We conducted our search in IEEE Xplore, ACM Digital Library, ScienceDirect, SpringerLink, Google Scholar, and comparable platforms. We looked specifically for studies on secure token transmission, related communication protocols, and cryptographic methods. We refined the query iteratively by adding or adjusting keywords. We screened titles and abstracts to focus on token-security issues. From the selected articles, we extracted additional terms to expand the search. This process followed the standardized review framework described in [7].

To ensure breadth and relevance, we used these terms (and their combinations):

secure token transmission

We limited our review to publications from 2018 through 2025. This range captured the latest advances and addressed current security challenges in token transmission.

The initial search returned over 2300 records. These covered a spectrum of topics, including token transmission architectures, encryption algorithms, and protocol analyses.

We applied strict criteria to maintain focus and quality:

Inclusion Criteria:

1. Peer-reviewed journal articles or conference papers.

2. Studies on communication protocols, cryptographic techniques or secure token transmission.

3. Publications in English.

Exclusion Criteria:

1. Non-peer-reviewed materials (e.g., editorials, white papers).

2. Works unrelated to token security or cryptographic methods.

3. Papers focused exclusively on legal, financial or policy aspects without technical analysis.

We refined the corpus in three stages:

1. Title and Abstract Screening: We reviewed over 2300 titles and abstracts. We retained 537 papers that aligned with our focus.

2. Full-Text Review: We performed detailed evaluations of those 537 papers, narrowing the set to 152 technically relevant studies.

3. Final Selection: Applying our inclusion criteria to the 152 studies yielded 166 papers for in-depth analysis.

We organized the final selection into six thematic areas:

1. Token Types: Hardware vs. software tokens and their authentication roles.

2. Transmission Protocols: Secure channels such as SSL/TLS and IPsec, and their effectiveness in preserving data confidentiality and integrity.

3. Cryptographic Algorithms: Symmetric (e.g., AES) and asymmetric (e.g., RSA, ECC) encryption, hashing, and digital signatures.

4. Application Domains: Implementation challenges in e-commerce, online banking, cloud services, and IoT.

5. Vulnerabilities: Token theft, session hijacking, and man-in-the-middle attacks.

6. Mitigation Techniques: Multi-factor authentication, advanced cryptographic protocols, and hybrid security models.

This rigorous approach provided a thorough and structured evaluation of token-transmission methods, as shown in Fig. 1 below. It exposed key security vulnerabilities and revealed promising directions for future research.

Tokens grant users access to products or services within a specific platform and enable transactions there. For example, they can cover transaction fees, unlock premium features, or allow users to participate in platform governance [14]. This role is most pronounced in Decentralized Finance (DeFi), where utility tokens support a wide range of financial services without intermediaries, resulting in greater efficiency and lower transaction costs [15]. Consequently, tokens are essential to blockchain ecosystems because they foster user engagement and interaction.

A security token represents a tangible asset, such as company shares, debt instruments, or property, in digital form [16]. These tokens grant investors rights like dividends or voting privileges and are subject to securities regulations. By integrating smart contracts, compliance can be automated so that only accredited investors can purchase the tokens and all sale processes are recorded on the blockchain. This automation enhances efficiency and reduces errors and fraud. For example, in real estate, security tokens enable fractional property ownership, improving investment accessibility and liquidity. In equity markets, companies issue tokens to represent shares, facilitating capital raising and fractional ownership. Tokenized debt instruments, such as bonds, benefit from increased tradability and liquidity. Art and collectibles can also be tokenized, offering fractional ownership of high-value items and broadening investor participation. Smart contracts on these tokens automate regulatory compliance—such as enforcing accredited-investor rules and distributing dividends—further boosting efficiency and reducing fraud.

Payment tokens, or cryptocurrencies, serve as digital currencies for purchasing goods and services, remittances, or stores of value [17]. Examples include Bitcoin, Ethereum, and Litecoin. These tokens enable faster, cost-effective, and borderless transactions compared to traditional payment methods. They are widely used on e-commerce platforms, for international money transfers, and as components of investment portfolios. By reducing transaction fees and processing times, payment tokens improve the overall user experience and make global financial activities more accessible.

Non-fungible tokens (NFTs) are unique digital assets that prove ownership of a specific item or piece of content [18]. NFTs use cryptography and smart contracts to record ownership and enforce the terms of transfer automatically. They provide provenance and authentication for digital art, music, videos, virtual real estate, and collectibles. On platforms like OpenSea and Rarible, artists sell exclusive digital artworks as NFTs. In gaming, NFTs enable trading of rare characters or skins. Virtual worlds such as Decentraland and Cryptovoxels allow users to buy and sell tokenized land parcels. Smart contracts ensure the security, uniqueness, and traceability of each NFT.

