Nima Karimian

Prof. Nima Karimian

Computer Engineering Department, San José State University, San Jose, CA 95192, USA
orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 June 2020 in IEEE Access
Verified
Journal Article
Open access
MIMohit Ingale
Mohit Ingale
RCRenato Cordeiro
Renato Cordeiro
STSiddartha Thentu
Siddartha Thentu
YPYounghee Park
Younghee Park
Nima KarimianNima Karimian
Nima Karimian
Robust authentication and identification methods become an indispensable urgent task to protect the integrity of the devices and the sensitive data. Passwords have provided access control and authentication, but have shown their inherent vulnerabilities. The speed and convenience factor are what makes biometrics the ideal authentication solution as they could have a low probability of circumvention. To overcome the limitations of the traditional biometric systems, electrocardiogram (ECG) has received the most attention from the biometrics community due to the highly individualized nature of the ECG signals and the fact that they are ubiquitous and difficult to counterfeit. However, one of the main challenges in ECG-based biometric development is the lack of large ECG databases. In this paper, we contribute to creating a new large gallery off-the-person ECG datasets that can provide new opportunities for the ECG biometric research community. We explore the impact of filtering type, segmentation, feature extraction, and health status on ECG biometric by using the evaluation metrics. Our results have shown that our ECG biometric authentication outperforms existing methods lacking the ability to efficiently extract features, filtering, segmentation, and matching. This is evident by obtaining 100% accuracy for PTB, MIT-BHI, CEBSDB, CYBHI, ECG-ID, and in-house ECG-BG database in spite of noisy, unhealthy ECG signals while performing five-fold cross-validation. In addition, an average of 2.11% EER among 1,694 subjects is obtained.

18 September 2021 in Sensors
Verified
Journal Article
Open access
PDF file
RCRenato Cordeiro
Renato Cordeiro
Nima KarimianNima Karimian
Nima Karimian
Younghee ParkYounghee Park
Younghee Park
A growing number of smart wearable biosensors are operating in the medical IoT environment and those that capture physiological signals have received special attention. Electrocardiogram (ECG) is one of the physiological signals used in the cardiovascular and medical fields that has encouraged researchers to discover new non-invasive methods to diagnose hyperglycemia as a personal variable. Over the years, researchers have proposed different techniques to detect hyperglycemia using ECG. In this paper, we propose a novel deep learning architecture that can identify hyperglycemia using heartbeats from ECG signals. In addition, we introduce a new fiducial feature extraction technique that improves the performance of the deep learning classifier. We evaluate the proposed method with ECG data from 1119 different subjects to assess the efficiency of hyperglycemia detection of the proposed work. The result indicates that the proposed algorithm is effective in detecting hyperglycemia with a 94.53% area under the curve (AUC), 87.57% sensitivity, and 85.04% specificity. That performance represents an relative improvement of 53% versus the best model found in the literature. The high sensitivity and specificity achieved by the 10-layer deep neural network proposed in this work provide an excellent indication that ECG possesses intrinsic information that can indicate the level of blood glucose concentration.

1 July 2020 in IEEE Transactions on Biometrics, Behavior, and Identity Science
Verified
Journal Article
Closed access
Nima KarimianNima Karimian
Nima Karimian
DWDamon Woodard
Damon Woodard
DFDomenic Forte
Domenic Forte
The increased need for access control has motivated a widespread deployment of biometric systems in the last few years. However, recent works indicate that some modalities are fragile and more susceptible to malicious presentation attacks. This has in turn led to the exploration of alternative modalities such as electrocardiogram (ECG) due to its individualized and ubiquitous nature, difficulty in copying, stealing, and/or spoofing, and well-studied acquisition and analysis in the medical domain. In this study, we show that it is indeed possible to exploit previously captured ECG signals. First, we develop a novel “cross-subject attack where a short template of the victim’s ECG captured by an attacker is used to map the attacker’s ECG into the victim’s. Second, we explore “cross-device attacks” where mapping functions are used to replay ECGs collected on a device other than the victim’s device. Third, we explore countermeasures that utilize ECG signal characteristics such as heart rate variability and PPG signal to detect and reject fake samples. Simulation experiments are carried out using two freely available ECG databases under popular fiducial and non-fiducial features. Our proposed cross-device attack framework achieves 45% improvement in success rate compared with the previous state-of-the-art. Moreover, the attack success rate is degraded by 100% when our proposed countermeasure is employed.

