Iosif Polenakis

Post-doctoral Researcher, Department of Computer Science & Engineering - University of Ioannina

Born in Athens in 1990, in 2006 me and my family moved to Ioannina where I graduated from the 3rd (Epifaneios) High School in 2008. In 2012 I obtained my B.Sc in Informatics from the Department of Informatics of the Ionian University . In 2014 I received my M.Sc in Theoretical Computer Science from the Department of Computer Science and Engineering, of the University of Ioannina. In 2019 I obtained my Ph.D. on "Algorithmic Techniques for Digital Object Detection and Classification" from the same department under the supervision of Professor Stavros D. Nikolopoulos.

I have served as adjunct lecturer (academic scholar) [full-courses: "Advanced Web Technologies", "e-Commerce" and lab-courses: "Databases I", "Databases II", "Operating Systems" in the Department of Informatics and Telecommunications of the University of Ioannina (Arta) and currently, under the program "Acquisition of Academic Teaching Experience" I teach the courses "Graph Theory" and "Discrete Mathematics I" in the Department of Computer Science and Engineering of the University of Ioannina, continuing as laboratory teaching-assistant in the course "Design and Analysis of Algorithms".

My research interests mainly focus in Computer Security and more precisely in the field of graph-theoretic apporaches applied for the detection and classification of malicious software. Since 2019, I work a post-doctoral researcher in the Algorithms Engineering Laboratory on the research filed of behavioral malware detection and classification through graph-based techniques.

For additional information you can download my CV here or: (CV in Greek).




Education

Dept. of Computer Science and Engineering, University of Ioannina

Ph.D. in Computer Science
Algorithmic Techniques for the Detection and Classification of Digital Objects (Suprevisor: Prof. Stavros D. Nikolopoulos)
December 2014 - June 2019

Dept. of Computer Science and Engineering, University of Ioannina

M.Sc in Theoretical Computer Science
Algorithmic Techniques for Malicious Software Detection and Classification based on System-call Dependency Graphs (Suprevisor: Prof. Stavros D. Nikolopoulos)

GPA: 9.15/10

October 2012 - June 2014

Dept. of Informatics, Ionian University

B.Sc in Informatics
Experimental Research on New Generation Malware Spread - Specialization Field: Information Systems (Suprevisor: Assoc. Prof. Emmanouil (Manos) V. Magkos)

GPA: 8.78/10

October 2008 - September 2012

Research Projects

A graph-based model for malware detection and classification using system-call groups

AlgoLab - Dept. of Computer Science and Engineering UoI

The projects focuses on the developmenta graph-based model that, utilizing relations between groups of System-calls, detects whether an unknown software sample is malicious or benign, and classifies a malicious software to one of a set of known malware families. More precisely, we utilize the System-call Dependency Graphs (or, for short, ScD-graphs), obtained by traces captured through dynamic taint analysis. We design our model to be resistant against strong mutations applying our detection and classification techniques on a weighted directed graph, namely Group Relation Graph, or Gr-graph for short, resulting from ScD-graph after grouping disjoint subsets of its vertices. For the detection process, we propose the \Delta -similarity metric, and for the process of classification, we propose the SaMe-similarity and NP-similarity metrics consisting the SaMe-NP similarity. Finally, we evaluate our model for malware detection and classification showing its potentials against malicious software measuring its detection rates and classification accuracy.

February 2013 - Present

Preventing malware pandemics in mobile devices by establishing response-time bounds

AlgoLab - Dept. of Computer Science and Engineering UoI

The spread of malicious software among computing devices nowadays poses a major threat to the systems security. Since both the use of mobile devices and the growth of malware propagation increase rapidly, this project focuses in investigating how the time needed by a counter-measure (i.e., an antivirus or a cleaner) to detect and remove a malware from infected devices affects the malware propagation. In this work, we study the effect of counter-measure response-time on the propagation of a malicious software and propose a model for establishing reasonable response-time bounds for its activation in order to prevent pandemic. More precisely, given an initial infected population in a network of mobile devices nd a specific city area (town planning), our model establishes upper response-time bounds for a counter-measure which guarantee that, within a period of time, not all the susceptible devices in the city get infected and the infected ones get sanitized. To this end, we first propose a malware propagation model along with a device mobility model, and then we develop a simulator utilizing these models in order to study the spread of malware in such networks. Finally, we present experimental results for the pandemic prevention taken by our simulator for various response-time intervals and other factors that affect the spread deploying different epidemic models.

June 2016 - Present

Malicious Software Detection and Classification utilizing Temporal Graphs of Discrete and Cummulative Modification

AlgoLab - Dept. of Computer Science and Engineering UoI

This project focuses on the development of a graph-based model that, utilizing relations between groups of System-calls, distinguishes malicious from benign software samples utilizing a behavioral graph representing their interaction with the operating system. More precisely, given a System-call Dependency Graph (ScDG) that depicts the malware's behavior, we first transform it to a more abstract representation, utilizing the indexing of System-calls to a set of groups of similar functionality, constructing thus a mutation tolerant graph that we call Group Relation Graph (GrG); we pointed out that behavior-based graph representations had not leveraged the aspect of the temporal evolution of the graph. Hence, the novelty of our work is that, preserving the initial representations of GrG graphs, we focus on augmenting the potentials of theses graphs by adding further features that enhance its detection abilities. To that end, we construct periodical instances of the graph that represent its temporal evolution concerning its structural modifications, creating another graph representation that we call Temporal Graphs. In this paper, we present the theoretical background behind our approach, and demonstrate the overall architecture of our proposed detection model alongside with its underlying main principles and its structural key-components.