Transport Layer Security (TLS) is a widely adopted cryptographic protocol that secures data transmission over computer networks. By encrypting and authenticating the data exchanged between parties, TLS prevents eavesdropping, tampering, and phishing attacks, making it indispensable for secure token exchange. Binding tokens to a TLS session further mitigates risks of token theft and replay attacks by ensuring each token is valid only within its original session context [33]. Mutual authentication schemes—such as OAuth 2.0’s mutual-TLS client authentication—leverage this binding to verify both client and server identities [34].

Hypertext Transfer Protocol Secure (HTTPS) pairs HTTP with TLS to protect web-based token transactions. HTTPS encrypts token exchanges between clients and servers, safeguarding financial systems and other token-based services from interception and manipulation. When combined with elliptic curve cryptography and trusted token formats like JSON Web Token (JWT), TLS provides robust authentication of devices communicating with backend servers. This dual-layer security is especially important in Internet of Things (IoT) applications, where device integrity is critical [35].

TLS 1.3 enhances security by eliminating static RSA key exchanges, reducing handshake latency, and easing migration from older, more error-prone versions [6]. Older implementations, however, have suffered from vulnerabilities such as the Heartbleed bug in OpenSSL, which allowed attackers to steal private keys and session tokens from server memory [6]. Such flaws underscore the importance of rigorous protocol maintenance and patching.

Despite its strengths, TLS’s complexity can lead to misconfigurations that expose tokens to interception or unauthorized access [36]. Implementation issues—ranging from flawed certificate validation to improperly configured cipher suites—can undermine TLS’s protections. In man-in-the-middle (MITM) attacks, for example, an adversary can impersonate a server to capture and modify tokens in transit [37]. These threats are exacerbated when clients blindly trust compromised or misused TLS certificates, highlighting the need for strict certificate management and validation processes [36].

Inter-blockchain Communication (IBC) protocols enable seamless asset transfers across distinct blockchains without sacrificing security or privacy [25]. These protocols lock tokens on the source chain and mint equivalent tokens on the destination chain. Upon return, the destination tokens are burned and the original tokens are released.

However, IBC’s modular design can introduce challenges. As the number of connected blockchains grows, communication overhead increases—particularly in Byzantine Fault Tolerant (BFT) systems that require extensive inter-node messaging [38]. This added traffic can degrade performance during periods of high transaction volume [39].

Reliance on third-party relayers also creates trust vulnerabilities. For example, the Open Digital Asset Protocol (ODAP) depends on multiple gateways, which can be targeted by malicious actors [40]. Cross-chain transactions often experience high latency due to varying authentication processes across heterogeneous chains. The absence of standardized protocols exacerbates these delays and raises transaction costs [41]. Such fragmentation hampers efficient token transfers and slows broader adoption of IBC solutions.

WebSocket is a protocol that supports full-duplex communication between clients and servers. It delivers real-time updates and enables secure token exchange with minimal delay [42]. This capability helps market participants respond swiftly to changing conditions, making digital-token markets more efficient and dynamic. WebSocket also has lower latency and overhead than traditional HTTP methods, which makes it ideal for high-performance, responsive applications [43].

A key security risk for WebSocket is man-in-the-middle (MitM) attacks, especially when SSL/TLS is missing or misconfigured [44]. Such vulnerabilities can expose sensitive tokens and compromise message integrity. Persistent WebSocket connections can also be exploited if session tokens lack strong protection or proper expiration, leading to token theft or replay attacks [45]. Finally, because WebSocket keeps connections open to continuously send data, it can be vulnerable to denial-of-service (DoS) attacks, where an adversary floods the channel and disrupts service [46].

This protocol provides a standard framework for linking one payment network and ledger to another. It enables straightforward token exchange between different blockchains, ensuring secure cross-border transfers between financial systems. By using Hashed Timelock Contracts (HTLCs), it guarantees that assets move atomically and securely across parties and platforms, resolving compatibility issues among diverse systems. This ensures that transactions are either fully completed or fully rolled back to maintain integrity, as shown in Fig. 2 [47]. Fig. 3 shows how this functionality is essential for atomic swaps and the support of efficient ledger management. Recent studies also highlight its role in the Interledger Protocol (ILP) for decentralized access control and asset management [48].

Recent protocol enhancements have improved scalability and performance but also raised concerns about transparency and trust in cross-border transactions [49]. One significant risk is timing attacks, which can exploit the anonymous, multi-hop locking mechanisms used during token transfers [50]. Two-way pegs also introduce vulnerability: a single compromised connector handling large volumes of data can jeopardize the entire transaction.

Secret sharing between parties further complicates security. If these secrets are not managed carefully, they can inadvertently expose token information [51]. Finally, the lack of strong cryptographic standards in many ledgers hinders interoperability and poses a barrier to efficient token transfers across diverse systems [50].

