Secure Multi-Party Computation (MPC) facilitates cooperative computation on confidential data. Homomorphic Encryption (HE) offers primitives to compute on encrypted data, but protecting the communication channel with classical key exchange is increasingly exposed to quantum attackers. This work outlines a hybrid model where Paillier HE supports secure additive aggregation, while BBM92 QKD simulation generates quantum-resistant keys for AES-GCM, which in turn protects inter-party communication of HE ciphertexts. The model takes advantage of Paillier HE for secure additive aggregation and simulated BBM92 QKD protocol for generating information-theoretically secure symmetric keys, as opposed to keys obtained from traditional protocols such as Diffie-Hellman. These keys protect the exchange of intermediate homomorphically encrypted values among parties with AES-GCM. We outline the system architecture, Python library-based implementation (Qiskit, phe, cryptography), and simulation results proving the feasibility and improved security against quantum eavesdropping over a fully classical solution. The framework efficiently calculates aggregate sums while maintaining input confidentiality and guarantees communication security that withstands simulated eavesdropping attacks on the quantum channel.
Secure Multi-Party Computation (MPC) facilitates cooperative computation on confidential data. Homomorphic Encryption (HE) offers primitives to compute on encrypted data, but protecting the communication channel with classical key exchange is increasingly exposed to quantum attackers. This work outlines a hybrid model where Paillier HE supports secure additive aggregation, while BBM92 QKD simulation generates quantum-resistant keys for AES-GCM, which in turn protects inter-party communication of HE ciphertexts. The model takes advantage of Paillier HE for secure additive aggregation and simulated BBM92 QKD protocol for generating information-theoretically secure symmetric keys, as opposed to keys obtained from traditional protocols such as Diffie-Hellman. These keys protect the exchange of intermediate homomorphically encrypted values among parties with AES-GCM. We outline the system architecture, Python library-based implementation (Qiskit, phe, cryptography), and simulation results proving the feasibility and improved security against quantum eavesdropping over a fully classical solution. The framework efficiently calculates aggregate sums while maintaining input confidentiality and guarantees communication security that withstands simulated eavesdropping attacks on the quantum channel.
Secure multi-party computation has been playing a fundamental role in terms of classical cryptography. Quantum homomorphic encryption (QHE) could compute the encrypted data without decryption. At present, most protocols use a semi-honest third party (TP) to protect participants’ secrets. We use a quantum homomorphic encryption scheme instead of TP to protect the privacy of parties. Based on quantum homomorphic encryption, a secure multi-party quantum summation scheme is proposed in which N participants can delegate a server with strong quantum computing power to assist computation. By delegating the computation and key update processes to a server and a semi-honest key center, participants encrypt their private information data using Pauli operators to get the sum. Besides, the server can design and optimize the summation lines itself, and the correct results can be obtained even if the secret information is negative. The correctness analysis showed that the participants could correctly obtain the results of the calculation. The security analysis proves the scheme is resistant to both outside attack and participant’s attack, and is secure against collusive attack by up to N-2 participants. From the theoretical point of view, our protocol can extend to other secure multi-party computing problems.
This paper explores the design and implementation of a secure multi-party computation (MPC) protocol within a quantum network environment. The core aim is to facilitate computation among multiple parties while guaranteeing the confidentiality of their inputs and the overall computation results. This is achieved by leveraging the principles of Quantum Key Distribution (QKD) and the inherent security provided by the quantum state's properties. We present a protocol that utilizes QKD for secure key exchange among participants and employs quantum state manipulation to obscure intermediate values during computation. The protocol addresses the challenges posed by quantum eavesdropping and ensures the integrity of the final outcome. The key contributions of this work lie in the integration of established MPC techniques with the unique capabilities of a quantum network, offering a novel approach to secure distributed computation. The theoretical analysis demonstrates the protocol's security under specific assumptions, and outlines potential avenues for future research and optimization.
Digital communication development creates an increasing threat to data security because emerging quantum computing technologies easily overcome traditional methods of encryption. A security system that integrates traditional encrypting with quantum computing methods shows promise for enhancing safety of networks mechanisms. The Hybrid Quantum Classical–Advanced Encryption System (HQC–AES) integrates the safe symmetrical functionality of the Advanced Encryption Standard (AES) with Quantum Key Distribution (QKD) procedures, specifically BB84 and E91, to ensure quantum resiliency. A secure key exchange together with real-time eavesdropper detection becomes possible through this combined approach, which maintains data confidentiality at a high level. A synthesis of post-quantum cryptography methods, such as Kyber and Falcon, safeguards traditional ways of communicating alongside quantum structures that lack comparability. The HQC–AES model provides solutions to three key cryptographic problems including secure key handling and distribution as well as encrypted transmission and long-term protection. Quantum mechanics enables protection enhancement for both conventional and quantum-based attacks by integrating it with advanced classical encryption methods. Theoretically, simulators and models show that the hybrid model maintains the technical agility of networks via several networked connections while simultaneously securing the reliability of data. The architecture delivers scalable security features to protect high-security cloud applications and financial systems and Internet of Things (IoT) resources by ensuring paramount secure communication capabilities. In safeguarding the transfer of data across several network circumstances, the suggested HQC–AES approach attained an overall accuracy of 98.7%. The fact that it is resistant to both conventional and quantum-based assaults and manages to keep data secure and intact is reflected in its excellent accuracy.
