James Okafor

General 11 min

James Okafor • 2 days ago

Token Fingerprinting vs AST Matching on 1,000 Refactored Java Programs

When students rename variables, extract methods, and reorder statements to hide copied code, which detection algorithm actually holds up? A controlled experiment pits winnowing, token-based matching, and AST structural hashing against a ladder of refactoring transformations — and reveals why single-technique checkers miss the cases that academic-integrity panels care about most.

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General 9 min

James Okafor • 1 week ago

Finding Stack Overflow Code in Student Submissions With Fingerprints

A study of 5,000 Java assignments from three US universities found that nearly one in four contained code blocks directly traceable to Stack Overflow answers — yet traditional similarity checkers missed them all. We applied token-sequence fingerprinting and a web index of 1.2 million programming snippets to surface hidden web plagiarism at scale.

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General 11 min

James Okafor • 1 week ago

How Perplexity-Based AI Code Detectors Actually Work

Perplexity-based detectors aren’t magic — they measure how surprising a sequence of code tokens would be to a model trained on real human code. This report breaks open the inner math, real false-positive rates from Stanford and Edinburgh benchmarks, and why the strongest detectors stack statistical signals with AST fingerprinting and web-source checks.

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General 6 min

James Okafor • 3 weeks ago

Bootcamps Are Automatically Scanning Every Submission for AI Code

Coding bootcamps that graduate thousands of developers a year are shifting from manual spot-checks to automated AI code detection on every single submission. Here’s a hands‑on guide to building that pipeline with Codequiry’s API — from single‑file scanning to a full CI‑grade batch checker you can run in a GitHub Action.

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General 8 min

James Okafor • 3 weeks ago

How Code Similarity Detection Grew From Diff to AI

From the early days of the Unix diff command to the rise of MOSS, JPlag, and AI-powered detectors, code similarity detection has undergone a quiet revolution. This retrospective traces the key technical milestones—tokenization, ASTs, fingerprinting, web-source matching, and the new frontier of AI-generated code—showing how each layer made plagiarism harder to hide. See how modern platforms like Codequiry unify these techniques into a single pipeline.

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General 8 min

James Okafor • 3 weeks ago

Running a Side-by-Side Accuracy Benchmark of Code Plagiarism Checkers

We ran 2,400 real student Java assignments through MOSS, JPlag, Turnitin, and Codequiry with known ground truth. The F1 scores and false positive rates diverged by over 20 percentage points. Here’s what worked, what broke, and how to run your own benchmark.

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General 11 min

James Okafor • 4 weeks ago

How an Engineering Team Automated Code Originality Checks for Contractors

When a mid-sized software firm started scaling external contractor contributions, they needed a way to verify code originality at scale. By integrating Codequiry’s API into their CI/CD pipeline, they built an automated gate that flagged plagiarized open-source snippets and AI-generated code before it ever hit the main branch. Here’s a look at their process, the false-positive tradeoffs, and the integration that saved their legal review hours.

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General 9 min

James Okafor • 1 month ago

Contractor Code Audit at a 50-Person SaaS Startup

When a growing SaaS startup suspected a third‑party deliverable contained unattributed open‑source code, they built a verification pipeline that now scans every contractor commit. Here’s what they learned about trade‑offs, accuracy, and the tools that stuck.

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General 8 min

James Okafor • 1 month ago

Why Cross-Language Code Plagiarism Detection Is Now Essential

Modern CS courses often span multiple programming languages, but traditional plagiarism tools like MOSS only compare files within the same language. This case study walks through a practical detection pipeline that catches students rewriting Java logic in Python, using token-normalised AST comparisons and Codequiry’s cross-language API.

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General 10 min

James Okafor • 1 month ago

A DevOps Engineer's Playbook for Plagiarism and Code Smells in CI

This practical guide walks DevOps engineers through integrating code smell detection and plagiarism checking into a single CI pipeline. Using SonarQube and the Codequiry API, you'll learn how to catch refactoring-resistant copy-paste, known vulnerabilities, and code-quality regressions before they reach production. The guide includes a complete GitHub Actions workflow, token-based authentication, and advice on setting meaningful thresholds.

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General 8 min

James Okafor • 1 month ago

How Code Similarity Detection Advanced From Strings to Semantics

From manual diff checks to AI-powered semantic analysis, code plagiarism detection has undergone a fundamental transformation. This article traces the key milestones—MOSS, JPlag, AST fingerprinting, and the new frontier of LLM-written code—and explains why a single method is no longer enough.

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General 8 min

James Okafor • 1 month ago

Cross-Language Code Plagiarism Detection Methods Tested

A rigorous head-to-head comparison of three cross-language code plagiarism detection approaches—tokenization, AST matching, and semantic fingerprinting—tested on 100 student-style assignments translated between Java, Python, and C++. We reveal which method catches translated loops, renamed variables, and switched control flow, and which one drowns in false positives.

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