The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 29, 2013
Filed:
Feb. 28, 2007
Eric Garrido, Montmorency, FR;
Sandrine Agagliate, Paris, FR;
Eric Garrido, Montmorency, FR;
Sandrine Agagliate, Paris, FR;
Thales, Neuilly sur Seine, FR;
Abstract
A method for managing keys making it possible for a user to access one or more given services S in a communication system, in which the user is not able to be continuously connected to this service. A key K(t) is generated, which provides access to the service of day [t] for all the t<tby using a one-way function in the following manner (a one-way function being defined as being a function for which it is not currently possible by computing means to obtain the inverse function). A root key K(t) is used and the key K(t) is generated for the day [t] prior to the day t, by using a function f such that K(t−1)=f(K(t)). The new value of key K(t) is used in order to generate the key for the previous day K(t) and this step is reiterated over the limited time period of day [t] to day [t+d] in order to obtain the chain K(t+d−1), K(t+d−2), etc. Each day t the key K(t+d) is sent to the users or user group having a trust level d (giving potential access to the service for d consecutive days).