Security in the workspace - Part 3

It seems that we will have to learn to live and work in a de-perimeterized world. Acceptance of the problem is often the first step towards a solution. So, what alternatives to perimeter defense are there? And what is the impact of these alternatives on the future workspace and vice versa? Below are some thoughts. I hesitate to call these conclusions. Please consider these as starting points for a discussion.

• Defense in depth is the complete opposite of perimeter defense (when considering the location where controls are implemented). This security principle advises to apply multiple layers of security controls, so that if one layer fails other layers take over.
  
  • Unfortunately, complete defense in depth is increasingly expensive as it is difficult to maintain,
  • and because too many layers of security get in the way. (Is there a usabilty vs security trade-off? I'm not sure. But usability is probably not helped with adding multiple layers of security.)


• Most experts see a shift from perimeter defense (and other location based defenses) to data oriented security. (Perhaps that should be information oriented security?)
  
  • Because of the multiple contexts in which employees now process data, this requires some sort of watermarking of sensitive and valuable data. If, for example, lost information can be tracked back to employees responsible for that information than those employees can be held accountable for the loss. But wasn't DRM declared dead?
  • Moreover, data oriented security makes valuation of information necessary: relative sensitivity and value to the organization should be made explicit. Valuation of assets should be done anyway (as part of information risk management), but that doesn't mean that it is easy, cheap or common practice today!
  • Related to the above point: information should be stored and processed with a clear goal in mind (for reasons of Governance, Regulations, Complicance). This is at least as difficult as valuation.


• Accountability (the other A-word) may be an alternative to access control. Access control is somewhat problematic in the absence of a perimeter after all. Access control is expensive in the future workspace since employees join and leave the organization on a more regular basis (access credentials management is costly). Accountability certainly seems to be more compatible with the greater responsibility given to employees as part of the future workspace trends.


• Identity management is necessary, as accountability usually means a great deal of logging (of actions of employees). Logging obviously requires the capability to distinguish between employees (try holding individuals accountable for their actions when you can't tell them apart). However, since we left the perimeter behind us, we can't rely on the classical identity management process which involves provisioning, authentication, and authorization.
  
  • The provisioning problem could be overcome if we could use an established identity provider's infrastructure which extends beyond the bounds of the organization. The existing identity provider (I'm thinking of national governments) has the infrastructure for issuing authentication means to individuals already in place. If such a global identity provider is not (yet) possible, federated identity management and user-centric identity management may be alternatives (in the mean time).
  • Authentication has to be done decentralized (in absense of a perimeter with check points) and preferably as often as possible yet also as unobtrusive as possible. Perhaps context-information could help here?
  • Authorization, on the other hand, is better done centralized so as to achieve consistent rules which are easy to manage. Well-defined roles could be useful here
    

Other points? Leave a comment!

Security in the workspace - Part 2

The word de-perimeterization is used by security experts both to describe a problem and a solution. The problem is clear: when we rely on perimeter defense, a disappearing perimeter is problematic. The solution says that instead of fighting de-perimeterization, by trying to rebuild parts of the perimeter, we should admit that perimeters will be gone soon and implement our security measures on a different level.

What is causing the problem? Here are three major factors which seem to drive de-perimeterization:

• Networked Business: Suppliers, customers, and service providers all work with the organization on a much finer grained level than they used to. This is the result of specialization. An example is outsourcing: It can be very cost-effective to outsource certain tasks to more specialized organizations. Outsourcing requires so-called service level agreements: contracts between the organization and service provider about the quality of the services rendered. Security should be a part of such agreements as these parties operate within the perimeter.
• Governance, Regulations, Compliance: Organizations need to comply with more and more external laws and regulations. Often these call for more transparency towards shareholders, governments and the general public. This means that these parties need to pass the perimeter.
• Insider Threats: Employees are not the loyal workers they once were. Maybe most of them still are, yet some of them will try to gain access to your most valuable assets for personal gain. If you cannot trust your own employees, who operate within the perimeter, then you might as well get rid of the perimeter.

It is clear that each of these factors impacts the perimeter. Are there more?

The de-perimeterization factors are closely related to trends typically attributed to Future Workspaces. The difference is in the perspective. When I think of securing an organization, I tend to take the perspective of the organization. When I try to imagine what the workspace of the future will look like I tend to take the perspective of employees. We identify the following trends:

• Relation to employer (or, perhaps, loyalty to the organization)
  
  • Employees no longer work for one employer for 40 years but switch jobs regularly.
  • Employees work for different employers at the same time (I used to work here and here at the same time, which rarely led to conflicts of interest).
  • Professional social network of most employees is bigger than it used to be, extending well beyond the organization’s borders.
• Responsibilities
  
  • Employees are given greater responsibility in representing the organization.
  • Organizations are less hierarchically managed.
  • Employees (are encouraged to) write about their professional lives in blogs.
• Collaboration
• Not every organization has experts in every field. Organizations are aware of external experts (thanks to openness of other organizations) and encourage employees to collaborate with them.
• Work in different contexts
• Employees can work from home.
• Employees (especially knowledge workers) travel much more and work while in transit (using mobile devices).
• Employees work (while outsourced) at client.
• Employees work irregular hours.
• Employees work shorter hours, some colleagues may almost never meet in person.

