几乎公开的量子硬币
Almost Public Quantum Coins
AI总结：
本文提出一种将私有量子硬币方案提升为几乎公开的量子硬币方案的技术，通过对称子空间投影实现验证，并基于标准假设证明其安全性，首次构造出接近公开且可证明安全的量子货币方案。
摘要：
在量子货币方案中，银行可以发行用户无法伪造的货币。与纸币类似，大多数量子货币方案为每个货币态分配一个唯一的序列号，从而可能损害量子货币用户的隐私。然而，在量子硬币方案中，就像传统的货币硬币方案一样，所有货币态彼此完全相同，从而为用户提供了更好的隐私保护。量子货币方案可以是私有的，即只有银行能够验证货币态，也可以是公开的，即任何人都可以验证。在这项工作中，我们提出了一种方法，将任何私有量子硬币方案——根据Ji、Liu和Song（CRYPTO'18）的工作，已知其基于单向函数的存在而存在——提升为一种非常接近公开量子硬币方案的方案。新硬币的验证通过将其与用户已经拥有的硬币进行比较来完成，使用投影到对称子空间上的投影算子。在此工作之前，没有任何公开硬币方案是已知的。这也是第一个非常接近公开量子货币方案、并且基于标准假设可证明安全的构造。最后，当用私有量子硬币方案（文献[MS10]）实例化该提升技术时，得到了第一个接近低效但无条件安全的公开量子货币方案的构造。
英文摘要：
In a quantum money scheme, a bank can issue money that users cannot counterfeit. Similar to bills of paper money, most quantum money schemes assign a unique serial number to each money state, thus potentially compromising the privacy of the users of quantum money. However in a quantum coins scheme, just like the traditional currency coin scheme, all the money states are exact copies of each other, providing a better level of privacy for the users. A quantum money scheme can be private, i.e., only the bank can verify the money states, or public, meaning anyone can verify. In this work, we propose a way to lift any private quantum coin scheme -- which is known to exist based on the existence of one-way functions, due to Ji, Liu, and Song (CRYPTO'18) -- to a scheme that closely resembles a public quantum coin scheme. Verification of a new coin is done by comparing it to the coins the user already possesses, by using a projector on to the symmetric subspace. No public coin scheme was known prior to this work. It is also the first construction that is very close to a public quantum money scheme and is provably secure based on standard assumptions. Finally, the lifting technique, when instantiated with the private quantum coins scheme~\cite{MS10}, gives rise to the first construction that is close to an inefficient unconditionally secure public quantum money scheme.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
