Day 13 Naive Bayes


Day 13 Poster

Today, I dove into one of the oldest and surprisingly effective ML classifiers โ€” Naive Bayes.

๐Ÿ”น Itโ€™s based on Bayesโ€™ Theorem: P(Class | Features) = [ P(Features | Class) ร— P(Class) ] / P(Features)

๐Ÿ”น The โ€œnaiveโ€ part? It assumes all features are independent โ€” rarely true in reality, but often good enough, especially for text classification.

Naive Bayes is like a doctor diagnosing a patient by looking at symptoms one at a time, assuming each symptom (like cough, fever, fatigue) occurs independently. In reality, symptoms often correlate โ€” but this simplified model still gets the diagnosis right surprisingly often.


๐Ÿ› ๏ธ Common Use Cases

  • โœ… Spam Filtering

  • โœ… Text Classification

  • โœ… Intrusion Detection Systems (IDS)

๐Ÿง  Despite its simplicity, Naive Bayes performs surprisingly well โ€” particularly on high-dimensional datasets like emails and documents.


๐Ÿšง Limitations

  • Struggles with non-linear relationships or complex interactions between features.

  • Can be sensitive to skewed class distributions if not properly calibrated.

But that independence assumption? A sweet spot for attackers.


๐Ÿ” Security Lens

โš ๏ธ Independence Assumption Abuse

Attackers inject correlated features to game the classifier. &#xNAN;Example: A spam email might include benign terms like โ€œinvoiceโ€ or โ€œteam updateโ€ to lower its spam score and evade detection.

โš ๏ธ Feature Poisoning

Adversaries inject mislabeled or crafted data into the training set to skew feature probabilities, corrupting the model's logic.

โš ๏ธ Privacy Leaks via Probabilistic Outputs

Naive Bayes outputs probabilities. Confidence scores can leak info about the training data, enabling membership inference attacks.


๐Ÿ“š Key References

  • Rubinstein et al. (2009) โ€” Privacy-Preserving Classification

  • Lowd & Meek (2005) โ€” Adversarial Learning in Naive Bayes Spam Filters

  • Biggio et al. (2013) โ€” Evasion Attacks against Machine Learning at Test Time


๐Ÿ’ฌ Question

How much do you trust simple models like Naive Bayes in high-stakes systems? Letโ€™s discuss โ€” sometimes old tools still hold up, but only when you know their limits.


๐Ÿ“… Up next (Day 14): Support Vector Machines (SVM) โ€” and how attackers can shift the decision boundary to their advantage โš–๏ธ

๐Ÿ”— Missed Day 12? Catch up here: https://lnkd.in/ghkbH6Nb


#100DaysOfAISec #AISecurity #MLSecurity #MachineLearningSecurity #NaiveBayes #CyberSecurity #AIPrivacy #AdversarialML #LearningInPublic #100DaysChallenge #ArifLearnsAI #LinkedInTech

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