe events can cause organizations to face significant financial losses and damage their reputation. Such incidents may have severe consequences for both individuals and organizations. As indicated by statistics from published reports, there have already been over five million instances of computer-related violations [8, 9]. A substantial number of cybercrimes remain undocumented, as victims often refrain from reporting them to authorities. These victims may feel embarrassed or uncertain or perceive that the authorities are not adequately addressing the issue to hold perpetrators accountable. Moreover, the government must work to curb cybercrime by addressing the gaps in expertise and workforce competencies.

Law enforcement agencies are becoming more reliant on DF to catch and prosecute criminals, as the use of digital devices in criminal acts continues to grow [10, 11]. Identifying abnormal or suspicious behavior within digital forensics (DF) data is crucial, yet it presents a significant challenge. Designing an intelligent detection system is vital as it empowers investigators to ascertain unusual behavioral patterns that could indicate criminal activity. Traditionally, anomaly detection in DF has relied on statistical methods and rule-based systems [12]. These techniques may fail to detect subtle irregularities intended to deceive investigative frameworks.

AI, especially through Machine Learning (ML) and Deep Learning (DL) approaches, offers efficient and sophisticated methods for generating valuable insights for decision-makers. These approaches involve analysing datasets from various angles and transforming them into meaningful formats. The aim of these approaches is to learn from past data to forecast future behaviors. By leveraging ML methods, researchers can enhance their ability to identify patterns in criminal activities and gain insights from historical data regarding when, where, and how cybercrimes are likely to occur.

Several ML algorithms, such as Support Vector Neural Networks (SVNN), Support Vector Machines (SVM), Multi-layer Neural Networks, and K-Nearest Neighborhood (KNN), are deployed for the detection of anomalies in DF systems. These techniques are used in numerous fields like financial fraud detection and intrusion detection. But these algorithms need to be studied extensively so they can be applied in DF analysis. Hence, the current approaches need the brighter light of improvisation in terms of DF data. Inspired by the aforementioned drawbacks, this article aims to examine the challenges in determining anomalies in DF data pertaining to criminal activity. The paper proposes the novel ensemble of centrality-based feature extraction with an enhanced Walrus Evoked multi-layer learning framework for anomaly detection in forensic digital data. The key contributions are as follows:

(1) The paper recommends centrality feature extraction methods for better detection of anomalies in DF data.

(2) An enhanced Walrus Evoked multi-layer framework for achieving the robustness and scalability of the scheme is recommended in this research.

(3) The paper proposes a novel synthetic data generation method based on Wireshark and the Python environment to evaluate the proposed model.

(4) Extensive evaluation is facilitated by utilizing the above datasets, and various evaluation metrics are measured, analyzed, and examined with the varied schemes. From the experimental outcomes, the recommended model has outshined the other available schemes.

The structure of the study is organised in the following manner: The relevant studies by distinct authors on ML models deployed for anomaly detection in DF investigations are discussed in Section 2. The novel dataset generation, feature extraction, and learning networks are discussed in Section 3. Implementation details are provided in Section 4. Experimental outcomes and evaluative assessments are outlined in Section 5. Finally, the study concludes with suggestions for future improvements in Section 6.

2. Related Works

Wang et al. [13] proposed a novel fusion model combining Isolation Forest (IF), GAN, and transformer for Network Anomaly Detection (NAD) and log analysis. They address key challenges in handling high-dimensional data and complex network topologies through this integrated approach. The IF enables quick anomaly identification, while GAN generates synthetic training data, and transformer processes time-series data. While their experimental results demonstrate improved accuracy and reduced false alarm rates, the model’s computational poses integration challenges in real-world deployments.

Nkashama et al. [14] investigated the critical issue of data contamination in DL-based NAD systems. Their research evaluates six unsupervised DL algorithms' robustness against contaminated training data. They propose an enhanced auto-encoder with constrained latent representation to improve resilience to data contamination. However, the study could benefit from broader evaluation across diverse network environments and attack scenarios to validate generalizability.

Islam et al. [15] proposed a Novel Support Vector Neural Network (NSVNN) for anomaly detection in DF. They evaluated the NSVNN against existing algorithms like SVM and neural networks using DF data. The research highlights feature importance and the decision-making process, contributing to effectiveness examining in DF. Meanwhile, the research does not discuss the scalability of the NSVNN for larger data and its effectiveness in real-time Forensics investigations.

