Question

3. Ciphers are broadly categorized as using transposition, substitution or trap-door functions. Please provide an example of each type of cipher.

Answer 1

Transposition Cipher:

Example:

->Lets take a line "ABCDEF" and we want to encrypt it using Transposition Cipher.

NOTE: Transposition Cipher encrypt plain text by moving small piece of message around. Anagram are primitive transposition cipher. It do not change original text with different text.

1^st Row->Plain text

2^nd Row->Encrypted text ( by swapping the words in pair of 2)

A	B	C	D	E	F
B	A	D	C	F	E

Substitution Cipher:

-> The substitution cipher replace bits , character or block of character with different bits,character or blocks.It changes the original text with different text.

Example:

->Lets take a line "ABCDEF" and we want to encrypt it using Substitution Cipher.

->1^st Row = Plain Text

->2^nd Row =Encrypted key or bits or digit that we are adding in original text to making text encrypted.

->3^rd Row=Encrypted Text (After adding the encrypted key)

A	B	C	D	E	F
+3	+3	+3	+3	+3	+3
D	E	F	G	H	I