The Interrelated Nature of Authentication and Encryption

Authentication is needed to identify people and devices. It provides people or devices
with the authority to access delivery or memory bandwidth—including the right to
deposit information in and retrieve information from secure storage. It provides
people or devices with the authority to change network parameters—for instance,
software upgrades or hardware reconfiguration. It also provides people or devices
with the authority to change handset parameters—software upgrades or hardware
reconfigurations.

Authentication may be used for:
 Identification and the enforcement of access rights and security policies
 Content distribution
 Application distribution
 Transaction processing
 Virtual data warehousing (storage)
We may need to authenticate device hardware in a network to prevent a security
breach. For example, it is technically feasible to replace a router without a network
operator’s knowledge and then use the router to eavesdrop on traffic or filter out traffic
of commercial or political value.
We may also need to authenticate to provide transaction security, for example, if we
are using a digital cellular handset to make micro or macro payments.
Authentication can be given for a particular period of time—the length of a session,
for example—and then needs to be renewed. Authentication can also be for a long
length of time. The right to access storage 900 years from now (recall the Domesday
project in Chapter 6) would be an extreme example.
Absolute authentication does not exist. We can never be totally certain that a device
is the device that it claims to be or the person is the person he or she claims to be. The
more certain we are, however, the more value we confer on the authentication process.
Certainty is achieved by distance, which is how unique we make the authentication.
Distance confers value but also incurs cost. The cost is processor overhead and delay.
Usually, authentication requires more information to be sent and therefore also absorbs
delivery bandwidth and RF power. 198