With quantum computing technology getting better and faster, many current encryption methods may no longer be safe. One major concern is the SNDL or “Store Now, Decrypt Later” attack [1]. In this scenario, attackers collect and store encrypted data now, planning to decrypt it in the future once quantum computers become strong enough. This is especially risky for public-key systems like RSA and Elliptic Curve Cryptography [2]. This research focuses on how to keep data safe during the time before post-quantum cryptographic standards are fully rolled out. We review and compare several existing encryption methods. RSA is discussed in terms of its known weaknesses and how it is still used in some hybrid systems. AES, especially AES-256, is looked at for its better performance and stronger protection even in a post-quantum world. We also explore hybrid systems that mix different methods to cover up each other's weak spots. Lastly, we present a new layered hybrid model that brings together classical and post-quantum techniques. The proposed system uses PQC for authentication, Quantum Key Distribution for secure key exchange, and AES for encrypting the actual data.
With quantum computing technology getting better and faster, many current encryption methods may no longer be safe. One major concern is the SNDL or “Store Now, Decrypt Later” attack [1]. In this scenario, attackers collect and store encrypted data now, planning to decrypt it in the future once quantum computers become strong enough. This is especially risky for public-key systems like RSA and Elliptic Curve Cryptography [2]. This research focuses on how to keep data safe during the time before post-quantum cryptographic standards are fully rolled out. We review and compare several existing encryption methods. RSA is discussed in terms of its known weaknesses and how it is still used in some hybrid systems. AES, especially AES-256, is looked at for its better performance and stronger protection even in a post-quantum world. We also explore hybrid systems that mix different methods to cover up each other's weak spots. Lastly, we present a new layered hybrid model that brings together classical and post-quantum techniques. The proposed system uses PQC for authentication, Quantum Key Distribution for secure key exchange, and AES for encrypting the actual data.
The threats are existential to the traditional cryptosystems of public keys, including RSA, Diffie-Hellman, and elliptic curve cryptography (ECC), due to the rapid progress in quantum computing. Such algorithms as the Shor and Grover algorithms prove that as soon as large scale quantum computers are achieved, these classical cryptographic protocols will not provide any privacy and integrity to online communication. This has created an emergency to find post-quantum cryptography (PQC), or quantum-safe cryptography, which will resist attacks by both classical and quantum attackers. The paper is a review of the latest research and development in post-quantum cryptographic algorithms and their implementation in current security systems. We organize quantum-safe methods into significant organizations such as lattice-based, hash-based, multivariate polynomial-based and code-based encrypted communications. Each type has been evaluated critically based on computational efficiency, key sizes, speed of encryption/decryption and security proofs. The survey also examines the current standardization activities happening in the world and especially the U.S. National Institute of Standards and Technology (NIST) PQC competition, which lists candidate algorithms that have advanced to standard adoption. Besides this, the paper addresses hybrid cryptographic designs that use both classical and post-quantum bases in ensuring a seamless migration in the transition phase. Internet security protocols like TLS, VPNs and blockchain consensus as applications of PQC are examined in detail. Lastly, we pinpoint open research issues, which include creating lightweight PQC to support resource-constrained IoT devices, balancing performance and strong security assurances, and interoperability between the new PQC algorithms and existing infrastructures. Through detailed survey we inform the future of researchers, practitioners, and policymakers on the preparation of the post-quantum era of secure digital communications.
With the current increase in the rate of quantum computing, traditional cryptographic algorithms face a significant risk of compromise, as they are based on mathematical problems that quantum algorithms can efficiently solve. One solution to this challenge has come up in the form of post-quantum cryptography (PQC). By having a hybrid encrypted solution that combines the two different encryption algorithms, NTRU quantum-resistant and fast AES symmetric-key, with a well-integrated combination presented in this paper, we aim to usher in secure and safe data in the post-quantum era. This mixed regime is the most advanced approach that combines classical and quantum encryption. We compare the performance of the system with that of standalone AES, NTRU, and RSA-based systems, examining aspects such as encryption, decryption, key generation, and key size. Benchmarks indicate that the hybrid system has an overhead, but its performance is passable; encryption times are 60ms and 14000ms for 1 KB and 5000 KB of data, respectively, compared to 12ms for 1 KB and 50ms for 5000 KB by AES and NTRU. The same can be said about decryption, with the hybrid system being more efficient than NTRU but still slower than AES. The NTRU key generation times were depicted as unfavorable compared to those of AES, and this margin was seen to increase as the key sizes of NTRU were varied. Compared to executing the same algorithm on a classical computer, the hybrid system is relatively computationally expensive but offers strong quantum resistance. A hybrid encryption system based on the AES-NTRU is a solution to the quantum computing threat to data security. Later projects will be based around various efforts to optimize the NTRU system, also including hardware acceleration opportunities and an increase in the system utilization in real-life environments.
