Transposition cipher
This document discusses transposition ciphers, which is a method of encryption where the positions of plaintext units are shifted according to a regular system to produce the ciphertext. The order of units is changed by using a bijective function on the characters' positions to encrypt and an inverse function to decrypt. Some common transposition ciphers mentioned include the rail fence cipher, route cipher, columnar transposition, double transposition, and Myszkowski transposition. Cryptanalysis techniques for transposition ciphers involve analyzing letter frequencies and determining the number of columns. One-time pads are also briefly discussed, which use random bit strings for encryption but have limitations such as requiring the key to be securely transported.
Transposition cipher
- 1. TranspositionTransposition CipherCipher A . Antony Alex MCA Dr G R D College of Science – CBE Tamil Nadu - India
- 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
- 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.