Microelectronics Institute of Seville (IMSE-CNM), University of Seville, CSIC, C/Américo Vespucio 28, 41092 Seville, Spain.
Sensors (Basel). 2021 Apr 30;21(9):3119. doi: 10.3390/s21093119.
Non-fungible tokens (NFTs) are widely used in blockchain to represent unique and non-interchangeable assets. Current NFTs allow representing assets by a unique identifier, as a possession of an owner. The novelty introduced in this paper is the proposal of smart NFTs to represent IoT devices, which are physical smart assets. Hence, they are also identified as the utility of a user, they have a blockchain account (BCA) address to participate actively in the blockchain transactions, they can establish secure communication channels with owners and users, and they operate dynamically with several modes associated with their token states. A smart NFT is physically bound to its IoT device thanks to the use of a physical unclonable function (PUF) that allows recovering its private key and, then, its BCA address. The link between tokens and devices is difficult to break and can be traced during their lifetime, because devices execute a secure boot and carry out mutual authentication processes with new owners and users that could add new software. Hence, devices prove their trusted hardware and software. A whole demonstration of the proposal developed with ESP32-based IoT devices and Ethereum blockchain is presented, using the SRAM of the ESP32 microcontroller as the PUF.
非同质化代币（NFT）在区块链中被广泛用于表示独特且不可互换的资产。当前的 NFT 通过唯一标识符来表示资产，作为所有者的拥有物。本文提出的新颖之处在于，建议使用智能 NFT 来表示物联网设备，这些设备是物理智能资产。因此，它们也被标识为用户的实用程序，它们具有区块链账户（BCA）地址，以积极参与区块链交易，它们可以与所有者和用户建立安全的通信渠道，并通过与令牌状态相关的几种模式动态运行。智能 NFT 通过使用物理不可克隆函数（PUF）物理绑定到其物联网设备，该函数允许恢复其私钥，然后恢复其 BCA 地址。令牌和设备之间的链接很难打破，并且可以在其生命周期内进行跟踪，因为设备执行安全启动并与新的所有者和用户执行相互身份验证过程，这些用户可能会添加新软件。因此，设备证明了其可信的硬件和软件。使用 ESP32 微控制器的 SRAM 作为 PUF，展示了使用基于 ESP32 的物联网设备和以太坊区块链开发的整个提案。
