IPv6: The Next Generation Internet Protocol
A practical, hands-on guide to the new version of the Internet Protocol, written for network administrators and managers who will work with IPv6.
TABLE OF CONTENTS IPv6: The Next Generation Internet Protocol
Chapter 15: IPv6 Architectural Specifics
15.1 INTRODUCTION
This chapter looks at the DES-CBC security transform for the IP Encapsulating Security Payload (ESP) described in Chapter 14. As discussed earlier, the Encapsulating Security Payload (ESP) yields confidentiality for IP data-grams as it encrypts the payload data to be protected. In this section we will look at how ESP uses the Cipher Block Chaining (CBC) mode. However, it is important to point out that security relies completely upon the power of the US Data Encryption Standard (DES) algorithm. The accuracy of that algorithm's implementation, the security of the key management mechanism, and the power of the key all depend on the accuracy of the implementations that are present in the cooperating nodes.
Any implementation that states it has conformance or compliance with the Encapsulating Security Payload specification is required to implement this DES-CBC transform. This section builds upon the Security Architecture for the Internet Protocol outlined in the last chapter which designates the overall security plan for IP, and yields an important foundation for this specification.
15.2 SECRET KEYS
The secret DES key is used jointly between the communicating parties measures eight octets in length. This key is composed of a 56-bit quantity employed by the DES algorithm. The 56-bit key is recorded as a 64-bit eight octet quantity, which has the least significant bit of each octet employed as a parity bit. Both encryption and authentication in transport and tunnel modes are shown in Figure 15.1.
The specific mode of DES needs an Initialization Vector (IV)...
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