A Novel Lightweight Symmetric Encryption and Decryption Hardware for Cloud Security

The increasing reliance on cloud servers for data storage and processing, with ensured secure data transmission has become a critical challenge. While significant efforts focus on mitigating external threats, internal vulnerabilities remain a substantial risk. This paper proposes a lightweight symmetric encryption framework aimed at enhancing data security in cloud environments. The design integrates three layers of encryption to achieve robust protection: symmetric key-based XOR encryption, salt-based randomness, and a data-reversing operation. The encryption process begins by XORing the plaintext with a dynamically generated 8-bit symmetric key, followed by appending a 4-bit salt value to introduce randomness. A final reversing operation is applied to the encrypted data to add an additional layer of obfuscation, strengthening resistance to potential attacks. The decryption process sequentially reverses these steps: the data is restored to its original order, the salt is removed, and XOR is applied with the symmetric key to retrieve the plain text. The proposed method is implemented in Verilog HDL, with validation conducted through a test bench designed to process text data for encryption and decryption. The test bench demonstrates accurate functionality for a pre-decided limited maximum limit on the number of letters that a word can contain. A comparative evaluation highlights the superior security and performance of the proposed algorithm against vis-a-vis. This study underscores the effectiveness of hardware-based symmetric cryptography in addressing both internal and external threats to cloud server security, offering a reliable solution for secure data exchange.