论文标题
游击堆:分布式,容忍故障,遗忘数据访问
SHORTSTACK: Distributed, Fault-tolerant, Oblivious Data Access
论文作者
论文摘要
许多受益于数据卸载到云服务的应用程序都在私人数据上运行。如今的工作线已经表明,即使以加密形式卸载数据,对手也可以通过分析数据访问模式来学习敏感信息。现有的遗忘数据访问的技术 - 防止访问模式攻击 - 重新获得集中且具有州的可信赖代理,可协调从应用程序到云服务的数据访问。我们表明,在容易失败的部署中,这样的集中式和状态代理违反了遗忘数据访问安全保证和/或系统不可用。因此,我们启动了分布式,容忍,遗忘的数据访问的研究。 我们介绍了ShortAck,这是一种分布式的代理体系结构,用于忽略失败的部署中的数据访问。游击队实现了经典的遗忘保证 - 对手观察到的访问模式独立于输入 - 甚至在强大的被动持久性对手下,该对手可能会在任意时间迫使代理服务器的任意(有限尺寸)子集的失败。我们还介绍了一个安全模型,该模型可以通过分布式,容易发生的服务器来研究忽略的数据访问。我们提供了一个正式的证据,表明游击群在此模型下可以忽略数据访问,并从经验上证明,游击群的性能与分布式代理服务器的数量接近线性缩放。
Many applications that benefit from data offload to cloud services operate on private data. A now-long line of work has shown that, even when data is offloaded in an encrypted form, an adversary can learn sensitive information by analyzing data access patterns. Existing techniques for oblivious data access-that protect against access pattern attacks-require a centralized and stateful trusted proxy to orchestrate data accesses from applications to cloud services. We show that, in failure-prone deployments, such a centralized and stateful proxy results in violation of oblivious data access security guarantees and/or system unavailability. We thus initiate the study of distributed, fault-tolerant, oblivious data access. We present SHORTSTACK, a distributed proxy architecture for oblivious data access in failure-prone deployments. SHORTSTACK achieves the classical obliviousness guarantee--access patterns observed by the adversary being independent of the input--even under a powerful passive persistent adversary that can force failure of arbitrary (bounded-sized) subset of proxy servers at arbitrary times. We also introduce a security model that enables studying oblivious data access with distributed, failure-prone, servers. We provide a formal proof that SHORTSTACK enables oblivious data access under this model, and show empirically that SHORTSTACK performance scales near-linearly with number of distributed proxy servers.