12 April 2019 in IEEE Access
Verified
Journal Article
Open access
Nima KarimianNima Karimian
Nima Karimian
MTMark Tehranipoor
Mark Tehranipoor
DWDamon Woodard
Damon Woodard
DFDomenic Forte
Domenic Forte
With the emergence of the Internet-of-Things, there is a growing need for access control and data protection on low-power, pervasive devices. Key-based biometric cryptosystems are promising for IoT due to its convenient nature and lower susceptibility to attacks. However, the costs associated with biometric processing and template protection are nontrivial for smart cards, and so forth. In this paper, we discuss the cost versus the utility of biometric systems and investigate frameworks for improving them. We propose the noise-aware biometric quantization framework (NA-IOMBA) capable of generating unique, reliable, and high entropy keys with low enrollment times and costs with several experiments. First, we compare its performance with IOMBA and one-class-SVM on multiple biometric modalities, including popular ones (fingerprint and iris) and emerging cardiovascular ones (ECG and PPG). The results show that NA-IOMBA outperforms them all and that ECG provides the best trade-off between reliability, key length, entropy, and implementation cost. Second, we examine the impact on key reliability with ECGs obtained at different sessions and trained with a different number of heartbeats. Finally, implementation results show that incorporating noise models with NA-IOMBA reduces power and utilization overhead by more than 60% by adapting the pre-processing, feature extraction, and post-processing modules.

8 January 2025 in IEEE Access
Verified
Journal Article
Open access
PBP. Banerjee
P. Banerjee
ASAnurag Srivastava
Anurag Srivastava
Donald AdjerohDonald Adjeroh
Donald Adjeroh
RRRamana Reddy
Ramana Reddy
Nima KarimianNima Karimian
Nima Karimian
Large Language Models (LLMs) like ChatGPT have become the most popular regenerative AI applications, used for obtaining responses for queries in different domains. The responses of ChatGPT are already becoming mainstream and are challenging conventional methods of learning. This article focuses on the application of ChatGPT for academic instructional purposes in the field of computer engineering and related majors. The capability of ChatGPT for instructional purposes is evaluated based on the responses to different questions about these engineering streams. This article explores different opportunities (with use cases), that ChatGPT can provide in augmenting the learning experience. It also provides scenarios of limitations and modifying the evaluation process to prevent the use of ChatGPT, which may lead to an inaccurate dissemination of accepted facts. In this paper, common classroom problems and their respective responses from ChatGPT in the domains of Computer Science, Cyber Security, Data Science, and Electrical Engineering are analyzed to determine the categories of queries for which ChatGPT offers reliable responses and those for which it may be factually incorrect. A student survey is performed to demonstrate that students must be made aware that ChatGPT may not be suitable for certain types of queries and means of upgrading the evaluation process.

19 October 2020 in IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Verified
Journal Article
Closed access
RCRenato Cordeiro
Renato Cordeiro
DGDhruv Gajaria
Dhruv Gajaria
ALAnkur Limaye
Ankur Limaye
TATosiron Adegbija
Tosiron Adegbija
Nima KarimianNima Karimian
Nima Karimian
FTFatemeh Tehranipoor
Fatemeh Tehranipoor
Electrocardiogram (ECG) biometric authentication (EBA) is a promising approach for human identification, particularly in consumer devices, due to the individualized, ubiquitous, and easily identifiable nature of ECG signals. Thus, computing architectures for EBA must be accurate, fast, energy efficient, and secure. In this article, first, we implement an EBA algorithm to achieve 100% accuracy in user authentication. Thereafter, we extensively analyze the algorithm to show the distinct variance in execution requirements and reveal the latency bottleneck across the algorithm’s different steps. Based on our analysis, we propose a domain-specific architecture (DSA) to satisfy the execution requirements of the algorithm’s different steps and minimize the latency bottleneck. We explore different variations of the DSA, including one that features the added benefit of ensuring constant timing across the different EBA steps, in order to mitigate the vulnerability to timing-based side-channel attacks. Our DSA improves the latency compared to a base ARM-based processor by up to $4.24\times $ , while the constant timing DSA improves the latency by up to 19%. Also, our DSA improves the energy by up to $5.59\times $ , as compared to the base processor.