Establishing Multi-level Security in Mobile Data Access

Transaction processing over mobile networks faces new challenges due to limitations in bandwidth and available power, as well as due to intermittent connectivity that causes loss of data and transaction aborts. Besides, the possibility of security breach increases substantially due to the frequent motion of clients across cells, which gives rise to novel forms of covert channels. In this paper, we first investigate to what degree this breach may occur and we also assess the suitability of existing protocols for avoiding the appearance of covert channels in mobile database access. Based on the discovery of certain vulnerabilities in these protocols, we propose an optional multi-granularity locking protocol that ensures secure access to shared data in mobile environments without compromising their consistency or the atomicity of transactions.