Network and Communications Security (IN3210/IN4210)
Introduction
Introduction
● Nils Gruschka− University Kiel (Diploma in Computer Science)
− T-Systems, Hamburg
− University Kiel (PhD in Computer Science)
− NEC Laboratories Europe, Bonn + Heidelberg
− University of Applied Science Kiel
− University of Oslo
● Contact:− [email protected]
● Areas of interest:− Security: Network, Web, Cloud Computing, Industrial Networks
− Privacy, Data Protection
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Nils Gruschka
Introduction
● Nils A. Nordbotten
− Cand.Scient and Ph.D. in informatics from UiO, and Executive Master of Management from BI Norwegian Business School
− Simula Research Laboratory (2003-2007)
− UniK-University Graduate Center (20 %) (2012-2014)
− Norwegian Defence Research Establishment (FFI) (2007-2020)
− University of Oslo (20 %) (2014-)
− Thales Norway (2020-)
● Contact
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Organisation
● “Cloned” course: IN3210 (Bachelor) + IN4210 (Master)
● Course page (also for IN4210):− https://www.uio.no/studier/emner/matnat/ifi/IN3210/h20/index.html
● Lecture− Home study: Pre-recorded lecture videos
− Online conference: Discussion and Q&A during the scheduled slots
● Workshop− Practical tasks, done individually or in groups
− Not mandatory, but helps understanding the concepts from the lecture
− Home work
− Online conference: Discussion and Q&A during the scheduled slots
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Organisation
● Canvas course:
− https://uio.instructure.com/courses/28965
● Quizzes:
− For every topic a “learning progress control” quiz is offered
− Not mandatory, but highly recommended
● Discussion board:
− Ask / answer course-wide questions
● Groups (will be activated mid of September):
− For the semester task
− Discuss and exchange files inside the group
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Examination
● Semester Task (in groups):
− IN3210: write a report
− IN4210: create a seminar presentation
● Written Exam (individually):
− 3 hour digital exam at home
● Both parts of the exam must be passed and must be passed in the same semester.
● Final Grade
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Semester Task 30%
Written Exam 70%
Semester Task (general)
● Select a network security topic (as a group):
− https://uio-my.sharepoint.com/:x:/g/personal/nilsgrus_uio_no/EbEqNbzhIN5AsA6zuFlCae8BAg0eOvDXtRz8jgDynPmNJQ?e=esDJ2P
● Deadline for selecting group and topic:
− 15. September
● (Optional) Propose own topics:
− Submit your proposal: https://nettskjema.no/a/158011
− Deadline for topic proposal: 31. August
− Approved topics will be added to the selection spreadsheet
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Semester Task (just IN3210)
● Group size: 2 or 3 students
● Write a (scientific) report on the selected topic
● Length: 4 – 5 pages per person
● Language: English or Norwegian
● Submission via Inspera (more info later)
● Submission deadline: 20. November
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Semester Task (just IN4210)
● Group size: 3 or 4 students
● Create a seminar presentation on the selected topic
● Presentation (submission of slides: 20. November)− Approx. 10 min per persons
− Performed via Zoom
− Presented to the whole course (teachers + students)
− During the scheduled slots in November (details soon)
− Language: English
● Handout (submission: 1 day before the talk)− 1 page, text + figures
− Summarizes the most important facts
● Final exam (IN3210 + IN4210) will contain questions from seminar talks!
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Exact length ofpresentations will be
announced end ofSeptember!
Semester Task (general)
● Scientific work:
− Used sources (books, article, online recourses) must be referenced (at end of the report/on the last slide of the presentation)
− Plagiarism → failed semester task → failed course
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Content
● Cryptography
● Certificates & PKI
● Transport Layer Security
● IP Security
● MAC Security
● Wireless LAN Security
● Email Security
● DNS Security
● Firewalls
● Routing Security
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Recommended Books
● https://link.springer.com/book/10.1007/978-3-642-04101-3
● https://link.springer.com/book/10.1007/978-1-4471-6654-2
● https://link.springer.com/book/10.1007%2F978-3-030-33649-3
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Questions?
