Exploring Cryptographic Key Management Schemes for Enhanced Security in WSNs

Figure 1.

Pre-distribution Key Management Schemes_

Scheme Name	Year	Description	Advantages	Disadvantages	References
Eschenauer-Gligor Scheme	2002	Randomly pre-distribute keys to nodes from a key pool to establish common keys post-deployment.	Simple, scalable for small networks.	Vulnerable to node capture.	[23]
Q-Composite Scheme	2009	Improves Eschenauer-Gligor by requiring multiple shared keys to establish communication.	Higher resilience against node capture.	Increased memory usage.	[24]
Enhanced Random Key Distribution	2018	Adds redundancy and hashing to random pre-distribution for better resilience.	Stronger security, low overhead.	Increased computational costs.	[25]
Multiple Key Pools	2020	Nodes are preloaded with keys from region-specific key pools to improve localization security.	Reduces key exposure.	Limited adaptability for mobility.	[26]
Hybrid Key Pre-distribution	2022	Combines deterministic and random methods to ensure both security and scalability.	Balances security and efficiency.	Implementation complexity.	[27]

Challenges in key management in WSNs_

Challenge	Description	References
Resource Constraints	SNs have limited computational power, memory, and energy, making it challenging to implement complex cryptographic algorithms.	[10,11]
Scalability	Large networks with thousands of SNs require scalability but key distribution and maintenance increase the complexity.	[12,13]
Dynamic Topology	SNs join or leave frequently due to mobility, failures, or environmental changes that require real-time key updates.	[14,15]
Physical Vulnerability	SNs in hostile environments are prone to tampering and physical capture that can risk key exposure and network compromise.	[16,17]
Adversarial Threats	WSNs face eavesdropping, spoofing, and man-in-the-middle attacks which necessitate the need for robust key management protocols.	[18,19]
Energy Efficiency	Cryptographic operations consume significant energy, affecting the lifespan of battery-powered SNs.	[20,21,22]

Public Key Cryptography (PKC) Approaches in WSN_

Scheme Name	Year	Description	Advantages	Disadvantages	References
RSA-Based Encryption	2010	Uses large prime factorization for key generation in resource-constrained networks.	High security; well-established protocol.	High computational requirements.	[43]
ECC-Based Key Management	2015	Utilizes elliptic curve cryptography for secure communication with smaller keys.	High security with low resource usage.	Computationally expensive for real-time updates.	[44]
Hybrid PKC-Symmetric Schemes	2019	Combines PKC for initial key exchange with symmetric encryption for ongoing communication.	Efficient after initial exchange; scalable.	Vulnerable during the key negotiation phase.	[45]
Lightweight ECC	2020	Optimizes ECC for WSNs by reducing algorithm complexity.	Suitable for resource-limited nodes; strong encryption.	Still more complex than symmetric methods.	[46]
Quantum-Resilient PKC	2022	Adapts public key schemes to counter quantum computing attacks.	Future-proof against quantum threats.	Not yet standardized; higher energy consumption.	[47]
Blockchain-Based Key Management	2023	Uses blockchain to manage and distribute public keys securely.	Decentralized and tamper resistant.	High storage and energy requirements.	[48]
ECC with Energy-Aware Protocol	2023	Integrates ECC with energy-aware protocols to minimize power consumption.	Balances security and energy usage.	Limited testing in large networks.	[49]
Post-Quantum ECC	2024	Enhances ECC with post-quantum algorithms to future-proof against advanced attacks.	High security and forward compatibility.	Computationally heavy for small nodes.	[50]

Research Solutions and description to Key Management in WSN_

Research Solution	Description	Reference
Hybrid Cryptographic Solutions	Combining lightweight cryptographic techniques with quantum-resistant algorithms for efficient security in WSNs.	[66,67]
Adaptive Key Management	Dynamically adjusting key parameters based on factors like network conditions, traffic, and energy usage.	[68,69]
Machine Learning for Optimization	Using AI to optimize energy usage, predict threats, and adjust cryptographic techniques in WSNs.	[70,71,72]

Matrix-based key management schemes in WSN_

Scheme Name	Year	Description	Advantages	Disadvantages	References
Blom’s Scheme	2012	An asymmetric matrix-based scheme that generates unique pairwise keys using a shared secret matrix.	High resilience to node capture.	Memory and computation overhead increase with network size. Not scalable for large networks.	[39]
			Efficient for small to medium networks.
Triple Key Matrix Scheme	2017	Extends matrix-based schemes to provide triple key distribution for enhanced communication security.	High resilience to single-node capture.	Increased memory requirements.	[40]
			Supports multi-tier security.	Computationally intensive for large networks.
Attack Matrix Scheme	2018	Uses dominance key sets in a cost-effective matrix design to secure communication.	Cost-effective design.	Limited applicability in highly dynamic networks.	[52]
			Resistant to various attacks.	Requires careful dominance set design.
			Suitable for clustered WSNs.
Polynomial and Matrix-Based Scheme	2019	Combines polynomial-based key pre-distribution with matrix design for enhanced security.	Combines benefits of polynomial and matrix methods.	Higher computational overhead due to polynomial calculations.	[53]
			Strong security against node capture.	Complex setup for large networks.

