Here is a practical problem that has me frustrated.... Situation: Assume that I am the treasurer at my local church. This implies responsibility to record each Sunday's offering (the money collected) in the church financial books. An account is maintained for each member of the church. Money received from members each Sunday is credited to their respective accounts. Each January, a report is prepared for each parishioner showing a summary of the charitable contributions for the previous year. This information is used for tax purposes. Currently, the treasurer knows EVERYTHING about EVERYONE (regarding charitable giving). As a privacy advocate, this is indeed uncomfortable (for giver and treasurer). Problem: I want to know as little as possible about church member giving. Give and Take: It will be difficult/impossible to prevent the treasurer from seeing each weeks' checks. However, a privacy improvement may be achieved if the running totals are kept hidden. How can I provide a comprehensive year-end statement to each parishioner while maintaining maximum privacy? Does cryptography have anything to offer to this situation? What procedures/protocols could be implemented? What privacy enhancements could be included with the church accounting software? Cort.