Yang et al. [16] presented an approach that includes multi-perspective feature engineering, Unsupervised Anomaly Detection (UAD), and extensive outcome refinement processes. The framework employs a combination of Gaussian Mixture Model (GMM) While the study portrays the capability of the recommended approach on real-world evolving network data, it lacks comparison with varied cutting-edge anomaly identification techniques in the context of DF.

Jones et al. [17] proposed a scheme to recognize suspicious drug-related activity on mobile devices using Forensics and Natural Language Processing (NLP) approach. But it does not address the challenges of applying these techniques to diverse types of mobile Forensics data and discuss the model's performance on unseen data.

Ashraf et al. [18] developed a model for behaviour detection utilizing social media forensic analysis on social media accounts. Although the framework demonstrates potential benefits for cybercrime and cyber-security agencies, it does not address privacy concerns or ethical considerations in analysing social media data for behaviour detection.

Wei et al. [19] introduced a novel UAD framework utilizing Cascaded Auto Encoders (CAEs) and integrated optimization network for threat recognition. Their end-to-end framework utilizes Bidirectional Long Short-Term Memory (BiLSTM) for feature extraction and includes a hypergraph correction module to reduce false positive rates. The discussion on the framework's adaptability to varied types of organizational data is missing.

Studiawan and Sohel [20] developed a DL technique to ascertain anomalous events in a Forensics timeline using deep autoencoders. Their method preprocesses system logs, applies deep and sparse autoencoders to build a Forensics timeline, and plots the outcome using Time sketch. In experiments with four public Forensics datasets, the recommended approach achieved good results than existing approaches.

Li et al. [21] introduced Swiss Log, a reliable and integrated DL approach for identifying various anomalies in digital log data. Experiments on real-world and synthetic data highlights the efficiency of Swiss Log, the paper falls short in providing detailed performance metrics and comparisons with other anomaly detection methods.

3. Proposed Methodology

The proposed framework consists of four components such as synthetic data generation, data-pre-processing, centrality feature extractor and walrus optimized extreme learning networks have shown in Figure 1. The detailed description of the each and every module is as follows.

Figure 1. Overall Architectures for the recommended framework

3.1 Synthetic data generation

The research utilizes synthetic data generation to evaluate the proposed model in detecting anomalies within the DF framework. To generate the synthetic data, Wireshark, a network packet analyzer, is used to capture network packets and attempt to reveal the packet data. The detailed components of Wireshark are presented in Table 1. Figures 2-4 show the screenshots from Wireshark, capturing packets from different devices.

Table 1. Components of Wireshark used for the synthetic data generation

Sl. No.

Components of Wireshark

Description

1

T-Shark

Command Line Inputs

2

External Capture Interface

To capture the packets from the network devices

3

ETwdump

To display and capture the packets from the external devices

4

AndriodDump

To capture and display the packets from the Android Mobiles

5

SShdump, WIFIDump

To capture and display the packets from the networked devices

6

UDPdump

To display the packets from the UDP mechanism

Figure 2. Wireshark-capturing the packets from the networked devices

Figure 3. Filtering the data using the Wireshark installed devices

To inject the anomalies, Python programming was employed. Multiple attack models were designed and injected from neighboring devices using Wi-Fi and Ethernet networks. Several research works [22-24] have demonstrated that DF data are vulnerable to various types of attacks. The categorization of significant anomalies is presented as follows.

Figure 4. Anomaly data injected from devices and transmitted to Wireshark

3.1.1 Denial of Service (DoS)

A DoS attack occurs when excessive unwanted traffic originates from a single source or receiver. In this scenario, the attacker overwhelms the target with numerous malicious packets, rendering its services inaccessible to other users [25].

3.1.2 Distributed Denial of Service/Botnet attacks (DDoS)

These attacks focus on compromising a large number of vulnerable IoT devices, enabling the attacker to execute a much more potent DoS attack or other forms of assault [26].

