Peter Williams Radu Sion Bogdan Carbunar Building castles out of mud: practical access pattern privacy and correctness on untrusted storage. 139-148 2008 ACM Conference on Computer and Communications Security http://doi.acm.org/10.1145/1455770.1455790 conf/ccs/2008 db/conf/ccs/ccs2008.html#WilliamsSC08