Playing with cryptography for Tech for Business @ Cornell Tech. Read the paper here.
This paper will discuss several ciphers in their historical context. Where it is within the authors' skill level, the cipher will be reduced to python code; where it isn't, the cipher will be described mathematically; where even that escapes us, it will be described through narrative. We intend to describe the strength and weaknesses of each cipher, what led to their development and obsolescence, and any notable stories of their use.
This paper will discuss:
- Atbash cipher, a simple monoalphabetic substitution cipher with a keyspace of 1;
- Scytale cipher, a simple transposition cipher with a small practical keyspace;
- Caesar cipher, a simple monoalphabetic substitution cipher with a keyspace the size of the alphabet used;
- Vigenère cipher, a more complex polyalphabetic substitution cipher with complexity increasing with the size and randomness of the key;
- one time pads, a specific subset of Vigenère ciphers still in use, that are not crackable;
- Enigma machine cipher, a complex polyalphabetic substitution cipher; and
- RSA cipher, a complex polyalphabetic substitution cipher that employs public private key encryption.
While this is not a complete list of cryptographic developments, it allows us to highlight several important developments in cryptography.
Excellent work on your essay! I'm impressed that you took the time and effort to convert a lot of the more basic ciphers and encryption schemes to Python code in addition to the written component of the project. Writing a survey about historical ciphers and encryption schemes and analyzing their individual and comparative security was definitely an ambitious task for this project, and you performed it quite well. You demonstrated a great deal of understanding about some of the key basic concepts in cryptography as well, such as the nature of certain cryptographic attacks, information leakage, and security's correlation to a scheme's keyspace. Very well done!
Written by Johanan Ottensooser and Matthew Stichinsy All contents of this repo are MIT Open Source licensed.