This document provides an overview of cryptography and security. It discusses symmetric and asymmetric cryptography, comparing their basic approaches. Symmetric cryptography uses the same key for encryption and decryption, while asymmetric cryptography uses different public and private keys. The document also defines basic cryptography terms like plain text, cipher text, and encryption/decryption. It describes traditional substitution and transposition ciphers as well as modern symmetric and asymmetric techniques. The goal is to maintain data security, confidentiality, authentication, and integrity through the appropriate use of encryption.

2. SECURITY
SECURITY THREATS
SECURITY GOALS
WHAT IS CRYPTOGRAPHY
BASIC TERMS
ENCRYPTION & DECRYPTION
CATEGORIES OF CRYPTOGRAPHY
COMPARISON
CONCLUSION

3. SECURITY???
Network security is an over arching term.

4. 1. Passive threats
2. Active threats

7.  PLAIN TEXT
 CIPHER TEXT
 CIPHER
 ENCRIPTION & DECRYPTION
 KEYS

9. A. Symmetric cryptography
B. Asymmetric cryptography

10. SYMMETRIC KEY CRYPTOGRAPHY
o also known as secret key cryptography.
o Sender & receiver uses same key for
encryption & decryption namely public key

12. a. Traditional cipher
b. Modern cipher
Two types traditional cipher
i. Substitution cipher
ii. Transposition cipher

13. A substitutional cipher is one in which the
letters/numbers/symbols is replaced by other
letters/numbers/symbols
e.g
A d, t z
2 5, 3 6

15.  Also known as public key
 Sender and receiver uses
 different keys for encryption and
 decryption namely public & private key

18. COMPARISON
Symmetric key cryptography Asymmetric key cryptography
1. The same algorithm with
same key is used for
encryption & decryption
2. The key must be kept
secret
3. may be impossible or at
least impractical to
decipher a message if no
other information is given
1. One algorithm is used for
encryption & other for
decryption with a pair of
keys respectively
2. One of the key must be
kept secret
3. It may be impossible or at
least impractical to
decipher a message if no
other information is given

19. • Defense services
• Secure data manipulation
• Business transactions
• Internet payment systems
• User identification systems
• Acess control
• Data security

20.  By using of encryption techniques ,a fair unit of
confidentiality,authentication,integrity,acess control and
availability of data is maintained

21. thanks