The fast development of cyber communications, multimedia distribution, remote working have promoted the demand to transmit sensitive information through secure means in both the public and the private networks. The advent of massive quantum computers is rendering traditional cryptographic algorithms like RSA and Elliptic Curve Cryptography (ECC) insecure because they can crack the classical public-key algorithms like the Shor and Grover algorithms. This brings an immediate need of hybrid cryptographic systems, which integrate classical, quantum, and post-quantum algorithms to provide confidentiality, integrity, authentication, and future security beyond the quantum threat horizon.The paper is a proposal of a Hybrid Quantum-Post-Quantum Cryptographic Framework of transmitting files safely. It starts by aggregating files, which is a process to compress several files, images, videos, and multimedia files that users have chosen into one file to minimize redundancy and ease encryption. The AES-256 encrypted file is in GCM mode and provides confidentiality and integrity of the compressed file.The dual-layer mechanism ensures key establishment security. To begin with, Quantum Key Distribution (QKD) based on the protocols of BB84/E91 allows the Sender and the Receiver to generate a Quantum Secret Key (QSK) by exchanging quantum bits in quantum channel. Constant monitoring of the error rate facilitates automatic eavesdropping detection, and guarantees the keys generation is made when the conditions are secure, as well as the safeguarding of interception and man-in-the-middle attacks.A post-quantum layer is provided to ensure long-term security against quantum cryptanalysis, which uses Kyber, a NIST-approved lattice-based Key Encapsulation Mechanism (KEM). The Receiver creates a key pair of Kyber and disseminates the public key to the Sender. By using encapsulation, the Sender gets a PQC ciphertext and a Shared Secret (SS), with decapsulation on the Receiver side giving ensure that only participants of good faith get the same secret value.The hybridization phase consists of combining the QSK of QKD and SS of Kyber with the help of HKDF-SHA256 to obtain a Final Wrap Key (FWK). AES-GCM encrypts the key of file encryption by wrapping it with FWK which allows a secure and authenticated transfer of the key. The Sender sends four messages: encrypted file, Kyber ciphertext, wrapped AES key and the initialisation vector. At Receiver end, FWK is calculated once again with the help of QSK and SS so that the original data can be decrypted with the help of AES key.The suggested framework provides a defense-in-depth solution based on the combination of quantum security, post-quantum resilience and authenticated symmetric encryption. It can be analyzed that there is a strong resistance to classical and quantum adversaries, scalability, and compatibility with the existing communication networks. This renders the model to be appropriate to secure government communication, military systems, data exchange in healthcare environments, cloud storage and financial infrastructures. Keywords— Quantum Key Distribution (QKD), Post-Quantum Cryptography (PQC), Kyber,Key Encapsulation Mechanism (KEM), HKDF-SHA256, Quantum Secret Key (QSK), GCM Mode.
This paper presents a novel protocol for secure multi-party computation (MPC) within a quantum network, integrating Quantum Key Distribution (QKD) and quantum state secure computation techniques. The core objective is to enable multiple parties to collaboratively perform computations without revealing their individual inputs. The proposed protocol establishes a secure communication channel using QKD, guaranteeing the exchange of secret keys. Subsequently, a quantum state secure multi-party computation algorithm is employed, ensuring the confidentiality and integrity of the computation process. The utilization of quantum key distribution significantly enhances the security of the entire system, mitigating vulnerabilities associated with traditional MPC schemes. The theoretical analysis demonstrates the protocol's resilience against various attacks, providing a foundation for building robust and secure quantum network applications. The protocol's effectiveness hinges on the ability to maintain quantum coherence during the computational steps and accurately manage the quantum key distribution process. This research contributes to the advancement of secure quantum computing and communication technologies.
Secure multi-party computation (MPC) is one of the most important primitives in cryptography. Several directions to construct and improve MPC protocols have been studied over the past decades. The majority of existing MPC protocols rely on assumptions such as every party communicates with every other party or every party needs to know every other party and the computation algorithm well in advance. Such assumptions can be difficult to achieve in modern large scale networks. This thesis explores two distinct lines of work leading to new practical models in response to these scenarios.First, we examine communication locality, the total number of other parties that each party communicates with in the protocol, as a new measure for an MPC protocol. Although progress has been made, the question of achieving low communication locality and round complexity at the same time for adaptive adversaries corrupting t < n/2 parties remains open. We show that by assuming a public-key infrastructure (PKI) and a symmetric-key infrastructure (SKI) the above question can be answered affirmatively, under standard assumptions. In particular, we describe a protocol with polylogarithmic communication locality and round complexity which tolerates up to t < n/2 adaptive corruptions. Our results are based on a new model of hidden random graphs obtained from the SKI, and using them to emulate a complete network in polylogarithmic rounds and polylogarithmic locality.We then examine multi-key fully homomorphic encryption (MFHE) schemes, which allow computation on data encrypted under different public keys chosen independently of each other. One of the main problems left in MFHE has been on how to deal with malicious users without trusted setup assumptions. We show how this can be done through circuit privacy, which guarantees that even if both ciphertexts and public keys are not well-formed, no information is revealed regarding the computation, other than what follows from the output on some well-formed inputs. Generalizing the result for circuit-private FHE, we provide a framework for adding circuit privacy to existing MFHE schemes.Finally, we incorporate the circuit privacy in a variant of server-assisted MPC, called on-the-fly MPC, where a server or a “cloud” performs an arbitrary dynamically chosen computation on a subset of data uploaded by multiple clients and encrypted under different keys on-the-fly. Circuit privacy allows the server to keep the algorithm used in the computation private even from a malicious adversary corrupting any number of clients. In particular, we construct a three-round on-the-fly MPC protocol with circuit privacy against malicious clients without the trusted setup.