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Introduction into (Network) Security
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What is Security?
Attacker
Threat
Assets
Counter-measure
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Computer Security
● Security of computers and networks
● Protection of digital assets
● Axioms of Computer Security:− Confidentiality (e.g. of transmitted secret information)
− Integrity (e.g. of stored data)
− Availability (e.g. of services)
● Further goals:− Authenticity
− Non-repudiation
− Privacy
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Motivations for attacks
● Financial advantages− Free of charge use service with costs
− Performing financial transactions
− → Spoofing different identity
● “Fun”− Challenging security systems
● “Revenge”− Vandalism
− Intrigues
● Political or religious motives
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Security Threats
● Examples for attacks
− Services:▪ Denial-of-Service
− Communication:▪ Eavesdropping
▪ Modification
− Stored data:▪ Espionage
▪ Deletion
▪ „Vandalism“
● Basic attack measureson communication− Sniffing
− Redirection, e.g.▪ ARP Spoofing
▪ DNS Poisoning
▪ Phishing
− Man-in-the-middle
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“Nomenclature”
● The “good” ones:
− Alice
− Bob
● The “bad” ones:
− Eve (passive attacker)
− Mallory (active attacker)
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Bob
Alice
Eve
Mallory
Sniffing
● Requires access to the communication medium
● Passive Attacks, e.g.:
− Eavesdropping
− Traffic analysis
Bob Alice
Eve
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Redirection
● Can be used as preparation for man-in-the middle attacks
Bob Alice
Eve / Mallory
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Man-in-the-middle
● Passive attacks (see „Sniffing“)
● Active attacks, e.g.− Packet drop
− Packet modification
− Packet injection
− Packet replay
AliceBob Eve / Mallory
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Adversary Model
● Important question:
− What capabilities do I assume for the attacker?
− What kind of attacks can the attacker perform?
● → Adversary model
● Required for implementing countermeasures/testing security protocols
● Typical adversary model (Dolev and Yao, 1983):
− The attacker can perform any of the aforementioned action on transmitted packets
− The attacker can not break “secure” algorithms (e.g. AES)
● Security schemes (e.g. cryptographic protocols) must guarantee their security goals in the presence of this attacker
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Attack Examples
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ARP
● Address Resolution Protocol
● Maps inside local networks from IP address to MAC address
10.0.0.8Who has 10.0.0.8?
10.0.0.8 = FA … B3
FA … B3
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ARP Spoofing (Redirection Attack)
10.0.0.8
Who has 10.0.0.8?
10.0.0.8 = DC … A710.0.0.24
FA … B3
DC … A7
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Denial-of-Service (DoS)
● Attacker tries to overload the target service or network
● → „Service Denial“ for legitimate users
● Attack can target different service layers:
− Network (e.g. gateway, TCP/IP stacks)
− Representation (e.g. XML processing)
− Application
− Database
● Attacker looks for the bottleneck inside the service processing chain!
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DoS Example: SYN Flooding
SYN
SYN ACK
ACK
SYN
SYN ACK
SYN
SYN ACK
SYN
SYN ACK
Client Server
Client Server
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DDoS: Distributed DoS
● Often executed by multiple attackers: Distributed Denial of service (DDoS)
● Either controlled by botnet or „crowd“
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DDoS: Mirai Botnet
● Millions of infected IoT devices (routers, IP cameras)
● Offers DDoS as a service: 50.000 devices for 2 weeks: 3000$ - 4000$
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DDoS: Mirai Botnet
● Illustrating the infection with Mirai
Sou
rce:
Tw
itte
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DDoS: Mirai Botnet
● One victim
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Sou
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Attack Examples
● ... many more to come throughout the class
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