©Brooks/Cole, 2003 Chapter 16 Security
©Brooks/Cole, 2003 Define four aspects of security in a network: privacy, authentication, integrity, and nonrepudiation. Understand how these aspects can be achieved using encryption and decryption. Understand the difference between secret-key and public-key encryption. After reading this chapter, the reader should be able to: O BJECTIVES Realize how a digital signature can provide privacy, integrity, and nonrepudiation.
©Brooks/Cole, 2003 Figure 16-1 Aspects of security
©Brooks/Cole, 2003 PRIVACYPRIVACY 16.1
Figure 16-2 Secret key encryption
©Brooks/Cole, 2003 In secret key encryption, the same key is used in encryption and decryption. However, the encryption and decryption algorithms are the inverse of each other. Note:
©Brooks/Cole, 2003 Figure 16-3 DES
©Brooks/Cole, 2003 Figure 16-4 Public key encryption
©Brooks/Cole, 2003 Figure 16-5 RSA
©Brooks/Cole, 2003 Figure 16-6 Combination
©Brooks/Cole, 2003 DIGITALSIGNATUREDIGITALSIGNATURE 16.2
Figure 16-7 Signing the whole document
©Brooks/Cole, 2003 Figure 16-8 Signing the digest
©Brooks/Cole, 2003 Figure 16-9 Sender site
©Brooks/Cole, 2003 Figure Receiver site