rights management

hi who can program a rightsmanagement? the rights should be given or altered for a single dataset for example a posting or a picture which has an entry in a table in the databse...the entry consists of the creatorID, date/time and contents. in addition there should be another table in which is stored the information about who is allowed to see the dataset. you should write a function which gets as an input the contents of the dataset to be built, the creator and the info about who may see it. another function alters the dataset and a third return a list with the datasets who can be seen by a special person (referenced by userid) ...there should also be a possibility to set a dataset visible if you are in a special 'group'/category of the website (the info yout where you are is given by the GET-variable).