CSS Tutor Study Hub

Computersystemsicherheit 2025/26

CSS Tutor Study Hub

섹션별로 빠르게 들어가고, 상세 페이지에서 깊게 보는 시험 대비 허브입니다.

시험 구조와 출제 신호Crypto / AuthNetwork / DNS / BGP / TLSWeb / Software SecurityPrivacy / Forensics / SecLab

메인 화면의 역할

메인은 전체 강의 내용을 다 펼치지 않고, 시험 대비 섹션을 빠르게 고르는 대시보드입니다. 긴 설명과 시각 자료는 상세 페이지로 분리했습니다.

49source files
553source windows
17topic groups
0weakness rows

Study Routes

30-minute quick review

Fast active recall over high-signal concepts, with short true/false and oral prompts.

python .\scripts\make_quiz_prompt.py --mode true-false --topic "Exam memory and format, Crypto foundations, Symmetric crypto, Asymmetric crypto, Authentication, Network basics" --count 10

90-minute exam drill

Mixed exam clone: answer frames, scenario tracing, crypto calculation, and code/web audit.

python .\scripts\make_quiz_prompt.py --mode exam-clone --topic "mixed CSS exam" --count 12

Weakness repair

Start from the most recent weakness_key, then log misses and rebuild the hub.

python .\scripts\make_quiz_prompt.py --mode scenario --topic "exam-memory-and-format" --count 6

Exam Visual Cards

Static scan cards for topics where drawing the flow prevents common CSS exam mistakes.

Exam visual card

DNS resolution + DNSSEC vs DoH/DoT

Trace who asks whom, then separate signed answers from encrypted transport.

  1. Stub
  2. Resolver
  3. Root
  4. TLD
  5. Authoritative
  6. Cache
  • DNSSEC: authenticity/integrity of records, not confidentiality.
  • DoH/DoT: protects client-resolver channel, not resolver trust by itself.
  • Poisoning answer needs forged response, accepted cache entry, and TTL effect.

Exam visual card

BGP hijack / RPKI / AS path

Write prefix, origin AS, AS_PATH, why the route wins, and what defense checks.

  1. Victim prefix
  2. Honest AS_PATH
  3. Attacker prefix
  4. Receiver route
  5. RPKI/ROV
  • Sub-prefix hijack wins by longest-prefix match.
  • ROA/ROV checks authorized origin and maxLength.
  • BGPSec targets path validation; deployment limits remain.

Exam visual card

DHCP DORA / ARP spoofing / firewall direction

Network basics become easy when sender, receiver, and packet function are visible.

  1. Discover
  2. Offer
  3. Request
  4. Ack
  5. ARP reply
  6. Firewall rule
  • ARP spoofing is usually same-LAN forged mapping.
  • Firewall answers need direction, state, protocol, source, destination, port, action.
  • DDoS targets availability; DNS tunneling can still pass allowed port 53.

Exam visual card

TLS certificate chain / domain validation

Separate browser validation from CA issuance validation.

  1. ClientHello
  2. Certificate chain
  3. Hostname check
  4. Key exchange
  5. CA challenge
  • Traffic redirect alone fails without a valid target-domain cert/key.
  • CA HTTP/DNS challenge can be abused if validation traffic is steered to Eve.
  • A valid certificate does not prove website honesty or absence of XSS/SQLi.

Exam visual card

SQL injection / XSS data flow

Follow untrusted input into the interpreter context before naming the fix.

  1. Input
  2. Sink line
  3. SQL/HTML context
  4. Impact
  5. Fix
  • SQLi fix: prepared statement with bound parameters.
  • XSS fix: context-aware output encoding, not SQL escaping.
  • Audit answer needs vulnerable line, attacker input, impact, and repair.

Exam visual card

CBC / CTR / OTP reuse + RSA/signature order

For crypto calculations, draw the order before calculating.

  1. CBC: XOR then Enc
  2. CTR: Enc counter then XOR
  3. OTP: C=P xor K
  4. RSA n,phi,e,d
  5. Sign with private key
  • CTR nonce reuse and OTP key reuse leak P1 xor P2.
  • CBC uses IV/previous ciphertext before encryption.
  • Signature proves authenticity/integrity, not confidentiality.

Mini Mock Set

Mixed exam pack: Wahr/Falsch, protocol trace, crypto calc/game, web/code audit, and forensics/privacy short answer.

Task 1: Wahr/Falsch

Wahr/Falsch

DNSSEC encrypts DNS queries so the local network cannot see the requested domain.

Answer-frame check

Verdict false; name the trap; DNSSEC signs records, while DoH/DoT encrypts the client-resolver channel.

Task 2: Protocol trace

Protocol trace

Fill sender, receiver, and function for DHCP Discover, Offer, Request, Ack, then add one rogue-DHCP attack line.

Answer-frame check

C -> broadcast, D -> C, C -> D/broadcast, D -> C; rogue server offers malicious gateway/DNS; DHCP snooping blocks untrusted offers.

