Sybex CEH Certified Ethical Hacker Version 8 Study Guide

404 Chapter 17 ■ Physical Security
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Lock types include
Mechanical (warded and pin-and-tumbler)
Cipher locks (smart and programmable)
Warded locks are the simplest form of mechanical lock. The design of mechanical locks
uses a series of wards that a key must match up to in order to open the lock. Although it is
the cheapest type of mechanical lock, it is also the easiest to pick. Pin-and-tumbler locks
are considered more advanced. These locks contain more parts and are harder to pick than
warded locks. When the correct key is inserted into the cylinder of a pin-and-tumbler lock,
the pins are lifted to the right height so that the device can open or close. More advanced
and technically complex than warded or pin-and-tumbler are cipher locks, which have a
keypad of fixed or random numbers that requires a specific combination to open the lock.
Figure 17.3 shows a cipher lock.
FIGURE 17.3 One kind of cipher lock
Locks are good physical deterrents and work quite well as a delaying mechanism, but
a lock can be bypassed through lock picking. Lock-picking is not the fastest way to
bypass a lock but can be used to avoid detection. Criminals tend to pick locks because it is