Basic S3ORAM

Basic implementation of S3ORAM appeared in CCS'17 (free version). This project is built on CodeLite IDE. It is recommended to install CodeLite to load the full S3ORAM workspace.

S3ORAM Extension (ACM TOPS'20) is now available. Check out the new branch here!!

Updates

• 2017-12-25: S3ORAM now supports more than 3 servers with higher privacy levels.

Required Libraries

1. NTL v9.10.0

2. ZeroMQ

Configuration

All S3ORAM configurations are located in S3ORAM/config.h.

Highlighted Parameters:

#define BLOCK_SIZE 128                                -> Block size (in bytes)

#define HEIGHT 4                                      -> Height of S3ORAM Tree

#define BUCKET_SIZE 333                               -> Bucket size

#define EVICT_RATE 280                                -> Eviction frequency

static const unsigned long long P = 1073742353;       -> Prime field (size should be equal to the defined TYPE_DATA)

#define NUM_SERVERS 3                                 -> Number of servers \ell.
#define PRIVACY_LEVEL 1                               -> Privacy level t. 

const long long int vandermonde[NUM_SERVERS]          -> The first row of inverse of vandermonde matrix (should be defined according to SERVER_ID from 1....n)

const std::string SERVER_ADDR[NUM_SERVERS]            -> Server IP addresses
#define SERVER_PORT 5555                              -> Define the first port for incremental to generate other ports for client-server / server-server communications

Notes

Due to the imperfection of PRF, it is recommended to select BUCKET_SIZE larger than EVICT_RATE to avoid bucket overflow.

The folder S3ORAM/data is required to store generated S3ORAM data structure.

Build & Compile

Goto folder S3ORAM/ and execute

make

, which produces the binary executable file named S3ORAM in S3ORAM/Debug/.

Usage

Run the binary executable file S3ORAM, which will ask for either Client or Server mode. The S3ORAM implementation can be tested using either single machine or multiple machines:

Local Testing:

1. Set SERVER_ADDR in S3ORAM/config.h to be localhost.
2. Choose unique SERVER_PORT and SERVER_RECV_PORT for each server entity.
3. Compile the code with make in the S3ORAM/ folder.
4. Go to S3ORAM/Debug and run the compiled S3ORAM file in different Terminals, each playing the client/server role.

Real Network Testing:

1. Copy the binary file S3ORAM compiled under the same configuration to running machines.
2. For first time usage, run the S3ORAM/Debug/S3ORAM file on the client machine to initialize the S3ORAM structure first.
3. Copy the folder S3ORAM/data/i/ to server i, or follow the instruction on the client machine to transmit all data to corresponding server (It is recommend to manually copy the folder to avoid interuption during tranmission).
4. For each server i, run the compiled file S3ORAM and select the server role (option 2) and the corresponding ID i.

Android Build

Since android device is resource-limited, it is recommended to generate ORAM data using resourceful client machine (e.g., desktop/laptop), and then copy generated client local data (S3ORAM/data/client_local/ folder) to the android device for running the experiment. Here the instruction to generate android executable file:

1. Download Android NDK
2. Add the location of ndk-build file (i.e., in $android-ndk-path/build/) to PATH environment variable via e.g.,

1. vim ~/.profile
2. add `` export PATH=$PATH:$android-ndk-path/build/`` at the end of the file, where $android-ndk-path is the (absolute) path of the android NDK
3. save and reload the profile

3. Goto folder android-jni/jni. Open the file Android.mk and fix SRC_PATH and NDK_PATH variables, where SRC_PATH is the absolute path to the S3ORAM src code (e.g., $home/S3ORAM/S3ORAM/), and NDK_PATH is the absolute path to the Android NDK (e.g., $home/$android-ndk-path).
4. Disable NTL_LIB macro in file S3ORAM/config.h.
5. Goto folder android-jni/jni , execute ndk-build command, which will generate executable file s3oram_client and library file libgnustl_shared.so in android-jni/libs/armeabi/ folder.
6. Create a folder named s3oram in the android phone (via adb shell). Inside s3oram folder, create a folder named bin.
7. Copy files s3oram_client and libgnustl_shared.so to folder s3oram/bin/ in the android phone via adb push. Copy S3ORAM client data folder (i.e., S3ORAM/data/client_local/) to s3oram/ in the android phone.
8. Access to the Android phone via adb shell. Set the LD_LIBRARY_PATH to s3oram/bin/

export LD_LIBRARY_PATH=$home/s3oram/bin

9. Locate to folder s3oram/bin, run the file s3oram_client to run the program.

Citing

If the code is found useful, we would be appreciated if our paper can be cited with the following bibtex format

@inproceedings{hoang2017s3oram,
  title={S3ORAM: A Computation-Efficient and Constant Client Bandwidth Blowup ORAM with Shamir Secret Sharing},
  author={Hoang, Thang and Ozkaptan, Ceyhun D and Yavuz, Attila A and Guajardo, Jorge and Nguyen, Tam},
  booktitle={Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security},
  pages={491--505},
  year={2017}
}

Further Information

For any inquiries, bugs, and assistance on building and running the code, please contact me at [email protected].