SwiftEnc: Hybrid Cryptosystem with Hash-Based Dynamic Key Encryption

With the emerging need to store massive data in cyberspace and cross platforms, whether in local file systems or cloud- based services, certain security requirements must be met to efficiently protect confidentiality and privacy and manage the large number of keys and access policies. Most of the current encryption standards emphasize one of two trade-off factors: speed of encryption versus ease of key management. Though asymmetric-key encryption does not require the sender and receiver to share a common secret similar to symmetric-key encryption, the cost of the mathematical computations may be unaffordable. In this paper, we first review the state-of-the-art of hybrid cryptosystems. Then, we propose a novel scheme for lightweight encryption of bulk data based on recursive cryptographic hashes and dynamic keys. The effectiveness of the proposed scheme is demonstrated on three files having different sizes, types and contents.