## Base rate fallacy computer security

the base-rate fallacy may affect the operational effectiveness of an intru-sion detection system. 2. INTRUSION DETECTION The field of automated computer intrusion detection (intrusion detection for short) is currently about 20 years old [Anderson 1980], with interest gathering pace during the past 10 years.

The Base Rate Fallacy / Bias When you ignore (or don’t understand) general statistical data and make a judgment based on specific data, you’re falling prey to the base rate fallacy. This happens all the time ; People not well-versed in the technical rules of prior probability usually don’t take the prior statistical data into account, as it doesn’t seem relevant. This is due to the base-rate fallacy phenomenon, that in order to achieve substantial values of the Bayesian detection rate P(Intrusion***Alarm), we have to achieve a (perhaps in some cases unattainably) low false alarm rate. A selection of reports of intrusion detection performance are reviewed, and the conclusion is reached that there are indications that at least some types of intrusion detection have far to go before they can attain such low false alarm rates. Conclusions This chapter demonstrated that intrusion detection in a realistic setting is harder than was perhaps thought. This is due to the base-rate fallacy problem, because of which the factor limiting the performance of an intrusion detection system is not the base-rate fallacy may affect the operational effectiveness of an intru-sion detection system. 2. INTRUSION DETECTION The field of automated computer intrusion detection (intrusion detection for short) is currently about 20 years old [Anderson 1980], with interest gathering pace during the past 10 years. The base rate fallacy, also called base rate neglect or base rate bias, is a fallacy. If presented with related base rate information and specific information, the mind tends to ignore the former and focus on the latter. Base rate neglect is a specific form of the more general extension neglect. BASE-RATE FALLACY: "If you overlook the base-rate information that 90% and then 10% of a population consist of lawyers and engineers, respectively, you would form the base-rate fallacy that someone who enjoys physics in school would probably be categorized as an engineer rather than a lawyer.

## This is due to the base-rate fallacy phenomenon, that in order to achieve substantial the setting of computer security intrusion detection. There is, however

The base-rate fallacy and the difficulty of intrusion detection. S Axelsson S Axelsson. European Symposium on Research in Computer Security, 309-325, 2003. Analogous developments emerged from cyber security exercises, which have A common problem for intrusion detection metrics is the base-rate fallacy; e.g.,  Security Data Scientist CTI: Cyber Threat Intelligence. • Will be using Use your own telemetry - given the base rate fallacy, places that ”everyone” goes to are  This paper explores how four approaches to cyber security are constructed, motivated and justified by different values such as privacy, economic order and

### The base-rate fallacy and the difficulty of intrusion detection. S Axelsson S Axelsson. European Symposium on Research in Computer Security, 309-325, 2003.

Those who do so commit the "base rate fallacy. If the base rate is known, then a Fourfold table, also called a 2 x 2 table or matrix, is a mechanism that helps us understand the correct

### 2.3 Base Rate Fallacy . A firewall is a security control designed to prevent unauthorized access from an external network Personal firewall (on a computer).

Someone making the ‘base rate fallacy’ would infer that there is a 99% chance that the detected person is a terrorist. Although the inference seems to make sense, it is actually bad reasoning, and a calculation below will show that the chances they are a terrorist are actually near 1%, not near 99%. The base-rate fallacy is people’s tendency to ignore base rates in favor of, e.g., individuating information (when such is available), rather than integrate the two. This tendency has important implications for understanding judgment phenomena in many clinical, legal, and social-psychological settings. base-rate fallacy affects the required performance of the intrusion detection system with regard to false alarm rejection. In what follows, Section 4 gives a description of the base-rate fallacy. 18-487 Introduction to Computer Security This course will introduce students to the fundamentals of computer security. We will focus on software security, applied cryptography, network security, OS security, and privacy. A recurring theory, focusing on the base rate fallacy.

## 2.3 Base Rate Fallacy . A firewall is a security control designed to prevent unauthorized access from an external network Personal firewall (on a computer).

This is due to the base-rate fallacy phenomenon, that in order to achieve substantial values of the Bayesian detection rate P(Intrusion***Alarm), we have to achieve a (perhaps in some cases unattainably) low false alarm rate. A selection of reports of intrusion detection performance are reviewed, and the conclusion is reached that there are indications that at least some types of intrusion detection have far to go before they can attain such low false alarm rates.

A high rate of false alerts is - according to Axelsson [3] - the limiting factor for the and the number of false negatives the IT security personnel is willing to accept. He received a MSc in Computer Science from the University of Venice, Italy, with a [3] Axelsson, S., "The Base-Rate Fallacy and the Difficulty of Intrusion  Computer Security and Privacy. Module 3. Operating OS keeps mapping from segment name to its base physical Another example of the base rate fallacy  how the base-rate fallacy affects the operational effectiveness of any intrusion detection system. 2 Problems in Intrusion Detection The ﬁeld of automated computer security intrusion detection—intrusion detection for short—is currently some nineteen years old. The seminal paper that is most often mentioned is James P. If its 0% false-positives and 10% false-negatives, that would be a 90% where teh chances of that one guy being a terrorist is 90%. On the other side, a 10% false-positive rate and 0% false-negative rate also yields 90%, but the percentage chance of a positive test subject being at terrorist depends highly on the terrorist population at large. CCS '99: Proceedings of the 6th ACM conference on Computer and communications security The base-rate fallacy and its implications for the difficulty of intrusion detection. Pages 1–7. This is due to the base-rate fallacy phenomenon, that in order to achieve substantial values of the Bayesian detection rate, P(Intrusion