Random words

So what does cryptography really mean?

The word cryptography is actually two words mushed together

Cryptography = Crypto + graphy

• Crypto → secret\hidden
• Graphy → writing

OK Ahmad get to the point, define cryptography now!

Cryptography is the science and art of using methods of message concealment.

Other terms you should know in relation to this course are the following:

• Cryptanalysis which is the breaking of message concealment.
• Cryptology which is the study of cryptography, cryptanalysis and the intersection between them.
  • logy → study.

Our friends throughout this course

Believe it or not there are a few names we need to familiarize ourselves with because we’ll hear them often! These are the friends of this course who each tend to have their own routine we’ll be exploring.

• Alice and Bob → Alice and Bob are good friends who want to have a private conversation without anyone hearing them or getting between them.
• Eve → This is Alice and Bobs’ curious acquaintance who isn’t invited to their private conversation but keeps trying to find ways to eavesdrop ( see what i did there?) :3 .
  • we call eve a passive attacker.
• Malory → This is our villain in the story, she want’s to end Alice and Bobs’ friendship by changing the contents of their messages and have them miscommunicate, Malory has malicious intent ;).
  • we call Malory an active attacker.

Basic Components of Cryptography

Okay so we have two basic components here

• Plaintext → Human readable text (without cryptography stuff in it).
• Ciphertext → Gibberish stuff that we as humans cant read without performing some operation (data with cryptography stuff in it).