AUTHENTICATION METHODS FOR A SATELLITE-BASED NAVIGATION SYSTEM, DEVICES FOR AUTHENTICATING MESSAGES AND AUTHENTICATION SYSTEM

The present disclosure provides an authentication method for a satellite-based navigation system (100), SNS, comprising: obtaining, by an authentication server (160), a plurality of message authentication bundles from a plurality of reference receiver stations (130), each message authentication bundle comprising at least one hash for authenticating a corresponding SNS message received by a respective reference receiver station (130) from at least one satellite (110) of the SNS (100); inserting, by the authentication server (160) at least a subset of the hashes of the obtained message authentication bundles into a probabilistic data structure, PDS, which forms at least a part of a validation filter for authenticating a corresponding subset of SNS messages; and distributing the validation filter to at least one receiver-side device (140). The disclosure further provides authentication methods performed by a reference receiver station (130) and a receiver-side device (140), respectively, as well as devices and systems for authenticating SNS messages.