11 WLANs.
2.2.5.1 Concepts of Secure Communications
Communications security is often described in terms of three elements:
??? Authentication ensures that nodes are who and what they claim to be.
??? Confidentiality ensures that eavesdroppers cannot read network traffic.
??? Integrity ensures that messages are delivered without alteration.
Authentication is typically based on demonstrating knowledge of a shared secret, such
as a username and password pair. In more complex systems, possession of the shared secret
may be demonstrated by proving possession of a token that is more difficult to steal or
forge, such as a certificate or a smart card.
Confidentiality is typically protected by encrypting the contents of the message.
Encryption applies a known, reversible method of transformation (called a cipher or
encryption algorithm) to the original message contents (called the plaintext), scrambling or
disguising them to create the ciphertext. Only those who know how to reverse the process
(decrypt the message) can recover the original text. The most common forms of encryption
are mathematical transformations which use a variable called a key as a part of their
Guide to Wireless LAN Analysis 20
manipulations.
Pages:
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111