Message Queuing Telemetry Transport (MQTT) is an extremely lightweight token-transmission technique designed for constrained devices and low-bandwidth networks. In this method, tokens are exchanged within Internet of Things (IoT) environments to enable device authentication and facilitate microtransactions. MQTT’s low-overhead publish/subscribe model supports real-time messaging while minimizing bandwidth usage, making it ideal for resource-limited applications such as smart homes and industrial IoT deployments [52].

MQTT relies on three primary entities: the publisher, the subscriber, and the broker. The broker manages all message distribution and enforces token-based authentication by validating session-specific tokens before permitting publish or subscribe actions [53]. This mechanism ensures that only authorized devices participate in messaging and helps protect data from unauthorized access or tampering [54].

However, MQTT lacks built-in security features. Without additional layers such as Transport Layer Security (TLS), both data integrity and privacy remain at risk. The broker-centric architecture also introduces a single point of failure: if the broker is compromised, all connected clients become vulnerable to attacks like man-in-the-middle and replay exploits [55,56]. Furthermore, MQTT’s dependence on TCP can introduce latency and performance challenges, particularly when scaling to large deployments [57]. Finally, many MQTT implementations omit proper encryption, allowing tokens to be intercepted or modified during transmission [58].

Peer-to-peer (P2P) protocols enable fully decentralized operations by allowing nodes to communicate and exchange tokens directly, without a central server. In these networks, each participant acts as both client and server. For example, atomic cross-chain transactions let users swap assets between blockchains like Bitcoin and Ethereum without intermediaries [59].

P2P token exchange underpins decentralized applications and file-sharing platforms such as BitTorrent. The Bitcoin protocol itself uses P2P messaging to move tokens securely and reliably. This decentralization improves system resilience and reduces single points of failure in the digital economy.

However, P2P networks lack inherent trust between peers, which can lead to token theft, manipulation, and other fraud risks. New participants have no established reputation, increasing the chance of malicious actors joining the network. To address these challenges, robust trust and reputation management mechanisms are essential but difficult to implement [59].

P2P systems also face performance issues under heavy network load. Unpredictable peer bandwidth can cause delays in token transmission and higher latency, undermining the real-time benefits of peer-to-peer exchanges [60].

Symmetric encryption uses a single secret key for both encrypting and decrypting data, as depicted in Fig. 4. It delivers strong security with relatively low computational overhead compared to asymmetric methods. Because of its efficiency, symmetric encryption is widely adopted for securing data in transit and ensuring fast, reliable token transmission [63].

Advanced Encryption Standard (AES) enhances security by using keys of 128, 192, or 256 bits for token transmission [64]. AES is widely applied to encrypt token data in e-commerce and secure communications because it is computationally efficient and suitable for bulk encryption. However, symmetric encryption faces key distribution challenges: the sender and receiver must share the secret key over a secure channel, which is not always feasible [64]. Although symmetric algorithms are faster and less resource-intensive than asymmetric ones, the need to share keys increases the risk of key compromise and exposure, undermining their security benefits [65]. When multiple nodes use the same symmetric key, a single key breach can expose all transmitted data, endangering the entire network [66]. Moreover, AES does not include built-in mechanisms for key management or revocation, making it difficult to maintain long-term security in dynamic environments [65].

This algorithm creates a pair of keys: a public key for encryption and a private key for decryption. The public key is freely shared, while the private key remains secret with the recipient. Unlike symmetric encryption, this method does not require the sender and receiver to share a secret key in advance, thereby reducing the risk associated with key distribution. Fig. 5 illustrates a common principle used in Asymmetric encryption.

Two leading asymmetric encryption methods for token transmission are RSA and Elliptic Curve Cryptography (ECC). RSA is valued for its reliability and speed in securing data during transit [67]. Its security depends on the difficulty of factoring large prime numbers. In contrast, ECC achieves comparable security with much smaller key sizes, reducing CPU and memory demands. This efficiency makes ECC ideal for resource-constrained environments.

Asymmetric encryption is primarily used for key exchange and verifying the identities of communicating parties, rather than for bulk data encryption, which remains the domain of faster symmetric methods. Integrating asymmetric techniques into micro-application architectures enhances both authentication and authorization processes, thereby safeguarding token transmission [68]. Beyond token exchange, these methods secure data flows in diverse applications such as genomics and IoT systems [67].

However, asymmetric algorithms incur higher computational costs. Operations like RSA encryption and decryption introduce latency, which can be problematic on low-power devices [69,70]. Emerging threats also challenge the long-term viability of public-key schemes. For example, Shor’s Algorithm can, in theory, break RSA and ECC by factoring or solving discrete logarithms in polynomial time [71]. Finally, key management remains critical: if a private key is compromised, all tokens and data protected by its matching public key become vulnerable [72].

Token transmission is incomplete without considering digital signatures, which play a crucial role in verifying the authenticity of transmitted tokens. The technology behind digital signatures relies on asymmetric key encryption, such as RSA, enabling secure communication even over insecure channels [73].

