Four-Square Cipher encrypts pairs of letters (like playfair), which makes it significantly stronger than substitution ciphers etc. since frequency analysis becomes much more difficult.

Four-Square Cipher
Four-Square Cipher encrypts pairs of letters (like playfair), which makes it significantly stronger than substitution ciphers etc. since frequency analysis becomes much more difficult.
Bifid Cipher is a cipher which combines the Polybius square with transposition, and uses fractionation to achieve diffusion.

Bifid Cipher
Bifid Cipher is a cipher which combines the Polybius square with transposition, and uses fractionation to achieve diffusion.
Beaufort Cipher, is a polyalphabetic substitution cipher that is similar to the Vigenère cipher, except that it enciphers characters in a slightly different manner.

Beaufort Cipher
Beaufort Cipher, is a polyalphabetic substitution cipher that is similar to the Vigenère cipher, except that it enciphers characters in a slightly different manner.
Atbash Cipher is a substitution cipher with a specific key where the letters of the alphabet are reversed. I.e. all 'A's are replaced with 'Z's, all 'B's are replaced with 'Y's, and so on. It was originally used for the Hebrew alphabet, but can be used for any alphabet.

Atbash Cipher
Atbash Cipher is a substitution cipher with a specific key where the letters of the alphabet are reversed. I.e. all 'A's are replaced with 'Z's, all 'B's are replaced with 'Y's, and so on. It was originally used for the Hebrew alphabet, but can be used for any alphabet.
The Vigenère Cipher is a method of encrypting alphabetic text where each letter of the plaintext is encoded with a different Caesar Cipher, whose increment is determined by the corresponding letter of another text, the key.

Vigenère Cipher
The Vigenère Cipher is a method of encrypting alphabetic text where each letter of the plaintext is encoded with a different Caesar Cipher, whose increment is determined by the corresponding letter of another text, the key.
Type 7 Cipher, also known as Cisco Type 7 Encryption, is a method commonly used by Cisco networking devices to obfuscate sensitive information such as passwords in configuration files. While it's referred to as encryption, Type 7 is actually a weak form of encoding designed to obscure passwords rather than securely encrypting them.

Type 7 Cipher
Type 7 Cipher, also known as Cisco Type 7 Encryption, is a method commonly used by Cisco networking devices to obfuscate sensitive information such as passwords in configuration files. While it's referred to as encryption, Type 7 is actually a weak form of encoding designed to obscure passwords rather than securely encrypting them.
Braille Cipher is a substitution cipher, it could encoding and substituting the letters in a message into

Braille Cipher
Braille Cipher is a substitution cipher, it could encoding and substituting the letters in a message into "Braille" characters.
Scytale Cipher is a transposition cipher, which means it rearranges the order of letters in a message rather than substituting them with other characters.

Scytale Cipher
Scytale Cipher is a transposition cipher, which means it rearranges the order of letters in a message rather than substituting them with other characters.
Regression Cipher is a cipher that uses regression to encrypt a word.

Regression Cipher
Regression Cipher is a cipher that uses regression to encrypt a word.
Rail Fence Cipher is a classical type of transposition cipher. It derives its name from the manner in which encryption is performed, in analogy to a fence built with horizontal rails.

Rail Fence Cipher
Rail Fence Cipher is a classical type of transposition cipher. It derives its name from the manner in which encryption is performed, in analogy to a fence built with horizontal rails.
Polybius Square Cipher is essentially identical to the simple substitution cipher, except that each plaintext character is enciphered as 2 ciphertext characters. It can ususally be detected if there are only 5 or 6 different characters in the ciphertext.

Polybius Square Cipher
Polybius Square Cipher is essentially identical to the simple substitution cipher, except that each plaintext character is enciphered as 2 ciphertext characters. It can ususally be detected if there are only 5 or 6 different characters in the ciphertext.
Playfair Cipher is a manual symmetric encryption technique and was the first literal digram substitution cipher. It encrypts pairs of letters (bigrams or digrams), instead of single letters as in the simple substitution cipher and rather more complex Vigenère cipher systems then in use.

Playfair Cipher
Playfair Cipher is a manual symmetric encryption technique and was the first literal digram substitution cipher. It encrypts pairs of letters (bigrams or digrams), instead of single letters as in the simple substitution cipher and rather more complex Vigenère cipher systems then in use.