Key Escrow Scheme with the Cooperation Mechanism of Multiple Escrow Agents

To combat crime and terrorist organizations, government expects to monitor the suspicious communication but the leak of personal privacy is a common problem. Assuming that there are two Escrow Agent groups (Escrow party), one is designated by the government, while the other is unofficial. The two groups can achieve mutual supervision and dependence, thus implementing monitoring for users by the cooperation rather than by only a single one. If the number of the mutual participation is less than the required threshold number, the monitoring cannot be achieved. Therefore, an equation set corresponding to the specific program can be constructed, for example, multiply i(th) equation and j(th) equation to get an (i+j)(th) equation. As long as this kind of equation set is established, various key escrow schemes involved by several Escrow Agent groups can be constructed. Nowadays, the increasing political, economic, and cultural exchanges all over the world will lead to more and more transnational crime and terrorist attacks, so this program can be adapted to the multinational (or multi-organization) key escrow cooperation.