Abstract: There is provided an anonymous service method of providing local linkability. The anonymous service method providing local linkability according to exemplary embodiments of the invention, an anonymous authentication operation based on a short group signature is performed, for which the concept of a local linkability is introduced to secure linkability within the same service domain. Namely, in the interior of a service provider, a virtual index having a fixed value is calculated for each service user, and in this case, although a plurality of service providers collude with each other, they cannot calculate a virtual index having the same value, whereby the linkability can be secured within the same service domain but not within the interiors of different service domains.

Abstract: There is provided an anonymous service method of providing local linkability. The anonymous service method providing local linkability according to exemplary embodiments of the invention, an anonymous authentication operation based on a short group signature is performed, for which the concept of a local linkability is introduced to secure linkability within the same service domain. Namely, in the interior of a service provider, a virtual index having a fixed value is calculated for each service user, and in this case, although a plurality of service providers collude with each other, they cannot calculate a virtual index having the same value, whereby the linkability can be secured within the same service domain but not within the interiors of different service domains.