Design And Implementation Of A Threshold-Based Linking Scheme To Extend Browser Fingerprint Lifespan

Browser fingerprinting is a powerful tool for user identification in financial and othersecurity-critical applications that require strong authentication. However, due to theinstability of browser attributes, fingerprints often change rapidly, reducing theirlifespan and negatively impacting user convenience. We propose ThresholdFP, anovel linking algorithm designed to extend the durability of browser fingerprintswithout compromising precision.Instead of replacing the fingerprint after even a small change, ThresholdFP computesa difference score between fingerprints. If the total change remains below aconfigurable threshold, the new fingerprint is linked to its predecessor, forming a lineageover time. This allows minor attribute fluctuations to be tolerated, improvingpersistence without triggering additional identity checks.To ensure realistic performance evaluation, we collected and utilized two real-worlddatasets: one institutional dataset with over 235,000 fingerprints and a labeledvolunteer dataset containing 5,774 fingerprints from known browser instances. Thebest-performing variant of ThresholdFP achieved an average tracking duration (i.e.fingerprint lifetime) of 55.7 days on the institutional dataset and 50.1 days on thevolunteer dataset, while maintaining over 98% estimated precision and 99.5% actualprecision, respectively. Compared to rival methods in the literature, ThresholdFPimproves average fingerprint tracking duration by 24.33% to 106.30%, demonstratingits effectiveness and robustness under real-world conditions.