Secure Log Tokenization Using Aho–Corasick and Spring

Modern microservices, payment engines, and event-driven systems are generating massive volumes of logs every second. These logs are critical for debugging, monitoring, observability, and compliance audits.

But there is an increasing and hazardous problem: Sensitive data — things like credit card numbers, email addresses, phone numbers, SSNs, API keys, and session tokens — often accidentally appear in logs. Once it’s stored in log aggregators such as ELK, Splunk, CloudWatch, Datadog, or S3, this sensitive data becomes a high-risk liability.