Task 3: Crypto calc/game

Crypto calc/game

Two OTP ciphertexts use the same key. Show the equation that leaks the relation between plaintexts. Then state the forbidden query in IND-CCA.

Answer-frame check

C1 xor C2 = P1 xor P2 when K is reused; IND-CCA forbids asking the decryption oracle for the challenge ciphertext.

Task 4: Web/code audit

Web/code audit

A PHP login builds SQL with string concatenation from GET parameters and echoes the username into HTML. Identify two vulnerabilities and fixes.

Answer-frame check

SQLi: query syntax changed by input; fix prepared statements and password hashing. XSS: untrusted username in HTML; fix context-aware output encoding.

Task 5: Forensics/privacy short answer

Forensics/privacy short answer

Explain how a forensic image, hash, write blocker, and chain of custody support integrity. Add one privacy limitation of DoH.

Answer-frame check

Protect original, image it, hash original/image, log handovers, analyze copies; DoH can hide DNS content from local observers but not from the resolver.

python .\scripts\make_quiz_prompt.py --mode exam-clone --topic "mixed CSS exam visual mock set" --count 5

Weakness Repair Queue

No `data/weakness_log.jsonl` file exists yet. After a tutoring session, log missed concepts and rebuild the hub to turn this panel into a repair queue.

Expected JSONL row

{"timestamp":"2026-07-11T18:30:00+02:00","weakness_key":"crypto-foundations","topic":"Crypto foundations","note":"Mixed up IND-CPA and IND-CCA forbidden query","severity":"high","source":"tutor-session"}

Command flow

python .\scripts\make_quiz_prompt.py --mode true-false --topic "Crypto foundations" --count 8
# append missed concepts to data\weakness_log.jsonl
python .\scripts\build_study_hub.py

Stable starter keys: exam-memory-and-format, crypto-foundations, symmetric-crypto, asymmetric-crypto, authentication, network-basics

Drill Launcher

high signal

Asymmetric crypto

Weakness key: asymmetric-crypto

python .\scripts\make_quiz_prompt.py --mode oral --topic "Asymmetric crypto" --count 6

high signal

Authentication

Weakness key: authentication

python .\scripts\make_quiz_prompt.py --mode scenario --topic "Authentication" --count 6

high signal

BGP

Weakness key: bgp

python .\scripts\make_quiz_prompt.py --mode scenario --topic "BGP" --count 6

high signal

Crypto foundations

Weakness key: crypto-foundations

python .\scripts\make_quiz_prompt.py --mode crypto-calc --topic "Crypto foundations" --count 6

high signal

DNS

Weakness key: dns

python .\scripts\make_quiz_prompt.py --mode scenario --topic "DNS" --count 6

high signal

Exam memory and format

Weakness key: exam-memory-and-format

python .\scripts\make_quiz_prompt.py --mode oral --topic "Exam memory and format" --count 6

high signal

Network basics

Weakness key: network-basics

python .\scripts\make_quiz_prompt.py --mode scenario --topic "Network basics" --count 6

high signal

Software security

Weakness key: software-security

python .\scripts\make_quiz_prompt.py --mode code-audit --topic "Software security" --count 6

Study Sections

71 actual-exam subquestions

WS2025/26 실제 시험 학습

18쪽·200점 실제 시험지를 Krypto, Networking, Web Sicherheit, Security Engineering의 소문제 71개로 나누어 학습합니다.

추가 검토 0 실제 원문·배점 대조 완료
71문항 풀어보기 실제 시험 해설 학습

1 detail blocks

시험 구조와 출제 신호

WS2025/26 memory protocol과 Moodle exam 형식으로 답안 프레임을 잡는 페이지

Exam memory and format
상세 페이지 열기

4 detail blocks

Crypto / Auth

IND 모델, symmetric modes, RSA 계산, signature, password/authentication을 강의 흐름으로 복습

Crypto foundationsSymmetric cryptoAsymmetric cryptoAuthentication
상세 페이지 열기

4 detail blocks

Network / DNS / BGP / TLS

sender, receiver, message, attacker position 중심의 시나리오 페이지

Network basicsBGPDNSTLS and domain validation
상세 페이지 열기

2 detail blocks

Web / Software Security

vulnerable line, attacker input, impact, fix 답안 훈련

Web application securitySoftware security
상세 페이지 열기

3 detail blocks

Privacy / Forensics / SecLab

adversary model, chain of custody, 실습 파일과 시험 개념 연결

Censorship and privacyForensicsSecLab bonus
상세 페이지 열기

Priority Sources

  1. actual_exam_ws2025_26
    CSS_Altklausur_WiSe_2526.pdf
  2. actual_exam_transcript_ws2025_26
    computersystemsicherheit_wise25-26_questions_only.md
  3. moodle_exam_probeklausur
    CSS_Exam_WiSe21_SoSe22_Altklausur.pdf
  4. local_extra_exam
    CSS_Altklausur_WiSe_2425.pdf
  5. exam_memory_ws2025_26
    Gedächtnisprotokoll Computersystemsicherheit WS2025_26.md

