Data Engineering & AI Interview Playbook

Pigpen cipher is used by freemasons in 18th century.For that reason it is also called as masonic cipher.It is different from other ciphers as a fact that it does not substitute another letter in place of letter like other ciphers rather it uses symbols substituted in place of letters.Each of the 26 letters have different symbols.The freemasons actually made four different structures with letters embed in them and used part of that structure as a symbol of that particular letter. So for A they used   __| B they used    |__| for J      __.|  for S     \ / for W   \./ It is also named as rosicrucian cipher as it is believed that variations of ciphers was used by Rosicrucians  brotherhood along with freemasons.The pigpen cipher is used in Dan brown Novel "The lost symbol".It is also used in the game "Assassins creed II".It was also published in the website  The Science of Deduction  created by Sherlock series BBC a...

The Vignere cipher is a method of encryption which uses caesar cipher on each letter based on the letters of keyword.In caeser cipher each letter of the plaintext is shifted number of tomes depending upon the key value for examlple if the key=2 then the letter A is shifted two times and encrypted as C.Vignere cipher uses this technique on each of the letters but with different keys each time.That is the reason it appears unbreakable at first.But it is quite easy to understand and implement. For encrypting the plaintext vignere cipher uses vignere square or tabula recta which is like 26 X 26 table consisting of alphabets A-Z on ech row and columns.The columns in a table are such that each next column first alphabet is obtained by shifting previous column alphabet by one. Here is the figure of vignere square or tabular recta For the Encryption process the cipher uses different alphabets from the rows each time depending upon the alphabet key is having.So the process of encr...

Rail Fence cipher is transposition cipher.In this cipher plaintext is written as diagonally downwards or you can say wave sort of pattern called "Rails".For example take a plaintext "I LIKE THIS BLOG" and arrange it in a wave pattern I         E            S          G   L    K   T     I     B    O      I           H           L So the encrypted code for this plaintext will be IESGLKTIBOIHT.To make it more easy to decrypt we can indicate spaces as * in the rails. I         K          H        B   *    I     E    T    I    *   L     G     L           *          S         O So n...