Data telecommunications method based on frequency hops in a first frequency band, wherein the frequency hops follow a predetermined time sequence, known at least to a transmitter of the data, characterized in that it comprises the following steps, implemented by said data transmitter: - defining, based on a pseudorandom draw, successive values of respective frequency spacings (Δfs1, Δfs2, Δfs3,...) in order to determine the hop time sequence based on a first frequency, - transmitting synchronization data to at least one receiver • at a first frequency, said first frequency being chosen randomly within the first frequency band, • and then at a first set of successive frequencies (fs2, fs3,...) complying, based on the first frequency, with said successive values of respective frequency spacings (Δfs1, Δfs2, Δfs3,...), said successive values of frequency spacings defining, at reception, a succession of reception frequencies of payload data to be received from said data transmitter, - defining a sequence (Δfd1, Δfd2, Δfd3,...) for the transmission of the payload data based on a sequence used to transmit synchronization data, using a predetermined rule, known to the transmitter and the receiver, said sequence used to transmit synchronization data being stored in a database storing pseudorandom draws defining sequences used to transmit synchronization data, the receiver being connected to said database, - transmitting the payload data to the receiver • at the first frequency (fd1=f1), • and then at a second set of successive frequencies complying, based on the first frequency, with the transmission sequence defined by the predetermined rule; the method furthermore comprising the following steps, implemented by the data receiver: - scanning the first frequency band to identify the first frequency and at least a first portion of said successive frequencies complying, based on the first frequency, with said successive values of respective frequency spacings (Δfi, Δfi+1,...), - determining successive frequency spacings based on the first frequency identified by the scanning of the first frequency band, - comparing said successive frequency spacings with frequency spacings of sequences corresponding to the pseudorandom draws stored in the database, and - identifying, at the end of said comparison, the time sequence used by the transmitter to receive payload data on the successive frequencies of the sequence thus identified, using the predetermined rule based on the sequence used for the synchronization data. - defining, based on a pseudorandom draw, successive values of respective frequency spacings (Δfs1, Δfs2, Δfs3,...) in order to determine the hop time sequence based on a first frequency, - transmitting synchronization data to at least one receiver • at a first frequency, said first frequency being chosen randomly within the first frequency band, • and then at a first set of successive frequencies (fs2, fs3,...) complying, based on the first frequency, with said successive values of respective frequency spacings (Δfs1, Δfs2, Δfs3,...), said successive values of frequency spacings defining, at reception, a succession of reception frequencies of payload data to be received from said data transmitter, • at a first frequency, said first frequency being chosen randomly within the first frequency band, • and then at a first set of successive frequencies (fs2, fs3,...) complying, based on the first frequency, with said successive values of respective frequency spacings (Δfs1, Δfs2, Δfs3,...), said successive values of frequency spacings defining, at reception, a succession of reception frequencies of payload data to be received from said data transmitter, - defining a sequence (Δfd1, Δfd2, Δfd3,...) for the transmission of the payload data based on a sequence used to transmit synchronization data, using a predetermined rule, known to the transmitter and the receiver, said sequence used to transmit synchronization data being stored in a database storing pseudorandom draws defining sequences used to transmit synchronization data, the receiver being connected to said database, - transmitting the payload data to the receiver • at the first frequency (fd1=f1), • and then at a second set of successive frequencies complying, based on the first frequency, with the transmission sequence defined by the predetermined rule; • at the first frequency (fd1=f1), • and then at a second set of successive frequencies complying, based on the first frequency, with the transmission sequence defined by the predetermined rule; - scanning the first frequency band to identify the first frequency and at least a first portion of said successive frequencies complying, based on the first frequency, with said successive values of respective frequency spacings (Δfi, Δfi+1,...), - determining successive frequency spacings based on the first frequency identified by the scanning of the first frequency band, - comparing said successive frequency spacings with frequency spacings of sequences corresponding to the pseudorandom draws stored in the database, and - identifying, at the end of said comparison, the time sequence used by the transmitter to receive payload data on the successive frequencies of the sequence thus identified, using the predetermined rule based on the sequence used for the synchronization data.