Anastasios Bikos

Mr. Anastasios Bikos

Department of Computer Engineering and Informatics, University of Patras, Pátrai, Greece
orcid
Senior Researcher | BSc, MA, MSc, PhD

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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22 October 2012 in IEEE Security & Privacy
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Journal Article
Closed access
Anastasios BikosAnastasios Bikos
Anastasios Bikos
Nicolas SklavosNicolas Sklavos
Nicolas Sklavos
The authors give an overview on the state of the art of potential security issues that occur in the deployment of the LTE/SAE (Long-Term Evolution/System Architecture Evolution) protocol in emerging 4G wireless technologies. Although security concerns and challenges in wireless networks will remain a hot topic in the future, the LTE/SAE standard could adapt to these rising challenges, becoming more robust and secure. By looking at the authentication and ciphering algorithms, such as EAP-AKA (Extensible Authentication Protocol for Authentication and Key Agreement), currently operating within the LTE protocol, the authors analyze several vulnerabilities in LTE/SAE security architecture - specifically, insecure AKA key derivation procedures and the lack of fast reauthentications during handovers.

30 October 2023 in Cryptography
Verified
Journal Article
Open access
PDF file
Anastasios BikosAnastasios Bikos
Anastasios Bikos
PNPanagiotis E. Nastou
Panagiotis E. Nastou
GPGeorgios Petroudis
Georgios Petroudis
YSYannis Stamatiou
Yannis Stamatiou
In this paper, we present approaches to generating random numbers, along with potential applications. Rather than trying to provide extensive coverage of several techniques or algorithms that have appeared in the scientific literature, we focus on some representative approaches, presenting their workings and properties in detail. Our goal is to delineate their strengths and weaknesses, as well as their potential application domains, so that the reader can judge what would be the best approach for the application at hand, possibly a combination of the available approaches. For instance, a physical source of randomness can be used for the initial seed; then, suitable preprocessing can enhance its randomness; then, the output of preprocessing can feed different types of generators, e.g., a linear congruential generator, a cryptographically secure one and one based on the combination of one-way hash functions and shared key cryptoalgorithms in various modes of operation. Then, if desired, the outputs of the different generators can be combined, giving the final random sequence. Moreover, we present a set of practical randomness tests that can be applied to the outputs of random number generators in order to assess their randomness characteristics. In order to demonstrate the importance of unpredictable random sequences, we present an application of cryptographically secure generators in domains where unpredictability is one of the major requirements, i.e., eLotteries and cryptographic key generation.

21 April 2022 in IEEE Access
Verified
Journal Article
Open access
Anastasios BikosAnastasios Bikos
Anastasios Bikos
SKSathish A.P. Kumar
Sathish A.P. Kumar
With the faster maturity and stability of digitization, connectivity and edge technologies, the number of the Internet of Things (IoT) devices and sensors is flourishing fast in important junctions such as homes, hotels, hospitals, retail stores, manufacturing floors, railway stations, airports, oil wells, warehouses, etc. However, in this extremely connected world, the security implications for IoT devices are getting worse with the constant rise in malicious cyberattacks. The challenge is how to secure IoT sensors, services and data. The blockchain technology, a prominent distributed ledger technology (DLT), is being pronounced as the way forward for safeguarding IoT devices and data. The Directed Acyclic Graph (DAG)-based DLT has the inherent potential to realize the benefits of blockchain with better performance. IOTA is a DAG-based blockchain implementation for the IoT era. The Tangle, the IOTA’s network immutably records the exchange of data and value. It ensures that the information is trustworthy and cannot be tampered with nor destroyed. In this work, we depict a thorough analysis of the existing security studies for IOTA. Then, we identify the gaps and the limitations of these security solution schemes, and finally, propose future security research recommendations that can potentially fill these gaps to secure DLT-enabled IoT devices.

24 October 2016 in IEEE Transactions on Dependable and Secure Computing
Verified
Journal Article
Closed access
Anastasios BikosAnastasios Bikos
Anastasios Bikos
Nicolas SklavosNicolas Sklavos
Nicolas Sklavos
The whole security architecture of LTE/SAE (Long Term Evolution/System Architecture Evolution) is being consisted of four main hardware-oriented cryptographic algorithms: KASUMI block ciphers, SNOW-3G stream cipher, the MILENAGE algorithm set, and the 4G development of ZUC algorithm. This paper presents an FPGA deployment of a universal security architecture crypto processor for 4G LTE, consisting of both four ciphers enabling each one on demand, which is based on two novel design principles. One is a more intelligent implementation of the four algorithm's substitution boxes (S-boxes) based on a common intersection assumption of their contents. The second includes the use of a common data path hardware block deployed along the four cipher's architectural design. This universal security architecture crypto processor proves to reduce the area space at least 1.5 times, and also provides almost double throughput compared with the state-of-the-art realizations of the individual ciphers, something which is a high necessity when producing components for the demanding post-4G cellular market.

23 September 2014 in Journal of Optical Communications and Networking
Verified
Journal Article
Closed access
PDF file
KRKostas Ramantas
Kostas Ramantas
KVKyriakos Vlachos
Kyriakos Vlachos
Anastasios BikosAnastasios Bikos
Anastasios Bikos
GEGeorgios Ellinas
Georgios Ellinas
AHAntonis Hadjiantonis
Antonis Hadjiantonis
This work presents a new converged access architecture for LTE mobile backhaul networks. In the proposed architecture, evolved NodeBs (eNBs) are interconnected with local ring-based wavelength-division-multiplexed (WDM) passive optical networks (PONs), which aggregate and efficiently transport traffic to the evolved packet core (EPC). The proposed WDM-PON ring design supports a dynamic setup of virtual circuits for inter-base-station communication, over a dedicated λLAN channel. It also supports load balancing, by dynamically reallocating and sharing the capacity of the downstream wavelengths. The reservation mechanism is arbitrated by the optical line terminal, which monitors the traffic imbalances of downstream channels and orchestrates the setup of subwavelength “transient flows.”

14 September 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
Anastasios BikosAnastasios Bikos
Anastasios Bikos
PNPanagiotis E. Nastou
Panagiotis E. Nastou
GPGeorgios Petroudis
Georgios Petroudis
YSYannis Stamatiou
Yannis Stamatiou
This paper we present approaches for generating random numbers along with potential applications. Rather than trying to provide extensive coverage of several techniques or algorithms that have appeared in the scientific literature, we focus on some representative approaches presenting their workings and properties in detail. Our goal is to delineate their strengths and weaknesses as well as their potential application domains so as the reader can judge what would be the best approach for the application in hand, possibly a combination of the available approaches. For instance, a physical source of randomness can be used for the initial seed, then suitable preprocessing can enhance its randomness and then the output of the preprocessing can feed different types of generators, e.g. a linear congruential generator, a cryptographically secure one and one based on the combination of one way hash functions and shared key cryptoalgorithms in various modes of operation. Then, if desired, the outputs of the different generators can be combined giving the final random sequence. Moreover, we present a set of practical randomness tests which can be applied on the outputs of random number generators in order to assess their randomness characteristics. In order to demonstrate the importance of unpredictable random sequences, we present an application of cryptographically secure generators in domains where unpredictability is one of the major requirements, i.e. eLotteries and cryptographic key generation.