American Gas Ass'n, Cryptographic Protection of SCADA Communications Part 1: Background, Policies and Test Plan (Mar. 14, 2006) (full-text).
AGA 12, Part 1 is intended to serve as a guideline for voluntary implementation of a comprehensive cyber security posture. It focuses on providing background information for improved assessment of a company's cyber security posture, suggesting policies for a comprehensive cyber security plan and offering a sample test plan for operator implementation.
The premise for AGA 12, Part 1 is rooted in the operator's performance of risk assessment analysis on his/her cyber system. A consistent risk assessment analysis equips the operator with the information necessary to understand consequences and formulate an objective business case. Following the performance of a cyber risk assessment analysis, the operator may elect to deploy the encryption methodology that follows in the AGA 12 series of technical reports (i.e., Part 2 and so on).