The introduction of quantum computers is moving fast and one issue that should nt be overlooked is that they would be capable of breaking modern cryptographic systems easily. This scenario is likely to become real because with the help of Shor's algorithm they could break the only widely used public-key systems (e.g. RSA and ECC) which would mean that the security of internet communications,digital signaturesand sensitive stored data could be compromised. Even if post-quantum cryptography (PQC) is the right direction of development, there are many problems with it like low performance, complex implementation plans, complicated migration approaches and uncertain security eventually. This paper highlights the risk that quantum computers pose to current encryptions and gives an overview of the top PQC solutions that have been standardized by NIST. It also pinpoints the main problems that are still unsolved and offers practical strategies for mitigating the risk in this area. Based on an extensive review of literature and a computational experiment on hybrid key exchange, the article points out that hybrid approaches are the most efficient ones, cryptographic agility is necessary, and migration should be phased, these measures are aimed at making the transition to the post-quantum era safe and smooth.
The advent of quantum computing poses a significant challenge to classical cryptographic protocols, threatening to undermine the security of widely used security systems like RSA, ECC, and AES. This paper investigates the vulnerabilities of traditional public-key and symmetric cryptographic schemes to quantum decryption techniques, such as Shor’s and Grover’s algorithms, while analyzing the efficacy of post-quantum cryptography (PQC) as a mitigation strategy. Through a review of current literature and simulations of quantum attacks on legacy protocols, this research identifies critical gaps in preparedness and evaluates emergent quantumresistant solutions. The findings highlight the immediate risks of “store now, decrypt later” attacks, emphasizing the importance of transitioning to PQC algorithms. Despite promising advances, challenges related to performance, interoperability, and standardization remain. This study concludes with a call for collaborative efforts in research, policy development, and widespread adoption of quantum-safe practices to ensure the resilience of digital communications in the quantum era.
The accelerated advancements in quantum computing substantially threaten classical cryptographic systems, particularly those that rely on RSA, ECC, and other public key encryption methods. Particularly Shor's method shows how easily conventional cryptographic techniques might be broken; therefore quick development of quantum resistant substitutes is necessary. Rising as a potential answer with cryptographic algorithms meant to resist quantum attacks is post quantum cryptography (PQC). Nonetheless, performance trade-offs, compatibility problems, and the absence of standardized implementations make the shift to completely quantum-safe cryptographic systems very difficult. Hybrid PQC systems that combine conventional and quantum resistant cryptographic mechanisms have been suggested as a workable method for tackling these difficulties so guaranteeing security in the post quantum future. Emphasizing their security, performance, and practical implementations, this review article offers a thorough study of hybrid PQC methods. The resistance of many hybrid cryptographic models including lattice-based, code-based, and multivariate cryptographic techniques against quantum attacks is comprehensively investigated in this work methodologically, we review current PQC hybrid models, evaluate their computing efficiency, and examine security criteria grounded on recent research and standardizing initiatives like those under NIST. Our results show that hybrid PQC models create difficulties in terms of key management, computational overhead, and implementation complexity even if they improve security by reducing risks related with both conventional and quantum attacks. A comparative study shows among several hybrid systems the trade-offs in terms of encryption speed, key sizes, and resource use. Moreover showing the feasibility of PQC hybridizing in IoT, cloud computing, and block chain security are pragmatic uses of PQC hybridizing in which case appropriate protocols are needed for broad acceptance. At last, our work emphasizes the significant contribution hybrid PQC models provide in the transitional period producing a quantum secure environment. To enable basic integration into the present digital infrastructure, future research should focus on improving the efficiency of hybrid cryptosystems, optimizing key exchange mechanisms, and regulating standardization concerns. The findings of this study support the present discussion on post quantum security and provide data for academics and corporate leaders aiming for the next generation of cryptographic solutions. https://doi.org/10.5281/zenodo.17873992
The rapid progress of quantum computing is changing the assumptions on which many modern security systems are built. Public-key methods such as RSA and Elliptic Curve Cryptography (ECC) remain dependable against conventional computers, yet their underlying mathematical problems can be solved efficiently by a sufficiently capable quantum computer using algorithms such as Shor's algorithm. This creates a practical need to evaluate cryptographic techniques that can continue to protect information in a post-quantum environment. This study compares representative classical algorithms - RSA, ECC, and the Advanced Encryption Standard (AES) - with post-quantum approaches, with particular attention to CRYSTALS-Kyber and CRYSTALS-Dilithium. The comparison considers security assumptions, key-generation cost, encryption and decryption time, key size, memory demand, and resistance to quantum attacks. The reported benchmark values indicate that RSA has the highest processing cost among the evaluated schemes, whereas CRYSTALS-Kyber provides comparatively fast key generation, encryption, and decryption while maintaining resistance to known quantum attacks. The study also discusses a hybrid migration model in which established classical mechanisms and post-quantum algorithms operate together during the transition period. Overall, the findings support a gradual move toward quantum-resistant communication systems while recognising the deployment and storage overhead introduced by larger post-quantum keys.