Transmitting secure navigation signals via applying encryption

A client device comprising:

• at least one first receiver configured to receive a secure navigation signal transmitted by a satellite, wherein the secure navigation signal includes encrypted navigation message data modulated with an encrypted ranging signal;
• at least one second receiver configured to receive key data corresponding to the secure navigation signal;
• and
• at least one processor configured to execute operational instructions that cause the at least one processor to perform operations that include:
• generating an internal encrypted ranging signal by applying the key data to a spreading code of the satellite in accordance with an encryption scheme, wherein the encryption scheme is a block cipher encryption scheme;
• generating ranging data based on correlating the internal encrypted ranging signal with the secure navigation signal;
• determining a navigation message by utilizing the key data to decrypt the encrypted navigation message data, wherein determining the navigation message includes:
• generating each of a plurality of blocks having a first fixed-length via the block cipher encryption scheme;
• dividing the encrypted navigation message data into a plurality of sub-messages having the first fixed-length;
• and
• performing an exclusive-OR operation upon each of the plurality of sub-messages and a corresponding one of the plurality of blocks;
• and
• determining state data for the client device based on the ranging data and the navigation message.

A method comprising:

• generating a navigation message;
• generating encrypted navigation message data from the navigation message by applying an encryption scheme to the navigation message;
• generating an encrypted ranging signal by applying the encryption scheme to a spreading code;
• and
• generating a secure navigation signal based on modulating the encrypted navigation message data upon the encrypted ranging signal;
• and
• broadcasting the secure navigation signal for receipt by at least one client device, the secure navigation signal facilitating the at least one client device to determine state data of the at least one client device by utilizing key data associated with the encryption scheme, wherein the at least one client device determines the state data based on:
• applying the key data to the spreading code to generate an internal encrypted ranging signal;
• and
• determining ranging data based on correlating the internal encrypted ranging signal with the secure navigation signal, wherein the state data is determined based on the ranging data.