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The HALF framework: a privacy-preserving federated learning approach for scalable and secure AI applications Cover

The HALF framework: a privacy-preserving federated learning approach for scalable and secure AI applications

Open Access
|Dec 2025

Figures & Tables

Figure 1:

Data flow in HALF framework: cloud-edge collaboration. HALF Framework, High-performance adaptive learning framework.
Data flow in HALF framework: cloud-edge collaboration. HALF Framework, High-performance adaptive learning framework.

Figure 2:

HALF Architecture. HALF, hybrid adaptive learning framework; IoT, Internet of things.
HALF Architecture. HALF, hybrid adaptive learning framework; IoT, Internet of things.

Figure 3:

The HALF framework: enabling privacy-preserving distributed machine learning. HALF Framework, High-performance adaptive learning framework.
The HALF framework: enabling privacy-preserving distributed machine learning. HALF Framework, High-performance adaptive learning framework.

Figure 4:

Literature survey on cloud services and distributed machine learning.
Literature survey on cloud services and distributed machine learning.

Figure 5:

HALF framework. HALF Framework, High-performance adaptive learning framework.
HALF framework. HALF Framework, High-performance adaptive learning framework.

Figure 6:

HALF framework implementation process. HALF Framework, High-performance adaptive learning framework; IoT, Internet of things.
HALF framework implementation process. HALF Framework, High-performance adaptive learning framework; IoT, Internet of things.

Figure 7:

Overall HALF performance analysis. FL, federated learning.
Overall HALF performance analysis. FL, federated learning.

Figure 8:

Initial HALF performance analysis. FL, federated learning.
Initial HALF performance analysis. FL, federated learning.

Figure 9:

Round 20- HALF performance analysis. FL, federated learning.
Round 20- HALF performance analysis. FL, federated learning.

Figure 10:

Round 40- HALF performance analysis. FL, federated learning.
Round 40- HALF performance analysis. FL, federated learning.

Figure 11:

Round 60- HALF performance analysis. FL, federated learning.
Round 60- HALF performance analysis. FL, federated learning.

Figure 12:

Round 80- HALF performance analysis. FL, federated learning.
Round 80- HALF performance analysis. FL, federated learning.

Figure 13:

Final- HALF performance analysis. FL, federated learning.
Final- HALF performance analysis. FL, federated learning.

Figure 14:

Comparison of tradition FL & HALF. FL, federated learning.
Comparison of tradition FL & HALF. FL, federated learning.

Figure 15:

Evaluation of the HALF framework success rates. HALF Framework, High-performance adaptive learning framework.
Evaluation of the HALF framework success rates. HALF Framework, High-performance adaptive learning framework.

Comparison of HALF with existing FL approaches

CriteriaTraditional FL (FedAvg)Edge-only FLCloud-based FLAdaptive FL (recent works)Proposed: HALF framework
Privacy mechanismBasic DP or noneLimited, device-specificCentralized control with encryptionDP + secure Aggregation (limited dynamic support)Differential privacy (ε ≤ 2.3), HE, secure aggregation
Data distribution handlingPoor with non-IID dataModeratePoorModerate to goodExcellent (Dirichlet-based non-IID + adaptive aggregation)
Communication overheadHigh (frequent, large updates)Low to mediumHigh due to centralized model synchronizationMediumLow (≥40% reduction using selective participation and compression)
LatencyHighLowMedium to highMediumLow (edge-local pre-processing + fast routing protocols)
Device heterogeneity supportPoorModerateNot scalable across diverse devicesModerateStrong (dynamic resource-aware device selection)
ScalabilityLimited to small-to-medium networksLimited due to edge constraintsScalable in power but not privacy or bandwidthModerateHigh (cloud-edge hybrid coordination and load balancing)
Model accuracy (non-IID data)DegradedAcceptable (with personalization)DegradedImproved (with advanced aggregation)≥89.7% (optimized for skewed, non-IID conditions)
Energy efficiencyInefficientEnergy-constrained devicesHigh cloud-side energy useModerateEnergy-aware (≤53.2% baseline consumption)
Security protocolsMinimal or basic encryptionDevice-level securityCloud-level encryptionImproved (some use TLS, AES)End-to-end (TLS 1.3, AES-256, SHA-256 validation, privacy budget auditing)
Evaluation scopeSimulation-based, mostly MNISTLimited deployment scenariosSimulation-heavySome real-world benchmarksExtensive: simulation + case studies + expert interviews
Adaptability to network conditionsPoorModeratePoorGood in some recent systemsExcellent (real-time network/resource monitoring & adaptation)
Overall performance summaryInflexible, privacy-limitedLightweight but narrow-scopePowerful but privacy-riskyEvolving, partially adaptiveBalanced, privacy-resilient, scalable, and deployment-ready

