classical ciphersin python

classical ciphersin python

Transcript

1. ciphers using python @wwwy3y3 NCKU
2. Me • wwwy3y3 • 張仲威 • ncku student • python , nodeJs lover
3. classical_ciphers • pip install classical_ciphers • github: /wwwy3y3/ciphers • help you understand classical ciphers • DO NOT USE FOR PRODUCTION!!
4. ciphers • monoalphabetic • ceasar cipher • keyword • polyalphabetic • transposition
6. monoalphabetic- Ceasar cipher • simple shift • encrypter.ceasar(3)
7. monoalphabetic -keyword • keyword: william -> wilam • encrypter.keyword(‘william’) • plaintext ABCDEFGHIJKLMNOPQRSTUVWXYZ • ciphertext WILAMBCDEFGHJKNOPQRSTUVXYZ
8. polyalphabetic • keyword: snake -> 9, 14, 1, 11, 15 • plaintext HELLO HOW ARE YOU • -> 8-5-12-12-15 -8-15-23-1-18 -5 25-15-21 • ->19-14-1-11-5 -19-14-1-11-5- 19-14-1-11 • add up -> your ciphertext! • encrypter.poly(‘william’)
9. transposition • plaintext: hello how are you • window size=3! • ciphertext: hloro eoweu lhay • WHY? • letter frequency h e l l o h o w a r e y o u
11. encrypt.trans(4).poly(‘python’) decrypt.poly(‘python’).trans(4)
12. THANK U