3.1.3 Man-in-the-Middle (MitM)

This attack compromises the communication channel between the IoT device and its target data recipient. While the connection is breached, the attacker acts as an intermediary, allowing them to observe, insert, and alter the data being transmitted [27].

3.1.4 Data type Probing (D.P.)

The Data Probing attack involves altering the raw data packets as they travel between departure and arrival points [28].

Algorithm-1 presents the pseudocode for the data collection mechanism.

Sl. No.

Algorithm-1//Data Collection Mechanism

1

Input: Packets from the Different Sources of Devices

2

Outputs: Anomaly Data and Normal packets

3

While (True)

4

For t=1: 100000secs; t=time frame

5

Capture the Normal packets from the devices

6

Store it as the PCAP CSV files

7

End for

8

For t=100000:2000000secs; t=time frame

9

Capture the Anomaly data from the devices

10

Store it as the PCAP CSV files

11

End for

12

Go to Step 6

13

Go to Step 8

14

End While

3.1.5 Spying (SP)

In this attack, an intruder exploits system vulnerabilities and uses a backdoor channel to infiltrate the system, exposing sensitive information [29].

For efficient data collection, a series of malicious anomalies were documented over a span of three weeks for further predictive analysis. To ensure a thorough evaluation of the proposed framework, it is essential to create an expanded dataset that includes both benign and harmful data. The Python API developed was used to implement various types of attacks, and the information samples collected during the experimentation are presented in Table 2. All the data were captured and stored in PCAP CSV files in Wireshark, as shown in Figure 5.

Table 2. Dataset collected during experimentation

Data-Type Descriptions

Count of Samples Gathered

Normal Data

14,90738

Malicious Data-DoS Attack

890392

Malicious Data-DDoS Attack

378904

Data type Probing Data

250895

Spying Data

109034

MIM Data

105678

Figure 5. PCAP CSV file format stored in Wireshark after the pre-defined time stamps

3.2 Data pre-processing technique

It is considered the paramount technique in designing an efficient learning model and includes data cleaning, conversion, and scaling. As the first step, missing values and null values (NaN) are eliminated from the datasets. In the second step, categorical features are converted into numerical values using the Label Encoding technique, which is included as a separate library in Scikit-Learn. Finally, data normalization is applied to the datasets, converting all the inputs to a standard scale, which is essential to avoid misinterpretations during model training. In this research, the Min-Max scaling process is used, which converts each feature to a predefined range from 0 to 1.

3.3 Centrality feature extraction

The primary goal of this research is to design efficient attribute databases capable of distinguishing between normal and influential nodes. Various methods for detecting centrality measures have been proposed in previous literature to signify the significance of nodes. However, this paper emphasizes the application of an expanded set of centrality metrics to achieve the most precise classification of influential nodes.

3.3.1 Degree centralities

This refers to the number of connections linked to the nodes within a network. It comprises two variations: indegree centrality and outdegree centrality. The values of these centralities can be calculated using the equations provided below.

Indegree centrality

Din(Pi)=|PjiP|,ji          (1)

Pji is the edge going from Pi node to examined node P.

Outdegree centrality

Dot(Pi)=|PijP|,ij          (2)

3.3.2 Amongness centralities

Amongness centrality indicates the proportion of all shortest paths that pass through specific nodes. The formula for calculating betweenness centrality is presented below:

DB(Pi)=PsPiPdμPs,Pd(Pi)μPs,Pd          (3)

where, μPs,Pd(Pi) is the shortest paths among nodes PS and Pd relaying through node Pi and μPs,Pd.

3.3.3 Closeness centralities

This signifies the distance of nodes in the network, expressed mathematically as follows:

Dc(Pi)=NPyd(Py,Pi)          (4)

3.3.4 Eigen vector centralities

The eigenvector centrality method is used to derive the centralities of other nodes in the network. The formula for determining this is given below:

Ev(Pi)=1/AkγPk,PiEv(Pk)          (5)

where, A=α(k,i) is the adjacency matrix of a graph and γ a constant.

3.3.5 PageRank centralities

PageRank centrality ranks nodes based on their centrality within networks, with the expression used to calculate it given by:

Rp(Pi)=ρkAPk,PidkRp(Pk)+β          (6)

where, ρ and β are constant values, and dk indicates the outdegree of node Pk if the degree is greater than zero; if the outdegree of node Pk is zero, then dk is set to 1 . Furthermore, A=(ai,j) signifies the adjacency matrix of a graph, where A=α(k,i) serves as the adjacency matrix.

