Classical cryptography methods are becoming susceptible to quantum attacks like those implemented by Shor and Grover algorithms and can break RSA and symmetric-key encryption. Traditional communication channels are also susceptible to interception and even modification of the signal that causes data confidentiality to be compromised. In order to overcome these limitations, this paper proposes a three-layer quantum-hybrid communication framework, which integrates entanglement-based QKD, multi-channel redundancy, and steganographic hiding. The framework improves the security with an entanglement-assisted BB84-based protocol, the reliability with the help of multi-channel qubit transmission, and covert transmission with LSB/DCT-image embedding. The framework is developed and implemented as a simulator in Python using Qiskit, NumPy, and OpenCV and showed better Bit Error Rate (BER), SSIM, fidelity and security strength than classical systems. The proposed architecture mitigates key vulnerabilities in cryptographic strength, transmission stability, and communication detectability, providing a robust foundation for quantum-resilient and covert communication.
Classical cryptography methods are becoming susceptible to quantum attacks like those implemented by Shor and Grover algorithms and can break RSA and symmetric-key encryption. Traditional communication channels are also susceptible to interception and even modification of the signal that causes data confidentiality to be compromised. In order to overcome these limitations, this paper proposes a three-layer quantum-hybrid communication framework, which integrates entanglement-based QKD, multi-channel redundancy, and steganographic hiding. The framework improves the security with an entanglement-assisted BB84-based protocol, the reliability with the help of multi-channel qubit transmission, and covert transmission with LSB/DCT-image embedding. The framework is developed and implemented as a simulator in Python using Qiskit, NumPy, and OpenCV and showed better Bit Error Rate (BER), SSIM, fidelity and security strength than classical systems. The proposed architecture mitigates key vulnerabilities in cryptographic strength, transmission stability, and communication detectability, providing a robust foundation for quantum-resilient and covert communication.
Quantum computing threatens classical cryptography and the convergence of quantum key distribution (QKD), and steganography offers an unconditionally secure hybrid approach for postquantum communication. QKD ensures provable secrecy via quantum mechanics, while steganography conceals the existence of communication providing stealth and plausible deniability. This systematic review explores integrated frameworks that combine QKD with classical and quantum steganographic techniques to enhance confidentiality, integrity, and undetectability. The study categorizes existing hybrid models and evaluates their performance using metrics such as quantum bit error rate (QBER), entropy, and imperceptibility. It examines quantum steganographic protocols including quantum LSB, entangled‐state hiding, and covert key transmission, analyzing their resilience against quantum noise and steganalysis. Despite promising simulation tools and real‐time QKD implementations, challenges remain in scalability, interoperability, and formal security guarantees. This review identifies key limitations in current systems and highlights future directions for developing robust, scalable, and stealth‐aware quantum–classical security frameworks. To the best of current knowledge, this is the first systematic synthesis of hybrid QKD–steganography frameworks offering a novel taxonomy and critical analysis to advance secure communication infrastructures in the postquantum era.
The rapid advancement of quantum computing poses a serious threat to traditional cryptographic systems such as RSA and Elliptic Curve Cryptography (ECC), which rely on computational difficulty for security. Quantum algorithms like Shor’s and Grover’s have the potential to break or weaken these methods, putting modern communication systems at risk. To address this challenge, this work presents a quantum-safe com-munication framework that combines the BB84 Quantum Key Distribution (QKD) protocol with Post-Quantum Cryptography (PQC) techniques, aiming to ensure secure data exchange in the presence of quantum-capable adversaries. In this system, the BB84 protocol is simulated to enable secure key exchange between two parties over a virtual quantum channel. The generated key is refined through processes such as basis matching, error correction, and privacy amplification using SHA-256 to ensure reliability and secrecy. For secur-ing communication, One-Time Pad (OTP) encryption is used alongside HMAC-SHA3-256 to provide both confidentiality and message integrity. Additionally, file encryption is handled using the XChaCha20-Poly1305 algorithm, selected for its efficiency and strong protection against potential vulnerabilities like nonce reuse. To further enhance security, the framework integrates a hybrid key management approach using the Kyber-512 Key Encapsulation Mechanism (KEM) combined with a Key Deriva-tion Function (KDF), merging classical and quantum-resistant techniques. Experimental results demonstrate the effectiveness of the system, achieving a Quantum Bit Error Rate (QBER) of 2.5% and successful performance in both message and file en-cryption. Overall, this work contributes toward the development of practical and resilient communication systems designed for the emerging quantum era.
