How to Encrypt Substitution
How to Decrypt Substitution
Substitution Sample Problem
For a substitution to be correct, it is necessary for the same element to be substituted by only one other (valid in both cases, for encryption and decryption) so that there is never more than one possibility of encryption or decryption.
Example: The Caesar cipher is an alphabetical substitution which replaces each letter by the following in the alphabet: ABC becomes 'BCD'.
The condition for a successful substitution decryption is to know the correspondence table used.
Choose the best answer: