B2B Integration : A Practical Guide to Collaborative E-commerce

Internet Security 301
There are multiple organizations which function as certification
authorities. Leading among them is Verisign (http://www.verisign.com),
which caters to institutions as well as individuals. It issues the following:
• E-mail Certificate — verifies that the e-mail comes from the mentioned
address;
• Server Certificate — establishes the identity of a particular Internet
site; and
• Code Signing Certificate — used by software companies to sign the
released versions of their code.
10.6.7. Using SSL (Secure Sockets Layer) to
establish secure sessions
Secure Sockets Layer (SSL) provides privacy, integrity and authentication
to application protocols such as HTTP by using encryption, message
digests, digital signatures and certificates. This is very valuable on the
Internet since it allows a much greater degree of secure communication
than is available without SSL. Most Web servers and browsers today
support SSL and implement it automatically, so users using these
browsers can utilize it directly.
SSL operates on top of the TCP/IP network layer (see Figure 10.10).
Therefore, any communication that relies on TCP/IP such as FTP file
transfer, news protocol (NNTP), remote login sessions (telnet, rlogin,
rsh) and e-mail (SMTP) can, in theory, be secured by SSL.
SSL performs the following:
• Allows an SSL-enabled server to authenticate itself to an SSLenabled
client;
HTTP SMTP NNTP
Application Layer
Network Layer
TCP/IP Layer
Figure 10.10. — Protocol stack for communications