1. ow Encryption for Strong Security Works
WAN
firewall
link encryption
VPN
. – p.1/6

2. WAN
Wide Area Network (WAN) is a computer network that
covers a broad area (i.e., any network whose
communications links cross metropolitan, regional, or
national boundaries). Less formally, a WAN is a wireless
network that uses routers and public communications links.
. – p.2/6

3. firewall
A firewall is an integrated collection of security measures
designed to prevent unauthorized electronic access to a
networked computer system. It is also a device or set of
devices configured to permit, deny, encrypt, decrypt, or
proxy all computer traffic between different security
domains based upon a set of rules and other criteria.
. – p.3/6

4. link encryption
Link encryption is an approach to communications security
that encrypts and decrypts all traffic at each end of a
communications line (e.g. a teletype circuit). It contrasts
with end-to-end encryption where messages are encrypted
by the sender at the point of origin and only decrypted by
the intended receiver.
. – p.4/6

5. VPN
A virtual private network (VPN) is a computer network in
which some of the links between nodes are carried by open
connections or virtual circuits in some larger network (e.g.,
the Internet) instead of by physical wires.
. – p.5/6

6. References
Wikipedia
http://en.wikipedia.org/
Yahoo
http://www.yahoo.com/
. – p.6/6