A digital signature refers to the process of creating an exclusive digital code for a document using the sender’s private key. This is achieved by hashing the document and encrypting it using a cryptographic algorithm, such as RSA or ECC. The signature that is generated out of this is, in turn, validated by the receiver by using the public key of the sender. In one way, if the verification process is successful, it validates the fact that the data was sent by the claimed sender of the message and has not been changed in the course of transmission. Digital signatures are a reliable security that is used to build up confidence between the communicating parties, especially in situations where the content of the data is very sensitive and needs to be protected against any manipulation, such as in e-commerce and contracts.

Nonetheless, the integrity and authenticity of the digital signatures depend mainly on the safeguarding of the private key. This means that if the private key associated with any person is in the wrong hands or with the adversary, the individual will be capable of forging signatures and hence forging messages, which compromises trust in the system. Tokenized Message Authentication Code (TMAC) presents a way of implementing authentication between two parties and applies the concepts applied in quantum cryptography [26]. This is accompanied by the creation of multiparty hash time-lock contracts (MP-HTLC) which makes the swapping of tokens across multiple blockchains possible and effective which employing the concept of secure multiparty computation [74].

The use of these technologies further salient changes in the area of digital signatures and, especially, their use in the transmission of secure tokens. However, they possess several vulnerabilities that defeat the efficiency of the token’s transmission process. There is, however, one weakness that arises from the use of this protocol: they are prone to signature flooding attacks whereby the adversary floods most of the computational resources of the intended recipient, especially those operating under resource-limited environments such as mobile platforms. Further, the problem of hash collision is dangerous for data integrity because two different inputs may give the same hash value, thus endangering security measures related to the usage of signatures [75].

Another challenge is quantum attacks, which threaten many present-day digital signature algorithms because they are based on mathematical problems that are easy for quantum computers to solve [76]. Also, digital signatures are prone to man-in-the-middle attacks whereby an attacker arbitrates between two legitimate parties by masking and modifying the contents of transmission [77].

Since tokens are transmitted as data, hash functions are used to verify the integrity of the data being transmitted. Hashing works by accepting an input, or a “message”, and producing a string of bytes, normally referred to as the digest, that does not seem to have any pattern. It is very sensitive to any change in the input and provides a hash output that is different even after a minor input change, which makes it suitable for checking data integrity.

One of the most commonly used hash functions is SHA-256 (Secure Hash Algorithm 256-bit), which is adopted widely in several security protocols and blockchain technology. They are used in conventional cryptography to generate tokens for secure transmission. They are mostly used in timestamping services, which reveals their suitability in token generation that involves combining the input data with time stamps to generate tokens that can be compared with those stored in a public list [78]. This mechanism increases the strength of the digital tokens, for instance, in the NFT whose hash functions are important to ensure the uniqueness of the tokens [79].

One major risk stems from the improvements in terms of processing power and cryptanalysis, wherein hash algorithms that were relatively secure in the past are now easily compromised [80]. The former algorithms are compounded by the emerging sophistication in computational resources available to attackers, demanding constant improvement in hash functions [78]. For example, notably, despite the usefulness of hash functions such as Message Digest Algorithm 5 (MD5) and Secure Hash Algorithm 2 family (SHA2), they were equally found to be prone to collision attacks whereby different values resulted to a similar hash value, defeating the aim of hash functions particularly as computational power grows [78]. The SHA family has come under criticism because of the collision resistance problem; they pose a loophole to attackers aiming at forging tokens or even compromising data integrity [81].

The use of both symmetric and asymmetric encryption is possible since each method has its merits that can be of great security importance to tokens in transit. Asymmetric encryption is used in the transfer of the symmetric key, which is used for the actual encryption of the token. This is a method of key exchange that has superior security advantages as the asymmetric key is used in exchanging keys, while the efficiency of symmetric encryption is used in encrypting the token. This is employed in most protocols like SSL/TLS (Secure Sockets Layer/Transport Layer Security).

This approach boosts security by applying symmetric encryption as Advanced Encryption Standard (AES) and key distribution features of asymmetric approaches like RSA or Elliptic Curve Cryptography (ECC) [82]. For example, hybrid systems can greatly minimize the problem of processing large data that is typically found in public-key cryptography. The use of more than one encryption algorithm is not only enhancing the security aspect but also the performance, thus making hybrid encryption the best choice for today’s cryptographic requirements in token transmission [82].

In addition, one potential issue is the degree of security provided by both types of encryption; the security of both is fundamental to the encryption process, and if one is breached, then the other is affected as well [83]. The use of multiple encryption methods may lead to difficulty in managing the keys, especially due to the probability of key exposure [68].

