Method for obtaining encryption keys corresponding terminals, server and computer program products

摘要

A method and apparatus for obtaining an encryption key for an item of data transmitted from a client to a server. The method includes: determining a number R of registers available within the client for carrying out a plurality of calculations of encryption keys; determining a maximum number N of iterations necessary for obtaining at least one encryption key at the server; obtaining a structure of data representative of a key calculation state effected within the R available registers; calculating the at least one encryption key as a function: —of the number of available registers R, by performing at most N calls to a pseudo-random function F and —of the data structure; so that the at least one encryption key can be obtained from a combination of at most T=CR+NN−1 encryption keys based on a secret previously shared between the server and client.

主权项

1. A method for obtaining at least one key for encrypting at least one piece of data transmitted from a client to a server, wherein the method comprises:
determining a number R of registers available within said client to carry out a plurality of computations of encryption keys; determining a maximum number N of iterations needed to obtain at least one encryption key from said server; obtaining a structure of data pieces representative of a key computation state achieved within said R available registers; computing said at least one encryption key as a function of: said number of R available registers of said client, in performing at most N calls to a pseudo-random function F, and said structure of data pieces;and obtaining said at least one encryption key from a combination of at most T=CR+NN−1 encryption keys on a basis of a secret preliminarily shared between said server and said client.