LIQUID CRYSTAL GEOMETRICAL PHASE OPTICAL ELEMENTS AND A SYSTEM FOR GENERATING AND RAPIDLY SWITCHING HELICAL MODES OF AN ELECTROMAGNETIC WAVE, BASED ON THESE OPTICAL ELEMENTS
    9.
    发明公开
    LIQUID CRYSTAL GEOMETRICAL PHASE OPTICAL ELEMENTS AND A SYSTEM FOR GENERATING AND RAPIDLY SWITCHING HELICAL MODES OF AN ELECTROMAGNETIC WAVE, BASED ON THESE OPTICAL ELEMENTS 审中-公开
    光学液晶元件几何相位和生成系统,并在此光学元件的基础上电磁波的HELIX风尚的变化快

    公开(公告)号:EP2013647A2

    公开(公告)日:2009-01-14

    申请号:EP07735574.1

    申请日:2007-04-20

    发明人: MARRUCCI, Lorenzo

    IPC分类号: G02B5/18

    摘要: A description is given of geometrical phase optical elements comprising, as a birefringent means, a liquid crystal material with a spatially inhomogeneous orientation of the molecular director in a plane orthogonal to the direction of propagation of an input radiation beam, ordered according to a predetermined geometrical pattern. Also described is an optical system for generating helical modes of propagation of an optical radiation beam, including a geometrical phase optical element orientated transversely to the direction of propagation of the beam, whose optical axis is orientated according to a predetermined geometrical relation adapted to transform a circular polarized input radiation beam into a helical mode with a wavefront having a helical surface whose handedness is a function of the handedness of the input polarization, in which the switching between different orders of helicity of the radiation beam emerging from the geometrical phase optical element is carried out by switching the circular polarization state of the input radiation.

    A METHOD AND SYSTEM FOR IDENTIFYING AN AUTHORIZED INDIVIDUAL BY MEANS OF UNPREDICTABLE SINGLE-USE PASSWORDS
    10.
    发明授权
    A METHOD AND SYSTEM FOR IDENTIFYING AN AUTHORIZED INDIVIDUAL BY MEANS OF UNPREDICTABLE SINGLE-USE PASSWORDS 有权
    方法和设备识别授权不可预知的ONCE可用PASSWORTERN人

    公开(公告)号:EP1604257B1

    公开(公告)日:2006-12-06

    申请号:EP04708412.4

    申请日:2004-02-05

    IPC分类号: G06F1/00

    摘要: 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 or predetermined algorithms, the above-mentioned calcultaing 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 preestablished 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 authorsed 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.