Besides, in hybrid encryption, the trade-off between the encryption’s performance characteristics can introduce a significant level of latency, which is considered a matter of importance in places that can require fast encryption [84]. Sometimes two or more algorithms are incorporated to form hybrid schemes, and if the integration is not perfect, it may not yield the anticipated results on security enhancements, which could introduce breaches into the system [85].

The Zero-knowledge proofs (ZKP) have been identified as a secure means of token exchange, especially in applications like e-commerce and other cryptographic applications. They are beneficial for a prover since they require no detailed information to prove the validity of the statement, and with this data alone, confidentiality is maintained without revealing the contents of the data during token transmission. This property is important, especially in online transactions where payments should always be secure; this has been evident with the use of ZKPs in protocols such as Zcash [86]. These approaches are particularly important in privacy-preserving systems, where the details of the transaction must remain private while the validity of the transaction has to be verified, like in digital signatures and authentication systems [35].

Even though, through its usage, it would be possible to prove the certainty of the information without revealing its content, Zero-Knowledge Proofs (ZKPs) are associated with a considerable computational burden, which results in performance degradation when applied in real-world use scenarios. For example, the computational overhead in constructing and verifying ZKPs reduces their applicability due to scalability issues, especially in a large number of transactions in environments such as e-commerce [86].

Due to poor implementations, the use of ZKPs in practical applications has been severely constrained in the past. This is because ZKPs normally entail the deployment of complex cryptographic structures that could also present extra vulnerability factors, especially where the foundational hypothesis has not been well built. Nevertheless, as it was mentioned above, ZKPs improve privacy, but it is crucial to underline that they do not presuppose the complete absence of information leakage, as several works indicate that decoy-based anonymity may disclose some relationships [87]. Despite the design of the ZKPs to enhance privacy, a side-channel attack may access information leakage in the process of the proof [88]. It is this vulnerability that can negatively impact the security assurances that ZKPs set out to deliver.

The evolution of TLS, particularly the transition from TLS 1.2 to TLS 1.3, has introduced various enhancements, most notably in terms of speed, security, and the simplification of the handshake process [89]. TLS 1.3, standardized by the Internet Engineering Task Force (IETF) in 2018, eliminates outdated cryptographic algorithms and enforces stronger encryption methods, which significantly reduce the risk of various attack vectors present in earlier versions.

Bhat and Kavasseri highlight the application of TLS in securing communications within 5G networks for tele-surgery, emphasizing that any vulnerabilities in the authentication process can compromise patient safety and privacy. Their proposed enhancements, which include multi-factor and biometric authentication, build upon TLS’s foundation to provide robust security for critical applications [90]. Similarly, in the context of cloud computing, multi-factor authentication integrated with TLS demonstrates a highly secure authentication process, establishing a secure communication channel while verifying user identity through multiple verification factors, including passwords and one-time passcodes [91].

Furthermore, the need for reliable transmission of data in Industrial Internet of Things (IIoT) settings, such as SCADA systems, is addressed in Yang et al.’s work. They propose utilizing TLS not only for encryption but also for trusted token authentication, thereby preventing potential security breaches due to physical attacks [92].

To reduce risks associated with Transport Layer Security, it is advised to strictly follow the secure TLS configuration guidelines alongside applying strong cipher techniques and updating the protocol from time to time [93]. Further, it is known that the use of Datagram Transport Layer Security (DTLS) in situations where real-time communication is needed can increase the level of security without negatively affecting the speed [94].

The security architecture employed in IBC must be robust enough to withstand potential vulnerabilities such as unauthorized access or data tampering during cross-chain transactions. To address these concerns, it is advisable to employ additional encryption layers during transmission processes, as proposed by Chen et al., where a hybrid encryption algorithm can fortify the authentication procedures for tokens transmitted between blockchains [68].

The complexity of managing trust among multiple participants in an inter-blockchain environment poses additional hurdles. Trust management frameworks that leverage consensus mechanisms can significantly enhance security. As highlighted by Ghaffari et al., incorporating smart contracts can aid in ensuring data integrity and confidentiality, thus allowing for trustless interactions across different blockchain networks [95]. Implementing federated models that utilize multiple validators may also enhance trust without relying on a single point of failure, as discussed by Kumar et al. in the context of the pharmaceutical supply chain [96].

Beyond enhancing security and trust, scalability also remains a pivotal concern for inter-blockchain communication. The integration of a scalable architecture that can handle a growing number of transactions across various networks is crucial. Strategies involving Decentralized Autonomous Organizations (DAOs) and the implementation of industry standards could facilitate smoother data exchanges and improve transaction throughput. For instance, the introduction of interledger protocols aimed at supporting industrial Internet of Things (IoT) applications demonstrates a practical model that addresses scalability challenges and enables cross-chain communication [97].

