Low-Weight Primes for Lightweight Elliptic Curve Cryptography on 8-bit AVR Processors

Small 8-bit RISC processors and micro-controllers based on the AVR instruction set architecture are widely used in the embedded domain with applications ranging from smartcards over control systems to wireless sensor nodes. Many of these applications require asymmetric encryption or authentication, which has spurred a body of research into implementation aspects of Elliptic Curve Cryptography (ECC) on the AVR platform. In this paper, we study the suitability of a special class of finite fields, the so-called Optimal Prime Fields (OPFs), for a "lightweight" implementation of ECC with a view towards high performance and security. An OPF is a finite field Fp defined by a prime of the form p = u*2^k + v, whereby both u and v are "small" (in relation to 2^k) so that they fit into one or two registers of an AVR processor. OPFs have a low Hamming weight, which allows for a very efficient implementation of the modular reduction since only the non-zero words of p need to be processed. We describe a special variant of Montgomery multiplication for OPFs that does not execute any input-dependent conditional statements (e.g. branch instructions) and is, hence, resistant against certain side-channel attacks. When executed on an Atmel ATmega processor, a multiplication in a 160-bit OPF takes just 3237 cycles, which compares favorably with other implementations of 160-bit modular multiplication on an 8-bit processor. We also describe a performance-optimized and a security-optimized implementation of elliptic curve scalar multiplication over OPFs. The former uses a GLV curve and executes in 4.19M cycles (over a 160-bit OPF), while the latter is based on a Montgomery curve and has an execution time of approximately 5.93M cycles. Both results improve the state-of-the-art in lightweight ECC on 8-bit processors

Security for Ubiquitous Internet-Connected Smart Objects

Ubiquitous computing, also called the Internet of Things (IoT), is rapidly transforming our lives and our society. The vision of an interconnected world where physical devices are seamlessly integrated into the Internet is becoming a reality. The emergence of low-cost microcontrollers, energy-efficient wireless communications, and embedded sensors and actuators has transformed everyday devices into connected smart objects that can understand and react to their environment. These devices include both resource-constrained battery-operated devices, such as body sensors, and more powerful Internet-connected appliances, such as televisions and cameras. However, the security mechanisms for smart objects are still not ready for wide-scale deployment. There is additionally a concern that the existing solutions are not sufficiently usable for adoption in everyday devices, which often have very limited user interfaces. In this dissertation, we develop new secure deployment and communication methods for connected smart objects that are simple, user-friendly, and also energy efficient. We take into account the entire lifecycle of a smart object. We first build a secure and energy-efficient communication model that uses a proxy to serve data on behalf of sleeping resource-constrained smart objects, thereby allowing them to appear as always-online web servers. Next, we demonstrate how these smart objects can leverage the existing mobile network infrastructure to securely authenticate and communicate with Internet services. Thereafter, we study the deployment challenges of electronic displays. We found that deploying large numbers of ubiquitous displays is cumbersome as they need to be correctly configured to access both the Internet and online servers, despite their minimal input capabilities. In our secure bootstrapping solution, the displays show a bar code which, when scanned by the user, enables automatic configuration of the wireless network along with the online management service and content to be shown. For effortless deployment, we build our solution on standard protocols without requiring changes to the network infrastructure. Finally, we develop a solution for securely pairing mobile devices. Instead of relying on inconvenient user-entered codes, our solution uses an out-of-band (OOB) channel which is secret from anyone that is not physically present. The protocol development was motivated by the invention of a new human source for fuzzy secrets: synchronized drawing with two fingers of the same hand on two touch screens or surfaces. We show the feasibility of each of our proposed solutions with prototype implementation. Where relevant, we also provide experimental results confirming that our solutions incur minimal memory and computational overhead, while also being energy efficient and easy to use. Lastly, we actively contribute the research results to relevant standards bodies

Types of lightweight cryptographies in current developments for resource constrained machine type communication devices: challenges and opportunities

