The USPS operates a PKI to provide security for its electronic information. Security is achieved by using public key cryptography. The types of security services provided by a PKI are:
- Confidentiality - The transformation of data into a form unreadable by anyone without the proper key.
- Data Integrity - A service that addresses the unauthorized alteration of data by either confirming its integrity or warning about changes.
- Authentication - The process whereby users or information sources prove that they are who they claim to be.
- Non-repudiation - A service that limits denial of previous commitments or actions.
- USPS Public Key Infrastructure (PKI) X.509 Certificate Policy (CP)