Design, Analysis, and Statistics

Brute-Forcing an FSM Lock

A comprehensive module exploring why random brute force follows statistically a geometric distribution, and how statistical models adapt when search strategies learn from failed attempts.

The Core Problem

How does a Finite State Machine (FSM) respond to brute-force attacks? When designing secure systems, we must understand the probabilistic behavior of random guesses versus systematic, learning-based search strategies. This module provides the tools to analyze success probabilities, expected attempts, and engineering defenses.

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The Locker FSM Problem

Define the locking mechanism, understand the state transitions, and establish the baseline for our statistical analysis.

Explore the Problem
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Statistical Analysis

Step-by-step mathematical explanation covering how a the behavior of a determinstic design of FSM is subject to statistical analysis

Start Lesson
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Interactive Demo

Simulate brute-force attacks. Compare local next-attempt probability with the overall distribution of success.

Launch Demo
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Visual Summary

A graphical comparison of memoryless random search versus learning systematic search with key engineering takeaways.

View Summary

Knowledge Quiz

Test your understanding of the statistical models, expected values, and design tradeoffs discussed in the lesson.

Take Quiz

Engineering Perspective

The crucial question extends beyond "What is the chance of success on the next attempt?" to "What is the overall distribution of the first success, and how many attempts must our design tolerate?"