| 摘要 |
A system for securely using digital signatures in a commercial cryptographic system that allows industry-wide security policy and authorization information to be encoded into the signatures and certificates by employing attribute certificates to enforce policy and authorization requirements. In addition to value limits, cosignature requirements and document type restrictions that can be placed on transactions, an organization can enforce with respect to any transaction geographical and temporal controls, age-of-signature limitations, preapproved counterparty limitations and confirm-to requirements by using attribute certificates for the transacting user. Restrictions on distribution of certificates can be set using attribute certificates. Certificates can be used also to ensure key confinement and non-decryption requirements of smartcards in this system. |
