Seemingly everyone has insight into the open source versus closed source security debate. Each side provides plausible arguments for the benefits of their own model and points out drawbacks of the other. The proponents of open source argue that the source code is open and available for anyone to see, for many sets of eyes to examine, and is therefore more secure. Opponents of open source say that this "many eyes" theory is irrelevant since the vast majority of users will never look at the source code. Countless arguments ensue from there and can get quite derived, much like arguments over the exact number of episodes of Star Trek.

Looking past these arguments, it's helpful to examine the theory of security as it is approached by open and closed source software organizations. To that end I'll look at the security approach of the Debian Linux project as compared to the security approach of Microsoft - I'll use Microsoft as an example acknowledging the important role that they play as a target of security-related attacks due to their market share in the desktop operating system environment.

Security for both Debian and Microsoft is chiefly accomplished through the use of software patches. Debian issues patches for Debian-specific software problems as well as non-Debian-specific problems. These patches run the gamut of any of the thousands of software packages available with Debian. Some of this software isn't even Linux specific but runs on other operating systems as well, including Microsoft Windows. Microsoft releases patches only for Microsoft-specific software.

With the thousands of software packages available with Debian, security bugs are impossible to avoid. Most updates are not specific to Debian but rather affect the software as it runs on Linux, Mac OS X, and Microsoft Windows alike. Regardless, the software updates become available to users of Debian Linux through the apt package utility. Even if the problem isn't directly related to operating system functionality, the update is easily downloaded and automatically installed. On the other hand, updates for Microsoft through the default "Automatic Update" service consist of what Microsoft terms to be core functions. These core functions include updates to bundled products such as Internet Explorer and Media Player but don't include updates to other Microsoft software such as Microsoft Office, Exchange, SQL Server, and others. Security flaws in this additional software can lead to full compromise of the computer and the data contained therein, as is the case with operating system flaws.

The timing of security updates best reveals the differences in how the two models approach security. One of the aspects of open source security is transparency - virtually as soon as a security flaw, theoretical or practical, is reported, it's released to the general public so that users of the software can take steps to mitigate the effects of the security flaw. A patch follows very shortly after for all of the popular open source software packages. If a patch isn't readily available within hours, the community frequently steps up to release an intermediate patch and to help others mitigate problems associated with the flaw.

On the other hand, Microsoft has undertaken the policy of releasing patches only monthly for the operating system functions. While this results in fewer security notices to the public, it does nothing to enhance security. In fact, releasing patches on a monthly cycle rather than as necessary increases the possibility of exploit. The only people who know about the exploit are the people responsible for finding it and Microsoft. Of course, the people who find software exploits are all honest individuals with no ill intentions, right? Imagine that a burglar found a new way to pick door locks and shared this information with their friends-in-crime, and the police found out about the impending crime spree. Now imagine the police did nothing to alert the public about this danger because they only talked to the public monthly. Transparency and openness of security flaws and defects in products should be demanded by customers for their own safety.

Comparing the security approaches of open and closed source software organizations illustrates the inherent structural differences between the two models. Open source organizations such as Debian believe in greater protection, openness, and transparency of the security process so that their users can protect themselves. Closed source organizations such as Microsoft believe that they know best how, where, and when to disseminate information about security flaws. Unfortunately for users, this means quietly, discreetly, and belatedly.