security metrics

Security Management MetricsVicente Aceituno, 2008

Conferencia FIST Marzo/Madrid 2008 @

Sponsored by:

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About me

Vice president of the ISSA Spain chapter. www.issa-spain.org

Vice president of the FIST Conferences association. www.fistconference.org

Author of a number of articles: Google: vaceituno wikipedia

Director of the ISM3 Consortium The consortium promotes ISM3, an ISMS standard ISM3 is the main source for this presentation. www.ism3.com

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The world without Metrics

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Management vs Engineering

Security Engineering: Design and build systems than can be used securely.

Security Management: Employ people and systems (that can be well or badly engineered) safely.

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Targets vs Outcomes

Activity and Targets are weakly linked. Targets:

+Security / -Risk Trust

Activity: Keep systems updated Assign user accounts Inform users of their rights

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Definition

Metrics are quantitative measurements that can be interpreted in the context of a series of previous or equivalent measurements.

Metrics make management possible:1. Measurement – Some call this “metrics” too.

2. Interpretation – Some call this “indicator”.

3. Investigation – (When appropriate, logs are key here) Common cause Special cause

4. Rationalization

5. Informed Decision

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Qualitative vs Quantitative Measurement

William Thomson (Lord Kelvin): “I often say that when you can

measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be”:

Meaning: “What can’t be measured, can’t be managed”

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Interpretation

It doesn’t make sense to set thresholds beforehand. You have to learn what is normal to find out what is abnormal.

Thresholds can be fuzzy. False positives and false negatives. Example: 90% accuracy, 1000 students tested for HIV, 10 have it.

HIV Have HIV Don’t have HIV

Test positive for HIV 9 99

Test negative for HIV 1 891

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Is it successful? Is it normal? How does it compare against peers?

Interpretation

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Are outcomes better fit to their purpose? Are outcomes getting closer or further from target? Are we getting fewer false positives and false negatives? Are we using resources more efficiently?

Interpretation

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Rationalization

Is the correction/change working? Is it cost effective? Can we meet our targets with the resources we

have? Are we getting the same outputs with fewer

resources?

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Decisions

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Good Metrics are SMARTIED

S.M.A.R.T Specific: The metric is relevant to the process being measured. Measurable: Metric measurement is feasible with reasonable cost. Actionable: It is possible to act on the process to improve the metric. Relevant: Improvements in the metric meaningfully enhances the

contribution of the process towards the goals of the management system.

Timely: The metric measurement is fast enough for being used effectively. +Interpretable: Interpretation is feasible (there is comparable

data) with reasonable cost (false positives or false negatives rates are low enough)

+Enquirable: Investigation is feasible with reasonable cost. +Dynamic: The metric values change over time.

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Fashion vs Results

Real Time vs Continuous Improvement Management is far more than Incident Response.

Risk Assessment as a Metric Only as useful as Investigation results.

Certification / Audit Compliant / Not compliant is NOT a Metric.

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What are good Metrics?

Activity: The number of outputs produced in a time period;Scope: The proportion of the environment or system that is protected by the process. Update: The time since the last update or refresh of process outputs.Availability: The time since a process has performed as expected upon demand (uptime), the frequency and duration of interruptions, and the time interval between interruptions.Efficiency / ROSI: Ratio of losses averted to the cost of the investment in the process. Efficacy / Benchmark: Ratio of outputs produced in comparison to the theoretical maximum. Measuring efficacy of a process implies the comparison against a baseline.Load: Ratio of available resources in actual use, like CPU load, repositories capacity, bandwidth, licenses and overtime hours per employee.Accuracy: Rate of false positives and false negatives.

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Examples

Activity: Number of access attempts successful

Scope: % Resources protected with Access Control

Update: Time elapsed since last access attempt successful

Availability: % of Time Access Control is available

Efficiency / ROSI: Access attempts successful per euro

Efficacy / Benchmark: Malicious access attempts failed vs Malicious access attempts successful. Legitimate access attempts failed vs Legitimate access attempts

successful.Load: % mean and peak Gb, Mb/s, CPU and licenses in use.

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Metrics and Capability

Undefined. The process might be used, but it is not defined.

Defined. The process is documented and used. Managed. The process is Defined and the results

of the process are used to fix and improve the process.

Controlled. The process is Managed and milestones and need of resources is accurately predicted.

Optimized. The process is Controlled and improvement leads to a saving in resources

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Capability: Undefined

No metrics necessary

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Capability: Defined

Measurement - None Interpretation - None Investigation – (When appropriate, logs are key here)

Common cause (changes in the environment, results of management decisions)

Special cause (incidents)

Rationalization for use of time, budget, people and other resources – Not possible

Informed Decision – Not possible

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Capability: Managed

Measurement: Scope, Activity, Availability Interpretation - Accuracy. (rate of false negatives and false positives)

Is it normal? Find faults before they produce incidents. Is it successful? Is the correction/change working? See trends and understand where things are going - Compare to self

(over time to show progress) - Are outputs getting closer or further from target?

Benchmarking: Compare against industry/peers to show relative position Efficacy. (comparison with ideal outcome) Are outputs better fit to their

purpose? Update. (are outcomes recent enough to be valid)

Investigation (Common cause, Special cause) Rationalization for use of time, budget, people and other resources –

Possible Informed Decision – Possible

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Capability: Controlled

Measurement Load. (what resources are used to produce the

outcomes, finding bottlenecks) Interpretation

Can we meet our targets in time with the resources we have?

What resources and time are necessary to meet our targets ?

Investigation (Common cause, Special cause) Decision, Rationalization/justification, Planning –

Possible

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Capability: Optimized

Measurement Efficiency. (comparison of use of resources with goal)

Interpretation How efficient is it? Are we getting the same outcomes with fewer

resources? Are we getting more/better outcomes with the same

resources? Investigation (Common cause, Special cause) Decision, Rationalization/justification, Planning,

Tradeoffs. point of diminishing returns (ROSI) – Possible

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Metric Specification

Name of the metric;Description of what is measured;How is the metric measured;How often is the measurement taken;How are the thresholds calculated;Range of values considered normal for the metric;Best possible value of the metric;Units of measurement.

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Metrics Representation

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Using Metrics

Acumulado de Recomendaciones por Responsable (Suma de días)

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Using Metrics

Acumulado de Recomendaciones de Seguridad por Responsable - Suma en días

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Altas

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Using security management metrics

Key Goal Indicators Key Performance Indicators Services Levels Agreements / Underpinnig Contracts Balanced Scorecard (Customer, Internal, Stakeholder,

Innovation - Goals and Measures)

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