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BeginnerModule 4Lesson 4/5

Lab — Classic

Pack Caesar/Vigenère, XOR CTF, and freq analysis logs — classic cipher file from $CRYPTO_LAB only.

25 min+40 XP3 quiz
Module progress4 of 5

Visual · t28_classic_lab

Lab: classic cipher pack. $CRYPTO_LAB only. Original Cyberlium.

Opening

Classic pack merges three CTF toys — paperwork and flags before modern toy crypto module.

Lessons 4-1–4-3 covered Caesar/Vigenère, XOR CTF, and frequency analysis on YOUR plaintext. This lab merges classic CTF cards and freq log with M3 attack-class cross-reference and explicit YOUR-plaintext-only language. No stranger ciphertext — classic CTF paperwork and optional solver runs on toys you own. Next: Quiz — Classic Ciphers CTF.

1. Lab contract: classic cipher pack

Create $HOME/cyberlium-lab/t28-m04-l04-classic-lab.txt merging Caesar/Vigenère card, XOR CTF card, and freq analysis log with $CRYPTO_LAB toy filenames and planted flags.

Optional: paste recovered flag lines only — no full stranger message dumps.

Command guide

Try these commands — Lab contract: classic cipher pack

═══ LINUX / macOS (Terminal Practice) ═══

Check system state and user context

Command — copy this

id
whoami
uname -a

Inspect network sockets listening for connections

Command — copy this

ss -tuln 2>/dev/null || netstat -tuln

Audit active processes

Command — copy this

ps aux | grep -v "\[" | head -15

═══ WINDOWS (POWERSHELL) ═══ Query user identity and system information

Command — copy this

whoami /all
Get-ComputerInfo | Select-Object CsName, OsName, OsVersion

Primary tools to practice this lesson: python3, grep. Reference sites: Frequency analysis (https://cryptopals.com/); CWE-327 (https://cwe.mitre.org/data/definitions/327.html); OpenSSL (https://www.openssl.org/). Run every command in the box — install first, then the usage lines — only on YOUR lab / program scope.

2. Cross-check ethics

Grep for classmate names, scraped chat paths, unauthorized firmware — remove. Pack must state YOUR-plaintext-only scope.

Confirm toys match M1 inventory source field.

3. Lock the proof

chmod 600 on the pack. Quiz next — then AES Modes Named.

Classic CTF literacy feeds modern openssl module in M5.

4. What you ship: classic cipher pack for $CRYPTO_LAB

Merged Caesar, XOR, freq sections with YOUR flags. $CRYPTO_LAB named. NO stranger ciphertext. chmod 600.

5. What you record before the next lesson

Date. Classic pack path. $CRYPTO_LAB named. File t28-m04-l04-classic-lab.txt chmod 600.

6. Wrong vs right: prod crypto oracles vs CTF toys

Worked failure — same MSF word, opposite target. Right never needs a café Wi-Fi or classmate laptop.

  • Wrong

    Include decrypted stranger message in pack. Skip XOR toy section.

  • Right

    Write YOUR classic cipher pack for $CRYPTO_LAB. chmod 600. Next: Quiz — Classic Ciphers CTF.

Mission: freeze YOUR classic cipher pack

1) Merge M4 CTF sections. 2) Confirm YOUR-plaintext-only language. 3) List three planted flags. 4) chmod 600.

Stuck? Ask Cyberlium AI Mentor

Three small toys beat one ambiguous scraped blob.

Knowledge Check

1

APPLY: This lab requires:

Multiple choice

Knowledge Check

2

APPLY: True or False: Classic lab must reference YOUR-plaintext-only scope.

True or False

Knowledge Check

3

APPLY: Classic pack should include:

Multiple choice

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Answer all 3 knowledge checks to continue. (0/3 answered)