Crypto

Getting Started

In Wednesday's lecture we talked about single alphabetic encryption. The exercise today will ask you to write four methods that deal with that. The framework is already written and can be found in the code directory. A simple test framework in main is also included.

Classwork/Lab

  1. Write makeCode. You want the leave a jumbled encryption alphabet in the string encrypt. Its meaning is that the first letter in the string is what 'A' is mapped to, the 2nd, what 'B' is mapped to, etc.
  2. Write enCode. This method should use the alphabet in encrypt to translate your original message in clearText the an encrypted message in cryptText. (Note that non-letters, spaces and punctuation, should not be translated. Just leave them unchanged.)
  3. Write makeDecode. This method should create a decryption alphabet in decrypt that will be used the translate your encrypted message back to the original.
  4. Write deCode. Use the decryption alphabet to recover your original message into recoverText (Again: note that non-letters, spaces and punctuation, should not be translated. Just leave them unchanged.)

Sample Run 

Enter text 
testing one two three
Input text
TESTING ONE TWO THREE
Encryption alphabet
MALJCOEWSUQDIXKBVZTNPFHYGR
Encrypted text
NCTNSXE KXC NHK NWZCC
Decryption alphabet
BPELGVYWMDOCATFUKZISJQHNXR
Recovered text
TESTING ONE TWO THREE

Submit

Create a README file with both of your names in it if you work with a partner.

Electronically submit the classwork through Eclipse your Java code and README file to the Lab32 folder.