Towards Practical Oblivious RAM

We take an important step forward in making Oblivious RAM (O-RAM) practical. We propose an O-RAM construction achieving an amortized overhead of 20X-35X (for an O-RAM roughly 1 terabyte in size), about 63 times faster than the best existing scheme. On the theoretic front, we propose a fundamentally novel technique for constructing Oblivious RAMs: specifically, we partition a bigger O-RAM into smaller O-RAMs, and employ a background eviction technique to obliviously evict blocks from the client-side cache into a randomly assigned server-side partition. This novel technique is the key to achieving the gains in practical performance.

[1]  Peter Williams,et al.  Usable PIR , 2008, NDSS.

[2]  Rafail Ostrovsky,et al.  Efficient computation on oblivious RAMs , 1990, STOC '90.

[3]  Dan Boneh,et al.  Remote Oblivious Storage: Making Oblivious RAM Practical , 2011 .

[4]  Rafail Ostrovsky,et al.  On the (in)security of hash-based oblivious RAM and a new balancing scheme , 2012, SODA.

[5]  Peter Williams,et al.  Building castles out of mud: practical access pattern privacy and correctness on untrusted storage , 2008, CCS.

[6]  Michael T. Goodrich,et al.  Privacy-Preserving Access of Outsourced Data via Oblivious RAM Simulation , 2010, ICALP.

[7]  Benny Pinkas,et al.  Oblivious RAM Revisited , 2010, CRYPTO.

[8]  Desh Ranjan,et al.  Balls and bins: A study in negative dependence , 1996, Random Struct. Algorithms.

[9]  Michael T. Goodrich,et al.  Oblivious RAM simulation with efficient worst-case access overhead , 2011, CCSW '11.

[10]  Martin Raab,et al.  "Balls into Bins" - A Simple and Tight Analysis , 1998, RANDOM.

[11]  Michael K. Reiter,et al.  Integrity Checking in Cryptographic File Systems with Constant Trusted Storage , 2007, USENIX Security Symposium.

[12]  Oded Goldreich,et al.  Towards a theory of software protection and simulation by oblivious RAMs , 1987, STOC.

[13]  Rafail Ostrovsky,et al.  Private information storage (extended abstract) , 1997, STOC '97.

[14]  Rafail Ostrovsky,et al.  Software protection and simulation on oblivious RAMs , 1996, JACM.

[15]  Michael T. Goodrich,et al.  Privacy-preserving group data access via stateless oblivious RAM simulation , 2011, SODA.