Tuesday, July 30, 2013

The Cost of a Near-miss Data Breach

[This post originally appeared in the New School of Information Security blog on October 6, 2009.  This idea was incorporated in the breach impact model presented in this paper, where you can find more details: ]
How Bad Is It?–A Branching Activity Model to Estimate the Impact of Information Security Breaches

If one of your security metrics is Data Breach Cost, what is the cost of a near miss incident? This seemingly simple question gets at the heart of security metrics problem.

Jerry escapes death, but is it cost-free?
Consider the gleeful Jerry Mouse in this cartoon. Tom the Cat has just missed in his attempt to swat Jerry and turn him into mouse meat. Is there any cost to Jerry for this near miss? Is Jerry’s cost any different than if he was running with Tom no where in sight?

By “near miss” I mean a security incident or sequence of incidents that could have resulted in a severe data breach (think TJX or Heartland), but somehow didn’t succeed. Let’s call the specific near-miss event “NM” for short. For sake of argument, let’s assume that the lack of attack success was due to dumb luck or attacker mistakes, not due to brilliant defenses or detection. Let’s say that you only discover NM long after the events took place. For simplicity let’s assume that discovering NM doesn’t result in any extraordinary costs, meaning that out-of-pocket costs are the same just before and immediately after NM. Finally, assume that your expected cost of a successful large-scale data breach is on the order of tens of millions, with the worst case being hundreds of millions of dollars.

How much does NM cost? The realist answer is “zero”. (Most engineers are realists, by disposition and training.) There is a saying in street basketball that expresses the realist philosophy about losses and associated costs: “No blood, no foul”. If you ask your accountants to pour over the spending and budget reports, they will probably agree. Case closed, right?

Not so fast….

Monday, July 29, 2013

Think You Understand Black Swans? Think Again.

"Black Swan events" are mentioned frequently in tweets, blog posts, public speeches, news articles, and even academic articles.  It's so widespread you'd think that everyone knew what they were talking about. But I don't.

Coming soon: 23 Shades of Black Swans
I think the "Black Swan event" metaphor is a conceptual mess.

Worse, it has done more harm than good by creating confusion rather than clarity and by serving as a tool for people who unfairly denigrate probabilistic reasoning.  It's also widely misused, especially by pundits and so-called thought leaders to give the illusion that they know what they are talking about on this topic when they really don't.

But rather than just throwing rocks, in future posts I will be presenting better/clearer metaphors and explanations -- perhaps as many as 23 Shades of Black Swan.  Here are the ones I've completed so far:
  1. Grey Swans: Cascades in Large Networks and Highly Optimized/Critically Balanced Systems
  2. Green Swans: Virtuous Circles, Snowballs, Bandwagons, and the Rich Get Richer
  3. Red Swans: Extreme Adversaries, Evolutionary Arms Races, and the Red Queen
  4. Disappearing Swans: Descartes' Demon -- the Ultimate in Diabolical Deception
  5. Out-of-the-Blue Swans: Megatsunami, Supervolcanos, The Black Death, and Other Cataclysms
  6. Orange TRUMPeter Swans: When What You Know Ain't So
  7. The Swan of No-Swan: Ambiguous Signals Tied To Cataclysmic Consequences
  8. Swarm-as-Swan: Surprising Emergent Order or Aggregate Action
  9. Splattered Swan: Collateral Damage, Friendly Fire, and Mis-fired Mega-systems 
In this post, I just want to make clear what is so wrong about the "Black Swan event" metaphor.

Saturday, July 27, 2013

QOTW: Strategy is not predicting the future. Instead, it's about making decisions today to be ready for an uncertain tomorrow - Drucker

This quote is from Peter Drucker, p 125 of his 1974 classic book: Management: Tasks, Practices, Responsibilities (Harper and Row).  Though it talks about strategic planning, the same applies to risk management (emphasis added):
"Strategic planning does not deal with future decisions.  It deals with the futurity of present decisions.  Decisions only exist in the present.  The questions that faces the strategic decision-maker is not what his organization should do tomorrow.  It is, 'What do we have to do today to be ready for an uncertain tomorrow?'  The question is not what will happen in the future.  It is, 'What futurity do we have to build into our present thinking and doing, what time spans do we have to consider, and how do we use this information to make a rational decision now?'"

Friday, July 26, 2013

Visualization Friday: 14 dimensions represented in 2D using MDS, Colors, and Shapes

For the last three years I've been building an Agent-based Model (ABM) of innovation ecosystems to explore how agent value systems and histories mutually influence each other.  The focus to this point has been on Producer-Consumer relationships and the Products they produce and consume.

One of my key challenges has been how to visualize changes in agent value systems as new products are introduced.  Products have surface characteristics defined as a 10-element vector of real numbers between 0 and 1.  Consumers make valuation decisions based on their perception of these 10 dimensions compared to their current "ideal type".  But they realize utility after consuming based on three "hidden" dimensions.  Adding on the dimension of consumption volume, this means I need to somehow visualize 14 dimensions in a 2D dynamic display.

The figures below show my solution.  Products are represented by black squares, while Consumer ideal points are represented by blue dots.  (There are about 200 Consumers in this simulation.)  Products that are not yet introduced are represented by hollow dark red squares.  The 10 dimensions of Product surface characteristics are reduced to 2D coordinates through Multi-Dimensional Scaling (MDS).  Therefore the 2D space is a dimensionless projection where 2D distances between points is roughly proportional to distances in the original 10 dimensions.

The three utility dimensions are represented by colored "spikes" coming off of each Product.  The length of each spike is proportional to the utility offered by that Product on that dimension.

