Caesar Cipher

Caesar Cipher or Shift Cipher is one of the most basic and one of the first cryptographical approach ever used. Named after the famous Roman Ruler Gaius Julius Caesar the roots of this technique are very very old.

The technique is really simple, a secret key (a number) is shared between the sender and receiver, and in order to encrypt the message. The letters are substituted by another letter by a fixed number of position down the alphabets. This Shift is determined using the shared key, opposite is done to determine the actual message.

For Example: Upon giving a shift key of 2, A would be replaced by C, B by D and so on.

Setup instructions

There are 2 scripts.

• cipher.py: This Script is used to encrypt a human readable message into a secure string.

• decipher.py: This Script is used to decrypt a secure string message into a human readable.

Output

Sample Outputs -

• cipher.py

  Enter the text to be encrypted: Manchester is BLUE
  Enter the shift key: 5
  Text before Encryption: Manchester is BLUE
  Shift Key: 5
  Encrypted text: Rfshmjxyjw nx GQZJ

• decipher.py

  Enter the text to be decrypted: Rfshmjxyjw nx GQZJ
  Enter the shift key: 5
  Text before Decryption: Rfshmjxyjw nx GQZJ
  Shift Key: 5
  Decrypted text: Manchester is BLUE

Author(s)

Made by Vybhav Chaturvedi