Machine-type communication devices have become a vital part of the autonomous industrial internet of things and industry 4.0. These autonomous resource-constrained devices share sensitive data, and are primarily acquired for automation and to operate consistently in remote environments under severe conditions. The requirements to secure the sensitive data shared between these devices consist of a resilient encryption technique with affordable operational costs. Consequently, devices, data, and networks are made secure by adopting a lightweight cryptosystem that should achieve robust security with sufficient computational and communication costs and counter modern security threats. This paper offers in-depth studies on different types and techniques of hardware and software-based lightweight cryptographies for machine-type communication devices in machine-to-machine communication networks

Speeding-Up Elliptic Curve Cryptography Algorithms

During the last decades there has been an increasing interest in Elliptic curve cryptography (ECC) and, especially, the Elliptic Curve Digital Signature Algorithm (ECDSA) in practice. The rather recent developments of emergent technologies, such as blockchain and the Internet of Things (IoT), have motivated researchers and developers to construct new cryptographic hardware accelerators for ECDSA. Different types of optimizations (either platform dependent or algorithmic) were presented in the literature. In this context, we turn our attention to ECC and propose a new method for generating ECDSA moduli with a predetermined portion that allows one to double the speed of Barrett\u27s algorithm. Moreover, we take advantage of the advancements in the Artificial Intelligence (AI) field and bring forward an AI-based approach that enhances Schoof\u27s algorithm for finding the number of points on an elliptic curve in terms of implementation efficiency. Our results represent algorithmic speed-ups exceeding the current paradigm as we are also preoccupied by other particular security environments meeting the needs of governmental organizations

Security in smart object networks

Internet of Things (IoT) refers to an inter-connected world where physical devices are seamlessly integrated into the Internet and become active participants of business, information and social processes. This involves the inter-connection of a large number of heterogeneous networked entities and networks. Emergence of technologies such as Zigbee, Bluetooth low energy and embedded sensors has transformed simple physical devices into smart objects that can understand and react to their environment. Such smart objects form the building blocks for the Internet of Things. The communication infrastructure for these objects is based on an extension of the Internet protocol stack. Although the need for security is widely accepted, there is no clear consensus on how IP-based Internet security protocols can be applied to resource-constrained smart object networks. In this thesis, we develop a new secure and energy efficient communication model for the Constrained Application Protocol (CoAP), a light-weight communication protocol designed for smart object networks. We contribute to the standardization of the generic communication architecture by adding security and delegation components for smart objects that sleep for large amounts of time during their operational phase. This architecture ensures data integrity and authenticity over a multi-hop network topology. It also provides a mirroring mechanism that uses a proxy to serve data on behalf of sleeping smart objects, thereby allowing them to act as always-online web servers. A working prototype implementation of the architecture is also developed. The security features in the architecture presented in this thesis are based on using strong public-key cryptography. Contrary to popular belief, our performance evaluation shows that asymmetric public-key cryptography can be implemented on small 8-bit micro-controllers without modifying the underlying cryptographic algorithms

All the Polynomial Multiplication You Need on RISC-V

Polynomial multiplication is a core operation for public key cryptography, such as pre-quantum cryptography (e.g. elliptic curve cryptography) and post-quantum cryptography (e.g. code-based cryptography and multivariate-based cryptography). For this reason, the efficient and secure implementation of polynomial multiplication has been actively conducted for high availability and security level in application services. In this paper, we present all polynomial multiplication methods on modern 32-bit RISC-V processors. We re-designed expensive implementations of polynomial multiplication on legacy microcontrollers (e.g. 8-bit AVR, 16-bit MSP, and 32-bit ARM) for new instruction sets of 32-bit RISC-V processors. Secondly, we suggest the optimal operand length for each polynomial multiplication on 32-bit RISC-V processors. With this implementation technique and Karatsuba algorithm, we achieved scalable features, which ensures the polynomial multiplication in any operand lengths with reasonably fast performance. Third, we propose instruction set extensions for the optimal implementation of polynomial multiplication on 32-bit RISC-V processors. This new feature introduces significant performance enhancements. Lastly, the proposed implementation is a public domain and following researchers can easily re-produce the result

