摘要：The emergence of a multi-GNSS world will inevitably require the civil GNSS user community to address the issue of signal authentication: confirming that a pretended identity of a user or transmitted information is, in fact, real and correct.
This two-part column focuses on the concepts and methods for achieving authentication in GNSS operations. In the July/August issue, the column began by introducing some of the cryptographic concepts, terminology, and techniques used to develop and implement authentication methods in navigation systems in general.
