Sharif Digital Repository

Hardware Trojans have emerged as a major concern for integrated circuits in recent years. As a result, detecting Trojans has become an important issue in critical applications, such as finance and health. In this work, a trusted platform for detecting Trojans in FPGA bitstreams is presented. The proposed methodology takes advantage of increased Trojan activation, caused by transition aware partitioning of the circuit, while it benefits partial reconfiguration feature of FPGAs to reduce area overhead. Simulation results, performed for the transition probability thresholds of 〖10〗^(-4) and 〖2×10〗^(-5), show that this method increases the ratio of the number of transitions in the Trojan... 

In recent years, in addition to traditional cryptographic blocks, a hardware blocks in this work namely PUF, has been used mostly for chip ID generation, authentication and so on. In this work we study recent proposed PUFs and their implementations on FPGA, and the measurement of quality metrics on them. Some of most important characteristics of PUFs are unpredictability, reliability, number of challenge response pairs and area. According to experiments that have been performed in this study and also according to previous work, one high-quality PUF in term of uniqueness and reliability is Ring Oscillator PUF. However, the disadvantage of this PUF is small number of challenge and response... 

Due to the expansion of digital system threats, trusted computation with a new approach for countering such threats has emerged. This approach is based on using a hardware module for implementing a trusted platform (TPM). TPM includes a chipset and the trusted systems core. Nowadays many of mobile computers do include this technology. This hardware creates trust using a trust chain and expanding this trust to other parts of the system. The starting point in this chain is the computer BIOS. BIOS is the first code that the system usually executes. One of the most powerful recent attacks on computer systems is to infect the BIOS and other firmware. One of such complicated attacks is the rootkit... 

Public key encryption (PKE) cryptography plays a big role in securing communication channels of internet. The security of every PKE scheme is usually based on a hard problem that has no polynomial time solution using any computational structure. However, widely used classic PKE schemes such as RSA or ECC, are based on hard problems that have polynomial solutions using a quantum computer. Therefore, such PKE schemes will not be secure in post-quantum era. Among quantum-resistant schemes, lattice-based cryptography and especially learning with errors (LWE) problem have gained high attention due to their low computational complexity. In this thesis, different LWE-based cryptosystems are... 

Cloud computing has a significant role in expanding applications of the Internet of Things (IoT). Currently, applications such as virtual reality and augmented reality require low latency, which is not achievable using traditional cloud computing in some scenarios. Edge computing is a new approach in IoT, which solves some of the limitations of the cloud computing by extending and developing its operations. Reducing response time and network traffic are some of the most important achievements of edge computing. Despite of its numerous advantages over cloud computing, edge computing faces serious challenges such as virtualization, implementation infrastructure, resource allocation and task... 

Due to the widespread growth in the use of IoT devices, authors consider these devices as an attractive target platform. Several approaches have been proposed to defend IoT devices against various attacks. However, most of them suffer from some shortcomings such as being computationally expensive, not being general, or not being robust enough.Due to the attacks such as firmware modification and the existence of computational limitations, the use of local approaches is inefficient. Another approach is to use remote attestation techniques, which are divided into two categories, static and dynamic. However, static detection techniques are vulnerable to runtime attacks. Furthermore, existing... 

A distributed ledger is a method of digital data storage and sharing in different places, and the blockchain technology is a way of implementing a distributed ledger. This technology has been employed in many of the cryptocurrencies like Ethereum to store transactions. In addition to storing transactions, Ethereum deploys scripts called smart contracts that are automatically executable. These scripts execute transparently and without preserving the privacy of participants. On the other hand, confidentiality and privacy are among the important components in data, network, and system security. Models such as Hawk and Enigma have been presented to obtain privacy-preserving in smart contracts;... 

Nowadays, with the advancement of internet of things, The number of nodes within the network has increased and there is huge traffic in these networks despite the small volume of data sent and received each node. The current architecture of the Internet network does not have the functionality required for Internet of things, as a result of designing a new architecture for Internet - based Internet of things. Content - based network is a new architecture introduced to the Internet, and its purpose is to change the network from host-centric to content-centric. One of the features of content-based networks is the use of in network caching that helps increase productivity and reduce the traffic... 

Today Internet of Things (IoT) applications are growing rapidly around us and alongside this trend, the topics of security and trust in this field are getting more serious. A big part of this field is composed of embedded systems. Remote attestation is a prominent security option in regards of attesting to the integrity of these type of systems and consequently establishing trust remotely. Remote attestation has been an active field of research to attest different type of systems against various types of threats. A noteworthy security hardware, enabling this type of process, is the Trusted Platform Module (TPM). Incorporating this chip in traditional personal computers for security purposes... 

Classic public key cryptographic systems are based on difficult mathematical problems that will lose their security with the advent of high-speed quantum computers. Isogeny-based cryptography is one of the five main methods in post-quantum cryptography, the hard problem of which is finding large-degree isogenies between elliptic curves. The most important advantage of isogeny-based protocols is the shorter public key length and the main problem is their low speed and low performance compared to other cryptographic systems. Due to the fact that these protocols are implemented on a finite field using basic operations, such as multiplication, squaring, addition, and subtraction, improving the... 

