The days of creating an enterprise security border, defining a set of controlled applications, and designing a security system that can assure security, privacy, and compliance within a corporation's confines are gone. Today, it's daunting to simply try to define where a business begins and ends--in an era of mobile workers, huge social networks, and IT infrastructures that mix in-house applications with SaaS options.

In conjunction with the upcoming RSA security conference, I asked a group of CIOs and security analysts for their suggestions on dealing with security in an increasingly wide-open world.

How wide open? As background, consider these recent pieces of security news:

-- Nortel Networks suffered a series of hacks that allowed access to a wide range of corporate email, documents, and other data for nearly a decade.

-- Some security experts advise that companies with employees traveling overseas (especially China) tell travelers to leave the regular laptop and smartphone at home, grab a new system before boarding the plane, and get rid of it after the trip.

-- The computer hacking group Anonymous has evolved from rudimentary hacking skills to a sophistication level that some government officials contend can threaten key infrastructure, including the power grid.

Now, consider some security advice for this new environment.

Fran Rabuck, formerly the director of the real time asset labs at Bentley Systems and director of applied business technology at Towers Perrin, is an independent technology consultant with a focus on mobile applications. "If mobile applications are part of your future plans and rollout, you need to pay even more attention to securing them than you do desktops or laptops," Rabuck stated via email.

Why are mobile applications particularly vulnerable? Rabuck listed four key reasons:

Global CIOs: A Site Just For You Visit InformationWeek's Global CIO -- our online community and information resource for CIOs operating in the global economy.

1. Desktops aren't lost or misplaced like smartphones.