Metaverse is a vast virtual world parallel to the physical world, where the user acts as an avatar to enjoy various services that break through the temporal and spatial limitations of the physical world. Metaverse allows users to create arbitrary digital appearances as their own avatars by which an adversary may disguise his/her avatar to fraud others. In this paper, we propose an anti-disguise authentication method that draws on the idea of the first impression from the physical world to recognize an old friend. Specifically, the first meeting scenario in the metaverse is stored and recalled to help the authentication between avatars. To prevent the adversary from replacing and forging the first impression, we construct a chameleon-based signcryption mechanism and design a ciphertext authentication protocol to ensure the public verifiability of encrypted identities. The security analysis shows that the proposed signcryption mechanism meets not only the security requirement but also the public verifiability. Besides, the ciphertext authentication protocol has the capability of defending against the replacing and forging attacks on the first impression. Extensive experiments show that the proposed avatar authentication system is able to achieve anti-disguise authentication at a low storage consumption on the blockchain.

中文翻译：

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元宇宙中利用虚拟形象第一印象的防伪装认证系统


元宇宙是一个与物理世界平行的广阔虚拟世界，用户作为虚拟角色享受各种突破物理世界时空限制的服务。 Metaverse 允许用户创建任意数字外观作为自己的化身，对手可以通过这种方式伪装他/她的化身来欺骗他人。在本文中，我们提出了一种反伪装身份验证方法，该方法利用物理世界的第一印象来识别老朋友。具体来说，元宇宙中的第一次会议场景被存储和调用，以帮助虚拟人物之间的身份验证。为了防止对手替换和伪造第一印象，我们构建了基于变色龙的签密机制，并设计了密文认证协议，以确保加密身份的公开可验证性。安全性分析表明，所提出的签密机制不仅满足安全性要求，而且满足公开可验证性。此外，密文认证协议还具有防御第一印象替换和伪造攻击的能力。大量实验表明，所提出的头像认证系统能够在区块链上以较低的存储消耗实现反伪装认证。