Course Template
Secret Writing Programming
Caesar Encryption, Substitution Cipher, Vigenère and Simple Hash Functions in Python.
Didactic Objective
This template enables a structured introduction to basic procedures of cryptography through their algorithmic implementation in Python. Professional competencies are built up through the implementation of classical encryption methods and simple hash functions, and linked to central programming concepts such as loops, conditions, and data structures. The connection between modeling cryptographic procedures, their structured algorithmic implementation and the concrete implementation in code is systematically established. Professionally, the template can be located in the area of algorithmic modeling and data processing.
Competency Focus
- Implementation of Caesar Encryption using ord()/chr() and Modulo Logic for cyclic letter shifting.
- Implementation of Caesar Decryption using function reuse and reverse shift.
- Systematic trial of possible keys (Brute-Force) for decryption with loops and formatted output.
- Implementation of a substitution cipher through index mapping with secret alphabet as well as verification of uniqueness and length.
- Construction of a reverse mapping using dictionary for decryption of substitution-based procedures.
- Implementation of the Vigenère encryption with keyword-based shift and position-dependent modulo calculation.
- Development of a simple hash function for password testing by adding letter values (A=1..Z=26).
Structure of components
Caesar encryption (A–Z) in Python
Introduction to the algorithmic implementation of a cyclic shift of letters for uppercase letters using ord()/chr() and modulo.
Caesar decrypt (Decrypt function)
Supplementing a decryption function as the inverse of encryption using reusable functional logic.
Caesar cracking: Brute-Force 1–25
Application of loops for systematic testing of all possible keys and output of potential plaintexts.
Substitution cipher: Secret Alphabet
Implementation of a substitution-based encryption through index mapping with validation of a secret alphabet.
Substitution code decrypt with Dictionary
Building an automated reverse mapping using a dictionary to revert encrypted text into plain text.
Vigenère encryption with Keyword
Implementation of position-dependent encryption based on a keyword and modulo calculation.
Vigenère decrypt with Keyword
Development of the inverse function while maintaining keyword-index logic and reverse shifting.
Simple Password Hash & Mini-Login
Introduction to the principle of hash functions through addition of letter values and comparison of stored hash values.
The clearly structured modules enable transparent goal orientation and can be flexibly integrated into existing lesson series.
A demo access allows the testing of the template and its adaptation to the respective learning group in the classroom context.