The amount of data over networks are increasing rapidly, and accordingly, smart devices are being encountered severe challenges by the advancement of security threats. In order to create safe communications among smart devices, employing public-key cryptography is needed. But, public-key and classic cryptography, such as RSA, have high computation complexities and are not resistant to quantum attacks. Due to mentioned reasons, using these types of cryptography algorithms in internet-of-things (IoT) devices is unreasonable. In the past decade, lattice-based cryptography has been one of the pioneer post-quantum cryptography members, which benefits from comparatively lower computational... 

Post-quantum cryptography, as one of the newest groups of cryptographic algorithms, is thought to be secure against most sophisticated attacks by the groundbreaking quantum computers. Isogeny-based cryptography is an appealing contender among them due to its exceptional characteristics, especially the shortest public key in key encapsulation, encryption and decryption amid the other nominees of NIST post-quantum standard. However, its high computational complexity is a significant drawback. This research aims to increase the performance of isogeny-based cryptography in the most compute-intensive part, both in throughput and latency perspectives on GPUs and CPUs, which are the most widespread... 

Performance-enhancing mechanisms such as branch prediction, out-of-order execution, and cache hierarchy, have been wildly employed in today’s modern processing units. Although successful in increasing the CPU performance, exploiting the design flaws and security bugs in these components have set the background for various types of microarchitectural attacks. For instance, Spectre and Meltdown have made a serious impact on commercial processors such as ARM, Intel, and AMD. Given the exponential growth in number of smartphones and IoT devices, using ARM processors, as well as the high demand for Intel processors in Desktop PCs and servers, many researchers have tried to evaluate the security... 

Elliptic curve cryptography (ECC) has received attention because it can achieve the same security level as other classical asymmetric methods while using a key with smaller length. Although ECC is more efficient compared to AlGemal and RSA cryptosystems, fast computation of ECC is always desirable. Point multiplication is an essential operation in cryptographic computations. Low-latency and low-complexity multiplication architectures lead to more efficient cryptosystems.In this thesis, a fixed-base comb point multiplication method has been used to perform regular point multiplication. Additionally, two low-complexity (LC) and low-latency (LL) architectures for the regular point... 

Security of cryptographic devices lies amongst the most important issues in the field of hardware security. It is frequently seen that in the process of designing cryptographic systems insufficient attention is paid to the physical implementation details. This is happening while a lot of secret information is known to be leaked through side-channels such as power consumption, electromagnetic emission and execution time. Side-channel attacks are able to reveal secret keys by using these side-channel leakages. Additionally, side-channel attacks are one of the most powerful but low-cost attacks that put the security of cryptographic systems in vain. It can be claimed that the most dangerous... 

Hyperledger Fabric is an open-source modular platform to launch permissioned-blockchains for use cases like banking and supply chains. This system uses the elliptic curve digital signature algorithm to authenticate transactions. The advent and progress of quantum computers have threatened the security of classical cryptographic schemes; therefore, the process of re- placing these schemes with post-quantum alternatives has gained considerable importance.This research intends to replace the elliptic curve digital signature algorithm with post-quantum digital signatures by using the algorithms passed to the third round of the National Institute of Science and Technologies (NIST) post- quantum... 

Elliptic curve cryptography (ECC) has received attention because it can achieve a security level similar to other asymmetric methods while using a key with smaller length. Although ECC is more efficient compared to other asymmetric methods, fast computation of ECC is always desirable. In this thesis,a fixed-base comb point multiplication method has been modified to perform regular point multiplication. Additionally, two low-complexity and lowlatency architectures for the modified point multiplication algorithm has been proposed. In order to achieve these architectures, a low-latency pipelined digit-level field multiplier for all national institute of standards and technology (NIST)... 

Convolutional Neural Networks are a kind of neural network applicable in machine vision and image processing. The accuracy of these networks is dependent on different features such as network size network and input size. Today, researchers are improving the accuracy of neural networks by increasing their size. As a result, networks' computation will increase as well. The bigger the size of the neural network, the harder its hardware implementation. One of the proposed solutions to overcome this issue is to change the number representation while preserving the network accuracy. It's challenging to implement floating-point computation on hardware as it consumes a high amount of power and... 

Public-key cryptography is vital to secure digital communication. The classic instances of these cryptosystems are insecure against large-scale quantum computers. As a result, post-quantum cryptography has emerged as a replacement, which includes different categories. Isogeny-based schemes are one of the promising candidates mainly because of their smaller public key length. Due to high computational cost of such schemes, efficient implementations are significantly important. In this thesis, we have presented various solutions at three different abstraction layers. At the lowest layer, which deals with modular arithmetic, two hardware architectures are presented to perform modular... 

Elliptic curve cryptography (ECC) has received attention because it can achieve a security level similar to other asymmetric methods while using a key with smaller length. Although ECC is more efficient compared to other asymmetric methods, fast computation of ECC is always desirable. In this thesis, a fixed-base comb point multiplication method has been modified to perform regular point multiplication. Additionally, two low-complexity and lowlatency architectures for the modified point multiplication algorithm has been proposed. In order to achieve these architectures, a low-latency pipelined digit-level field multiplier for all national institute of standards and technology (NIST)...