3.3.6 Position centrality

This is considered the most important measure, representing the position of nodes relative to key nodes identified by the PageRank method.

Sc(Ui)=BkγUi,UkRU(Ui)          (7)

where, B=(ai,j) is the adjacency matrix of a graph and RU(Ui) is the Page Rank of the node.

3.3.7 Clustering co-efficient

This factor denotes the fraction of triangles found among the residing triangles in the nodes' neighborhood. The quantitative expression for calculating the clustering coefficient is given by:

Cc=2MU,i/Oi(Oi1)          (8)

Apart from these centralities, this paper also discusses another important parameter called Clique, which plays a crucial role in improving the classifier's performance. Reference [30] contains additional information regarding this measure, which is incorporated into the recommended scheme. The methods for assessing K-Score and K-Shell are explored in reference [31].

Another crucial metric used for classification includes neighborhood variability and timestamp centrality.

All attribute vectors utilized for classification are detailed in Table 3.

Table 3. Summary of centrality feature extraction mechanism

Centrality Features

Significance

In degree Centrality

Signifies the number of connections tied to the nodes.

Out degree Centrality

Amongness Centrality

Indicates the proportion of all shortest paths that traverse the nodes.

Closeness Centrality

Illustrates the spatial relationships of nodes in the networks.

Eigen Vector Centrality

Utilized for calculating the centrality measures of other nodes in the network

PageRank Centrality

Evaluates the hierarchy of nodes according to their centrality within the networks

Position Centrality

Indicates the location of nodes in relation to significant nodes.

Clustering Co-efficient

Indicates the proportion of triangles that exist relative to all triangles in the neighborhood of the nodes.

K-Shell Centrality

Indicates the K count for decomposing networks.

K-Score Centrality

Determines the K number of eliminated nodes in the networks.

Time Stamp Centrality

Assessment of the time lag among transmitted and received messages in the network.

3.4 Walrus evoked multilayer network classification

This section discusses the working principles of the Walrus Optimization Algorithm (WaOA) and the proposed model.

3.4.1 Walrus Optimization Algorithm (WaOA)

The walrus is a substantial aquatic species characterized by flippers and a patchy dispersion in the Arctic Ocean and subarctic regions surrounding the North Pole. The detailed characteristics of living habitat and its hunting nature are detailed in previous study [32]. Conversely, walruses can defend themselves with their tusks during such encounters.

(i) Directing individuals to follow the lead of a walrus possessing the longest tusks. Identifying the top member of the population during the search phase guides the algorithm toward favorable regions. In walrus social structures, the most dominant individual, recognized by its extended tusks, plays an essential role in leading the group. The movement of these walruses causes notable shifts in their positions. Mimicking these substantial relocations enhances the method’s global search capabilities and exploration efficiency.

(ii) The walrus’s migration towards shores is a natural behaviour triggered by the warming climate during summer.

During this process, walruses significantly alter their locations, often moving toward outcrops or rocky coastlines. In the WaOA simulation, the positions of various walruses are treated as potential migration targets. One of these locations is chosen at random, and the walrus navigates toward it. By emulating this strategy, WaOA improves its global search and exploration abilities. Unlike the foraging behavior driven by the dominant walrus, the migration strategy allows for a population update mechanism that does not rely on any specific individual, such as the top-contributing member. This updating method helps avoid premature convergence and prevents the algorithm from becoming trapped in local optima.

(iii) Defending or evading predators. Walruses defend themselves against natural predators, including polar bears and killer whales, using a prolonged pursuit tactic. This pursuit occurs within a limited zone surrounding the walrus, resulting in minor positional shifts. By simulating these subtle movements during confrontations, the WaOA enhances its capacity for local searching and exploitation, enabling it to converge on superior solutions.

