| 摘要 |
A system and method for cryptographic communication among multiple users and a central service provider using in situ generated cryptographic keys. Each user communicates with the central service provider preferably using a user communication interface that includes a local key generator, which, after initialization with the user's own individual seed value, generates a unique cryptographic key. By distributing different user individual seeds unitque to each user, each user's a local key generator generates a unique set of keys. The central service provider also possesses a local key generator, and also preferably possesses a copy of all the individual seeds assigned to authorized users. The central service provider preferably communicates in a secure encrypted fashion with each user using cryptographic keys generated from that user's individual seeds. Distribution of additional seed values common to more than one user, via encrypted communication using said unique individual crpytographic key generations, then permit secure conditional access to said users via signal encryption using key generations resulting from a seed value common to the intended group of users. |
