Year 2000 problem | Waring's problem | The Final Problem | quadratic formula | The Problem with Popplers | Hume and the Problem of Causation | Dirichlet problem | Boolean satisfiability problem | The Dog Problem | Tammes problem | Species problem | Quadratic function | problem solving | Problem gambling | Packing problem | packing problem | chess problem | Znám's problem | Year 10,000 problem | Yamabe problem | Weber problem | Undecidable problem | Travelling salesman problem | travelling salesman problem | The Problem of Thor Bridge | The Problem of the Media: U.S. Communication Politics in the 21st Century | The Problem of Social Cost | Tarski's circle squaring problem | Steiner tree problem | Shortest path problem |
An early example of such requirements and proof was given by Goldwasser and Micali for semantic security and the construction based on the quadratic residuosity problem.