Corpus Mix

  • actual_exam_transcript_ws2025_26: 1
  • actual_exam_ws2025_26: 1
  • exam_memory_ws2025_26: 1
  • exercise_sheet: 6
  • exercise_solution: 6
  • lecture: 17
  • local_extra_exam: 1
  • moodle_exam_probeklausur: 1
  • seclab_bonus: 13
  • superseded_local_uebung4: 2

Next Practice

python .\scripts\make_quiz_prompt.py --mode exam-clone --topic "mixed CSS exam" --count 8
python .\scripts\make_quiz_prompt.py --mode scenario --topic "BGP hijacking and domain validation"
python .\scripts\make_quiz_prompt.py --mode web-audit --topic "PHP login"

High-Signal Topic Coverage

TLS and domain validation

285 source windows

  • Vorlesung / 10 Web Application Security.pdf 29
  • Vorlesung / 08 Domain Name System.pdf 17
  • Vorlesung / 09_1.pdf 16

Crypto foundations

194 source windows

  • Vorlesung / 02_Grundlagen_Krypto_RMU_v2.pdf 31
  • Vorlesung / 04 Asymmetrische Kryptographie.pdf 30
  • Vorlesung / 03 Symmetrische Kryptographie.pdf 20

Censorship and privacy

161 source windows

  • Vorlesung / vl13.pdf 19
  • Vorlesung / 08 Domain Name System.pdf 15
  • Vorlesung / 09_1.pdf 15

Web application security

129 source windows

  • Vorlesung / 10 Web Application Security.pdf 29
  • Vorlesung / 05 Authentifizierung.pdf 13
  • Vorlesung / 09.pdf 9

Network basics

128 source windows

  • Vorlesung / 06 Netzwerkgrundlagen.pdf 26
  • Vorlesung / 07 Border Gateway Protocol.pdf 10
  • Übung / 04 / Übung4_solution__moodle_2026-06-30.pdf 7

Forensics

116 source windows

  • Vorlesung / Vorlesung IT-Forensik 2026.pdf 63
  • Vorlesung / 09_1.pdf 7
  • Vorlesung / 03 Symmetrische Kryptographie.pdf 6

Asymmetric crypto

104 source windows

  • Vorlesung / 04 Asymmetrische Kryptographie.pdf 30
  • Vorlesung / 09.pdf 9
  • Vorlesung / 07 Border Gateway Protocol.pdf 7

Symmetric crypto

90 source windows

  • Vorlesung / 04 Asymmetrische Kryptographie.pdf 30
  • Vorlesung / 03 Symmetrische Kryptographie.pdf 20
  • Vorlesung / 02_Grundlagen_Krypto_RMU_v2.pdf 6

Software security

82 source windows

  • Vorlesung / 11_software-security 10.pdf 27
  • Vorlesung / Vorlesung IT-Forensik 2026.pdf 11
  • Vorlesung / 10 Web Application Security.pdf 7

Exam Profile Snapshot

# CSS Exam Profile Priority order: 1. `CSS_Altklausur_WiSe_2526.pdf` 2. `computersystemsicherheit_wise25-26_questions_only.md` 3. exercise solutions and lecture slides 4. `Gedächtnisprotokoll Computersystemsicherheit WS2025_26.md` (comparison) Corpus counts: - actual_exam_transcript_ws2025_26: 1 - actual_exam_ws2025_26: 1, 18 PDF pages - exam_memory_ws2025_26: 1 - exercise_sheet: 6, 37 PDF pages - exercise_solution: 6, 85 PDF pages - lecture: 17, 823 PDF pages - local_extra_exam: 1, 18 PDF pages - moodle_exam_probeklausur: 1, 17 PDF pages - seclab_bonus: 13 - superseded_local_uebung4: 2, 24 PDF pages Observed exam-prep emphasis: - Large `Wahr oder Falsch?` blocks by area are central. - Open questions often require exact attacker-model definitions and differences. - Application tasks require protocol/message traces, table filling, and scenario reasoning. - Crypto hand calculations such as RSA encryption/signing remain exam-relevant. - Networking topics need diagrams/tables: DNS resolution, BGP hijack, DHCP, ARP, firewall rules. - Web/software security tasks ask for concrete vulnerable lines, impact, and repair. Priority-source topic signal: - Moodle exam/probeklausur: 22 chunks - TLS and domain validation: 19 chunks - Crypto foundations: 15 chunks - Web application security: 15 chunks - Network basics: 11 chunks - BGP: 10 chunks - Censorship and privacy: 9 chunks - Symmetric crypto: 8 chunks - DNS: 8 chunks - Software security: 8 chunks - Authentication: 7 chunks - Forensics: 6 chunks - Asymmetric crypto: 5 chunks - Introduction and security goals: 3 chunks - Exam memory and format: 1 chunks - SecLab bonus: 1 chunks Harness implication: Use the actual WS2025/26 exam as the source of truth for wording, point values, code, tables, and order. Use official exercises and lecture slides to verify explanations; use the memory protocol only to audit the earlier reconstruction.