GNU Privacy Guard (GnuPG)

See the following -

Keeping Patient Data Safe with Open Source Tools

Healthcare is experiencing a revolution. In a tightly regulated and ancient industry, the use of free and open source software makes it uniquely positioned to see a great deal of progress. I work at a scrappy healthcare startup where cost savings are a top priority. Our primary challenge is how to safely and efficiently manage personally identifying information (PII), like names, addresses, insurance information, etc., and personal health information (PHI), like the reason for a recent clinical visit, under the regulations of the Health Insurance Portability and Accountability Act of 1996, HIPAA, which became mandatory in the United States in 2003.