programming-for-dummies

640
Secure Computing
That’s one of the reasons why Microsoft Windows XP (and earlier incarnations
of Windows) has proven so vulnerable to malware and hackers.
Windows was designed under the assumption that only one person would
use the computer and no programs (or people) would deliberately try to
wreck the computer.
Then along came the first wave of computer viruses, followed by a second
wave of computer worms, Trojan horses, and spyware that has cluttered and
clogged most Windows computers as effectively as throwing sand and metal
shavings inside a Formula One race car engine.
Now the assumption is that malware will try to take down computers and
hackers will try to break into them. That’s why secure computing tries to
build security into a program as part of the design process. So not only must
programmers learn the basics of object-oriented programming and algorithm
analysis, but they must also learn the practices of secure computing as well.
Patching as an afterthought
Because so many programs were originally designed without security in
mind, it’s no surprise that much computer security work involves analyzing
the security flaws of an existing program and then writing a patch that fixes
those problems.
Every program has flaws, so every program needs patching. Armies of programmers
love probing programs — especially the major ones, like Windows
XP, Linux, Max OS X, and Vista — so they can be the first one to report a possible
flaw in a program. Programmers devote their time to uncovering the
flaws in other programs to enhance their own reputation (which can translate
into better job opportunities), but also for the sheer challenge of looking
for weaknesses in other people’s programs.
After someone discovers a flaw in a program, other programmers typically
verify that the flaw does exist, examine how the flaw could be exploited as a
security risk, and then write a software patch that fixes that problem (and
hopefully doesn’t introduce any new problems).
Microsoft’s service packs for Windows are typically one massive patch to fix
numerous flaws found in Windows. Of course, people find flaws in Linux and
Mac OS X regularly too, but Windows gets the most attention because it’s
been the dominant operating system for so many years.
Security in coding
Rather than wait for flaws to appear and then waste time patching these
flaws that shouldn’t have been in the program in the first place, another
form of computer security involves making securing programs from the