Internet & Intranet Security Management - Risks & Solutions

has not been altered during transmission.
• IP Encapsulated Security Payload (ESP). ESP provides data confidentiality. This means, only
legitimate recipients of an IP packet (hosts) are able to read its content.
Secure Sockets Layer
The Secure Sockets Layer protocol (SSL) (Bhimani, 1996) is a protocol layer developed by Netscape
Communications Corporation which may be placed between a reliable connection-oriented network
layer protocol (e.g. TCP) and the application protocol layer (e.g. HTTP). SSL protects the
communication stream between client and server by providing mutual authentication, integrity and
privacy. One common use of SSL is to secure HTTP communication between a Web client and a Web
server. In this case, SSL connections are initiated from a Web client through the use of special URL
prefix. For example,
Table 9.
SSL runs above TCP/IP and below application protocols (e.g. HTTP)
the prefix ''https:" is used to indicate an HTTP connection over SSL (see Figure 9).
SSL provides a range of security services for client/server sessions. The SSL protocol includes two
sub-protocols: the SSL record protocol and the SSL handshake protocol. The SSL record protocol is
layered on top of some reliable transport protocol (e.g., TCP) and deals with data fragmentation,
compression, authentication, and encryption/decryption. The SSL record protocol provides:
• Integrity. Data items transferred in the session are protected against modification with an integrity
check-value.