Stephen G Sherman

US Patent:

55442463, Aug 6, 1996

Filed:

Sep 17, 1993

Appl. No.:

8/122631

Inventors:

Richard Mandelbaum - Manalapan NJ
Stephen A. Sherman - Hackettstown NJ
Diane R. Wetherington - Bernardsville NJ

Assignee:

AT&T Corp. - Murray Hill NJ

International Classification:

H04L 932

US Classification:

380 23

Abstract:

A smartcard that allows different Service Providers to coexist on the smartcard with none of the Service Providers, nor the owner of the smartcard, having access to the files created for, or by, each of the resident Service Providers. The operating system of the smartcard includes a root directory that is owned by the smartcard's issuer/owner, and each Service Provider is a "user" that is installed by the issuer/owner. Each such user is provided with a subdirectory of the root directory, and within the subdirectory the user creates files and subdirectories with files, as the user deems necessary. The operating system prevents all users of the smartcard, including the smartcard's issuer/owner and the smartcard's holder, from accessing any files that are owned by any other user, when that user chooses to prevent such access. This power to exclude is effected through a password file that is owned by the user and which cannot be altered by any other user, including the smartcard's issuer/owner. Optionally, the smartcard's issuer/owner is given the power to erase all files of a given user.