At the very least we can claim that the Future Workspace trends reinforce the de-perimeterization factors. The de-perimeterization problem is made bigger and more urgent for organizations to deal with. In fact, many of the security incidents that organizations are faced with can be explained in terms of security controls which are part of the old perimeter defense interacting with employees' new found freedom.

In part 3 I will look at ways forward in the de-perimeterized future workspace.

A "Game-Theoretic" Analysis of De-perimeterization

De-perimeterization is a word which (despite being impossible to pronounce or spell correctly) is used more and more in discussions about security of organizations. Studying the effects of the disappearing perimeter in practice is difficult because organizations are complex and it is difficult to measure the quality of newly deployed security measures. Instead, let’s describe some of the issues of de-perimeterization here using an analogy with the well known board game Risk.

In Risk players occupy countries by placing armies on them. Given a configuration of the board where every player has a number of countries with armies, players can attack countries owned by other players from a neighboring country. If all armies of the defending player are completely defeated then that country is conquered and the attacker can place a number of armies on it.

Although luck is certainly a factor (the game uses no less than five dice) the general rule is that the more armies you bring to a fight, the bigger the odds that the country will (still) be yours at the end of the attack. When attacking, a great number of armies can be moved on to the newly conquered country. Armies can also be moved from one country to a neighboring country if owned by the same player when not attacking, but the number of movements is limited per turn. Playing Risk demonstrates that logistics is one of the most difficult parts of administering security.

Countries are organized in six continents. Continents are a lot like organizations: they contain assets (countries, armies) and they have a perimeter. A player receives bonus armies at the start of every turn in which a continent was completely owned by that player and was successfully defended.

Countries on the border of a continent form the perimeter of that continent. Perimeter countries need special attention because enemies need to first travel through perimeter countries before they can attack an inner country. Recall that if an attacker occupies any country of a continent held by a player, then the defender will not get his bonus at the beginning of their next turn. For the defender, moving most armies to the border countries seems therefore a good strategy. We will call this strategy Perimeter Defense.

At first, Perimeter Defense seems like a good idea. All players are each other’s enemies, after all. In practice, however, what happens is that players form temporary alliances so as to effectively attack a common enemy. The common enemy is typically the player with the most armies. This means, for example, that the members of an alliance agree to follow a certain attack strategy and agree not to attack each other for a number of turns so that they can keep borders between alliance-owned continents minimally manned. The armies no longer needed to defend alliance-owned borders can be better used to attack the common enemy with greater force.

But there are far more complex forms of cooperation possible within an alliance. A pattern that is often seen is that one player in the alliance allows another player to move troops over territory owned by the first player. The first player creates a corridor of countries occupied with only 1 army on them. The countries in the corridor are easily conquered by the second player when he attacks them with a great number of armies. Since moving armies during an attack is free, this allows a player to move a great number of troops towards the common enemy’s border, circumventing the per-turn troop movement limits. The second player also leaves only 1 army on the countries in the corridor, allowing the first player to easily recover the original countries of his continent later on.

So what are the alternatives to perimeter defense? It is tempting to think of Defense in Depth as the complete opposite of Perimeter Defense. In the Risk analogy naive Defense in Depth means equally distributing one’s armies over every country of a continent, both inner and border countries. Obviously this means that it becomes easier for a single enemy to occupy a border country (which means the defender won’t get his bonus armies). Yet at least the continent is more difficult to completely conquer by attackers. It very much depends on the situation (the agenda of other players, alliance agreements) whether Defense in Depth is a good strategy.

Defense in Depth also makes it more difficult to move armies to specific places, for example to allow a fellow alliance member to move troops across your continent. Yet, if one doesn’t completely trust the other players in the alliance a certain degree of Defense in Depth is actually a good thing. After all, when alliance member are moving troops through our corridors they should not be tempted too much to occupy our complete continent while they’re at it.

The real world consisting of real organizations is in many aspects much more complex than than simple board game world, if only because the goals of organizations are much more complex than simply ‘winning the game’. Still, real organizations also deal with security strategies. Two organizations will work together if it is of benefit to both of them (although usually not to mount an attack on the security perimeter of some competitor). At the same time organizations need to restrict access to their assets from outsiders as much as possible.

The problem is not that the perimeter is disappearing. The problem is that it is continually changing. The quality of a security strategy depends greatly on external forces such as the goals of other organizations. That these external forces change dynamically makes things even more complex.

Perimeter Defense and Defense in Depth are still good concepts to use when defining a mixed security strategy but much more important seems to be the ability to quickly change strategy. If security controls are resilient rather than brittle (see Schneier’s book Beyond Fear for an explanation of these concepts) then they can easily be used as part of a dynamically configurable perimeter.

(Thanks to Tim, Marcella, Victor, Suzana, Dragan, and Georgi for playing numerous games of Risk. Disclaimer: The author lost most of these games.)