In response to rising cyber threats and the limitations of traditional security, this project proposes a hybrid framework combining quantum cryptography and text-based steganography for secure and concealed communication. Using the BB84 Quantum Key Distribution (QKD) protocol, a secure quantum key is established and extended with SHA-256 to encrypt a secret message via XOR operations. The encrypted data is embedded into a cover text using three steganographic techniques: case-based, zero-width, and color-based methods, the latter including double-color and double-color overlay variants. The techniques are evaluated on embedding efficiency, payload capacity, entropy, and deviation percentage. Among them, double-layer color-based steganography demonstrates superior performance, achieving up to 6 bits/symbol and 95% efficiency, with minimal error and high integrity. The system is implemented using Qiskit and HTML rendering, validating its practical feasibility. This dual-layer security model ensures confidentiality and invisibility, offering a robust, quantum-enhanced approach to secure communication in sensitive applications.
Quantum computing threatens traditional cryptographic systems based on integer factorization and discrete logarithm problems. This paper proposes a hybrid secure communication framework integrating Quantum Key Distribution (QKD) with Post-Quantum Cryptography (PQC) for authentication. The BB84 protocol is used for quantum key generation, while CRYSTALS-Dilithium signatures secure the classical communication channel. A Python-based simulator models photon transmission, Quantum Bit Error Rate (QBER), intercept-resend attacks, and authentication verification. Results show that QBER increases proportionally with eavesdropping probability, enabling reliable attack detection. The integration of QKD secrecy with PQC authentication ensures both confidentiality and integrity. Performance evaluation demonstrates that the additional latency introduced by PQC authentication remains within acceptable limits. The proposed hybrid framework provides a scalable and quantum-resistant solution suitable for next-generation secure communication systems.
Quantum computing threatens traditional cryptographic systems based on integer factorization and discrete logarithm problems. This paper proposes a hybrid secure communication framework integrating Quantum Key Distribution (QKD) with Post-Quantum Cryptography (PQC) for authentication. The BB84 protocol is used for quantum key generation, while CRYSTALS-Dilithium signatures secure the classical communication channel. A Python-based simulator models photon transmission, Quantum Bit Error Rate (QBER), intercept-resend attacks, and authentication verification. Results show that QBER increases proportionally with eavesdropping probability, enabling reliable attack detection. The integration of QKD secrecy with PQC authentication ensures both confidentiality and integrity. Performance evaluation demonstrates that the additional latency introduced by PQC authentication remains within acceptable limits. The proposed hybrid framework provides a scalable and quantum-resistant solution suitable for next-generation secure communication systems.
Quantum communication leverages the principles of quantum mechanics, such as superposition and entanglement, for inherently secure data transmission that can detect any eavesdropping attempt. This research addresses the limitations of classical encryption by proposing a hybrid Quantum Key Distribution (QKD) protocol that integrates the Bennett & Brassard 1984 Protocol(BB84) and Scarani-Acín-Ribordy-Gisin 2004 Protocol(SARG04) protocols. The primary objective is to enhance resilience against advanced threats such as Photon Number Splitting (PNS) and collective attacks, which are significant vulnerabilities in standard QKD implementations. The quantum channel is modeled using Qiskit Aer's noise framework, incorporating fiber attenuation (0.1−0.25dB/km), depolarization (1−5%), and detector dark counts (0.01−0.03probability), varied across 10 rounds. A simulation spanning 10 rounds evaluated key metrics, including Quantum Bit Error Rate (QBER), photon loss, and final key entropy. The results demonstrate the protocol's robustness, achieving a 0 % QBER in 50 % of the trials, representing a significant improvement in secure key generation. The average QBER across all rounds was 12.5 %, which is well below the 11 % theoretical threshold for secure communication. The highest QBER recorded was5 0 %in Round 02, where high depolarization and an eavesdropping attempt were simulated. The work's findings indicate that the hybrid BB84-SARG04 protocol significantly enhances the security and reliability of quantum communication.