Abstract: The steel according to the invention is characterized in that, in order to keep its weight content of molybdenum below 0.45%, its chemical composition, besides the iron and the inevitable residual impurities that result from the smelting of the steel, corresponds to the following analysis, given as percentages by weight: 0.3?C %?0.5 0.20?Mo %<0.45 0.4?Mn %?1.0 0.4?Cr %?2.0 0.04?Ni %?0.8 0.02?Nb %?0.045 0.03?V %?0.30 0.02?Ti %?0.05, with Ti>3.5 N 0.003?B %?0.005% S %?0.015 P %?0.015, and optionally 0.05?Si %?0.20; Al %?0.05 and N %?0.015. By cold forming a hot-rolled wire rod resulting from continuous casting, it is possible to obtain, after heat treatment, “ready-to-use” coined parts, such as cap screws for example for the automotive industry, that offer a tensile strength from 1200 to more than 1500 MPa while having a good hydrogen embrittlement resistance, and this with a specially controlled “raw material” production cost.

Abstract: The invention concerns a method for guaranteeing certification of a user's public key by reducing requests to key-certifying appropriate authorities. More particularly, the invention concerns a method for managing a public key of a user capable of being implemented in an asymmetric cryptosystem. According to the invention, a certification, or validation of the correspondence between a public key and a user, is performed by a validating entity, a provider separate from the certifying authority via a validation step. The password is verifiable by the validating entity, but without the latter being aware of it.