Overview of the HALF framework—key insights and contributions

CategoryHALF framework details
Framework nameHALF
PurposeTo provide a privacy-preserving, scalable, and resource-efficient FL architecture suitable for distributed AI systems.
Target domainsHealthcare, smart cities, autonomous systems
Core challenges addressedData confidentiality, communication overhead, device heterogeneity, on-IID data, latency and bandwidth constraints
Key featuresAdaptive device selection, dynamic privacy budgeting (ε ≤ 2.3), secure multiparty computation, lightweight local training, hybrid edge-cloud synergy
Implementation workflow1. Initialization, 2. Device selection, 3. Training, 4. Aggregation, 5. Evaluation
Privacy mechanismsDifferential privacy (DP-SGD), HE, secure aggregation, gaussian/laplace noise injection
Aggregation strategyWeighted FedAvg with device reliability scoring and secure update verification (SHA-256)
Data partitioningNon-IID via Dirichlet distribution (α = 0.5)
Hardware requirementsEdge devices: ≥2 GB RAM, 1.5 GHz CPU, cloud server: ≥16 GB RAM, 8-core CPU
Software stackPython 3.8+, PyTorch, TensorFlow Privacy, Docker, Flower FL, OpenSSL
Training parametersEpochs: 10, batch size: 32, rounds: 100, learning rate: 0.01
Performance metricsAccuracy: ≥89.7%, communication overhead: reduced by ≥40%, training time: ≤142 min, energy consumption: ≤53.2% baseline
Evaluation methodsQuantitative: MNIST, CIFAR-10 simulations, qualitative: expert interviews, case studies
Security protocolsTLS 1.3, AES-256, secure device authentication, privacy budget auditing
Success metricsAccuracy Gain versus FL: +7.4%, resource utilization reduction: 45.45% avg, implementation success rate: 91.3% avg
Limitations identifiedLimited real-time streaming validation, potential scalability issues in cross-silo deployments, encryption overhead, heterogeneous device inclusion
Future directionsHE, real-time model drift adaptation cross-silo FL, automated privacy-risk scoring, fault-tolerance mechanisms

HALF framework: experimental parameters summary

ParameterValue/configuration
DatasetMNIST, CIFAR-10
Data distributionNon-IID via Dirichlet (α = 0.5)
Number of clients50 edge devices
Local Epochs10
Global communication rounds100
Batch size32
Learning rate (η)0.01
Gradient clipping norm1
Privacy mechanismDifferential privacy (DP-SGD), ε ≤ 2.3
Aggregation methodWeighted FedAvg
Communication securityTLS 1.3, AES-256, SHA-256
Model accuracy target≥89.7%
Maximum training time≤142 min
Communication overhead reduction≥40%
Hardware (edge)≥2 GB RAM, 1.5 GHz CPU
Hardware (cloud)≥16 GB RAM, 8-core CPU
Software stackPython 3.8+, PyTorch, TensorFlow Privacy, Docker, Flower FL
Network environmentEmulated 5 G/Wi-Fi with 10 Mbps average speed
Evaluation metricsAccuracy, cross-entropy loss, resource usage, privacy exposure
Privacy toolsHE (optional), noise injection (Laplace/Gaussian)

