1. Cryptography Introduction

2. Definition Origin Objectives Terminologies References Agenda

3. The word is derived from the Greek word kryptos, meaning hidden or secret. Cryptography is the practice and study of techniques for secure communication in the presence of third parties called adversaries. Definition

4. The origin of cryptography is usually dated from about 2000 BC, with the Egyptian practice of hieroglyphics (complex pictograms) The first known use of a modern cipher was by Julius Caesar, who did not trust his messengers when communicating with his governors and officers. For this reason, he created a system in which each character in his messages was replaced by a character three positions ahead of it in the Roman alphabet. Origin

5. 1.Confidentiality (the information cannot be understood by anyone for whom it was unintended) 2.Integrity (the information cannot be altered in storage or transit between sender and intended receiver without the alteration being detected) 3.Non-repudiation (the creator/sender of the information cannot deny at a later stage his or her intentions in the creation or transmission of the information) 4.Authentication (the sender and receiver can confirm each others identity and the origin/destination of the information) Objectives

6. 1.Plaintext - information a sender wishes to transmit to a receiver 2.Ciphertext - result of encryption performed on plaintext using an algorithm 3.Encryption - process of translating plain text data (plaintext) into something that appears to be random and meaningless (ciphertext) 4.Decryption - process of converting ciphertext back to plaintext 5.Cryptanalysis - how to crack encryption algorithms or their implementations 6.Cryptology - the Math Behind Hiding and Breaking Messages Terminologies

7. References: https://en.wikipedia.org/wiki/Cryptography http://searchsoftwarequality.techtarget.com/definition/cryptography

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