July 2018 - Present

An Algorithmic Framework for Malicious Software Detection Exploring Structural Characteristics of Behavioral Graphs

AlgoLab - Dept. of Computer Science and Engineering UoI

Through this project there has been obtained the development of an algorithmic framework for the behavioral detection of malicious software utilizing a set of measurements to explore the structural characteristics of behavioral graphs. We first present the construction of the Group Relation Graphs produced by a specific type of behavioral graphs, the so called System-call Dependency Graphs obtained through taint-analysis after the execution of a malicious sample. Then, we discuss the utilization of a set of measurements applied to compute the structural characteristics of Group Relation Graphs, namely the application of the Page Rank algorithm on such graphs and the Betweeness Centrality on the vertices of the graph. We present the architecture of our proposed framework and how we deploy the computation of similarity metrics in order to measure the closeness between such characteristics exhibited among malicious and benign samples in order to perform the malware detection process. Finally, we proceed to a series of experiments in order to evaluate through five-fold cross validation the detection ability of our proposed model and prove its potentials against a set of System-call Dependency Graphs to distinguishing malicious from benign software samples.

September 2019 - Present


SARiSsa - A Mobile Application for the Proactive Control of SARS-CoV-2 Spread

AlgoLab - Dept. of Computer Science and Engineering UoI

Through this project we propose the design principles behind the development of a smart application utilized by mobile devices in order to control the spread of SARS-CoV-2 coronavirus disease that caused the COVID-19 pandemic. Through the deployment of this application utilizing their Bluetooth enabled devices, individuals may keep track of their close contacts, and if nearby contacts using the same application are reported later as infected the proximate individual is informed in order to be quarantined for a short of time, preventing hence the spread of the virus. Through the latest year, there have been developed several applications in the Google Play Store that can be deployed by smart devices utilizing their Bluetooth connectivity for the nearby device tracking. However, in this work we propose an open architecture for the development of such applications, that also incorporates a more elaborated graph-theoretic and algorithmic background regarding the contact tracing. The proposed contact tracing algorithm, that can be embedded in the deployment of the application, provides a more immediate tracking of the contacts of an infected individuals, providing a wider extent in the tracing of the contacts, leading hence to a more immediate mitigation of the epidemic.

September 2020 - Present


ParaGraph: A Graph-based Model for Text Indexing utilizing Synonym-Class Relations produced through Text Paraphrasing

AlgoLab - Dept. of Computer Science and Engineering UoI

This is a comprehensive study of the algorithmic techniques of text indexing based on the utilization of classes of synonyms. The methods presented, utilize a set of synonym classes to develop a more abstract representation of any given text focusing on the indexing of texts that express semantic similarity, according to the terms utilized, while also trying to improve the mentioned similarity. The content of the texts under consideration is represented by a set of terms that correspond to the class of synonyms substituting each term of the sentences of the text. In the proposed approaches the terms are either stored into vectors where the uniqueness or the multiplicity of their appearance inside the text are considered to deploy a corresponding similarity metric or being used in the context of an adjacency matrix where the uniqueness or the multiplicity of their appearance are considered not only inside the text but within the sentence as well, while still deploying the corresponding similarity metric. Through the development of our model, we omit words that consist of monograms, di-grams and tri-grams, where a novel approach is deployed considering the optimally discriminating words over each class of synonyms that characterize each thematic area on which a text is indexed according to its relevance with semantically similar texts.

September 2021 - Present


Digital Object Watermarking and Information Hiding

AlgoLab - Dept. of Computer Science and Engineering UoI

Through this project we investigate novel watermarking schemes based on the repetitive application of watermarks inside a digital image. The approach proposed in this work focuses mainly on securing the watermarked image against crop attacks and compression attacks that constitute the most important attacks through the attack vectors. Our approach provides a significant improvement over the computational cost required for the embed procedure of the watermark inside a digital image, achieving an adequately imperceptible and robust watermarking technique.

October 2021 - Present

Publications


Courses

Discrete Mathematics (slides in Greek)

Dept. of Computer Science & Engineering, University of Ioannina, Ioannina

Introduction to mathematical logic: Propositional logic, semantic approach. Propositional calculus and formal proofs, syntactic approach. Proof techniques: Reverse inversion, abduction, mathematical induction. Sets, relationships, functions: Operations and properties of set operations, inclusion-exclusion, functions 1-1, on, equivalence relations, order relations, extremes and barriers, asymptotic behavior of functions. Countability: Perched / infinite sets, dovecote beginning, Russell paradox, Cantor competition. Combinatorics: Sum / product rules, layouts and permutations, beads in boxes, non-ordered collection options with / without repetition. Discrete probability: Discrete sample space, fact, condition probability, Bayes rule, expected value of a variable.

