Table 2.
Comparative analysis of classical blockchain and QuantumShield-BC in terms of cryptographic security, consensus efficiency, and quantum resilience.
| Feature/metric | Classical blockchain (ECC + PoW) | QuantumShield-BC (PQC + QKD + Q-BFT) |
|---|---|---|
| Digital signature scheme | ECDSA (256-bit) | CRYSTALS-dilithium (level 2) |
| Consensus mechanism | Proof-of-work (PoW) | Quantum BFT (Q-BFT) |
| Key exchange | Classical public key exchange | Quantum key distribution (QKD) |
| Nonce generation | Pseudo-random generator | Quantum random number generator (QRNG) |
| Block finalization time | High (due to mining) | Low (QRNG-based leader selection) |
| Signature verification time | Fast | Moderate |
| Energy consumption (consensus) | High | Low |
| Resistance to quantum attacks | Weak (Shor’s applicable) | Strong (post-quantum secure) |
| Sybil attack mitigation | No (PoW susceptible) | Yes (validator authentication via PQC) |
| Replay attack mitigation | Limited | Strong (QRNG-based nonce uniqueness) |