Ciphers are methods of transforming information to conceal its meaning or structure. This organizes ciphers by their method, providing direct access to explanations, history, and practical usage for each technique.
☰
Book Ciphers 6
book and steganographic ciphers encode messages using external texts, such as books or documents, as keys.
⚙
Mechanical Ciphers 7
mechanical or composite ciphers apply multiple transformations, often using devices or algorithmic systems to automate encryption.
⌨
Modern / Complex Ciphers 18
↔
Polyalphabetic Ciphers 23
polyalphabetic ciphers use multiple substitution alphabets to encrypt plaintext, cycling through different mappings according to a key or repeating sequence.
#
Polygraphic Ciphers 26
polygraphic or fractionation ciphers encrypt plaintext in blocks (digraphs, trigraphs) or by splitting letters into coordinates before recombining.
⇄
Substitution Ciphers 23
substitution ciphers replace plaintext symbols with ciphertext symbols according to a fixed mapping. each symbol is replaced by another symbol, letter, number, or glyph, either directly or via a keyed alphabet.
↹
Transposition Ciphers 17
transposition ciphers rearrange the order of plaintext symbols without changing the symbols themselves. security comes from permutation rather than substitution.