(19)

(11)

EP 1 410 560 A1

(12)

(43) Date of publication: 21.04.2004 Bulletin 2004/17 (21) Application number: 01274364.7 (22) Date of filing: 18.12.2001

(51) International Patent Classification (IPC)7: H04L 9/30 (86) International application number: PCT/IT2001/000639 (87) International publication number: WO 2003/007540 (23.01.2003 Gazette 2003/04)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 13.07.2001 IT TO20010069 (71) Applicant: UNIVERSITA' DEGLI STUDI DI ROMA "LA SAPIENZA" 00185 Roma (IT)	(72) Inventors: BISI, Simonetta I-00135 Roma (IT) BISI, Walter I-00136 Roma (IT) (74) Representative: Jorio, Paolo et al STUDIO TORTA S.r.l.,Via Viotti, 9 10121 Torino 10121 Torino (IT)