A Secure Self-Encryption Scheme for Resource Limited Mobile Devices

Abstract

Recently, IT and mobile technology are developed rapidly. Mobile devices such as a smartphone and tablet PC have become widely popular, and many people store their private information into the devices. However, the portability and mobility of devices take risks such as being lost or stolen. These devices are the one of main cause to leak the sensitive and confidential information. To protect the information leakage from devices, the encryption algorithm is required. The existing encryption algorithms take long delay time and heavy battery consumption in mobile devices with restricted resources. Previously, the Self-Encryption (SE) which is a lightweight encryption algorithm for mobile devices was proposed, which had critical weaknesses. This paper proposes a novel SE scheme with a random permutation and bit-flipping process. Our proposed scheme derives the keystream from the plaintext itself, but the statistical correlations are effectively removed from the novel randomization process. It gives a solution to overcome weaknesses of the original SE scheme and the complexity to make adversaries it difficult to launch a brute force attack, and satisfies a 0/1 uniformity of key and cipher stream, which is an important property of the secure stream cipher. Moreover, it is faster and more energy-efficient than other ciphers such as AES and RC4. The evaluation is performed by the Android platform. The delay time and the battery consumption are measured and analyzed, which show that the proposed scheme is secure and best suited to the mobile platform.