Finally, the proportion of the Product population is represented by a dark red circle around each product (black filled square).

These two plots show the same simulation at different points in time, about 300 ticks apart, showing the effect of the introduction of several new products.  What we are looking for is patterns and trajectories of Consumer ideal points (blue dots).

Putting these all together:

  • Dots are close or distant in 2D space according to how they are perceived by Consumers based on surface characteristics.
  • Products that are close to each other in 2D space may or may not have similar utility characteristics (spikes).  This reveals the "ruggedness" of the "landscape", and thus the search difficulty faced by Consumers.
  • The circles around each product allow easy identification of popular vs unpopular products.
Initial Consumer ideal points (blue dots) after 1000 ticks, given 5 initial Products (black filled squares in center), plus one new Product (far left).  Red arrow points to a product with low utility on 3 dimensions.  -- click to see larger image.
Consumer ideal points (blue dots) after 1367 ticks, showing influence of new Product (black dot on far left).  Notice large increase in popularity of product pointed to by red arrow.  Though it has relatively low utility on all three dimensions, it is a "bridge" between products on right side and new (high utility) product on left side. -- click to see larger image.




Thursday, July 25, 2013

Tutorial: How to Value Digital Assets (Web Sites, etc.)

[This originally appeared in the New School of Information Security Blog in two posts, Oct 20 and 23, 2009]

Many security management methods don’t rely on valuing digital assets.  They get by with crude classifications (e.g. “critical”, “important”, etc.).  Moreover, I dont believe that it’s absolutely necessary to calculate digital asset values to do quantitative risk analysis.  But if you need to do financial justification or economic analysis of security investments or alternative architectures then you might need something more precise and defensible.

This tutorial article presents one method aimed at helping line-of-business managers (“business owners” of digital assets) make economically rational decisions. It’s somewhat simplistic, but it does take some time and effort. Yet it should be feasable for most organizations if you really care about getting good answers.

Warning: No simple spreadsheet formulas will do the job. Resist the temptation to put together magic valuation formulas based on traffic, unique visits, etc.

(This is a long post, so read on if you want the full explanation…)

Wednesday, July 24, 2013

The Bayesian vs Frequentist Debate And Beyond: Empirical Bayes as an Emerging Alliance

This is one of the best articles I've ever seen on the Bayesian vs Frequentist Debate in probability and statistics, including a description of recent developments such as the Bootstrap, a computationally intensive inference process that combines Bayesian and frequentist methods.
Efron, B. (2013). A 250-year argument: Belief, behavior, and the bootstrap. Bulletin of the American Mathematical Society, 50(1): 129-146.
Many disagreements about risk analysis are rooted in differences in philosophy about the nature of probability and associated statistical analysis.  Mostly, the differences center on how to handle sparse prior information, and especially the absence of prior information. "The Bayesian/frequentist controversy centers on the use of Bayes rule in the absence of genuine prior experience."

What's great about this article is that it presents the issue and alternative approaches in a simple, direct way, including very illuminating historical context.  It also presents a very lucid description of the advantages and limitations of the two philosophies and methods.

Finally, it discusses recent developments in the arena of 'empirical Bayes' that combines the best of both methods to address inference problems in the context of Big Data.  In other words, because of Big Data and the associated problems people are trying to solve now, pragmatics matter more than philosophical correctness.  Another example of empirical Bayes is Bayesian Structural Equation Modeling that I referenced in this post.

Tuesday, July 23, 2013

The Rainforest of Ignorance and Uncertainty

One of the most important books I've ever read is Michael Smithson's Ignorance and Uncertainty.  It gives a tour of many varieties of ignorance and uncertainty and the many strategies that have been developed in different disciplines and professional fields.  Through this tour, it becomes very clear that uncertainty is not a single phenomena, and not even a couple, but instead is like a rainforest ecosystem of species. (My metaphor, not his.)

One vivid illustration of this is the taxonomy of ignorance and uncertainty.  Here's the original taxonomy by Smithson in Ignorance and Uncertainty:
In 2000, I modified this for a presentation I gave at a workshop at Wharton Business School on Complexity Science in Business.  Here's my taxonomy (2000 version):

Smithson and his colleagues have updated their taxonomy, which is presented as Figure 24.1 in Chapter 24 "The Nature of Uncertainty" in: Smithson, M., & Bammer, G. (2012). Uncertainty and Risk: Multidisciplinary Perspectives. Routledge.   (I can't find an on-line version of the diagram, sorry.) If you are looking for one book on the topic, I'd suggest this one.  It's well edited and presents the concepts and practical implications very clearly.

I don't think there is one definitive taxonomy, or that having a single taxonomy is essential for researchers.  I find them useful in terms of scoping my research, relating it to other research (esp. far from my field), and in selecting modeling and analysis methods that are appropriate.

Of course, there are other taxonomies and categorization schemes, including Knight's distinction between risk (i.e. uncertainty that can be quantified in probabilities) and (true) uncertainty (everything else).  Other categorization you'll see is epistemic uncertainty (i.e. uncertainty in our knowledge) and aleatory uncertainty (i.e. uncertainty that is intrinsic to reality, regardless of our knowledge of it).  The latter is also known as ontological uncertainty.  But these simple category schemes don't really capture the richness and variety.

The main point of all this is that ignorance and uncertainty come in many and varied species.  To fully embrace them (i.e. model them, analyze them, make inferences about them), you can't subsume them into a couple of categories.

[Edit:  Smithson's blog is here.  Though it hasn't been updated in two years, there's still some good stuff there, such as "Writing about 'Agnotology, Ignorance and Uncertainty'".]