Policy is not enough. Ensuring sensitive information is handled in accordance with internal policy and regulatory constraints requires monitoring of all activities associated with it. In other words, inspect what you expect… continuously. Further, too much reliance on human behavior is a recipe for security disaster.
This week, we learned that the University of Michigan Health System, via a vendor, lost about 4000 patient records. The vendor, apparently authorized access, copied patient records from a database to an unencrypted device. The device, left unattended in a vehicle, was then stolen. Sound familiar? It should. This scenario appeared many times in news articles over the last several years. While the players differed, the gaps leading to the losses were largely the same.
This set of conditions is growing more common. They are strengthened with an increasing number of devices filling the role of insecure mobile data storage, as the BYOD (bring your own device) phenomenon continues to complete its hold on business operations. Managers and business owners who believe they can simply write a policy, train employees, and move on to the next challenge are kidding themselves.
(For a detailed look at how competing interests apply pressure every day to employees trying to do the right thing, see Bruce Schneier’s Liars and Outliers.)
So what can we do to protect ourselves from becoming the topic of yet another subject in an article about mobile data loss? Plenty.
For traditional access control environments…
First, ensure your policies have teeth. For example, what are the sanctions for a vendor or employee who fails to follow policy? Next, implement reasonable and appropriate technical controls to monitor traffic (e.g., IPFIX data) and aggregated logs (i.e., SIEM). IPFIX, for example, provides near real time information about anomalous data flows: like a vendor copying 4000 records from a database. Finally, implement a process whereby IPFIX and SIEM alerts prompt an immediate review of who did the copying, what they copied the data to, and whether the target device is in compliance with policies addressing data on the device category into which it falls. For example, if security sees a data transfer to a mobile device, they should confirm that the device is encrypted and the user authorized to carry the data out of the building…
For policy-based organizations…
As BYOD expands the corporate attack surface, policy-based access controls augment the steps listed above. By default, do not allow anyone to copy data to a mobile device that does not meet policy requirements for data protection. Policy-based controls authorize user access based on user role, the device used, the location of the user/device, the data and processes accessed, day of the week and time access is requested, and the device’s compliance with security policy. All of this is automated, preventing reliance on human behavior to protect data.
(For more information on policy-based access controls (also known as context-based access controls), see Chapter 9: Securing Remote Access. )
Again, policies are not enough. Without technical controls, they rely on human behavior to protect data. This is a bad idea. Instead, implement technical controls as far as is reasonable for your organization, and then monitor for compliance to ensure people, processes, and technology are producing expected security outcomes.