Appeal No. 2003-1942 Page 2 Application No. 09/260,796 Accordingly, the appellant uses an encryption value ("EV") to encrypt data before storing the data on an "untrusted" storage device. He then encrypts the EV; the EV is decrypted by solving an access formula describing a function of groups. Each group includes a list of at least one consumer client. A consumer client is granted access to the data if the client belongs to at least one group that solves the access formula. (Id. at 31.) A further understanding of the invention can be achieved by reading the following claim. 3. A method for the secure handling of information by at least one client using at least one untrusted storage device, each client connected to the at least one untrusted storage device using a network, the network further having a key manager for issuing private key and public key matched pairs for use with an asymmetric encryption and decryption scheme, the scheme allowing a file encrypted with a public key to be decrypted only with a matched private key, the method comprising: creating at least one group, each group comprising a list of at least one consumer client; acquiring a public key and a matched private key for each of the at least one group; encrypting an information set to produce a data set, the encryption based on a randomly generated number; determining an access formula expressing logical combination of the at least one group for which access to the information set will be granted, solution of the access formula by at least one solution groupPage: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 NextLast modified: November 3, 2007