Giving State to the Stateless: Augmenting Trustworthy Computation with Ledgers
Giving State to the Stateless: Augmenting Trustworthy Computation with Ledgers
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DOI：
10.14722/ndss.2019.23060
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Gabriel Kaptchuk;M. Green;Ian Miers
中科院分区：
文献类型：
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作者：
Gabriel Kaptchuk;M. Green;Ian Miers
在这项工作中，我们研究了通过将无状态可信设备与公共账本相结合可以实现的新计算特性。我们考虑一种混合范式，其中客户端设备（如协处理器或可信飞地）执行安全计算，同时通过可能恶意的主机计算机与公共账本进行交互。我们探讨了此类系统的建设性和潜在破坏性影响。我们首先表明，即使设备没有持久存储，这种组合也允许构建有状态的交互功能（包括通用计算）；这使我们能够使用廉价的可信硬件甚至纯密码混淆技术构建复杂的应用程序。我们进一步展示了如何使用这种范式实现与网络的抗审查通信，即使网络通信是由可能恶意的主机介导的。最后，我们描述了一些目前可以实现的实际应用。这些包括私有智能合约的同步；速率受限的强制日志记录；从弱密码进行强加密备份；在多方计算中强制公平性；以及诸如自主勒索软件之类的破坏性应用，它允许在没有在线方的情况下进行支付。
In this work we investigate new computational properties that can be achieved by combining stateless trusted devices with public ledgers. We consider a hybrid paradigm in which a client-side device (such as a co-processor or trusted enclave) performs secure computation, while interacting with a public ledger via a possibly malicious host computer. We explore both the constructive and potentially destructive implications of such systems. We first show that this combination allows for the construction of stateful interactive functionalities (including general computation) even when the device has no persistent storage; this allows us to build sophisticated applications using inexpensive trusted hardware or even pure cryptographic obfuscation techniques. We further show how to use this paradigm to achieve censorship-resistant communication with a network, even when network communications are mediated by a potentially malicious host. Finally we describe a number of practical applications that can be achieved today. These include the synchronization of private smart contracts; rate limited mandatory logging; strong encrypted backups from weak passwords; enforcing fairness in multi-party computation; and destructive applications such as autonomous ransomware, which allows for payments without an online party.