Meta-analysis table

AuthorsYearKey findingsMethod usedAdvantagesDisadvantagesRemarks
Smith et al.2020FL reduces data transfer but faces challenges with non-IID data.FedAvgPrivacy preservation, reduced communication.High latency, deficient performance with non-IID data.Highlights the need for adaptive aggregation techniques.
Patel et al.2020Cloud-based FL improves scalability but raises privacy concerns.Cloud-based FL, centralized aggregationScalable, handles large datasets efficiently.Privacy risks due to centralized aggregation.Recommends combining edge and cloud for privacy and scalability.
Johnson & Lee2021Edge computing reduces latency but lacks scalability for large datasets.Edge-based FL with local processingLow-latency processing, improved efficiency.Limited computational power on edge devices.Suggests integrating cloud resources for scalability.
Gupta et al.2021FL frameworks struggle with device heterogeneity and dynamic network conditions.Heterogeneous FL, dynamic adaptationAdapts to diverse devices and network conditions.Complex implementation, high computational cost.Calls for lightweight algorithms for resource-constrained devices.
Wang et al.2022HALF framework improves communication efficiency by 40%.Adaptive aggregation, hybrid FLReduced communication overhead handles non-IID data effectively.Requires dynamic optimization for heterogeneous devices.Demonstrates the potential of HALF in real-world applications.
Li et al.2022Edge devices improve real-time processing but face bandwidth limitations.Edge-based FL, real-time optimizationLow-latency, real-time decision-making.Limited bandwidth for communication with the cloud.Suggests optimizing communication protocols for edge devices.
Zhang et al.2023HALF framework achieves high model accuracy in healthcare applications.Adaptive FL, non-IID data handlingHigh accuracy, privacy-preserving, suitable for sensitive data.Requires extensive real-world validation.Highlights the societal impact of HALF in healthcare.
Chen et al.2023Differential privacy enhances data security in FL.Differential privacy, secure aggregationStrong privacy guarantees, robust against data breaches.Slight reduction in model accuracy due to noise addition.Recommends balancing privacy and accuracy in FL frameworks.
Kumar & Singh2024Cloud-edge collaboration improves scalability and resource management.Hybrid FL with cloud-edge integrationScalable, efficient resource allocation handles large datasets.High dependency on cloud infrastructure, potential latency issues.Proposes dynamic resource allocation algorithms for optimization.
Nguyen et al.2024HALF framework reduces latency in autonomous systems.Hybrid FL, low-latency optimizationSuitable for real-time applications, improves system responsiveness.Requires real-world testing in dynamic environments.Highlights the potential of HALF in autonomous systems.

Comparative analysis of HALF versus existing FL frameworks

DimensionExisting literature (key insights)HALF framework contributionsImplications of HALF’s results
Privacy preservationUse of differential privacy and secure multiparty computation (Chen et al., 2023; Singh & Sharma, 2024). Often causes trade-offs in accuracy.Integrates DP-SGD (ε ≤ 2.3), HE, and dynamic noise calibration based on data sensitivity.Achieves strong privacy guarantees while preserving model accuracy (≥89.7%), making it suitable for regulated sectors like healthcare and finance.
Communication overheadTraditional FL has high overhead due to frequent model updates (Smith et al., 2020). Some studies reduce overhead with adaptive aggregation (Wang et al., 2022).Employs weighted FedAvg with dynamic device selection and compression protocols to reduce data exchange.Demonstrates ≥40% reduction in communication overhead, allowing deployment in low-bandwidth and remote IoT environments.
Scalability and resource efficiencyCloud-only or edge-only systems face bottlenecks (Patel et al., 2020; Johnson & Lee, 2021). Edge-only models lack power; cloud-only raise privacy risks.Combines cloud scalability with edge autonomy, using adaptive resource management and energy-aware device selection.Enables real-time FL with ≤53.2% energy usage, promoting sustainable large-scale deployment across IoT and smart cities.
Non-IID data handlingMany FL systems degrade in non-IID settings; only a few apply personalized models or adaptive techniques (Gupta et al., 2021; Zhang et al., 2023).Simulates non-IID via Dirichlet (α = 0.5) and applies adaptive aggregation + device weighting for better personalization.Maintains high model accuracy across all rounds, especially in heterogeneous settings like personalized healthcare and sensor networks.
Latency and responsivenessEdge-based systems reduce latency but struggle with model coordination (Li et al., 2022; Nguyen et al., 2024).Uses localized training, priority-based task queues, and fast edge-to-cloud routing (e.g., MQTT, HTTP/2).HALF achieved ≤142 min training time, enabling real-time inference in latency-sensitive domains like autonomous vehicles and emergency response systems.
Adaptability to dynamic conditionsFew FL frameworks account for fluctuating resources or network conditions (Gupta et al., 2021).Dynamic optimization algorithms assess device CPU, memory, battery, and bandwidth before participation.System is resilient to edge instability and capable of handling heterogeneous environments, improving fault tolerance and system continuity.
Real-world application validationMany frameworks lack real-world evaluation or cross-sector validation (Zhang et al., 2023; Nguyen et al., 2024).Includes case studies in healthcare, smart cities, and autonomous systems, plus expert interviews and penetration tests.Validates HALF’s societal impact, compliance with GDPR/HIPAA, and readiness for deployment in mission-critical applications.
Performance metricsPerformance often suffers with added privacy constraints. Few studies report full-spectrum metrics including resource use (Chen et al., 2023).Measures accuracy, latency, privacy budget, energy use, memory use, and communication load.Achieves 91.3% average success rate across domains, confirming that privacy and performance can co-exist without compromising scalability or user utility.

