Yongho Ko

Mr. Yongho Ko


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

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

Representative Publications

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18 April 2017 in Sustainability
Verified
Journal Article
Open access
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YKYongho Ko
Yongho Ko
SHSeungwoo Han
Seungwoo Han
Precise and accurate prediction models for duration and cost enable contractors to improve their decision making for effective resource management in terms of sustainability in construction. Previous studies have been limited to cost-based estimations, but this study focuses on a material-based progress management method. Cost-based estimations typically used in construction, such as the earned value method, rely on comparing the planned budget with the actual cost. However, accurately planning budgets requires analysis of many factors, such as the financial status of the sectors involved. Furthermore, there is a higher possibility of changes in the budget than in the total amount of material used during construction, which is deduced from the quantity take-off from drawings and specifications. Accordingly, this study proposes a material-based progress management methodology, which was developed using different predictive analysis models (regression, neural network, and auto-regressive moving average) as well as datasets on material and labor, which can be extracted from daily work reports from contractors. A case study on actual datasets was conducted, and the results show that the proposed methodology can be efficiently used for progress management in construction.

29 November 2023 in Sensors
Verified
Journal Article
Open access
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HPHoonyong Park
Hoonyong Park
PAPhilip Virgil Berrer Astillo
Philip Virgil Berrer Astillo
YKYongho Ko
Yongho Ko
YPYeongshin Park
Yeongshin Park
TKTaeGuen Kim
TaeGuen Kim
IYIlsun You
Ilsun You
The advancement of cellular communication technology has profoundly transformed human life. People can now watch high-definition videos anytime, anywhere, and aim for the implementation of advanced autonomous driving capabilities. However, the sustainability of such an environment is threatened by false base stations. False base stations execute attacks in the Radio Access Network (RAN) of cellular systems, adversely affecting the network or its users. To address this challenge, we propose a behavior rule specification-based false base station detection system, SMDFbs. We derive behavior rules from the normal operations of base stations and convert these rules into a state machine. Based on this state machine, we detect network anomalies and mitigate threats. We conducted experiments detecting false base stations in a 5G RAN simulator, comparing our system with seven machine learning-based detection techniques. The experimental results showed that our proposed system achieved a detection accuracy of 98% and demonstrated lower overhead compared to other algorithms.

30 March 2026 in IEEE Internet of Things Journal
Verified
Journal Article
Closed access
YKYongho Ko
Yongho Ko
IPI. Wayan Adi Juliawan Pawana
I. Wayan Adi Juliawan Pawana
HKHoseok Kwon
Hoseok Kwon
SSSeonghan Shin
Seonghan Shin
Jongkil KimJongkil Kim
Jongkil Kim
IYIlsun You
Ilsun You
5G serves as a catalyst for transformative digital innovation by enabling convergence with various services in our daily lives. The success of this paradigm shift undeniably hinges on robust security measures, with primary authentication—securing access to the 5G network—being paramount. Two protocols, 5G authentication and key agreement (5G-AKA) and the extensible authentication protocol for authentication and key-agreement prime (EAP-AKA’), have been standardized for this purpose, with the former designed for third generation partnership project (3GPP) devices and the latter for non-3GPP devices. However, recent studies have exposed vulnerabilities in the 5G-AKA protocol, rendering it susceptible to security breaches, including linkability attacks. Furthermore, the advent of quantum computing poses significant quantum threats, underscoring the urgent need for the adoption of quantum-resistant cryptographic mechanisms. Although postquantum cryptography (PQC) is being standardized, the lack of real-world deployment limits its proven robustness. In contrast, conventional cryptographic schemes have demonstrated reliability over decades of practical application. To address this gap, the Internet Engineering Task Force (IETF) has initiated the standardization of hybrid PQC algorithms (HPQC), combining classical and quantum-resistant techniques. Consequently, ensuring forward secrecy and resilience to quantum threats in the 5G-AKA protocol is critical. To address these security challenges, we propose the 5G-AKA-HPQC protocol. Our protocol is designed to maintain compatibility with existing standards while enhancing security by combining keys negotiated via the Elliptic Curve Integrated Encryption Scheme (ECIES) with those derived from a PQC-Key encapsulation mechanism (KEM). To rigorously and comprehensively validate the security of 5G-AKA-HPQC, we employ formal verification tools such as SVO Logic and ProVerif. The results confirm the protocol’s security and correctness. Furthermore, performance evaluations highlight the computational and communication overheads inherent to 5G-AKA-HPQC. With an average of 56.5 ms (+112.32%) on a total authentication time, the proposed protocol provides its advantages. Also, on a environment of multiple UE registration, compared to single UE registration, the difference in the increased rate of average authentication time is only 0.01%. The negligible difference of 0.01% indicates that the addition of PQC does not lead to increased overhead in multi-UE registration environments, demonstrating its scalability and practical feasibility. In conclusion, our research provides significant insights into the design of secure, quantum-safe authentication protocols and lays the groundwork for the future standardization of secure authentication and key-agreement protocols for mobile telecommunications.

