Detailed Presentation about password security

1. ‘’ The Science of encrypTion ’’

2. • What is cryptography ?
• Why cryptography is important ?

3. Contents
• The purpose of cryptography
• History of cryptography and cryptanalysis
• Modern cryptography(Types of Algorithms)
- Secret Key Cryptography
- Hash Functions
- Public Key Cryptography
- Why Three Encryption Techniques?
- The Significance of Passwords & Password Security
• Conclusion

4. THE PURPOSE OF CRYPTOGRAPHY
Specific security requirements for communication:
Data transfer and telecommunication
Science of communications code
Computer writing in secret
 Authentication:
 Privacy/confidentiality:
 Integrity:
 Non-repudiation:

5. HISTORY OF CRYPTOGRAPHY
The history of cryptography can be divided into two
parts:
(1) From ancient civilizations to the 19th century and the
first part of the 20th century,
(2) Use of encrypting electro-mechanical
machines, around the period of the WW II.

6. HISTORY OF CRYPTOGRAPHY
Cryptography was used in three kinds of contexts in
Cryptography::
ancient times
 Private communications
Greek κρυπτός, kryptos,
 Art and religion
"hidden, secret"
 Military and diplomatic use

7. MODERN CRYPTOGHRAPHY
Here we have three types of algorithms that we can
talk about:
 Secret Key Cryptography
 Hash Functions
 Public Key Cryptography

8. MODERN CRYPTOGHRAPHY

9. SECRET KEY CRYPTOGHRAPHY
 Secret Key(Symmetric) Cryptography uses a single
key for both encryption and decryption.

10. SECRET KEY CRYPTOGHRAPHY
 A single key is used
 Sender uses the key to encrypt
 Receiver uses the same key to decrypt
 Key must be known to both the sender and the
receiver
 The difficulty is the distribution of the key

11. SECRET KEY CRYPTOGHRAPHY
Secret key cryptography algorithms that are in use
today :
 Data Encryption Standard (DES):
 Advanced Encryption Standard (AES):
 International Data Encryption Algorithm (IDEA):

12. SECRET KEY SUMMARY

13. HASH FUNCTIONS
 Hash functions(One-way cryptography) have no
key since plaintext cannot be recovered from the
ciphertext.

14. HASH FUNCTIONS
 Called message compiler and one-way encryption
 No key is used
 Digital fingerprint
 Provide the integrity

15. HASH FUNCTIONS
Hash algorithms that are in common use today:
 Message Digest (MD) algorithms:
 HAVAL (Hash of Variable Length):
 Tiger:

16. PUBLIC KEY CRYPTOGHRAPHY
 Public Key(Asymmetric) Cryptography. Two keys are
used. One for encryption, one for decryption.

17. PUBLIC KEY CRYPTOGHRAPHY
 Developed in the last 300-400 years.
 Martin Hellman and graduate student Whitfield
Diffie
 A two-key crypto system
 Mathematical functions

18. PUBLIC KEY CRYPTOGHRAPHY
Mathematical Functions :
 Multiplication vs. factorization:
 Exponentiation vs. logarithms:

19. PUBLIC KEY CRYPTOGHRAPHY

20. PUBLIC KEY SUMMARY

21. Why Three Encryption Techniques?
 Why are there so many different types of
cryptographic schemes?
 Why can't we do everything we need with just
one ?

22. THE SIGNIFICANCE OF PASSWORDS
 Every password can be decyrpted.
 In cryptography, size does matter.

23. How to create & use strong
Passwords

24. How to create & use strong
Passwords
 Use lengthy passwords.
THANK YOU symbols.
 Combine letters, numbers, and
FOR LISTENING TO US (:
 Use words and phrases.