3.4.2 Algorithm initialization

This algorithm is primarily based on the walrus population. It represents a potential remedy to the optimization challenge at hand. Consequently, the location of each walrus within the search space represents the potential values for the variables in the problem. During the initial stages of implementing WaOA, the walrus populations are generated randomly. This population matrix for WaOA is established using Eq. (9):

X=X1f1,1f1,jf1,m[Xi]N×m=[fi,1fi,jfi,m]N×m,XNfN,1fN,jfN,m          (9)

Let X represents the population of walruses, where Xi denotes the i-th walrus (representing a potential solution), and fi,j signifies the j -th decision proposed by the i -th walrus. Here, N indicates the total number of walruses, while mmm refers to the total count of decision variables. The calculated score for the objective function (OF) derived from the walruses are outlined in Eq. (10).

F1F(X1)F=[Fi]N×1[F(Xi)]N×1,FNF(XN)          (10)

F represents the vector of OFs, while Fi denotes the evaluated score of the OF based on the ith walrus. The values of the OF serve as the most effective indicators for assessing the quality of potential solutions. The potential solution yielding the highest value for the OF is referred to as the best member, whereas the solution that produces the lowest value is termed the worst member.

3.4.3 Phase 1: Exploration phase

Walruses exhibit a varied diet, consuming over sixty types of marine species. Nonetheless, they particularly favor benthic bivalves, especially clams, which they locate by foraging along the ocean floor. They search for food by utilizing vigorous flipper movements and their sensitive vibrissae. In this foraging process, the most robust walrus with the longest tusks leads other members of the group to food sources. The tusk length in walruses correlates with the integrity of the OF values of potential solutions. Thus, the optimal candidate solution, characterized by the best OF value, is regarded as the strongest walrus among the group. This foraging behavior allows walruses to cover several areas of the search space, enhancing the exploration abilities of the WaOA approach during global searches. The method for updating walrus locations is quantitatively designed based on their feeding habits, supervised by the leading member of the group, as represented in Eqs. (11) and (12):

fP1i,j=fi,j+randi,j(SWjIi,jfi,j)          (11)

Xi={XP1i,FP1i<Fi,Xi,else,          (12)

where, XP1i represents the recently instituted location for the ith walrus during the first phase, fP1i,j indicates its j th dimension, and FP1i denotes its corresponding OF value. The terms randi,j are random values drawn within the limit [0,1], while SW signifies the optimal candidate solution regarded as the most capable walrus. The integers Ii,j are randomly selected to be either 1 or 2 , which enhances the exploration capacity of the algorithm. Specifically, if Ii,j equals 2 , it results in more substantial and extensive alterations to the walrus positions, examined to a value of 1 , which represents the typical state of displacement. These parameters aid in enhancing the global search efficacy of the algorithm, enabling it to escape local optima and effectively locate the true optimal region within the problem-solving landscape.

3.4.4 Phase 2: Migration

One inherent behavior of walruses is their movement towards rocky outcrops or beaches as summer progresses and temperatures rise. This migratory behavior is utilized in the WaOA to help walruses explore the search space for optimal locations. This behavioral pattern is mathematically represented using Eqs. (13) and (14). According to Eq. (14), if this new position enhances the OF value, it replaces the walrus's prior location.

fP2i,j={fi,j+randi,j(fk,jIi,jfi,j),Fk<Fi;fi,j+randi,j(fi,jfk,j),else,          (13)

Xi={XP2i,FP2i<Fi;Xi,else,          (14)

where, XP2i denotes the upgraded position of the ith walrus based on phase two, fP2i,j represents its jth dimension, and FP2i denotes its OF value. Xk,k{1,2,,N} and ki signifies the locations of the choosen walruses that the ith walrus migrates towards, while fk,j is its j th dimension and Fk is its corresponding OF value.

3.4.5 Phase 3: Exploitation phase

Walruses often encounter dangers from polar bears and orcas. Their tactics for escaping and confronting these predators lead to changes in their locations within their habitat. By imitating these natural activities, the WaOA enhances its capability to exploit local search areas around potential solutions. This positional change among walruses is modeled as occurring within a walrus-centred neighborhood defined by a specific radius. Initially, the algorithm prioritizes a global search to identify optimal regions within the search space, which is why the radius is considered to be variable-beginning at a maximum value and gradually decreasing with each iteration of the algorithm. Consequently, local lower and upper bounds are utilized in the segment of the WaOA to adjust the radius dynamically through successive algorithm runs. To mimic its behavior, a neighborhood is established around them, wherein a new location is randomly constructed within this vicinity.