13 December 2024 in Sensors
Verified
Journal Article
Open access
PDF file
YKYongho Ko
Yongho Ko
IPI Wayan Adi Juliawan Pawana
I Wayan Adi Juliawan Pawana
IYIlsun You
Ilsun You
The 5G-AKA protocol, a foundational component for 5G network authentication, has been found vulnerable to various security threats, including linkability attacks that compromise user privacy. To address these vulnerabilities, we previously proposed the 5G-AKA-Forward Secrecy (5G-AKA-FS) protocol, which introduces an ephemeral key pair within the home network (HN) to support forward secrecy and prevent linkability attacks. However, a re-evaluation uncovered minor errors in the initial BAN-logic verification and highlighted the need for more rigorous security validation using formal methods. In this paper, we correct the BAN-logic verification and advance the formal security analysis by applying an extended SVO logic, which was adopted as it provides a higher level of verification compared to BAN logic, incorporating a new axiom specifically for forward secrecy. Additionally, we enhance the ProVerif analysis by employing a stronger adversarial model. These refinements in formal verification validate the security and reliability of 5G-AKA-FS, ensuring its resilience against advanced attacks. Our findings offer a comprehensive reference for future security protocol verification in 5G networks

4 October 2025 in Sensors
Verified
Journal Article
Open access
PDF file
JLJhury Kevin Lastre
Jhury Kevin Lastre
YKYongho Ko
Yongho Ko
HKHoseok Kwon
Hoseok Kwon
IYIlsun You
Ilsun You
Cross-border Fifth Generation Mobile Communication (5G) roaming requires secure N32 connections between network operators via Security Edge Protection Proxy (SEPP) interfaces, but current Transport Layer Security (TLS) 1.3 implementations face a critical trade-off between connection latency and security guarantees. Standard TLS 1.3 optimization modes either compromise Perfect Forward Secrecy (PFS) or suffer from replay vulnerabilities, while full handshakes impose excessive latency penalties for time-sensitive roaming services. This research introduces Zero Round Trip Time Forward Secrecy (0-RTT FS), a novel protocol extension that achieves zero round-trip performance while maintaining comprehensive security properties, including PFS and replay protection. Our solution addresses the fundamental limitation where existing TLS 1.3 optimizations sacrifice security for performance in international roaming scenarios. Through formal verification using ProVerif and comprehensive performance evaluation, we demonstrate that 0-RTT FS delivers 195.0 μs handshake latency (only 17% overhead compared to insecure 0-RTT) while providing full security guarantees that standard modes cannot achieve. Security analysis reveals critical replay vulnerabilities in all existing standard TLS 1.3 optimization modes, which our proposed approach successfully mitigates. The research provides operators with a decision framework for configuring sub-millisecond secure handshakes in next-generation roaming services, enabling both optimal performance and robust security for global 5G connectivity.

24 October 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
IYIlsun You
Ilsun You
JKJiyoon Kim
Jiyoon Kim
IPI Wayan Adi Juliawan Pawana
I Wayan Adi Juliawan Pawana
YKYongho Ko
Yongho Ko
The rapid evolution of mobile and optical communication technologies is driving the transition from 5G to 6G networks. This transition inevitably brings about changes in authentication scenarios, as new security demands emerge that go beyond the capabilities of existing frameworks. Therefore, it is necessary to address these evolving requirements and the associated key challenges: ensuring Perfect Forward Secrecy (PFS) to protect communications even if long-term keys are compromised and integrating Post-Quantum Cryptography (PQC) techniques to defend against the threats posed by quantum computing. These are essential for both radio and optical communications, which are foundational elements of future 6G infrastructures. The DMRN Protocol, introduced in 2022, represents a major advancement by offering both PFS and PQC while maintaining compatibility with existing 3rd Generation Partnership Project (3GPP) standards. Given the looming quantum-era challenges, it is imperative to analyze the protocol’s security architecture through formal verification. Accordingly, we formally analyze the DMRN Protocol using SVO logic and ProVerif to assess its effectiveness in mitigating attack vectors, such as malicious or compromised serving networks (SNs) and home network (HN) masquerading. Our research found that the DMRN Protocol has vulnerabilities in key areas such as mutual authentication and key exchange. In light of these findings, our study provides critical insights into the design of secure and quantum-safe authentication protocols for the transition to 6G networks. Furthermore, by identifying the vulnerabilities in and discussing countermeasures to address the DMRN Protocol, this study lays the groundwork for the future standardization of secure 6G Authentication and Key Agreement protocols.