Q-ChainX: A Quantum-Infused Blockchain Paradigm for Next-Generation Ultra-Secure Data Infrastructures

Ensuring data confidentiality and integrity in
critical infrastructures has become increasingly challenging
due to the rise of quantum computing and the limitations of
classical cryptographic systems. This paper presents QChainX,
a hybrid system, which combines the concepts of
Quantum Key Distribution (QKD) with a Post-Quantum
Cryptographic (PQC) enabled blockchain, to build ultra
secure, tamper resistant and resilient in the future data
infrastructures. The suggested architecture consists of two
communication layers, namely quantum and classical
communication to transmit data and secure keys, respectively,
and uses entanglement-based E91 QKD to generate symmetric
keys. The cryptographic core supports NTRU and
CRYSTALS-Dilithium algorithms to substitute the standard
RSA and ECC, which are resistant to quantum attacks. The
consensus is obtained by the modified Proof-of-Authority
mechanism supported by quantum randomness in the form of
QRNGs, to allow a secure and fair election of validators. The
key generation rates of a simulated Hyperledger environment
simulated in Hyperledger-SimulaQron were found to be over
3800 bps, transaction finality time was found to be 408 ms on
15 nodes, and the consensus success rate was found to be 99.5.
The hybrid quantum-PQC mode recorded 99.95 % data
integrity and zero key compromise, ranked above the classical
set up in all significant security parameters. These findings
confirm the practicability of applying Q-ChainX in practice to
the smart grids, defense communications, and medical data
platforms. The further upgrading will be oriented on the
optimization of quantum hardware, expansion of satellitebased
QKD, and interoperability with multi-chain ecosystems.
Q-ChainX is also a quantum leap to quantum resilient
distributed systems, and it guarantees privacy, trust, and
sustainability in the era of quantum computing.
Keywords—Quantum Key Distribution, Post-Quantum
Cryptography, Blockchain Security, Quantum Blockchain,
Consensus Mechanism, Data Integrity, Quantum Randomness