Dynamic Key Management Schemes in WSNs_

Scheme Name	Year	Description	Advantages	Disadvantages	References
LEAP (Localized Encryption and Authentication Protocol)	2013	Uses cluster heads for efficient key distribution in dynamic networks.	Scalable and efficient.	Cluster head compromise risk.	[28]
Diffie-Hellman Protocol	2013	Dynamically establishes keys post-deployment through public-private key exchanges.	No pre-shared keys are required.	High computational overhead.	[29]
Lightweight Key Update	2019	Reduces the cost of key updates in dynamic networks through periodic rekeying.	Energy-efficient updates.	Vulnerable to synchronization issues.	[30]
Cluster Key Negotiation	2021	Dynamic key management within clusters for better adaptability in mobile WSNs.	Better adaptability.	Increased cluster head workload.	[31]
An Efficient Secure Key Establishment Method in Cluster-Based WSNss	2022	Proposes lightweight key establishment using shared keys managed by cluster heads.	Low energy consumption and high efficiency.	Limited adaptability for heterogeneous networks.	[32]
Adaptive Key Management	2023	Adjusts key update intervals based on network topology changes and threats.	Dynamic and threat adaptive.	Complexity in threat assessment.	[33]
IHKM: An Improved Hierarchical Key Management Scheme	2024	An enhancement of hierarchical schemes, optimizing key distribution and security in cluster-based WSNs.	Better scalability and resilience to attacks.	Increased computational complexity.	[34]

Research Directions, Proposed Solutions, and Optimisation Methods Related to Key Management in WSN_

Research Direction	Proposed Solutions	Optimization Methods
Energy Efficiency	Lightweight cryptography	Energy-aware cryptographic protocols and duty-cycling techniques aim to reduce energy consumption while maintaining security levels.
	Symmetric encryption replacement	Replacing computationally expensive public-key cryptography with more energy-efficient symmetric algorithms.
	Energy-efficient key distribution	Use of localized or hierarchical key distribution techniques to reduce communication overhead.
Resilience to Node Capture	Dynamic key revocation	Adaptive protocols that revoke keys once a node is compromised, minimizing the impact on the overall network.
	Distributed trust models	Employing decentralized approaches to ensure that compromised nodes do not breach the entire network’s security.
	Physical-layer security	Incorporation of techniques such as secret sharing and random key pre-distribution to make key extraction harder.
Scalability	Cluster-based key management	Using a cluster-head model to divide responsibilities, minimize communication overhead, and enhance scalability in large networks.
	Hierarchical key management	Multi-tiered architecture that efficiently distributes keys among different levels of the network.
	Hierarchical revocation strategies	Improving scalability by implementing efficient key revocation and update mechanisms that can scale with the network size.
Post-Quantum Security	Lattice-based cryptography	Exploring quantum-resistant algorithms, such as lattice-based encryption, that can be applied in WSNs.
	Hash-based signatures	Use of quantum-secure hash-based schemes for signing messages and managing key distributions.
	Hybrid cryptosystems	Developing hybrid cryptographic schemes that combine classical and quantum-resistant algorithms for backward compatibility.

Pairwise Key Establishment in WSN_

Scheme Name	Year	Description	Advantages	Disadvantages	References
Blom’s Scheme	2012	Uses a matrix-based approach for generating unique pairwise keys between nodes.	High resilience to node capture.	Computationally intensive.	[39]
Polynomial-Based Scheme	2017	Employs polynomial functions for establishing secure pairwise keys among nodes.	Efficient for small groups.	Vulnerable to node tampering.	[40]
ECC-Based Pairing	2019	Utilizes elliptic curve cryptography for pairwise key establishment in resource-constrained WSNs.	Strong security.	High computational overhead.	[41]
ID-Based Key Agreement	2019	Leverages node identifiers for key establishment to reduce memory overhead.	Efficient and memory-saving.	Less flexible for dynamic networks.	[42]