Research comparing WebSocket with protocols like HTTP, MQTT, and gRPC reveals that while WebSockets excel in scenarios requiring low latency and real-time bidirectional communication, they might not be optimal for every use case. For example, REST and GraphQL can be more suitable for applications with less stringent real-time requirements due to their simplicity and established caching mechanisms [98]. Despite its advantages, WebSocket communication is not without its vulnerabilities. One study highlighted various security attacks, including cross-site scripting (XSS) and denial-of-service (DoS) attacks, that specifically target WebSocket implementations [99].

The open nature of WebSocket connections also opens them to potential eavesdropping if not properly secured, necessitating robust authentication and encryption strategies. In real-time chat applications, WebSockets are utilized for instant message delivery, providing users with a seamless communication experience [100].

Similarly, in project management applications, WebSocket communication enables instant synchronization among stakeholders, ensuring users receive real-time updates on project status and task completion [101]. Moreover, developments such as real-time auction platforms demonstrate how WebSockets enhance user interaction by providing immediate bid updates [102].

Smart contracts share a degree of code on platforms such as Ethereum, which poses vulnerabilities because of the interlink since one contract can affect others [103]. Real-life scenarios like the decentralized autonomous organization hack, famously known as The DAO hack, show the importance of installing adequate measures since these vulnerabilities can cause severe monetary losses as it was in the case of the DAO hack where $60 million was lost as a result of reentrancy injection [104] Oyente and Mythril are some of the modern tools that help developers spot these problems [105]. Therefore, the problem of insecure token transmission can be solved by combining automated vulnerability detection systems or tools, secure coding, and rigorous testing of smart contracts.

The Interledger Protocol (ILP) presents several challenges related to token transmission. First, it integrates multiple communication layers, which often requires additional transaction management. For example, notaries are typically needed to oversee transactions, creating potential points of failure. These intermediaries demand robust security measures to prevent unauthorized access. Therefore, there is a need to strengthen the security of ILP by incorporating strong cryptographic features and effective auditing processes. Enhancing the protection of secret-sharing protocols is also crucial to address these vulnerabilities and mitigate the associated risks [106].

For IoT applications, the MQTT protocol is commonly used because of its low bandwidth consumption and being an efficient “publisher/subscriber” model. However, the security of this protocol is questionable, particularly in the secure transmission of tokens. A noteworthy issue is the denial of service (DoS) attacks on the communication between clients and brokers, which may lead to data loss or unavailability of services.

MQTT, as a protocol, does not have a security feature enshrined in it, and therefore, to enhance security during the transmission of data, one has to secure it externally by use of Transport Layer Security (TLS) or Secure Sockets Layer (SSL) [107]. To address these risks, the appropriate mechanism includes secure forms of authentication and strong encryption standards, coupled with comprehensive security audits to determine areas within the system with possible flaws and measures for it [108].

Furthermore, for cooperating healthcare smart devices, it is useful to incorporate Secure Transport Layers, for instance, MQTT over TLS, which contributes to data integrity and confidentiality in the course of token transmission [45]. It needs to be noted that the utilization of blockchain technology for access control may also provide a decentralized way to enhance security in connecting MQTT [109]. Their application through the layers of strong authentication, secure transport protocols, and advanced access control will improve MQTT token transmission security and subsequently provide more reliable token transmission systems.

Research conducted by [110] emphasizes the importance of robust data management strategies within file-sharing systems to safeguard users’ identities and data. Likewise, Chen et al. [111] propose a privacy-preserving protocol for federated learning in P2P networks, illustrating the ongoing need for enhanced data protection mechanisms within decentralized systems.

There is a need to implement secure communication frameworks within Peer-to-peer (P2P) networks. For instance, as adaptive mechanisms, Bayesian games can be used to enhance security in mobile P2P ecosystems and ensure trusted authorization of resources, thereby preventing malicious actors from penetrating and tampering with token transmission. Additionally, this involves reputation management systems that utilize decentralized identity verification to prevent malicious actors from entering the technology environment and interacting with peers, thereby maintaining participants’ trust in token exchanges.

One common threat is the Sybil attack, in which an attacker registers multiple fake identities and can alter the normal functioning of a network, which may disrupt token exchange and endanger genuine transactions. Similar to conventional networks, P2P networks are prone to malware spread, where active worms penetrate the existing vulnerabilities on the network and increase the risks of token transfer tampering. The vulnerabilities with P2P network security should be solved using multiple approaches that include effective security measures and managing the reputation of token transmission [59].

Asymmetric encryption is the most adopted technique for securing token transmission since it is fast and efficient. studies have reported the development of secure key exchange methods that integrate new algorithms aimed at bolstering the stability and security of symmetric encryption against emerging quantum computing threats [112]. Furthermore, the design of methods specifically for the Internet of Things (IoT) has gained traction, emphasizing the need for both lightweight and efficient symmetric encryption solutions to protect sensitive data transmitted between IoT devices [113].

