PrintWatchDog: Lightweight Open-Architecture Framework for Printer Data Loss Prevention

Redacted documents, whether electronic or printed, help maintain confidentiality, especially when printed documents are accessible to individuals with varying clearance levels. This paper introduces PrintWatchDog, a customizable, open architecture, low-cost data redaction framework. The framework includes four modules: a daemon module (intercept print data), a parsing module (real-time parsing of sensitive tags), a redaction module (masking sensitive text), and a logging module (record print request and save redacted version for audit). The parser module is designed to work on XML format tags, which can be domainspecific custom tags. A prototype implementation confirms that increasing the size of redacted data from 100 to 10,000 bytes in a 20KB document only adds 2.26 milliseconds to processing time, highlighting PrintWatchDog's scalability and efficiency.