保护人员及其机器免受重大故障影响

中文摘要 AI 辅助

我们考虑草根平台——由自选公钥标识的人员及其机器（智能手机）组成的代理分布式系统——并希望使其免受\emph{重大故障}的影响：即私钥和/或智能手机的丢失。由于草根平台没有全局资源可用于恢复，我们的对等解决方案基于：(\ia) \emph{草根社交图}，其中代理建立并维护友谊；(\ib) 由每个人指定的\emph{身份托管人}，以及(\ic) \emph{状态托管人}，它们是特定于草根平台的。当人员遭遇身份丢失时，在得到该人员身份托管人的意愿超多数同意后，该人员的朋友在图内用新公钥替换旧公钥并恢复友谊，所有朋友充当社交图的状态托管人。选择新密钥对、获取新智能手机以及说服身份托管人同意密钥变更均“链下”进行。无密钥丢失的机器丢失恢复（例如智能手机被卡车碾压或内存被擦除）更简单，仅需状态托管人的帮助。我们将社交图及其安全版本规范为带守卫的多智能体原子事务，并通过通信的意志代理实现安全社交图，这是一种更接近实现的最终同步消息传递模型。我们证明该实现将具有可恢复故障的运行映射到规范的正确运行。我们遵循类似路径处理草根货币和债券，展示了共同核心以及状态恢复的平台特定方面：货币的单写入者日志被精确恢复，恢复的主权不会双花。

英文摘要

We consider grassroots platforms -- distributed systems of agents consisting of people identified by self-chosen public keys and their machines (smartphones) -- and wish to make them secure against \emph{major faults}: the loss of their private keys and/or their smartphones. As grassroots platforms have no global resource to rely on for recovery, our peer-based solution is based on: (\ia) \emph{a grassroots social graph} in which agents establish and maintain friendships; (\ib) \emph{identity custodians}, designated by each person, and (\ic) \emph{state custodians}, which are grassroots platform-specific. Upon a person experiencing identity loss, and given a willing supermajority of the identity custodians of the person, the friends of the person replace the old public key with the new one across the graph and restore friendships, where all friends serve as state custodians for the social graph. Choosing a new keypair, obtaining a new smartphone, and convincing identity custodians to will a change of key all happen ``off-chain''. Recovery from machine loss without loss of key (e.g. smartphone run over by truck, or its memory wiped) is simpler, requiring only the help of state custodians. We specify the social graph and its secure version as guarded multiagent atomic transactions, and implement the secure social graph via communicating volitional agents, an eventually synchronous message-passing model one step closer to implementation. We prove the implementation maps runs with recoverable faults to correct runs of the specification. We follow a similar path for grassroots coins and bonds, showing a common core as well as the platform-specific aspects of state recovery: a currency's single-writer log is recovered exactly, the recovered sovereign resuming without double-spending.

发表机构

• Technion – Israel Institute of Technology（以色列理工学院）
• London School of Economics and Political Science（伦敦政治经济学院）
• Weizmann Institute of Science（魏茨曼科学研究所）

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