Abstract: A system, method, and program code are given for secure communication. Multiple geographic cells are arranged in a hierarchical tree having a root node and internal nodes. The root node and each internal node in the tree have an associated node cryptographic key for secure communication with lower nodes in the tree. Each cell is associated with a leaf node of the tree and a cell cryptographic key for secure communications with devices located within the cell. A key management center is at the root node for determining an anticipated cell path of a mobile device from a current cell to a destination cell. The key management center distributes to the mobile device a set of cryptographic keys from the tree. This set contains a minimum number of cryptographic keys necessary to permit secure communications for the mobile device within each cell along the anticipated cell path, but no other cells.

Abstract: An entity which executes person authentication such as a service provider (SP) and a user device (UC) receives a request for person authentication from an entity which requests person authentication. The entity which requests person authentication can vary in form. The entity which executes person authentication decrypts the template by using a person identification certificate that can be owned by the entity which executes person authentication or provided from the outside, compares the template with sampling information input by a user and notifies the entity which requests person authentication of the result of comparison. The data for person identification is provided as encrypted information that can be decrypted only by the entity which executes person authentication, thereby performing safe authentication in various locations or devices, while preventing the template information from leaking out.