Privacy-Preserving Indexing of Documents on the Network Mayank Bawa, Roberto J. Bayardo Jr., and Rakesh Agrawal   View Paper (PDF)   Return to Potpourri - Access Control, Bioinformatics & Security (Session C10) Abstract We address the problem of providing privacy- preserving search over distributed access- controlled content. Indexed documents can be easily reconstructed from conventional (in- verted) indexes used in search. The need to avoid breaches of access-control through the index requires the index hosting site to be fully secured and trusted by by all participat- ing content providers. This level of trust is impractical in the increasingly common case where multiple competing organizations or in- dividuals wish to selectively share content. We propose a solution that eliminates the need of such a trusted authority. The solution builds a centralized privacy-preserving index in con- junction with a distributed access-control en- forcing search protocol. The new index pro- vides strong and quanti able privacy guaran- tees that hold even if the entire index is made public. Experiments on a real-life dataset val- idate performance of the scheme. The ap- peal of our solution is two-fold: (a) Content providers maintain complete control in de n- ing access groups and ensuring its compliance, and (b) System implementors retain tunable knobs to balance privacy and e ciency con- cerns for their particular domains. ©2004 Association for Computing Machinery