fP3i,j=fi,j+(lbtlocal,j+(ubtlocal,jrandlbtlocal,j))          (15)

Localbounds: {lbtlocal,j=lbjt,ubtlocal,j=ubjt,          (16)

Xi={XP3i,FP3i<Fi;Xi,else,          (17)

Figure 6. Flowchart of the WaOA model used for the tuning the network

3.4.6 Repetition process

After modifying the locations of the walruses following the first, second, and third phases, the preliminary iteration of the WaOA is concluded. New scores for the locations of the walruses and the OF are computed. Once the algorithm execution is complete, WaOA presents the most optimal candidate solution identified throughout the procedure as the resolution to the specified problem. The WaOA flow diagram is outlined in Figure 6.

3.5 Extreme feed forward training networks

The proposed model incorporates the concept of Extreme Learning Machines (ELM) as introduced by Huang et al. [33], aiming for rapid and precise classification of various grades. It employs a single hidden layer that does not require mandatory tuning. ELM leverages kernel functions to attain high accuracy and improved efficiency. One of the primary benefits of ELM is its ability to minimize training errors while providing superior approximation. Due to its automatic adjustment of weight biases and utilization of non-zero activation functions, ELM is widely used for classification tasks and deriving categorization values.

In this framework, the 'E' neurons within the hidden layer must utilize an activation function that is highly differentiable, such as the sigmoid function, while the output layer employs a linear function. Notably, the hidden layers in ELM do not require mandatory tuning. The weights for the hidden layer can be assigned arbitrarily, including the bias weights.

fL(x)=Li=1βili(v)=l(v)β          (18)

where, x : input features from encoder-decoder.

β: output weight vector

β=[β1,β2,..βL]T          (19)

l(v): output hidden layer as shown in the equation below:

l(v)=[l1(v),l2(v),..lL(v)          (20)

To ascertain Output Vector O, denotes target vector, the hidden layer E is expressed by Eq. (21).

E=[l(v1)l(v2)l(vN)]          (21)

The foundational execution of the ELM makes use of the minimal non-linear least squares techniques defined in Eq. (22).

β=EO=ET(EET)1O          (22)

where, E*: inverse of E known as Moore-Penrose generalized inverse.

β=ET(1CEET)1O          (23)

fL(v)=l(v)β=l(v)ET(1CEET)1O          (24)

where, l(v) stands for input feature, β is the output weight vector that is calculated using the Moore-Penrose generalized inverse theorem, represented by ET,C is a constant, and O denotes the target (or label) vector.

Y=Softmax(S)          (25)

Loss =(1K)Ki=1(Y(i)logY+η||θ||2)          (26)

where, K is the dimensional capsule feature length, η is the regularization co-efficient and |θ| is the constant.

3.6 Walrus evoked extreme feed forward networks

The recommended scheme aims to reduce complexity further. Before training the model, hyperparameter adjustments are made. The hyperparameters that require tuning include the number of hidden layers, hidden units, epochs, and batch size. In this research, the WaOA is used to fine-tune the network attributes for superior classification.

4. Implementation Details

The recommended scheme is implemented using the comprehensive open-source scikit-learn Python framework. The multi-classification algorithm was trained over 100 iterations. The WaOA approach was applied to optimize the loss functions within the networks, resulting in the minimal loss across the iterations.

4.1 Performance metrics

In this section, we highlight the advantages of the recommended scheme in comparison to various DL schemes. To evaluate the effectiveness of the proposed approach, we calculate specific performance metrics. Table 4 provides the quantitative definitions for the metrics used to assess the performance of the recommended scheme.

Table 4. Performance measures utilized in the evaluation

Evaluation Metrics

Mathematical Representations

Accuracy

TP+TNTP+TN+FP+FN

Sensitivity or recall

TPTP+FNx100

Specificity

TNTN+FP

Precision

TNTP+FP

F1-Score

2. PrecisonRecallPrecision+Recall

TP represents True Positive values, TN stands for True Negative values, FP denotes False Positive values, and FN refers to False Negative values.

