- Maintaining digital security and privacy are critical issues in the modern workplace. Sensitive and proprietary data is frequently transmitted electronically, and with the large volume of such transmissions, it is inevitable that some material will be inadvertently sent to unintended recipients, leading potentially to the unintended revelation of private data. The paper reports on the design of an automatic mechanism for password protection of digital documents on a per-user basis. Recommended practices and details of architecture, approach and implementation are presented for the specific protection of Microsoft Excel documents, although the scheme can be generalized to other digital document management software.