1) Propositional Logic
2) Formal Proofs
3) Induction
4) Sets
5) Boolean Algebra
6) Relations and Functions
7) Sets and Countability
8) Combinatorics
9) Discrete Probability
February 2020 - June 2020


Graph Theory

Dept. of Computer Science & Engineering, University of Ioannina, Ioannina

The course covers the basic concepts and definitions related to classical writing theory problems. The course also covers a number of applications whose graph modeling is known to lead to an effective solution. The course material studies the following topics: Introduction and basic definitions Graphic illustrations and graph isomorphism Trees - special properties and applications Connectivity, Euler routes and Hamiltonian circles Overlays and matches Clicks and independent sets Node coloring and edge coloring Guided graphs and applications Flat charts and networks General applications.

1) Introduction to Graph Theory (A)
2) Introduction to Graph Theory (B)
3) Paths and Cycles
4) Trees
5) Connectivity
6) Planarity
7) Coloring
8) Perfect Graphs
9) Directed Graphs
October 2019 - February 2020

e-Commerce

Dept. of Informatics & Telecommunication, University of Ioannina, Arta

E-commerce (electronic commerce) is the activity of electronically buying or selling of products on online services or over the Internet. Electronic commerce draws on technologies such as mobile commerce, electronic funds transfer, supply chain management, Internet marketing, online transaction processing, electronic data interchange (EDI), inventory management systems, and automated data collection systems. E-commerce is in turn driven by the technological advances of the semiconductor industry, and is the largest sector of the electronics industry. Modern electronic commerce typically uses the World Wide Web for at least one part of the transaction's life cycle although it may also use other technologies such as e-mail. Typical e-commerce transactions include the purchase of online books (such as Amazon) and music purchases , and to a less extent, customized/personalized online liquor store inventory services. There are three areas of e-commerce: online retailing, electronic markets, and online auctions. E-commerce is supported by electronic business. This course mainly focuses to explain and deeply integrate the main corpus of the technologies applied in e-commenrse with the adoption of web-app technologies in order to be in place to develop a primarly form of an electronic shop consisted by the adequate procedures demanded for its operation.

1) Introduction
2) Developing e-Commerce Web Apps with PHP & MySQL
3) Field Study
4) e-Tailing and e-Retailing
5) osCommerce V2.3
February 2019 - June 2019

Web-app Technologies

Dept. of Informatics & Telecommunication, University of Ioannina, Arta

The aim of the course is for students after the end to be able to: Understand the operation and development of web-based applications in using the HTTP protocol. To develop web applications with dynamic web creation and access data to databases using Java technologies (JSP, JDBC) or PhP To distinguish server technologies from client technologies and related their advantages. The primary purpose of the course is to acquaint students with the most common technologies applied on the Internet, while at a second but equally important level, if the theoretical background is understood, the use of these technologies by connecting what they have learned to develop throughout the semester a complete internet system. The aim of the laboratory part of the course is to apply the knowledge gained by the students by attending the lecture towards the development of integrated internet systems and the further bridging of the gap with the labor market. This methodology is estimated to contribute on the one hand to the completion of students' knowledge (including knowledge acquired from previous courses) to the development of a system that will combine much of what has been taught before, and on the other hand will provide them with a direct coupling with environments and situations that may be challenged in the job market and which they should be able to manage (eg design failures or implementation errors at an early stage, changes in requirements, etc.), offering students the opportunity (in a protected environment) to deal with the full development of a complete web system. Finally, it is worth noting that the use of Content Management Systems ( CMS) is severely discouraged as, despite being a widely used assistive technology in the development of online services, they deprive students of the opportunity to practice and improve their programming skills, providing them with a a very specific work environment that limits both their technical skills and the range of their personal choices, features that are of major importance to a developer.

1) Introduction
2) HTML and JavaScript
3) PHP and MySQL
4) XML and JSON
5) AJAX
October 2018 - February 2019

Interests

My research interests mainly focus on:

- Epidemic Models for Pandemic Prevention;
- Detection and Classification of Malicious Software;
- Behavioral Analysis of Malicious Software;
- Trusted Computing Systems;
- Cryptography


Apart from being computer "scientist" or a hatching academic, I enjoy most of my time playing music guitar/bass and learning drums or recording with my band (SonorousValley). When forced indoors, I mostly prefer to catch up recent trends and get updated on my other passion, i.e., mechanics and engineering or wasting my minimal free time experimenting on my own ad-hoc cooking recipes or watching documentaries on the spread of biological viruses or relative (apocalypse) movies regarding the aspects of an outbreak.



Contact

    For additional information you can contact me through:
  • ipolenakis@uoi.gr or ipolenak@cs.uoi.gr
  • or use the following form


  • (30) 26510-08831 - Office G5 [AlgoLab] or (30) 26510-08919 - Office A8

  • (30) 690 66 29 328 [Mob. - for special cases only!]

  • University of Ioannina - Department of Computer Science & Engineering - 1st Floor, Office A8