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1. Levels of System Information
Security
Presented by:
REETU PAWAR

2. 2
INTRODUCTION
• Multilevel security or multiple levels of security is the application of a
computer system to process information with incompatible classifications ,
permit access by users with different security clearances and needs-to-know,
and prevent users from obtaining access to information for which they lack
authorization.
• There are various ways to implement security:
Cryptography
Digital signature
Authentication using passwords
Authentication using a physical object
Authentication using biometrics

3. 3
CRYPTOGRAPHY
Relationship between the plaintext and the ciphertext

4. 4
DIGITAL SIGNATURES
• Computing a signature block
• What the receiver gets
(b)

5. 5
AUTHENTICATION USING
PASSWORDS
(a) A successful login
(b) Login rejected after name entered
(c) Login rejected after name and password typed

6. 6
AUTHENTICATION USING A PHYSICAL
OBJECT
• Magnetic cards
– magnetic stripe cards
– chip cards: stored value cards, smart cards

7. 7
AUTHENTICATION USING BIOMETRICS
A device for measuring finger length.