Question

Difference between substituiton and transposition in cryptography

Answer 1

Paramters
Substitution Cipher
Transportation Cipher

DefinitionA 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

TypeMonoalphabetic and Polyalphabetic substitution cipher.
Keyless and Keyed transportation cipher.

ChangesEach letter retains its position changes its identity

Each letter retains its identity but changes its positionDisadvantage

The last letters of the alphabet which are mostly low frequency tend to stay at the end.

Keys very close to the correct key will reveal long sections oflegibleplaintext

Example -Ceaser CipherRail fence Cipher