Cipher

1. TranspositionTransposition
CipherCipher
A . Antony Alex MCA
Dr G R D College of Science – CBE
Tamil Nadu - India

2. KeywordsKeywords
Cryptography
EncryptionEncryption
Decryption
Cipher

3. In cryptography, a TRANSPOSITION CIPHER is
a method of encryption by which the
positions held by units of plaintext are
shifted according to a regular system, soshifted according to a regular system, so
that the ciphertext constitutes a
permutation of the plaintext.

4. The order of the units is changed.
Mathematically a bijective function is used
on the characters' positions to encrypt
and an inverse function to decrypt.and an inverse function to decrypt.

5. Most Common GameMost Common Game --
AnagramAnagram
TSPSH ALSIS EASAM GIMEE
THIS IS A SAMPLE MESSAGE

6. Rail Fence cipher
Route cipher
Columnar transpositionColumnar transposition
Double transposition
Myszkowski transposition

7. Rail Fence cipherRail Fence cipher

8. Route cipherRoute cipher

9. Columnar transpositionColumnar transposition
ZEBRAS
"6 3 2 4 1 5“
EVLNA CDTES EAROF ODEEC WIREE

10. Double transpositionDouble transposition
STRIPE
"564231“
CAEEN SOIAE DRLEF WEDRE EVTOC

11. Myszkowski transpositionMyszkowski transposition
TOMATO
532164
TOMATO
432143
ROFOA CDTED SEEEA CWEIV RLENE

12. Break Columnar TranspositionBreak Columnar Transposition
CipherCipher
Cryptanalyst must be aware that he is
dealing with cipher
Frequency of E,T,A,O,I,N, etcFrequency of E,T,A,O,I,N, etc
No of Columns
Suspect
Assumption

13. OneOne--Time PadsTime Pads
Random Bit String
Converting plain text to bit String
◦ Converting plant text into its ASCII Representation
• EXCLUSIVE OR of two string
DisadvantageDisadvantage
• Key cannot be memorized – written
• The amount of data is limited to key available
• Sensitivity
Can de advantage in computers
Using storage devices along with huge data for
key transporting.

14. THANK U………….THANK U………….