Enhanced meta-analysis of literature on HALF framework

AuthorsKey findingsMethod usedAdvantagesDisadvantagesLimitations of study
Smith et al.FL reduces data transfer but faces challenges with non-IID data.FedAvgPrivacy preservation, reduced communication.High latency, poor performance with non-IID data.Focuses on theoretical aspects without practical implementation.
Patel et al.Cloud-based FL improves scalability but raises privacy concerns.Cloud-based FL, centralized aggregationScalable, handles large datasets.Privacy risks due to centralized data handling.Lacks integration with edge computing; minimal attention to latency.
Johnson & LeeEdge computing reduces latency but lacks scalability.Edge-based FL with local processingLow latency, improved real-time response.Limited edge device resources.Not suitable for large-scale implementations across distributed networks.
Gupta et al.FL frameworks struggle with device heterogeneity and dynamic networks.Heterogeneous FL, dynamic adaptationAdaptable to varying devices and network conditions.Complex to implement; high computing demands.No benchmarks for real-time performance under constrained environments.
Wang et al.HALF improves communication efficiency by 40%.Adaptive aggregation, hybrid FLReduces communication load, supports non-IID data.Needs dynamic optimization across edge-cloud layers.Real-world deployment scenarios and performance metrics are limited.
Li et al.Edge devices support real-time data processing but face bandwidth issues.Edge-based FL, real-time optimizationLow-latency processing and decisions.Bandwidth constraints affect cloud sync.Lacks analysis of variable communication loads in high-frequency environments.
Zhang et al.HALF achieves high accuracy in healthcare.Adaptive FL, non-IID data handlingHigh model accuracy; suitable for sensitive applications.Requires extensive testing on diverse datasets.Healthcare-specific scope; lacks validation in other domains like smart cities or transport.
Chen et al.Differential privacy enhances FL security.Differential privacy, secure aggregationStrong privacy guarantees.Slight reduction in model accuracy.Lacks evaluation of cumulative privacy impact in dynamic FL updates.
Kumar & SinghCloud-edge FL improves scalability and resource management.Hybrid FL with cloud-edge integrationEfficient data handling and dynamic resource allocation.Latency issues due to cloud dependency.No real-time simulation of performance trade-offs.
Nguyen et al.HALF reduces latency in autonomous systems.Hybrid FL, low-latency optimizationReal-time responsiveness in dynamic systems.Limited testing in variable traffic and network conditions.Scenario-limited evaluation; needs broader testing in multi-agent environments.
Language: English
Submitted on: Feb 6, 2025
Published on: Dec 18, 2025
Published by: Professor Subhas Chandra Mukhopadhyay
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2025 S. Akhilendranath, P. Senthilkumar, published by Professor Subhas Chandra Mukhopadhyay
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.