Cloud storage systems have become an essential platform for storing and managing large volumes of data, but their security depends not only on confidentiality but also on integrity, controlled key management, and resistance to active attacks. Many existing protection approaches emphasize encryption of data while giving less attention to context–aware verification and controlled object recovery in untrusted cloud settings. This study proposes a novel hybrid cryptographic model for cloud storage systems, Object-Centric Threshold–Sealed Encryption with Two Keys (OCTET). The model integrates AES chunk-based encryption to protect data confidentiality, ECC to secure key exchange, threshold–based secrets to reconstruct, HKDF–derived per chunk, and Merkle root to enforce a verification–before–decryption policy. The implementation of the proposed model is in an emulated cloud storage system and examined on a dataset of large objects, then compared against baseline schemes, including symmetric and hybrid encryption models, under the same experimental environment. The main outcome demonstrates that the proposed model achieves practical performance, minor overhead, and superior resistance to the attack models. In general, this study demonstrates that the proposed model offers trade–offs between security and efficiency and a robust integrity technique for large objects in cloud storage systems.
Almirdasi et al. (Thu,) studied this question.