A method is described for the identification of a party authorised to have the benefit of a service delivered by a provider party via a
telematics network, in which the provider party and each user party are connected to the network by means of a respective electronic communications and
processing system (S, C), and the provider party requests a temporary
password (PWD) identifying the user party to allow access to the services delivered. The method is characterised in that it involves autonomous execution of a procedure for calculating the
password (PWD) in the
processing systems (S, C) of both parties on the basis of predetermined algorithms, the above-mentioned calculating procedure comprising the operations of: generating a first string of characters (N30) by means of a first pre-established
algorithm (ALGN30), on the basis of a random number (RND) and a hidden dynamic variable (n; p) not transmitted over the network, but obtained by the
processing systems (S, C) independently; extracting a second string of characters (N3), a subset of the first string (N30), by means of a second pre-established
algorithm (ALGN3), as a function of the hidden dynamic variable (n; p) and of said random number (RND); and generating the temporary
password (PWD) by means of a third pre-established
algorithm (ALGPWD), on the basis of the above-mentioned second string of characters (N3). The authorised party is identified as a result of the comparison between the password (PWD) calculated by the processing
system (S) of the provider party and that calculated by the processing
system (C) of the user party, whereby access to the service is permitted if this comparison gives a positive result and otherwise is denied. The password thus obtained may also be used as a single-use key in a system for encrypting all the information exchanged between the authorised user party and the
service provider party.