In the domain of mobile communications, particularly for NFC (Near Field Communication) applications, symmetric encryption protocols have been shown to provide robust authentication measures that enhance security. These protocols often implement additional security features, such as time-stamping and hash functions, to further improve the confidentiality and performance of the authentication process [114]. This multifaceted approach illustrates the versatility and adaptability of symmetric encryption techniques in various technological contexts.

As researchers continue to identify vulnerabilities within existing encryptions, recent studies have also highlighted the need for improved S-Box constructions within symmetric systems, proposing new methods derived from chaos theory [115]. These enhancements aim to bolster the security of symmetric algorithms against cryptographic attacks while maintaining high performance levels.

In asymmetric encryption, one disadvantage is the low speed in data encryption and decryption as compared to symmetric encryption, this makes it difficult for bulk data transfer. Besides, these algorithms are vulnerable to attacks because of the slow processing of their computational capabilities while quantum computing can crack such computations with faster encryption time [116]. Han et al. developed an attribute-based encryption system for the Internet of Vehicles (IoV) that employs asymmetric encryption to ensure access control and data protection [117]. This demonstrates a shift towards specialized implementations of asymmetric methods tailored for specific applications, such as vehicular networks. Abdul and Arumugam proposed a hybrid encryption scheme that utilizes both symmetric and asymmetric encryption algorithms [118]. Their approach aims to balance security and efficiency, stating that the use of asymmetric encryption often comes with increased computational overhead.

Xu et al. introduced a lightweight mutual authentication and key agreement scheme that significantly reduces computational cost compared to traditional asymmetric encryption, particularly relevant for resource-constrained environments like the Internet of Things [119].

A significant drawback of asymmetric encryption is its computational intensity compared to symmetric methods. The overhead of using asymmetric keys for encryption and decryption processes can lead to performance bottlenecks, especially in environments requiring high throughput [120]. Despite providing enhanced security features, asymmetric encryption schemes are not immune to various attacks. For example, they can exhibit vulnerabilities to chosen-plaintext attacks, as noted in discussions regarding the limitations of complex encryption systems [121].

In applications requiring low latency, such as real-time communication frameworks, asymmetric encryption can introduce unacceptable delays. Jangid and Lin suggest that utilizing symmetric encryption can mitigate some of these performance concerns in connected vehicle systems by favorably opting for symmetrical keys over asymmetric ones [122].

Furthermore, improvements in cryptographical methods and adopting Quantitative risk analysis while incorporating other security features, increase the reliability of asymmetric encryption of tokens during transmission which is of paramount importance in defense against ever-evolving threats. For instance, homomorphic encryption techniques enable computations to be performed on encrypted data without necessarily decrypting them and thereby maintain the data confidentiality even when processing [123]. This can be adopted in token transmission as it has been applied in cases where integral data sharing is crucial, for instance, genomic data, which requires high levels of privacy [67].

Recent advancements in the field have explored novel digital signature schemes beyond conventional public key systems. For instance, quantum digital signatures (QDS) have emerged as a promising alternative, leveraging the principles of quantum mechanics to provide inherent security against potential quantum computing threats [124]. As outlined by Duan, the transition to quantum-resilient digital signatures is vital for future-proofing electronic communications, especially within sensitive domains like governmental and financial transactions [81]. Additionally, studies by Li et al. describe how newer hashing techniques can enhance the security landscape for digital signatures, allowing for improved integrity and authenticity in digital communications.

Exploration into alternative cryptographic foundations has also led to the evaluation of code-based and lattice-based digital signature schemes as candidates to replace traditional systems, which are susceptible to advancements in computational power [125,126]. Such schemes aim to maintain security and robustness while ensuring operational efficiency.

Historically, older hash algorithms such as MD5 and SHA-1 have been found to exhibit vulnerabilities under modern attack strategies, underscoring the pressing need for more secure alternatives. Studies have observed that improvements in processing power and analysis techniques have rendered these previously robust hash functions increasingly susceptible to cryptanalysis [80]. This has catalyzed efforts to develop innovative cryptographic hash functions that maintain essential security requirements while addressing these evolving threats.

The Keccak hash function, known for its implementation as SHA-3, exemplifies an advanced cryptographic hash function capable of providing high throughput [127]. Its design not only enhances performance but also significantly strengthens security against various attacks. The avalanche effect—where a slight alteration in input leads to significant changes in the output—remains a central characteristic of cryptographic hash functions, ensuring that even minor modifications are detectable [128].

Advancements also include the utilization of chaotic systems in hash function design, which leverage complex mathematical frameworks to enhance security. For example, Liu et al. introduced a keyed hash function based on hyper-chaotic systems, which significantly augments the diffusion properties essential for secure hashing [129]. Similarly, research has shown that chaotic neural networks can produce robust hash functions, furthering the security of applications such as message authentication and digital signatures [130].

