INTERNET SECURITY

Academic Year 2026/2027 - Teacher: MICHELE GIUSEPPE MALGERI

Expected Learning Outcomes

The course aims to provide students with a solid understanding of the principles and technologies underlying modern information security. The first part covers the theoretical foundations of information security, with particular emphasis on cryptographic mechanisms and their use in ensuring the confidentiality, integrity, authenticity, and non-repudiation of data. The second part focuses on the protocols, architectures, and mechanisms used to secure communication networks, while also providing an overview of the main cybersecurity challenges affecting various application domains, including distributed systems, web services, cloud infrastructures, and the Internet of Things.

Knowledge and Understanding Abilities:

Knowledge of the theoretical foundations and practical aspects of network security.
Understanding of the principles of cryptography and currently used ciphers.
Knowledge of the most important security protocols.
Familiarity with the technologies and algorithms for creating key network security services.
Understanding of the principles of secure application design.

Applying Knowledge and Understanding Abilities:

Ability to correctly configure security services such as authentication systems, privacy management, and local network management.

Ability of Making Judgments:

The student is capable of independently assessing risks and choosing from state-of-the-art technologies.

Communication Skills

The student can effectively communicate technical and theoretical aspects related to computer security.

Learning skill

Students learn to critically assess threats and vulnerabilities in information systems, as well as defense strategies and security protocols.

Course Structure

The primary teaching method is classroom-based lectures (5 ECTS credits, corresponding to approximately 45 hours). Class discussions on topics of interest are regularly organized, and selected issues are explored in greater depth through simulation activities, including group work exercises (1 ECTS credit, corresponding to approximately 15 hours).

In the event that the course is delivered in a blended or distance learning mode, necessary adjustments may be introduced compared to what was previously stated, in order to adhere to the planned program as indicated in the syllabus."

Required Prerequisites

Required

Knowledge and understanding of Network Protocols (TCP/IP):

Important

Basic Knowledge of Programming Languages
Fundamental understanding of operating systems.

Attendance of Lessons

Not mandatory but highly recommended.

Detailed Course Content

Cryptography

Fundamental Terminology and Concepts: Algorithms, Kerckhoff's Principle, Parameters and Robustness of a Encryption Algorithm, Cipher Vulnerability. Secure Cryptographic Systems. Diffusion and Confusion Principle. Codes, Alphabet Representation.
Overview of Classic Encryption Techniques: Monoalphabetic Techniques, OTP (Complexity Study, Robustness, Limits, Cryptanalysis); Polyalphabetic Techniques: Vigenere, Cryptanalysis; Transposition Techniques: Rail Fence, Columnar Transposition; Rotation Machines: Enigma, Construction Details, Operation Mechanism, Key Space Calculation.
Block Cipher: General Characteristics. Concept of Product Cipher. Feistel Cipher. DES, Double DES, and Triple DES Cipher, General Characteristics. Motivation, Operation, Robustness, F Function and S-Box Design. SAC and BIC Criteria. Key Generation. Cryptanalysis: Known Weak Elements, Keys, Complementation, Differential, Linear. AES, Criteria for Selection, General Characteristics, Operation, Robustness, Finite Field of Galois Overview.
Chaining Techniques for Block Ciphers: ECB, CBC, FCB, OFB, CTR (Details of Operation, Weaknesses and Strengths of Each Technique).
Stream Cipher: Structure of Stream Cipher, RC4 Cipher.
Key Distribution: Key Distribution Techniques, Secrecy Issues, Duration.
Public Key Algorithms: Diffie-Hellman Protocol. Public Key Cryptography Requirements. RSA.

Basic Mechanisms:

Message Authentication Code, Hashing. Hashing Algorithms, SHA, MD5.
Digital Signature.
Certificates, X.509, Revocation Management (OCSP), Public Key Infrastructure.
Authentication: Passwords, Salt, Criteria, OTP Systems. Kerberos (Operation, Distribution Problems, Possible Attacks).
PGP, History, Algorithms, Certificates, Trust Management.

Networks and Firewalls

Classification, and Main firewall Topologies.
IPSec, Architecture, AH and ESP, Key Management.
SSL, Protocols, Architecture, Transport Layer Security.
SSH, Features and Usage, Protocol, Handshaking, Authentication Types.
Email, Email Issues, S/MIME, Certified Email.

Overview of Risk Analysis Techniques, Cost-effectiveness.

Topics marked with (*) represent the minimum skill to pass the exam.

Textbook Information

Cryptography and Network Security, (minimum 5/Edition)
William Stallings
Publisher: Prentice Hall

Course Planning

	Subjects	Text References
1	"Insecurity Factors, Attack Techniques, Types, and Classification of the 'Availability' Problem." (4 hours)	textbook
2	"Cryptography: Classic Monoalphabetic Ciphers (Caesar, Playfair, Hill, One-Time Pad), Polyalphabetic Ciphers (Vigenere), Enigma Machine (Historical Overview and Operation), Transposition Ciphers, Cryptanalysis." (8 hours)	textbook
3	"Cryptography: Block Ciphers (DES and its derivatives 2-DES and 3-DES, AES). Chaining Techniques." (8 hours)	textbook
4	"Cryptography: Asymmetric Ciphers. Diffie-Hellman, RSA, ElGamal." (8 hours)	textbook
5	"Mechanisms: Random Number Generation, Message Authentication Code, Hash Functions and Algorithms (SHA, Whirlpool), Digital Signature, Certificates and their Management (PGP, X509)." Autentication (10 hours)	textbook
6	"Protocols and Standards: IPSec, SSL, SSH, *S/10 MIME, Certified Email." (10 hours)	textbook
7	"Firewall, Characteristics, Classification, Example Configuration." (4 hours)	textbook

Learning Assessment

Learning Assessment Procedures

The examination consists of an oral assessment and covers all the topics listed in this syllabus. To pass the examination with the minimum passing grade, students are required to demonstrate knowledge of all topics marked with (*) in the course description.

Should the course be delivered in a blended or fully online format, any necessary adjustments to the assessment procedures may be introduced in order to ensure compliance with the syllabus and the planned course content. Consequently, the examination may also be conducted remotely.

Examples of frequently asked questions and / or exercises

Struttura e funzionamento del cifrario DES
Struttura e funzionamento del cifrario AES
Struttura e funzionamento del cifrario RSA
Struttura e funzionamento del protocollo Diffie-Hellman
Descrizione della fase di handshake del protocollo TLS
Struttura delle PDU del protocollo IPSec
Meccanismo di funzionamenti della posta sicura
Descrizione delle diverse tipologie di Firewall
Valutazione della complessità dell'attacco meet in the middle
Descrizione di Kerberos

Degree Course in

Communications Engineering