Seluge++: A Secure Over-the-Air Programming Scheme in Wireless Sensor Networks

Over-the-air dissemination of code updates in wireless sensor networks have been researchers’ point of interest in the last few years, and, more importantly, security challenges toward the remote propagation of code updating have occupied the majority of efforts in this context. Many security models have been proposed to establish a balance between the energy consumption and security strength, having their concentration on the constrained nature of wireless sensor network (WSN) nodes. For authentication purposes, most of them have used a Merkle hash tree to avoid using multiple public cryptography operations. These models mostly have assumed an environment in which security has to be at a standard level. Therefore, they have not investigated the tree structure for mission-critical situations in which security has to be at the maximum possible level (e.g., military applications, healthcare). Considering this, we investigate existing security models used in over-the-air dissemination of code updates for possible vulnerabilities, and then, we provide a set of countermeasures, correspondingly named Security Model Requirements. Based on the investigation, we concentrate on Seluge, one of the existing over-the-air programming schemes, and we propose an improved version of it, named Seluge++, which complies with the Security Model Requirements and replaces the use of the inefficient Merkle tree with a novel method. Analytical and simulation results show the improvements in Seluge++ compared to Seluge

Improved Development Cycle for 8-bit FPGA-Based Soft-Macros Targeting Complex Algorithms

Developing complex algorithms on 8-bit processors without proper development tools is challenging. This paper integrates a series of novel techniques to improve the development cycle for 8-bit soft-macros such as Xilinx PicoBlaze. The improvements proposed in this paper reduce development time significantly by eliminating the required resynthesis of the whole design upon HDL source code changes. Additionally, a technique is proposed to increase the maximum supported data memory size for PicoBlaze which facilitates development of complex algorithms. Also, a general verification technique is proposed based on a series of testbenches that perform code verification using comparison method. The proposed testbench scenario integrates “Inter-Processor Communication (IPC), shared memory, and interrupt” concepts that lays out a guideline for FPGA developers to verify their own designs using the proposed method. The proposed development cycle relies on a chip that has Programmable Logic (PL) fabric (to hold the soft processor) alongside of a hardened processor (to be used as algorithm verifier), therefore, a Xilinx Zynq Ultrascale+ MPSoC is chosen which has a hardened ARM processor. The development cycle proposed in this paper targets the PicoBlaze, but it can be easily ported to other FPGA macros such as Lattice Mico8, or any non-Xilinx FPGA macros

Técnicas de segurança para a internet das coisas

Mestrado em Engenharia de Computadores e TelemáticaIoT assume que dispositivos limitados, tanto em capacidades computacionais como em energia disponível, façam parte da sua infraestrutura. Dispositivos esses que apresentam menos capacidades e mecanismos de defesa do que as máquinas de uso geral. É imperativo aplicar segurança nesses dispositivos e nas suas comunicações de maneira a prepará-los para as ameaças da Internet e alcançar uma verdadeira e segura Internet das Coisas, em concordância com as visões atuais para o futuro. Esta dissertação pretende ser um pequeno passo nesse sentido, apresentando alternativas para proteger as comunicações de dispositivos restritos numa perspetiva de performance assim como avaliar o desempenho e a ocupação de recursos por parte de primitivas criptográficas quando são aplicadas em dispositivos reais. Dado que a segurança em diversas ocasiões tem de se sujeitar aos recursos deixados após a implementação de funcionalidades, foi colocada uma implementação de exposição de funcionalidades, recorrendo ao uso de CoAP, num dispositivo fabricado com intenção de ser usado em IoT e avaliada de acordo com a sua ocupação de recursos.IoT comprehends devices constrained in both computational capabilities and available energy to be a part of its infrastructure. Devices which also present less defense capabilities and mechanisms than general purpose machines. It’s imperative to secure such devices and their communications in order to prepare them for the Internet menaces and achieve a true and secure Internet of Things compliant with today’s future visions. This dissertation intends to be a small step towards such future by presenting alternatives to protect constrained device’s communications in a performance related perspective as well as benchmarks and evaluation of resources used by cryptographic primitives when implemented on real devices. Due to security being on multiple occasions subjected to the resources available only after functionalities implementation, a minimalist implementation of functionalities exposure through the use of CoAP was also deployed in an IoT intended device and assessed according to resource overhead