- 
  
  Substituted letters with Symbols (originally designed for 25 letters)
 - 
  
  Meant to instruct women how to hide secret messages
Split alphabet substition method - 
  
  Created by Polybius
Based on a 5x5 letter matrix - 
  
  Subsitution method (basic building block for encryption techniques)
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  First mentioned in 1553 by Giovan Battista Bellaso
Misattributed to Blaise de Vigenère - 
  
  Created by: Francis Bacon
Binary Steganography - 
  
  Best known multiple-letter encryption
Sir Charles Wheatstone - 
  
  Based on the Vigenère cipher
Registered with Library of Congress in 1874 - 
  
  Base on the Polybius Cipher
 - 
  
  Created by: Felix Delastelle
Uses four 5x5 matrices place in a square pattern - 
  
  Created by: Gilbert Vernam
Works on binary bits instead of letters - 
  
  Suggested improvement to the Vernam Cipher
By: Joseph Mauborgne
Considered truly unbreakable if done right - 
  
  Used by: Germany & Japan during WWII
Paved the way for today's Data Encryption Standard (DES) - 
  
  Similar to Playfair - it hides single-letter frequencies
By: Lester Hill - 
  
  Phoneitc Navajo Language substitution
By: Philip Johnston