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.
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 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.
This research introduces a novel cryptographic system that enhances the security of steganographic images by integrating Quantum Key Distribution (QKD) with traditional encryption. Using the E91 QKD protocol, it generates a shared secret key between parties, leveraging quantum entanglement to provide superior protection against eavesdropping. The quantum key is then hashed with the Secure Hash Algorithm (SHA) to produce a fixed-length, high-entropy key for symmetric encryption . The Advanced Encryption Standard (AES) is employed to encrypt steganographic images, which conceal critical data within digital images, adding an extra layer of security through obscurity. Experiments with images of varying resolutions (64 × 64 to 512 × 512 pixels) show consistent encryption performance. The encrypted images exhibit high randomness, with an average entropy of 7.9929. Differential attack resilience is demonstrated by a Number of Pixels Change Rate (NPCR) averaging 99.6928% and a Unified Average Changing Intensity (UACI) of 56.1549%. The average E91 protocol key generation time is 5.78 s with a key rate of 7.43 bps. Encryption and decryption times for test images are 0.00149 and 0.00175 s, respectively. This research combines quantum and classical cryptography with steganography, providing a robust security framework highly resistant to both quantum and classical threats.
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.
Many people use the internet for communication, but there is a problem with protecting their information. To ward off the attackers, they need secure communication such as cryptography and steganography techniques. To maintain the security of information, improving the technology of steganography is necessary. In this paper, we propose a novel method to create the secret quantum text steganography more difficult for attackers to intercept. Firstly, the proposed method generates a secret message as a binary string by combining the secret key of the BB84 protocol and message. Then, the secret message is embedded in the first character of each line in the cover text. In the cover text, the first character of each line is changed to the case of the specific character, such as uppercase or lowercase, according to the secret message to be hidden. The cover text uses the English language. Experimental results describe the effectiveness of the proposed method for hiding data within the cover text while maintaining a high level of security. The proposed model is able to secure data transmission because it was difficult for the attacker to reveal or intercept data.
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.
With the rise of quantum computing and the limitations of traditional encryption methods, ensuring secure data transmission in IoT frameworks has become increasingly critical. This work presents a quantum-enhanced hybrid communication system that integrates adaptive audio techniques with quantum image processing. The proposed system operates in three main stages: first, text data is converted into binary format and encoded into quantum circuits using Qiskit; second, the quantum-encoded data is embedded into audio signals using an adaptive Least Significant Bit (LSB) technique; finally, the stego-audio’s robustness is evaluated under simulated IoT network conditions. Unlike conventional approaches, this method offers dual-layer security by combining dynamic audio embedding with quantum-based image representation, making it resistant to both quantum attacks and signal degradation. Experimental results demonstrate strong performance, with a Peak Signal-to-Noise Ratio (PSNR) ranging from 45 to 50 dB, a Bit Error Rate (BER) below 2%, and entropy values exceeding 7.5. These outcomes indicate the system’s effectiveness for secure, quantum-resilient communication in IoT environments with bandwidth and security constraints.