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  1. Free, publicly-accessible full text available March 15, 2025
  2. Free, publicly-accessible full text available September 1, 2024
  3. The Global Wearable market is anticipated to rise at a considerable rate in the next coming years and communication is a fundamental block in any wearable device. In communication, encryption methods are being used with the aid of microcontrollers or software implementations, which are power-consuming and incorporate complex hardware implementation. Internet of Things (IoT) devices are considered as resource-constrained devices that are expected to operate with low computational power and resource utilization criteria. At the same time, recent research has shown that IoT devices are highly vulnerable to emerging security threats, which elevates the need for low-power and small-size hardware-based security countermeasures. Chaotic encryption is a method of data encryption that utilizes chaotic systems and non-linear dynamics to generate secure encryption keys. It aims to provide high-level security by creating encryption keys that are sensitive to initial conditions and difficult to predict, making it challenging for unauthorized parties to intercept and decode encrypted data. Since the discovery of chaotic equations, there have been various encryption applications associated with them. In this paper, we comprehensively analyze the physical and encryption attacks on continuous chaotic systems in resource-constrained devices and their potential remedies. To this aim, we introduce different categories of attacks of chaotic encryption. Our experiments focus on chaotic equations implemented using Chua’s equation and leverages circuit architectures and provide simulations proof of remedies for different attacks. These remedies are provided to block the attackers from stealing users’ information (e.g., a pulse message) with negligible cost to the power and area of the design. 
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  4. Due to outsource manufacturing, the semiconductor industry must deal with various hardware threats such as piracy and overproduction. To prevent illegal electronic products from functioning, the circuit can be encrypted using a protected key only known to the designer. However, an attacker can still decipher the secret key utilizing a functioning circuit bought from the market, and the encrypted layout leaked from an untrusted foundry. In this paper, after introducing essential conformity and mutuality features for secure logic encryption, we propose DLE, a novel Distributed Logic Encryption design that resists against all known oracle guided and structural attacks including the newly proposed fault-aided SAT-based attack that iteratively injects a single stuck-at fault to thwart the locking effect. DLE forces the attacker to insert multiple stuck-at faults simultaneously in critical points to achieve a smaller but meaningful encrypted circuit; thus, exponentially reducing the chance to hit all the critical points with properly located stuck-at fault injections. Our experiments confirm that DLE maintains an exponentially high degree of security under diverse attacks with the polynomial area and linear performance overheads. 
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  5. In recent years, semiconductor industry has out-sourced the manufacturing to low-cost but not necessarily trusted foundries. This fabless business model encounters new security challenges, including piracy and overproduction. A well-studied solution to prevent unauthorized products from functioning is logic encryption, where a chip is encrypted using a key only known to the designer. However, the majority of the logic encryption solutions are vulnerable due to key uniformity and probing attacks. In this paper, we first present GSAT, a Global attack on existing IC-specific logic encryption schemes using the SAT model, that effectively deciphers the hidden global key pluggable to all the encrypted ICs. Next, we propose a highly secure and low-cost remedy called SPLEnD: Strong PUF -based Logic Encryption Design. Traditional I C-specific encryption schemes are vulnerable to GSAT attack, while SPLEnD not only effectively resists GSAT, but also balances security and efficiency. 
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  6. Chaos is a deterministic phenomenon that emerges under certain conditions in a nonlinear dynamic system when the trajectories of the state variables become periodic and highly sensitive to the initial conditions. Chaotic systems are flexible, and it has been shown that communication is possible using parametric feedback control. Chaos synchronization is the basis of using chaos in communication. Chaos synchronization refers to the characteristic that the trajectories of two identical chaotic systems, each with its own unique initial conditions, converge over time. In this paper, data extraction is performed on different chaotic equations implemented as circuits. Lorenz is the base system implemented in this paper, followed by Modified Lorenz, Chua’s, Lu¨’s, and Ro¨ssler systems. Additionally, more recent systems (e.g., SprottD Attractor) are included in the data extraction process. The robust system implementations provide an alternative to software chaos and architectures, and will further reduce the required power and area. These chaotic systems serve as alternatives for quantum era computing, which will cause synchronous and asynchronous techniques to fail. The data extracted organize different modes of chaos implementation based on the ease of their fabrication in integrated circuits. Performance metrics including power consumption, area, design load, noise, and robustness to process and temperature variant are extracted for each system to demonstrate a figure of merit. The figure of merit showcases chaos equations fitting to be implemented as a transmitter/receiver with a mode of chaotic ciphering in communication. 
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