A cipher is an pair of algorithms that can encrypt and decrypt data. If the algorithms are identical for encryption and decryption then the cipher is called an Reciprocal Cipher, the Beaufort Cipher and Enigma Cipher are examples.
Ciphers have evolved over time from ciphers that can be performed by hand to ones that require massive amounts of computing power.
Most ciphers can be split into 2 categories: Substitution and Transposition Ciphers. However some are a combination of substitution and transposition and some use fractionation to obscure data, all to increase security.
Substitution
- Affine Cipher
- Autokey Cipher
- Beaufort Cipher
- Bazeries Cipher
- Caesar Cipher
- Four Square Cipher
- Fractionated Morse Cipher
- Nicodemus Cipher
- Nihilist Substitution Cipher
- Playfair Cipher
- Porta Cipher
- Portax Cipher
- Progressive Cipher
- Quagmire I Cipher
- Quagmire II Cipher
- Quagmire III Cipher
- Quagmire IV Cipher
- Rotating Grille Cipher
- Running Key Cipher
- Simple Substitution Cipher
- Slidefair Cipher
- Tri Square Cipher
- Two Square Cipher
- Vigenère/Variant Cipher
Transposition
- AMSCO Cipher
- Cadenus Cipher
- Columnar Transposition Cipher
- Myszkowski Cipher
- Nihilist Transposition Cipher
- Rail Fence Cipher
- Redefence Cipher
- Swagman Cipher
Others
- ADFGX Cipher
- ADFGVX CipherB
- Bifid Cipher
- Checkerboard
- Conjugated Matrix Bifid Cipher
- Digrafid Cipher
- Hill Cipher
- Hill Cipher Extended
- Hill Cipher Substitution
- Homophonic Cipher
- Morbit Cipher
- Periodic Gromark Cipher
- Phillips Cipher
- Pollux Cipher
- Seriated Playfair
- Solitaire Cipher
- Straddling Checkerboard Cipher
- Trifid Cipher