Abstract: A method and apparatus are disclosed for managing components of a secret key according to a secret sharing scheme. The disclosed secret sharing scheme divides a secret value, R, into n secret components (R1, R2, . . . , Rn) and one super component, S, in such a way that R can be computed from (i) any k or more R1 components (k<n); or (ii) S and any one component of Rl. The secret components (R1 ,R2, . . . , Rn) are distributed to a number of authorized users. A multiple threshold secret sharing scheme assigns various users in a group into one of a number of classes. Each user class has a corresponding threshold level that indicates the number of users that must come together with their assigned components to obtain access to the shared secret. The multiple threshold scheme divides the secret into n components each having an assigned threshold level (i.e., the number of such components that are required to obtain the secret).

Abstract: A method and apparatus are disclosed for managing components of a secret key according to a secret sharing scheme. The disclosed secret sharing scheme divides a secret value, R, into n secret components (R1, R2, . . . , Rn) and one super component, S, in such a way that R can be computed from (i) any k or more R, components (k<n); or (ii) S and any one component of Rl. The secret components (R1 ,R2, . . . , Rn) are distributed to a number of authorized users. A multiple threshold secret sharing scheme assigns various users in a group into one of a number of classes. Each user class has a corresponding threshold level that indicates the number of users that must come together with their assigned components to obtain access to the shared secret. The multiple threshold scheme divides the secret into n components each having an assigned threshold level (i.e., the number of such components that are required to obtain the secret).

Abstract: A method and apparatus are disclosed for managing components of a secret key according to a secret sharing scheme. The disclosed secret sharing scheme divides a secret value, R, into n secret components (R1, R2, . . . , Rn) and one super component, S, in such a way that R can be computed from (i) any k or more Ri components (k<n); or (ii) S and any one component of Ri. The secret components (R1, R2, . . . , Rn) are distributed to a number of authorized users. A multiple threshold secret sharing scheme assigns various users in a group into one of a number of classes. Each user class has a corresponding threshold level that indicates the number of users that must come together with their assigned components to obtain access to the shared secret. The multiple threshold scheme divides the secret into n components each having an assigned threshold level (i.e., the number of such components that are required to obtain the secret).

Abstract: A method and apparatus are disclosed for managing components of a secret key according to a secret sharing scheme. The disclosed secret sharing scheme divides a secret value, R, into n secret components (R1, R2, . . . , Rn) and one super component, S, in such a way that R can be computed from (i) any k or more Ri components (k<n); or (ii) S and any one component of Ri. The secret components (R1, R2, . . . , Rn) are distributed to a number of authorized users. A multiple threshold secret sharing scheme assigns various users in a group into one of a number of classes. Each user class has a corresponding threshold level that indicates the number of users that must come together with their assigned components to obtain access to the shared secret. The multiple threshold scheme divides the secret into n components each having an assigned threshold level (i.e., the number of such components that are required to obtain the secret).

Abstract: A method and apparatus are disclosed for simultaneously establishing a user's identity and membership in multiple groups, using only a single identification card (or computer file). In a registration or enrollment phase, secret information is created between the user and any groups for which the user has registered. Once the user has been registered with one or more groups, the user may be authenticated to a verification agent to obtain access to one or more selected groups by providing an encrypted authentication request based on public identifiers relating to one or more groups, and an exponential function based on private identifiers and several randomly generated numbers. The verification agent is able to verify the user's registration with the selected groups without knowing the secret information. Optionally, for additional reliability, the verification agent may request the user to repeat the authentication process multiple times, each time altering one of the random numbers.