# Lab 01 - Some Basics

[Lab01.pdf from Moodle](https://elearning.hs-offenburg.de/moodle/pluginfile.php/683696/mod_resource/content/0/Lab%2001%20-%20Some%20Basics.pdf)

## 1 Algorithm and Key
### Skytale Cipher
- Key: Thickness of Stick
- Algorithm: Wrapping a vertical strip of letters around a Stick and reading on the Stick horizontally from Left to Right, because the letters are now neighboured horizontally on the Stick.

### Caesar Cipher
- Key: 23 (Amount of shift)
- Algorithm: Caesar algorithm consists of two alphabets mapping each other. The Key shifts the mapping to the right. In our case, Caesar cipher uses a 23-iteration shift. Example: A + right shift of 23 = X.

## 2 Modelling a Cryptographic Situation 1

### Communication diagram

- Sender, receiver? How is the key transmitted?
- Sender : User (past)
- Receiver : User (future)
- Key Transmission: 1. Remembering it 2. USB-Stick in Safe 3. Hiding it 4. Store it encrypted somewhere
- Potential attackers?
- Former Friends
- Malicious colleagues
- Intelligence agencies
- Potential protection goals?
- Confidentiality (Nobody reads my Data)
- Integrity (The Data is still the same)
- Primitives involved?
- Symmetric Key cryptography
- Symmetric or asymmetric cryptography?
- Symmetric cryptography because the same Key is used for encryption and decryption.
- Which attack models and attack goals make sense for each of the attackers you defined above?
- **Former Friends**:
- Attack Goals: Learning the Key
- Attack Models:
- COA (only in case of weak encryption)
- KPA (prefered) -> knows the victim
- CPA (prefered) -> fileShare/Security Copy
- **Malicious colleagues**:
- Attack Goals: Learning the Key
- Attack Models:
- COA (only in case of weak encryption)
- KPA (shared working Files)
- CPA (send private security copy to victim)
- CCA (send Work E-Mail back to attacker from disk)
- **Intelligence agencies**:
- Attack Goals: Learning the Key
- Attack Models:
- COA
- KPA
- CPA
- CCA

<u>How each type of attacker might go about attacking the cryptographic protection:</u>
Former Friends: Guessing the password
Malicious colleagues: Try destroy the Harddrive
Intelligence agencies: Brute-Force,

## 3 Modelling a Cryptographic Situation 2

- Sender, receiver? How is the key transmitted?
- Sender: Anti-air System
- Receiver: Flying Object
- Key Transmission: Hardcoded on Drone
- Potential attackers?
- Hostile Military
- Intelligence agencies
- Potential protection goals?
- Entity Authentication
- Primitives involved?
- Digital Signature
- Symmetric or asymmetric cryptography?
- Asymmetric
- Which attack models and attack goals make sense for each of the attackers you defined above?
- **hostile Military**:
- Attack Goals: getting past the defence system
- Attack Models: /
- **Intelligence agencies**:
- Attack Goals: getting past the defence system
- Attack Models: /

<u>How each type of attacker might go about attacking the cryptographic protection:</u>
hostile Military: Steal Drone, Brute Force Question (Answers), Jammer
Intelligence agencies: Brute-Force, Brute-Force Digital Signature Key
#
[> Lab 01](https://hackmd.io/7aGepAkLSfO7BJ3UtNovXg)
[> Lab 02](https://hackmd.io/@BhnA6Wd9SniQmnF2WZHKVw/rkolBj0Qj)
[> Lab 03](https://hackmd.io/@BhnA6Wd9SniQmnF2WZHKVw/rJIPW7SEj)
[> Lab 04](https://hackmd.io/jEcgjgKrT7-fpdKHOi12tA)
[> Lab 05](https://hackmd.io/NjswPGT_RmGT_OUcjShziQ)
[> Lab 06](https://hackmd.io/qWadbIMNSzizxSNwSV30RQ)
[> Lab 07](https://hackmd.io/bcNpycROQpO92ft34tXsTA)
[> Lab 08](https://hackmd.io/RSyTntnJRvuei4dei3CmXQ)
[> Lab 09](https://hackmd.io/md3d7vfzRw-VMuA4Ze6Zng)