Improved Reliability of FPGA-based PUF Identification Generator Design

Physical unclonable functions (PUFs), a form of physical security primitive, enable digital identifiers to be extracted from devices, such as field programmable gate arrays (FPGAs). Many PUF implementations have been proposed to generate these unique n -bit binary strings. However, they often offer insufficient uniqueness and reliability when implemented on FPGAs and can consume excessive resources. To address these problems, in this article we present an efficient, lightweight, and scalable PUF identification (ID) generator circuit that offers a compact design with good uniqueness and reliability properties and is specifically designed for FPGAs. A novel post-characterisation methodology is also proposed that improves the reliability of a PUF without the need for any additional hardware resources. Moreover, the proposed post-characterisation method can be generally used for any FPGA-based PUF designs. The PUF ID generator consumes 8.95% of the hardware resources of a low-cost Xilinx Spartan-6 LX9 FPGA and 0.81% of a Xilinx Artix-7 FPGA. Experimental results show good uniqueness, reliability, and uniformity with no occurrence of bit-aliasing. In particular, the reliability of the PUF is close to 100% over an environmental temperature range of 25°C to 70°C with ± 10% variation in the supply voltage. </jats:p

PUF-Assisted Radio Frequency Fingerprinting Exploiting Power Amplifier Active Load-pulling

This paper presents a novel radio frequency fingerprint (RFF) enhancement strategy by exploiting the physical unclonable function (PUF) to tune the RF hardware impairments in a unique and secure manner, which is exemplified by taking power amplifiers (PAs) in RF chains as an example. This is achieved by intentionally and slightly tuning the PA non-linearity characteristics using the active load-pulling technique. The motivation driving the proposed research is to enlarge the RFF feature differences among wireless devices of same vendor, in order to massively improve their RFF classification accuracy in low to medium signal to noise ratio (SNR) channel conditions. PUF is employed to dynamically tune the PA’s RFF feature which guarantees the security since the PUF response cannot be cloned. Specifically, a ring oscillator (RO)-based PUF is implemented to control the PA non-linearity by selecting unique but random configuration parameters. This approach is proposed to amplify the distinctions across same model PAs, thereby enhancing the RFF classification performance. In the meantime, our innovative strategy of PUF-assisted RFF does not noticeably compromise communication link performance which is experimentally tested. The resulting RFF features can be extracted from the received distorted constellation diagrams with the help of image recognition-based machine learning classification algorithms. Extensive experimental evaluations are carried out using both cable-connected and over-the-air (OTA) measurements. Our proposed approach, when classifying eight PAs from a same vendor, achieves 11\% to 24% average classification accuracy improvement by enlarging the RFF feature differences arising from the PA non-linearity

Secured Data Transmission Over Insecure Networks-on-Chip by Modulating Inter-Packet Delays

As the network-on-chip (NoC) integrated into an SoC design can come from an untrusted third party, there is a growing risk that data integrity and security get compromised when supposedly sensitive data flows through such an untrusted NoC. We thus introduce a new method that can ensure secure and secret data transmission over such an untrusted NoC. Essentially, the proposed scheme relies on encoding binary data as delays between packets travelling across the source and destination pair. The maximum data transmission rate of this inter-packet-delay (IPD)-based communication channel can be determined from the analytical model developed in this article. To further improve the undetectability and robustness of the proposed data transmission scheme, a new block coding method and communication protocol are also proposed. Experimental results show that the proposed IPD-based method can achieve a packet error rate (PER) of as low as 0.3% and an effective throughput of $\boldsymbol {2.3\times 10^{5}}$ b/s, outperforming the methods of thermal covert channel, cache covert channel, and circuit-based encryption and, thus, is suitable for secure data transmission in unsecure systems