The significance of a cryptograph method lies in its ability to provide high fidelity, high security, and large capacity. The emergence of metasurface-empowered cryptography offers a promising alternative due to its unparalleled wavefront modulation capabilities and easy integration with traditional schemes. However, the majority of reported strategies suffer from limited capacity as a result of restricted independent information channels. In this study, we present a novel method of cryptography that utilizes a dual-band complex-amplitude meta-hologram. The method allows for the encoding of 225 different patterns by combining a modified visual secret-sharing scheme (VSS) and a one-time-pad private key. The use of complex-amplitude modulation and the modified VSS enhances the quality and fidelity of the decrypted results. Moreover, the transmission of the private key through a separate mechanism can greatly heighten the security, and different patterns can be generated simply by altering the private key. To demonstrate the feasibility of our approach, we design, fabricate, and characterize a meta-hologram prototype. The measured results are in good agreement with the numerical ones and the design objectives. Our proposed strategy offers high security, ultra-capacity, and high fidelity, making it highly promising for applications in information encryption and anti-counterfeiting.

中文翻译：

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双频带复振幅超表面支持具有超大规模可编码模式的高安全性密码学


密码方法的意义在于它能够提供高保真度、高安全性和大容量。超表面加密技术的出现提供了一种有前途的替代方案，因为它具有无与伦比的波前调制能力并且易于与传统方案集成。然而，由于独立信息渠道有限，大多数报告的策略都受到能力有限的影响。在这项研究中，我们提出了一种利用双频带复振幅元全息图的新型密码学方法。该方法通过结合修改后的视觉秘密共享方案 (VSS) 和一次性一密私钥，允许对 225 种不同模式进行编码。复振幅调制和改进的 VSS 的使用提高了解密结果的质量和保真度。而且，通过单独的机制传输私钥可以大大提高安全性，并且只需更改私钥就可以生成不同的模式。为了证明我们的方法的可行性，我们设计、制造并表征了元全息图原型。测量结果与数值结果和设计目标非常吻合。我们提出的策略提供了高安全性、超大容量和高保真度，使其在信息加密和防伪方面的应用非常有前景。