On Reverse Elastic Channels and the Asymmetry of Commitment Capacity Under Channel Elasticity
On Reverse Elastic Channels and the Asymmetry of Commitment Capacity Under Channel Elasticity
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论逆弹性通道与通道弹性下承诺能力的不对称性
DOI：
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发表时间：
2021
影响因子：
16.4
通讯作者：
Anuj Kumar Yadav
中科院分区：
文献类型：
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作者：
Amitalok J. Budkuley;Pranav Joshi;Manideep Mamindlapally;Anuj Kumar Yadav
承诺是一个重要的密码原语。众所周知，噪声信道是一种很有前途的资源，以实现承诺的信息理论上的安全方式。然而，通常情况下，信道行为可能会很差，从而限制了承诺吞吐量和/或降低安全保证;当诚实方不知道的不诚实方恶意改变信道特性时，会出现特别有问题的情况。反向弹性通道（Reverse elastic channels，REC）是一类有趣的不可靠通道，只有不诚实的提交者，比如Alice，才能恶意地改变通道。最近，REC吸引了人们对几种密码原语的研究兴趣。我们的主要贡献是REC承诺能力表征，这证明了最近的相关猜想。一个关键的结果是我们的严格匡威分析了一个特定的作弊策略爱丽丝。沿着弹性信道（EC），其中只有不诚实的接收者Bob可以改变信道，REC也与经典的不公平噪声信道（UNC）密切相关。与UNC形成鲜明对比的是，REC和EC对于所有非平凡信道参数总是表现出正承诺吞吐量。有趣的是，我们的研究结果表明，渠道与独家单边弹性不诚实的当事人，表现出根本的不对称性，其中，一个提交者与单边弹性有一个显着更削弱的影响比一个类似的能力接收器的承诺吞吐量。
Commitment is an important cryptographic primitive. It is well known that noisy channels are a promising resource to realize commitment in an information-theoretically secure manner. However, oftentimes, channel behaviour may be poorly characterized thereby limiting the commitment throughput and/or degrading the security guarantees; a particularly problematic situation arises when a dishonest party, unbeknown to the honest one, maliciously alters the channel characteristics. Reverse elastic channels (RECs) are an interesting class of such unreliable channels where only a dishonest committer, say Alice, can maliciously alter the channel. RECs have attracted recent interest in the study of several cryptographic primitives. Our principal contribution is the REC commitment capacity characterization; this proves a recent related conjecture. A key result is our tight converse which analyses a specific cheating strategy by Alice. Along with elastic channels (ECs), where only a dishonest receiver Bob can alter the channel, RECs are also closely related to the classic unfair noisy channels (UNCs). In stark contrast to UNCs, both RECs and ECs always exhibit positive commitment throughput for all non-trivial channel parameters. Interestingly, our results show that channels with exclusive one-sided elasticity for dishonest parties, exhibit a fundamental asymmetry where, a committer with one-sided elasticity has a significantly more debilitating effect on the commitment throughput than a similarly capable receiver.