Question

Distinguish between a substitution cipher and a transposition cipher.

Answer 1

transposition cipher is a method of encryption by which the positions held by units of plaintext (which are commonly characters or groups of characters) are shifted according to a regular system, so that the ciphertext constitutes a permutation of the plaintext. That is, the order of the units is changed (the plaintext is reordered). Mathematically a bijective function is used on the characters' positions to encrypt and an inverse function to decrypt.

Sometimes the message written in code is itself called a cipher. Ciphercomes from the Arabic sifr, which means "nothing" or "zero." ... As early codes substituted numerals for letters to hide the word's meaning, codes became known as ciphers. If you crack a cipher, you break the code and can understand the message.

Answer 2

Substitution ciphe:A substitution technique is one in which the letters of plain text are replaced by other letters or number or symbols. Transposition cipher does not substitute one symbol for another instead it changes the location of the symbols

their types are:-
Monoalphabetic and Polyalphabetic substitution cipher.
example:-ceaser cipher.
transposition cipher:-
Transposition cipher does not substitute one symbol for another instead it changes the location of the symbol.
Their types are:- Keyless and Keyed transportation cipher.
example:-
Rain fence cipher