Combinatorial-based key management schemes in WSN_

Scheme Name	Year	Description	Advantages	Disadvantages	References
Scalable and Storage-Efficient Dynamic Key Management	2021	Proposes a scalable key management scheme that optimizes storage efficiency while ensuring secure key distribution in WSNs.	Reduces storage overhead, supports large-scale WSNs, and enhances security resilience.	Requires additional computational resources for key updates.	[54]
Key Updating for Combinatorial Design-Based Key Management	2014	Introduces efficient key update methods for combinatorial-based key management schemes to enhance security.	Improves resilience against key compromise and reduces overhead for rekeying.	May introduce synchronization delays in large networks.	[55]
Combinatorial Design-Based Key Pre-Distribution	2019	Develops a key pre-distribution scheme using combinatorial designs to optimize key sharing and security.	Enhances scalability, ensures deterministic key assignment, reduces storage requirements.	Requires careful parameter selection to balance security and connectivity.	[56]
Survey of Combinatorial Key Pre-Distribution in IoT	2021	Provides a comprehensive review of combinatorial design-based key management schemes for IoT and WSNs.	Identifies strengths and weaknesses of various combinatorial approaches, highlights emerging trends.	Some reviewed schemes may not be adaptable to dynamic network environments.	[57]

Comparison of Key Pool and Key Size in Key Management Schemes in WSN_

Criteria	Large Key Pool	Small Key Pool	Long Key Size	Short Key Size
Security	High (low key-sharing probability)	Moderate (higher key-sharing probability)	High (strong encryption)	Low (vulnerable to brute force)
Storage Needs	High (requires more memory)	Low (minimal memory requirements)	High (large memory usage)	Low (minimal memory usage)
Energy Efficiency	Low (more keys to process)	High (fewer keys to process)	Low (computationally intensive)	High (less computational demand)
Scalability	Suitable for large networks	Suitable for small networks	Suitable for critical applications	Suitable for low-security setups

Comparative Analysis of Key Management Schemes in WSN

Scheme	Advantages	Disadvantages	Ideal Scenarios
Random Key Pre-distribution	Simple to implement	Vulnerable to node capture	Small networks with low-security needs, where simplicity and cost-effectiveness are more important than high-security
	Minimal computation required	Limited security against node compromise
Dynamic Key Management	Flexible	High computational overhead	Suitable for dynamic networks where nodes frequently join or leave, such as mobile sensor networks or networks with changing topologies
	Adaptable to changes in the network	Requires communication for key exchange
Cluster-based Management	Scalable	Vulnerability of cluster head	Large-scale networks or hierarchical setups, where SNs are grouped into clusters and a cluster head controls key management
	Efficient key management due to centralized control by the cluster head	Single point of failure if the cluster head is compromised
Hierarchical Management	Efficient distribution and revocation of keys	Requires a central authority	Multi-tier networks, such as military surveillance or critical infrastructure, where different levels of security are required.
	Easy to scale in large networks	Single point of failure at higher tiers
Pairwise Key Establishment	High security	Complex setup	High-security applications such as military and defense where confidentiality between specific node pairs is critical.
	Resilient to node capture, as each pair has a unique key	Scalability issues with large networks
Public Key Cryptography (PKC)	Strong security with asymmetric encryption	High computational and memory overhead	Critical infrastructure and applications requiring high security, such as IoT networks in healthcare and finance.
	Can support digital signatures for authenticity	Not ideal for resource-constrained devices
Matrix-Based Key Management	High resilience to node capture	Computationally intensive Scalability challenges for very large networks	Small to medium-sized networks requiring high security, such as industrial IoT, military networks, or healthcare sensor systems.
	Enables secure pairwise communication
	Scalable with small to medium networks	Higher memory requirements for matrix storage
Combinatorial-Based Key Management	High scalability, resilience to node capture	Complex key distribution	Large-scale WSNs with high-security requirements and limited storage capacity
	Efficient key discovery	The trade-off between security and connectivity
	Reduced memory overhead	Limited adaptability

Hierarchical Key Management Schemes in WSNs_

Scheme Name	Year	Description	Advantages	Disadvantages	References
Logical Key Hierarchy (LKH)	2010	Uses a tree structure where higher-level nodes manage key distribution to lower-level nodes.	Efficient key revocation.	Requires central authority.	[35]
Multi-Tier Key Management	2015	Divides the network into multiple tiers with different keys for different levels.	Scalable and secure.	Management complexity.	[36]
Role-Based Key Distribution	2017	Assigns keys based on node roles within the network (e.g., sensors, aggregators).	Efficient and role aware.	Static role assignment challenges.	[37]
Hybrid Hierarchical Scheme	2022	Combines LKH with cluster-based management to optimize scalability and security.	Balances hierarchy and efficiency.	Increased resource usage.	[38]