Cryptology combines cryptography and cryptanalysis for secure data communication. Security comes from using secret keys to transform information. Cryptography originally focused on written messages, now applies to various data types
Vigenere cipher was invented by Blaise de Vigenère in 1586. It combines shift cipher with keyword to change shift at each step. Uses letters as keys and alphabet for encryption and decryption
Summertime Saga offers unique challenges including sister laptop password puzzle. Laptop password is "ilysister" for accessing sister's laptop
Ciphertext is encrypted information created using a cipher algorithm. Encryption transforms plaintext into unreadable form using a cipher. Decryption converts ciphertext back to readable plaintext
Substitution cipher replaces plaintext units with ciphertext according to fixed system. English alphabet has 26! possible substitution keys. Simple substitution cipher is weak due to frequency analysis vulnerability
Basic substitution replaces letters with symbols for message hiding. Base64 converts binary data to text for safe transmission. Morse Code remains effective in certain situations. Letter numbers replace letters with their position in alphabet