Biblio

The amount of connected devices in the industrial environment is growing continuously, due to the ongoing demands of new features like predictive maintenance. New business models require more data, collected by IIoT edge node sensors based on inexpensive and low performance Microcontroller Units (MCUs). A negative side effect of this rise of interconnections is the increased attack surface, enabled by a larger network with more network services. Attaching badly documented and cheap devices to industrial networks often without permission of the administrator even further increases the security risk. A decent method to monitor the network and detect “unwanted” devices is network scanning. Typically, this scanning procedure is executed by a computer or server in each sub-network. In this paper, we introduce network scanning and mapping as a building block to scan directly from the Industrial Internet of Things (IIoT) edge node devices. This module scans the network in a pseudo-random periodic manner to discover devices and detect changes in the network structure. Furthermore, we validate our approach in an industrial testbed to show the feasibility of this approach.

pubcrawl, Network on Chip Security, Scalability, resiliency, resilience, metrics, Vulnerabilities and design flaws in Network-on-Chip (NoC) routers can be exploited in order to spy, modify and constraint the sensitive communication inside the Multi-Processors Systems-on-Chip (MPSoCs). Although previous works address the NoC threat, finding secure and efficient solutions to verify the security is still a challenge. In this work, we propose for the first time a method to formally verify the correctness and the security properties of a NoC router in order to provide the proper communication functionality and to avoid NoC attacks. We present a generalized verification flow that proves a wide set of implementation-independent security-related properties to hold. We employ unbounded model checking techniques to account for the highly-sequential behaviour of the NoC systems. The evaluation results demonstrate the feasibility of our approach by presenting verification results of six different NoC routing architectures demonstrating the vulnerabilities of each design.

Polynomial masking is a glitch-resistant and higher-order masking scheme based upon Shamir's secret sharing scheme and multi-party computation protocols. Polynomial masking was first introduced at CHES 2011, while a 1st-order implementation of the AES S-box on FPGA was presented at CHES 2013. In this latter work, the authors showed a 2nd-order univariate leakage by side-channel collision analysis on a tuned measurement setup. This negative result motivates the need to evaluate the performance, area-costs, and security margins of combined \shuffled\ and higher-order polynomially masking schemes to counteract trivial univariate leakages. In this work, we provide the following contributions: first, we introduce additional principles for the selection of efficient addition chains, which allow for more compact and faster implementations of cryptographic S-boxes. Our 1st-order AES S-box implementation requires approximately 27% less registers, 20% less clock cycles, and 5% less random bits than the CHES 2013 implementation. Then, we propose a lightweight shuffling countermeasure, which inherently applies to polynomial masking schemes and effectively enhances their univariate security at negligible area expenses. Finally, we present the design of a \combined\ \shuffled\ \and\ higher-order polynomially masked AES S-box in hardware, while providing ASIC synthesis and side-channel analysis results in the Electro-Magnetic (EM) domain.

Polynomial masking is a glitch-resistant and higher-order masking scheme based upon Shamir's secret sharing scheme and multi-party computation protocols. Polynomial masking was first introduced at CHES 2011, while a 1st-order implementation of the AES S-box on FPGA was presented at CHES 2013. In this latter work, the authors showed a 2nd-order univariate leakage by side-channel collision analysis on a tuned measurement setup. This negative result motivates the need to evaluate the performance, area-costs, and security margins of combined \shuffled\ and higher-order polynomially masking schemes to counteract trivial univariate leakages. In this work, we provide the following contributions: first, we introduce additional principles for the selection of efficient addition chains, which allow for more compact and faster implementations of cryptographic S-boxes. Our 1st-order AES S-box implementation requires approximately 27% less registers, 20% less clock cycles, and 5% less random bits than the CHES 2013 implementation. Then, we propose a lightweight shuffling countermeasure, which inherently applies to polynomial masking schemes and effectively enhances their univariate security at negligible area expenses. Finally, we present the design of a \combined\ \shuffled\ \and\ higher-order polynomially masked AES S-box in hardware, while providing ASIC synthesis and side-channel analysis results in the Electro-Magnetic (EM) domain.

This work deals with key generation based on Physically Obfuscated Keys (POKs), i.e., a certain type of tamper-evident Physical Unclonable Function (PUF) that can be used as protection against invasive physical attacks. To design a protected device, one must take attacks such as probing of data lines or penetration of the physical security boundary into consideration. For the implementation of a POK as a countermeasure, physical properties of a material – which covers all parts to be protected – are measured. After measuring these properties, i.e. analog values, they have to be quantized in order to derive a cryptographic key. This paper will present and discuss the impact of the quantization method with regard to three parameters: key quality, tamper-sensitivity, and reliability. Our contribution is the analysis of two different quantization schemes considering these parameters. Foremost, we propose a new approach to achieve improved tamper-sensitivity in the worst-case with no information leakage. We then analyze a previous solution and compare it to our scenario. Based on empirical data we demonstrate the advantages of our approach. This significantly improves the level of protection of a tamper-resistant cryptographic device compared to cases not benefiting from our scheme.

Physical Unclonable Functions (PUFs) measure manufacturing variations inside integrated circuits to derive internal secrets during run-time and avoid to store secrets permanently in non-volatile memory. PUF responses are noisy such that they require error correction to generate reliable cryptographic keys. To date, when needed one single key is reproduced in the field and always used, regardless of its reliability. In this work, we compute online reliability information for a reproduced key and perform multiple PUF readout and error correction steps in case of an unreliable result. This permits to choose the most reliable key among multiple derived key candidates with different corrected error patterns. We achieve the same average key error probability from less PUF response bits with this approach. Our proof of concept design for a popular reference scenario uses Differential Sequence Coding (DSC) and a Viterbi decoder with reliability output information. It requires 39% less PUF response bits and 16% less helper data bits than the regular approach without the option for multiple readouts.