METHOD AND SYSTEM FOR RADIO NAVIGATION AUTHENTICATION Russian patent published in 2020 - IPC G01S19/03 G01S19/21 

FIELD: physics.

SUBSTANCE: group of inventions relates to authentication of radio navigation signals, and in particular to authentication, based on measurements of the range generated from encrypted spreading codes. Radio navigation system comprises receiver (4) and radio navigation infrastructure (6), comprising a plurality of installed on satellite transmitters (8, 8', 8'', 8''') and encryption component (10) configured to communicate with transmitters (8, 8', 8'', 8''') and receiver (4). In radio navigation infrastructure (6) sets of coding codes k_2,i are generated with respect to specified interval [0, T] of authentication with duration T and starting at moment of time t = 0. Signal e(t) encrypted with the spreading code is generated from the first radio navigation signal s₁(t) using the encryption code flow K₁(t), wherein the encryption code flow K₁(t) is generated using a secret encryption code k₁ radio navigation infrastructure (6). In radio communication infrastructure coding component (10), a re-encrypted sequence Ri is generated using the encryption code flow k_2,i generated by a set of coding codes k_2,i. Encryption component (10) transmits a re-encrypted sequence Ri to receiver (4) until time t = 0. Signal e(t) encrypted with a spreading code is transmitted from given transmitter (8) and a set of encryption codes k_2,i is transmitted from one of the plurality of transmitters (8, 8', 8'', 8'''). Method comprises stages of receiver (4), at which: (i) repeatedly encrypted sequence Ri is received and stored before time t = 0; (ii) receiving a signal e(t) encoded with a spreading code; (iii) receiving a set of encryption codes k_2,i; (iv) decrypting the re-encrypted sequence Ri using the sequence of encryption codes k_2,i to obtain encrypted Ei sequences. Receiver (4) correlates at least sections of the received signal e(t) encrypted with the spreading code with encrypted Ei sequences, and thereby generating a code phase measurement for given transmitter (8). Method may further comprise a step of extracting, in encryption component (10), from a signal e(t) encoded with a spreading code, a plurality of encrypted sequences Ei associated with corresponding time periods within a predetermined interval [0, T] of authentication, wherein re-encrypted sequence R'_i is generated from extracted encrypted sequences Ei, using encryption codes flow k_2,i, wherein repeatedly encrypted sequence Ri is connected to preset transmitter (8). In compliance with one version of invention, encryption component (10), in which repeatedly encrypted sequence Ri is generated, is a ground-based server. Also disclosed is a method implemented in radio navigation infrastructure (6) and receiver (4), as well as radio navigation system (2), infrastructure (6) and receiver (4).

EFFECT: technical result is operation of a radio navigation system receiver in an autonomous mode for long periods of time without a ground auxiliary channel, at the same time having possibility of authenticating a signal based on symmetrically encoded spreading codes, but without the need to store a secret encryption code.

15 cl, 3 dwg