Linear feedback shift registers (LFSRs) and nonlinear feedback shift register (NLFSRs) are major components of stream ciphers. It has been shown that, under certain idealised assumptions, LFSRs and LFSR-based stream ciphers are susceptible to cryptanalysis using simple power analysis (SPA). In this study, the authors show that SPA can be practically applied to a CMOS digital hardware circuit to determine the bit values of an NLFSR and SPA therefore has applicability to NLFSR-based stream ciphers. A new approach is used with the cryptanalyst collecting power consumption information from the system on both edges (triggering and non-triggering) of the clock in the digital hardware circuit. The method is applied using simulated power measurements from an 80-bit NLFSR targeted to an 180 nm CMOS implementation. To overcome inaccuracies associated with mapping power measurements to the cipher data, the authors offer novel analytical techniques which help the analysis to find the bit values of the NLFSR. Using the obtained results, the authors analyse the complexity of the analysis on the NLFSR and show that SPA is able to successfully determine the NLFSR bits with modest computational complexity and a small number of power measurement samples.

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Simple power analysis applied to nonlinear feedback shift registers

In recent years, the hardware implementation of stream ciphers has attracted the interest of many designers, mainly due to their low implementation area on a chip. However, to date, in comparison with block ciphers, side channel attacks have not been extensively analyzed for their applicability to stream cipher hardware implementations. In [1] it is shown that simple power analysis attacks are applicable to stream ciphers based on one linear feedback shift register. In this paper, we extend the SPA method to stream ciphers with multiple linear feedback shift registers. Then we apply the proposed method to the well-known stream cipher E0.
 
[1] S. Burman, et. al., "LFSR Based Stream Ciphers are Vulnerable to Power Attacks", INDOCRYPT 2007, Lecture Notes in Computer Science, vol. 4859, Springer, pp. 384-392.

Applicability of Simple Power Analysis to Stream Ciphers Constructed Using Multiple LFSRs

In the near future, one of the promising concepts which are going to change undoubtedly the whole automobile industry, vehicular networking, software industry, IT manufacturing industry, Industry, transportation sector, service provider, etc. is the Internet of Vehicles (IoV). It can have the capability to boost innovation in smart city applications(like intelligent transportation, smart health-care, smart environment etc). The IoV is a dynamic network system which allows data sharing between different entities like vehicles, their surrounding RSUs (Roadside Units), infrastructures, sensors, mobile devices, clouds, etc. It opened new opportunities in different services and applications to enhance road conditions, driver/passenger safety, transportation issues, non-safety applications, etc. However, ensuring Efficiency and security is one of the main challenges in an IoV scenario. In this paper, we introduce the new effective and efficient architecture for the next generation vehicular technologies for identify the inappropriateness of most existing work, and address the challenging issues of secure and efficient packet forwarding and energy efficient by proposing new effective and efficient scheme for VANETs using Internet of Vehicles and Mobile Femto Access Points.

Improving Throughput and Energy Efficiency in Vehicular Ad-Hoc Networks using Internet of Vehicles and Mobile Femto Access Points

We report on a collaboration project connected to net-on-demand. The aim is to develop techniques for secure communication on inductively coupled channels.

Ytrehus

Papers

Lightweight cryptography for RFID devices