Moreover, the SHA family of algorithms continues to evolve, with analyses emphasizing their importance in maintaining the integrity and authenticity of digital communications. Khan et al. provide an overview of the evolution and analysis of this family, highlighting its role in data verification and integrity assurance across various applications, including cryptocurrency [131]. Despite the advancements, the potential for vulnerabilities in these widely used algorithms necessitates continual refinement and adaptation, as shown in more recent works focusing on optimizing implementations for application-specific contexts, such as FPGA platforms [132].

In the realm of image processing, perceptual hashing has gained traction, enabling robust integrity verification against alterations, a crucial feature in high-resolution remote sensing applications [133]. By employing specialized hashing methods tailored for images, this approach aligns well with the requirements for maintaining data integrity without compromising security. Differentiating hash functions by their underlying structures and performance can guide developers in selecting the most appropriate algorithms to reinforce cryptographic applications [134].

One of the significant implementations of hybrid encryption involves the integration of Advanced Encryption Standard (AES) and public key encryption methods like RSA or Elliptic Curve Cryptography (ECC). For instance, Yang et al. propose a hybrid architecture employing AES and RSA that enhances computational speed while maintaining security for IoT environments [135]. Additionally, Liu et al. demonstrate a hybrid encryption approach that combines symmetric encryption with attribute-based encryption (CP-ABE) to ensure both efficiency and access control over sensitive medical data [136]. Such collaborations are essential in fulfilling the dual requirements of strong encryption and practical management of access rights.

Furthermore, the use of hybrid encryption has proven beneficial in securing video data transmission. Han et al. introduced a method that employs both elliptic curve and advanced encryption standards, achieving dual-layer encryption that amplifies security and efficiency in video file encryption [137]. Similarly, Shafiq et al. developed a hybrid approach for efficient internet transmission of video data using Modified Advanced Encryption Standard (MAES) combined with ECC, which highlights the growing importance of hybrid systems in addressing specific data types such as video [138].

Moreover, hybrid schemes have been effectively utilized in cloud computing environments. For instance, the study by Akter et al. assesses the performance of AES, RSA and their hybrid variant, illustrating that hybrid approaches substantially enhance data security while optimizing time efficiency during encryption and decryption processes in cloud storage scenarios [139]. Furthermore, the practicality of hybrid encryption is captured in the work of Ghaly and Abdullah, who present a hybrid model that significantly secures transactions and communications in software-defined networking (SDN) applications [140].

Recent innovations also emphasize hybrid encryption’s role in healthcare. Srivenkateswaran et al. propose a federated learning framework fortified with hybrid encryption, showcasing a modern application that addresses the intricate security needs within healthcare systems [141]. This is complemented by the work of Liu et al., who tackled the problem of access control in cloud storage for medical data through a combination of DES and CP-ABE, thus ensuring both data privacy and controlled access [136].

The examination of Zero-Knowledge Proofs (ZKPs) reveals their significance in enhancing security across various technological fields, particularly in ensuring identity verification without the risk of revealing sensitive information. The foundational concept of ZKPs was introduced in the late 1980s by distinguished cryptographers Goldwasser, Micali and Rackoff, establishing a framework that allows one party, the prover, to convince another party, the verifier, of the validity of a statement without disclosing any additional information about that statement [142].

Recent developments have highlighted the versatility of ZKPs in diverse applications, such as blockchain technology, e-commerce and secure device communication. For instance, the integration of ZKPs in blockchain technology allows for the construction of privacy-preserving transactions and secure smart contracts, as demonstrated in applications like Zcash, which uses ZKPs to ensure confidentiality during transactions [143]. The introduction of zk-SNARKs (Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge) by Gennaro et al. exemplifies how ZKPs can provide short proofs for various computations, enhancing efficiency without compromising security [144].

In the context of the Internet of Things (IoT), ZKPs are increasingly employed to facilitate secure device-to-device communication without compromising user privacy. Their application allows devices to authenticate each other and verify identity claims without exposing sensitive attributes, addressing critical challenges in a landscape where numerous devices are interconnected [145]. Chai et al. assert that zero-knowledge authentication is foundational for IoT security, facilitating a method where devices can confirm their identity while keeping their credentials confidential [146].

Further innovations in the realm of ZKPs include explorations into non-interactive ZKPs, which simplify the process by reducing the need for back-and-forth communication between the prover and verifier, enhancing efficiency. Studies on specialized protocols, such as those based on elliptic curves, have underscored the performance advantages and heightened resistance to specific cryptographic attacks, making them suitable for a range of applications from secure login mechanisms to two-factor authentication systems [147].

Moreover, recent research underscores the potential of combining ZKPs with other encryption techniques, such as in the context of intelligent connected vehicles, where such integration safeguards the privacy of users while enabling secure data sharing [148]. Luo’s work showcases the effectiveness of merging ZKPs with post-quantum cryptography, ensuring that systems remain secure against future quantum computing threats.