identity of the sender of the data, as well as the identity of the Authori-
tative Directory Service operator, is ensured using SSL and mutual
authentication. Further security of the database is assured by giving
users access only to their own data. After the identity of a user is estab-
lished through two-factor authentication, users cannot change or enter
data that does not belong to them. Finally, the use of SSL eliminates the
risk of data tampering, as well as providing privacy through encryption
of sensitive information.
■■ Physical security—The facilities in which the DNS servers reside are pro-
tected by physical security measures, including 24×7 secured access,
video camera surveillance, security breach alarms, and secured equip-
ment cabinets. State-of-the-art firewall appliances, VPN equipment, and
hardened server operating systems provide network security.Summary
The Internet Domain Name System is an essential component for Internet
communications, since it allows routing e-mails, telephone calls, and other
communication requests to the right services and to the desired party.
ENUM service is part of the DNS and is extremely valuable for users of the
existing switched telephone systems. ENUM remains valuable even in an end-
to-end IP communications environment. Since there will be a long transition
time to universal IP communications, if and when this happens, ENUM
remains a powerful service that is also application-independent.
DNS and ENUM security are critical to Internet communications and strong
security is used to protect the DNS and ENUM data.
References
[1] “Understanding DNS,” Microsoft Technet, 2005, http://technet
.microsoft.com/default.aspx.
[2] “DNS Tutorial at the 63 IETF,” http://edu.ietf.org/node/view/48.
[3] “The E.164 to Uniform Resource Identifiers (URI) Dynamic Delegation Dis-
covery System (DDDS) Application (ENUM)” by P. Fallstrom and M. Meal-
ing. RFC 3761, IETF, April 2004.
[4] “Universal Resource Identifiers in WWW: A Unifying Syntax for the
Expression of Names and Addresses of Objects on the Network as used in
the World-Wide Web” by T. Berners-Lee. RFC 1630, IETF, June 1994.
[5] See the IANA home page at http://www.iana.org.
[6] “The mailto URL scheme” by P. Hoffman et al. RFC 2368. IETF, July 1998.
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