Hybrid SHA3 Junk Encryption based Crystal ZEUS framework for secure client-side deduplication on cloud

With the growing reliance on cloud storage, ensuring secure client-side deduplication is essential to eliminate data redundancy without compromising confidentiality or integrity. Thus, this paper proposes a novel Hybrid SHA3-Recursive Junk Encryption based Crystal ZEUS framework. Existing models use SHA-2 for hashing, but its Merkle–Damgård construction is vulnerable to hash extension attacks, which leads to unauthorized deduplication and data leakage. To address this, a Hybrid SHA3-Recursive Deduplication is proposed, where multiple SHA3-512 hashing enhances deduplication accuracy while resisting hash extension attacks, and ensures secure fingerprinting for deduplication without leakage, thereby solve adversary to forge a valid hash. Traditional encryptions provide confidentiality and lack integrity verification, which causes vulnerability to key exposure and compromises metadata protection and data security. To mitigate this, a Hybrid Junk Triple Encryption is introduced, which increase confidentiality, integrity verification, and secure key exchange thereby provide robust key management. Additionally, post-quantum solutions solve quantum attacks, but their complex polynomial arithmetic and large key sizes, leaves systems exposed to token hijacking and data breaches. Thus, to provide post-quantum resilience, a Crystal ZEUS is introduced, which provide secure key exchange, secure post-quantum digital signatures, and generates unclonable device-specific keys without revealing sensitive data, thereby provide quantum-resistant identity management. On implementing the proposed model, it outperforms existing methods in terms of achieving lower duplication rate, encryption and decryption time.