5. Results and Discussion

Figure 7 portrays the confusion matrix of the recommended scheme for identifying both anomaly and normal attacks across various ratios of training and testing data. Figure 7 (a) depicts the confusion matrix of the recommended scheme using 60% of the data for training and 40% for testing. Figures 7 (b) and 7 (c) present the confusion matrices of the recommended scheme for 70% of the data used for training and 30% for testing, along with 80% for training and 20% for testing, respectively. From Figure 7, it is evident that the recommended scheme achieved a 96.5% detection rate for anomaly detection.

(a) 60:40

(b) 70:30

(c) 80:20

Figure 7. Confusion matrix of the recommended scheme in detecting the normal and anomaly data

Figure 8 illustrates the validation function used to evaluate the model’s effectiveness, with the primary objective being to minimize this loss. It is standard practice to display two distinct curves: one representing the model’s performance on the training dataset and the other showing its performance on the validation dataset.

Tables 5 and 6 showcase the benchmarking performance of various learning models in identifying normal conditions and anomalies in the Digital Forensic (DF) environment. Table 5 highlights the evaluation metrics for detecting normal conditions, where the proposed model achieves the highest accuracy of 96%, significantly outperforming other algorithms. Though ELM and ANN have produced the better performance among the other ML models, it can’t able to match the effectiveness of the recommended scheme. Similarly, Table 6 presents the results for anomaly detection, where the proposed model again leads with 96% accuracy and outstanding precision and recall values, indicating its robustness in handling diverse scenarios.

(a)

(b)

Figure 8. Validation-loss curve performance of the recommended scheme in detecting both normal and anomalies

Table 5. Benchmarking examination of the varied schemes in identifying the normal conditions in DF environment

Algorithm

Evaluation Measures

Accuracy

Precision

Recall

Specificity

F1-Score

SVM

78

77.6

77.6

0.23

77.6

RF

78.4

76.5

76.4

0.24

76.35

DT

75.5

74.3

74

0.26

74.4

ANN

68.5

67.5

67.3

0.334

67.4

ELM

87.4

86.5

86.4

0.114

86.4

Proposed Model

96

95.7

95.8

0.001

96

Table 6. Evaluation metrics of the varied schemes in identifying the anomalies in DF environment

Algorithm

Evaluation Measures

Accuracy

Precision

Recall

Specificity

F1-Score

SVM

78

77.6

77.6

0.23

77.6

RF

78.4

76.5

76.4

0.24

76.35

DT

75.5

74.3

74

0.26

74.4

ANN

68.5

67.5

67.3

0.334

67.4

ELM

87.4

86.5

86.4

0.114

86.4

Proposed Model

96

95.7

95.8

0.001

96

Figures 9 and 10 illustrate the benchmarking results of the learning models under two distinct scenarios: detecting normal conditions and anomalies in the DF environment. Figure 9 highlights the models’ performance in normal condition detection, with the proposed model emerging as the clear leader, achieving a substantially higher accuracy and F1-score compared to other models. Similarly, Figure 10 emphasizes the anomaly detection scenario, where the proposed model once again outperforms all others, showcasing its robustness and precision in identifying anomalies. From the results, it is clear that the WOA tuned Feed forward networks has played the significant role in detecting the anomalies attacks in the DF Environment.

Figure 9. Benchmarking examination of the varied learning models in normal scenario

Figure 10. Benchmarking examination of the varied learning models in anomaly detection

6. Conclusion

This study presents a forensic investigation framework for anomaly identification using an extreme feedforward learning system integrated with an enhanced walrus-inspired optimization algorithm. The proposed approach effectively addresses the challenges in digital forensic anomaly detection by incorporating centrality-based feature extraction and a robust optimization mechanism. Experimental results demonstrate that the model achieves superior performance with an accuracy of 96%, precision of 95.7%, recall of 95.8%, and an F1-score of 96%, outperforming existing methodologies. These findings highlight the potential of hybrid AI-driven approaches for forensic data analysis, ensuring high detection accuracy and efficiency. Future research can focus on reducing the computational complexity of the proposed framework while enhancing its adaptability to real-time forensic applications. Additionally, integrating advanced DL techniques and expanding dataset diversity could further improve anomaly detection accuracy in evolving digital forensic environments.

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