I'm currently working on an application with very very high data integrity requirements and we need to make sure that no one can ever update, create or delete rows directly in the database or via some other application.

Hence our idea would be to calculate, after each create, delete or update,
- a hash code of the modified row, stored in that row
- and another one for the table, stored in a special table

Would it be possible to plug in some code to do that just after Hibernate has persisted entities to the database ("after" because the id needs to be set first)?

By the way, we're using Hibernate 3 on an Oracle 10 database.